Any Relationship of the Remington 40X and the "M40" or "M24"?

[FP1201]

Wondering if there was any connection between the single shot 40X (early 1960's vintage) and models issued/used by Uncle Sam?
The stocks on these old beasts were a bit heavy, with barrel contact screws, t-slotted rail on the underside, and a relief cut on the comb to clear the striker....
At some point it was fitted with a newer (action was polished blue) "Remington" marked barrel in .308 with a parked finish...
I got this Rifle a decade ago in a trade and regtetted it until I shot the best .30 cal group of my life with it....know what they say about book covers.

 

[fdkay]

If memory serves, the 40X was the original basis for the M40, hence the nomenclature, M40.
No relation at all to the M24, which is a long action.

 

[Isaiah's Blacksmith]

Edit: Question answered in more detail below. I do have a M40 SSA action and it is considered a 40x. Best shooting R700 I own. Also, on the M40 forums is the guy who helped build the original M40 and his son who worked on the limited SSA run

 

[Random Guy]

The USMC reportedly tested two Remington rifles back in 1966, a Model 700 ADL, and a 40X. The 40X came out on top. It had a "medium-heavy" target barrel and an internally adjustable trigger. I presume the 700 ADL had a standard weight barrel. (Btw, I read the medium-heavy barrel became available on the standard M700 in 1976 or 77' in 308W as the "Varmint contour" barrel. I assume prior to that date, only the 40X had that heavier target barrel).

I am not an expert, but did the 1960's era single shot 40Xs have a flat bottomed receivers?, as opposed to the standard round profile? I read that somewhere but wasn't sure if it accurate or not. All M40 actions obviously had a round bottom receiver, but they got the clip-slotting from the 40X version, and the heavier target barrel as noted. Not sure about triggers on the original M40s circa 1966-69, but I do know that the M24 adopted by the US Army in 1988 did have a special adjustable trigger...sort-of adjustable - but it was set at the factory so the trigger pull could only be increased, but not decreased....reportedly Remington didn't want soldier's messing with the triggers on their M24 rifles. (They were typically set around 3 to 3.5 lbs).

As others noted, M24 receivers were just long-action M700s, but they also have "M24" stamped on the side to designate a military weapon.

 

[fdkay]

According to this article, the 40X in .308 was available as a repeater, I don't have my Peter Senich book available right now, and it has been many years since I read it, but I am almost certain that, at least during the initial evaluation stage, 40X actions were used.
The OP MIGHT have the 40XB-BR. This article appeared on the accurate shooter website.

A Short History of the Remington 40X Rifles
The .22LR Remington 40X was first released in 1955 as a replacement for the model 37 target rifle. The 40X was a pet project of Remington's Mike Walker, who wanted Remington to have a rifle that could beat "all comers", including Winchester's target rifles. The rimfire 40X "Rangemaster" was initially offered in both standard barrel (S1) and heavy barrel (H1/H2) versions, the H1 including Redfield Olympic target sights. In 1959 Remington introduced centerfire 40X models, again with both standard and heavy barrel versions. Initially offered in .308 Winchester, more chamberings were offered in 1960: 222 Rem, 222 Rem Magnum, .30-06, and .300 H&H Magnum.

As a sidenote, starting in 1959, Remington worked with the USAMU to develop a heavy, 15-lb International Free Rifle using the 40X action (both rimfire and centerfire). This gun employed a completely different stock, and was produced in very limited numbers. Only 123 rimfire "Free Rifles" rifles and 594 centerfire "Free Rifles" were sold from 1960 through the mid-70s.

Rem 700 Action Replaces 722 Action for 40X Series Rifles
A major change took place in 1965, when the Rem 722-style action on the 40X was replaced by a Rem 700 action, and the 40X was officially renamed the "40-XB". At this time, stainless barrels were offered as an option, and Remington introduced a mag-fed, centerfire repeater for National Match shooters. (Interestingly, though 40-XB repeaters were made in many calibers, only the .308 receivers were factory-slotted for clips.) A wide variety of centerfire chamberings were offered from 1965 through 1975 when the 40-XB was officially replaced by the 40-XR, only to be re-introduced in 1985. The rimfire model 40-XB continued as single-shot only until 1970 when Remington added the 40-XB Sporting Rifle, a deluxe mag-fed repeater with Monte Carlo stock.

40-XB BR -- The Cream of the Crop
The famous Remington 40-XB BR was introduced in 1971. This was a precision, single-shot rifle initially chambered in 222 Remington. It featured a wider forearm and either a 20" barrel (for Light Varmint class) or 26" barrel (for Heavy Varmint Class). Other chamberings were added to the 40-XB BR lineup in 1972, including .222 Rem Mag, 6mm Int'l, 6mm-47 and .308 Win. In 1978 Remington added the 22 Rem BR, and in 1979 the 6mm Rem BR was added. We think this makes the 40-XB BR the first factory rifle chambered for the 6mmBR.

It is important to distinguish the 40-XB BR from other 40X models. The action on the 40-XB BR was finish-machined differently -- in order to make the action straighter and more uniform. Because of the special machining process, the serial number could not be roll-stamped on the action, and was electro-etched instead. That's why you'll see "Remington Model 40XBR" and the serial number etched on the left side of the receiver. You may have read that all 40X and 40XB actions are machined or "blue-printed" after heat-treating. That's not true. Only the 40-XB BR models used a special production method for the receiver, and it's not equivalent to "blue-printing".

Are 40X Actions Superior to Other Rem Actions?
Is it safe to assume that 40X/40-XB actions are "better" than regular Rem 700 actions? Paul Coburn has written: "The receivers use the same barrel threads and same dimensions as the standard actions, BUT the 40-X series receivers are NOT taken from the standard production line and 'trued'; they are made (and serial numbered) in a different facility. The actions are NOT 'blue printed'. They are simply made true and square to spec, from the start. All the 40-X rifles I've owned had both lugs mated, all screw holes were true and in line, and they were impeccable."

For a complete history of the Remington 40X series of rifles, read The Remington 40-X Rifle -- A Legend in its Own Time by Paul Coburn. You may also enjoy reading the Rem 40X section of Roy Marcott's History of Remington Firearms. Marcott offers a definitive list of all the 40X models and chamberings, along with a production chronology.

 

[Random Guy]

According to this article, the 40X in .308 was available as a repeater, I don't have my Peter Senich book available right now, and it has been many years since I read it, but I am almost certain that, at least during the initial evaluation stage, 40X actions were used.

Yes, per Senich's The One-Round War, the repeater version of the Model 40XB was introduced in 1966, and evaluated by the USMC in 1966. They had clip slots and were marked "Model 40-X" during the evaluation. Once adopted they were marked "M700" just like other actions - but with a requirement for the clip slots, that according to Senich was a concession to the "rifle team influence."

(Page 138)
"Remington Rifle, Model 700-40X, cal. 7.62mm to be procured as a Sniper Rifle....Action to have clip-slot"

 

[five 0]

40-XB repeaters were made in many calibers, only the .308 receivers were factory-slotted for clips.
This is incorrect. I have a 40XB repeater in 6mm that is clip slotted.

 

[wadebrown]

The DARPA XM-3 rifles built for the USMC were made on 40x receivers they were stamped as such the same as any other 40x that I have seen. No an answer to the OP's question but a tiny bit of trivia.

 

[Isaiah's Blacksmith]

For crying out loud. A 40x was generally a custom shop R700 build with the best parts off assembly and tweaked as needed then proofed for accuracy as an R700 flagship factory rifle. With the exception of the early rimfires they are not that special. In recent history custom rifle builders were exceeding the Remington custom shop quality standards for less. Despite all that Savage came out with the 110 with Accutriger and off the factory floor accuracy exceeding the at that time current competition from the Remington custom shop 40x.

 

[fdkay]

For crying out loud. A 40x was generally a custom shop R700 build with the best parts off assembly and tweaked as needed then proofed for accuracy as an R700 flagship factory rifle. With the exception of the early rimfires they are not that special. In recent history custom rifle builders were exceeding the Remington custom shop quality standards for less. Despite all that Savage came out with the 110 with Accutriger and off the factory floor accuracy exceeding the at that time current competition from the Remington custom shop 40x.

Are 40X Actions Superior to Other Rem Actions?
Is it safe to assume that 40X/40-XB actions are "better" than regular Rem 700 actions? Paul Coburn has written: "The receivers use the same barrel threads and same dimensions as the standard actions, BUT the 40-X series receivers are NOT taken from the standard production line and 'trued'; they are made (and serial numbered) in a different facility. The actions are NOT 'blue printed'. They are simply made true and square to spec, from the start. All the 40-X rifles I've owned had both lugs mated, all screw holes were true and in line, and they were impeccable."

 

[Isaiah's Blacksmith]

They are a cherry R700 actions but if you want to believe those boys were not down on the assembly line cherry picking parts than that is fine with me.

 

[fdkay]

They are a cherry R700 actions but if you want to believe those boys were not down on the assembly line cherry picking parts than that is fine with me.

As the article said, the actions were not standard assembly line actions, the other parts, maybe.
Of course, we are also talking a different time frame as well.
I remember when the 700 PSS was a damn nice rifle, then they decided to just use production varmint rifles in an HS precision stock and changed the name to 700P. They did finally put the M24 triggers in them though.

 

[USMCSGT0331]

The DARPA XM-3 rifles built for the USMC were made on 40x receivers they were stamped as such the same as any other 40x that I have seen. No an answer to the OP's question but a tiny bit of trivia.

This is incredibly wrong. XM3 receivers were stainless S prefix Remington 700's, not 40X. My platoon had 4 of them and I own 2 originals (one of which is one of the four rifles my platoon had in Fallujah). I also have the entire USMC XM3 serial number list. Not just the few dozen the CMP received, I have the complete USMC serial number list. All XM3's are 700's with an S prefix, none of them are 40X.

Here's my XM3 with a real 6 digit M40 from 1966, both are 700's:

 

[Random Guy]

I remember when the 700 PSS was a damn nice rifle, then they decided to just use production varmint rifles in an HS precision stock and changed the name to 700P. They did finally put the M24 triggers in them though.

Well, I think the M700P got the pedestrian X-Mark Pro trigger. In fact, I'm pretty sure that actual M24 triggers were only used on military weapons given the rigorous testing of that trigger surpassed anything in the civilian side of production. Replacement M24 triggers included a little graph that validated the trigger weight for 5 pulls, and that is part of the reason the M24 trigger was so expensive - each had 100% Q/C and Q/A per the US Army contract. Here's what the former Remington Defense sales manager wrote re the M24 trigger (They were also used on the M40A5 USMC sniper rifles):

THE TRIGGER
One component of the M24 specification was the requirement for a user adjustable trigger (“the rifle shall have a trigger pull capable of being adjusted by the user”). The trigger weight was to be not less than 2 lbs 8oz and “more” than 4lbs (it could exceed 4 lbs). As a result of these specifications, Remington modified their existing trigger by adding a screw and a spring in the trigger shoe than can be adjusted by the operator. This trigger is called the “M24 Fire Control” and is normally only used on the M24 series of rifles (M24, M24A2, M24A3).

While the M24 Fire Control is technically unique, truthfully it is as stated a standard Remington commercial 700 trigger (fire control) with a screw and a spring in the trigger shoe to allow it to be adjusted by the user. It is worth noting that “adjustment” is a relative term when it comes to this trigger. What I mean is that the trigger is manufactured (set up) to be somewhere between 3.5 and 5 lbs (they try to get around 3.8 – 4lbs), however the adjustment screw can never make it any lighter, only heavier. In other words, the screw can be completely removed without making the trigger/weapon unsafe and in fact many sniper students do exactly that. The intent of the requirement was to give the sniper an adjustable trigger (as I know the shooters involved with development specified), however soldiers being soldiers, if there is a screw that can be manipulated, it will be and Remington did not want a weapon system that could be made unsafe.

It’s worth noting that each M24 Fire Control is set and then tested with 5 pulls; the trigger must produce a pull force less than 5lbs throughout the test to be used. Once the trigger is set, the sear engagement screw is peened; a punch is used to dent the screw pathway so that that it cannot back out. Also, all three adjustment screws are coated with a shellac material that dries hard. Usually this shellac is red, but I have seen clear as well."

....pretty sure that Remington didn't use that ~$250 'M24 Fire Control' trigger in any rifle except the military and Law Enforcement purchases of M24s that sold for $3500+...and certainly not in an M700P that sold for a measly $800. They got the 'X-Mark Pro' or 'X-Mark Pro adjustable' trigger. Just an fyi.

 

[fdkay]

Well, I think the M700P got the pedestrian X-Mark Pro trigger. In fact, I'm pretty sure that actual M24 triggers were only used on military weapons given the rigorous testing of that trigger surpassed anything in the civilian side of production. Replacement M24 triggers included a little graph that validated the trigger weight for 5 pulls, and that is part of the reason the M24 trigger was so expensive - each had 100% Q/C and Q/A per the US Army contract. Here what the former Remington Defense sales manager wrote re the M24 trigger (They were also used on the M40A5 USMC sniper rifles):

THE TRIGGER
One component of the M24 specification was the requirement for a user adjustable trigger (“the rifle shall have a trigger pull capable of being adjusted by the user”). The trigger weight was to be not less than 2 lbs 8oz and “more” than 4lbs (it could exceed 4 lbs). As a result of these specifications, Remington modified their existing trigger by adding a screw and a spring in the trigger shoe than can be adjusted by the operator. This trigger is called the “M24 Fire Control” and is normally only used on the M24 series of rifles (M24, M24A2, M24A3).

While the M24 Fire Control is technically unique, truthfully it is as stated a standard Remington commercial 700 trigger (fire control) with a screw and a spring in the trigger shoe to allow it to be adjusted by the user. It is worth noting that “adjustment” is a relative term when it comes to this trigger. What I mean is that the trigger is manufactured (set up) to be somewhere between 3.5 and 5 lbs (they try to get around 3.8 – 4lbs), however the adjustment screw can never make it any lighter, only heavier. In other words, the screw can be completely removed without making the trigger/weapon unsafe and in fact many sniper students do exactly that. The intent of the requirement was to give the sniper an adjustable trigger (as I know the shooters involved with development specified), however soldiers being soldiers, if there is a screw that can be manipulated, it will be and Remington did not want a weapon system that could be made unsafe.

It’s worth noting that each M24 Fire Control is set and then tested with 5 pulls; the trigger must produce a pull force less than 5lbs throughout the test to be used. Once the trigger is set, the sear engagement screw is peened; a punch is used to dent the screw pathway so that that it cannot back out. Also, all three adjustment screws are coated with a shellac material that dries hard. Usually this shellac is red, but I have seen clear as well."

....pretty sure that Remington didn't use that ~$250 'M24 Fire Control' trigger in any rifle except the military and Law Enforcement purchases of M24s that sold for $3500+...and certainly not in an M700P that sold for a measly $800. They got the 'X-Mark Pro' or 'X-Mark Pro adjustable' trigger. Just an fyi.

They had the X mark Pro for a short time, then returned to the 40x trigger.
ETA correct trigger

 

[Random Guy]

They had the X mark Pro for a short time, then returned to the M24 trigger

Umm, my last Remington catalog is dated 2016 and it doesn't state the M700P having the M24 trigger - at least not per my understanding. (The guy who ran Remington Defense beginning in 2004 left in 2016, so I don't know what happened in 2017-2018). Do you have a catalog or spec info re M24 triggers in a civilian M700? The catalogs refer to the X-Mark Pro. That would be noteworthy if a military M24 trigger was used given the cost of that item...

 

[fdkay]

My bad, I did misremember. It was the 40x trigger they installed. NOT the m24 trigger.

 

[Random Guy]

Okay, my understanding is different. BTW, NSN 1005-01-511-8314 was sort of expensive based on what Marty at BO posted years ago in the context of the M40A5/XM2010 program, and the guy who ran Remington Defense explained the process for each M24 Fire Control unit being empirically tested 5 times and recorded as part of the US military contract, which really drives up cost...but anyhow, what do those guys know, right?

 

[fdkay]

Okay, my understanding is different. BTW, NSN 1005-01-511-8314 was sort of expensive based on what Marty at BO posted years ago in the context of the M40A5/XM2010 program, and the guy who ran Remington Defense explained the process for each M24 Fire Control unit being empirically tested 5 times and recorded as part of the US military contract, which really drives up cost...but anyhow, what do those guys know, right?

Not sure if you caught my edit.
The 700p was getting the 40x.
Which is a significantly better trigger than the xmark but not nearly as pricey as the M24 trigger.

 

[Isaiah's Blacksmith]

I don't fucking believe it based in people that actually worked the custom shop over two generations. It was just a fucking shop. It was a cherry job at Remington but they were taking the best actions and everything else off the line and then squaring them up. There was no full blown blueprinting going on. Think about it. Why would they waste fucking manufacturing time when they can just cherry pick actions at some stage on the line to the same end. They would just tightened up on the tolorences for accuracy, put a beautiful stock on it, and stamp it 40x. About the time this site started good smiths got wise and were buying factory R700s and doing even more for accuracy in their own shops. They practically helped shut down the custom shop then Remington helped shut down Remington. The newer the 40x the less signicant it is. The downgraded QC process followed itself even to the custom shop with .75 moa being the goal. The 40x became nothing more than an overpriced R700 except for those special orders that received extra special attention. Like what @wadebrown mentioned above but even those had a third party involved to boot. Then there was the occasional tier 1 shooter or hunter that wanted a specific one-off rifle. Remington was lousy about documentation for the public. They thought their custom shop was some sort of Skunk Works. Probably because they were just putting a small amount of extra attention to a factory rifle.

 

[Random Guy]

Okay, that makes more sense. The 40X trigger is not nearly the cost of a real M24 trigger (each unit tested w/ 5 pulls and documented results, etc).

Fwiw, back in 2016 I bought an M40A5 replica locally that was made by a USMC MOS 2112 down at Quantico/PWS, circa 2015. It had a USMC stock and was nice, but the trigger was an X-Mark Pro that came with the M700 receiver he used (see 1st pic - the M24/M40A5 triggers have a grooved face, so they are easy to tell from the X-Mark Pro that has a smooth face, as seen here), and of course the 'M40 clone Nazis' (whom I consider friends) gave me grief over my trigger - since it was not correct for a USMC M40A5.

Marty at BO had just sold an M24/M40A5 trigger unit for $250 I think, and at first I couldn't fine one. Then I got lucky with Dave Clark, the former OIC of PWS had one and only one M24/M40A5 trigger on his work bench down in FL. He sold it to me for $200, which was about the same price I think Uncle Sam paid for those trigger units. My 24R also has one of those triggers of course. So that is why I have such an interest in this trigger, they were not used on civilian rifles given their exorbitant price from going through 100% QA/QC for each unit as part of the DoD contract. But I digress...

 

[Isaiah's Blacksmith]

Uncle Sam also bought toilet seats for $200. The military 40x orders were different animals than the commercial 40x. Ask Iron Brigade for example. But you already know all this so no offense @Random Guy

 

[Isaiah's Blacksmith]

And to add insult to injury I eventually took my so-called 40x SSA put a Remage and a M40 B&C on it, and damn if it didn't shoot better. I did that in the garage, lol. And yes that is a plain ol EGW.

 

[Isaiah's Blacksmith]

This is incredibly wrong. XM3 receivers were stainless S prefix Remington 700's, not 40X. My platoon had 4 of them and I own 2 originals (one of which is one of the four rifles my platoon had in Fallujah). I also have the entire USMC XM3 serial number list. Not just the few dozen the CMP received, I have the complete USMC serial number list. All XM3's are 700's with an S prefix, none of them are 40X.

Here's my XM3 with a real 6 digit M40 from 1966, both are 700's:

How many of those DARPAs were manufactured? And weren't these modified in the Marine shop and not the Remington custom shop? And didn't the Marines refer to the original M40 as "M700"?

 

[USMCSGT0331]

How many of those DARPAs were manufactured? And weren't these modified in the Marine shop and not the Remington custom shop? And didn't the Marines refer to the original M40 as "M700"?

52 issued rifles. Neither, they were all built at IBA. Yes, the M40 nomenclature didn't catch on until after the initial issue. I can't remember the exact time the publications first called them an M40, I'll have to look through my documents and get you that information.

 

[Random Guy]

1966 procurement verbiage
"Remington Rifle, Model 700-40X, cal. 7.62mm to be procured as a Sniper Rifle....Action to have clip-slot"
XM-3 manual:

 

[USMCSGT0331]

And didn't the Marines refer to the original M40 as "M700"?

As @Random Guy posted above, the original contract didn't refer to the new sniper rifle as an "M40". 700 of the rifles were made and shipped to the Corps in 1966, and the very first rifles were sent to Marines in Vietnam in early 1967. It appears that they still weren't referring to the rifles as an "M40" during this time.

I have an extremely early and incredibly rare copy of FMFM 1-3B from October 1967, which is probably the first version of the 1-3B Sniping manual. I also have an original 1-3B (August 1969 version) that was received by a unit in December 1969 and has some changes that were added to the book in June 1972. Both of these books are amazing pieces of history and it's very interesting to compare them side by side.

The October 1967 manual refers to the Remington sniper rifle as the M700, whereas the August 1969 manual refers to the same rifle as an M40. So, somewhere within this 2 year span the nomenclature changed. This also means that the very first Marine snipers to use the M40 were referring to the rifle as an M700 or something similar. Quick side note, decades later this also happened with the Mk13 Mod 0.

If anyone has a copy of FMFM 1-3B that was published between October 1967 and August 1969, please post it here. If such a publication exists, it would help narrow down when this name change occurred.

Here's a comparison between the same pages of these two 1-3B manuals. Interestingly, the 1967 manual has a lot of Winchester M70 and Unertl 8x information in it, since the M40 hadn't completely replaced the M70 at that time:

Here's another set of pages to compare/contrast:

So, I hope that helps answer your question. Unfortunately I can't give you an exact date that they started calling this new sniper rifle the "M40," but we've narrowed it down to sometime between 1967 and 1969 (which is after the rifles were first issued). Maybe there's another source out there with this information, maybe it's in one of Senich's books and I completely missed it. Hopefully others can chime in with some better information.


I don't just collect the rifles and parts, I also collect information. I enjoy looking through all of this knowledge and seeing the changes over the years/decades. Some stuff is very minor, such as definitions we have to memorize. Other stuff is a major change, such as switching to the next rifle in the M40 series. This knowledge isn't just valuable to the snipers who put it to use, it's also extremely important to historians/researchers/anyone interested in preserving Marine Corps history. These primary sources are worth saving. Here's some of the information I ended up with when I was in an SSP (I'm not an 0317, I never went to the school, I'm just a dirty PIG). Just realized there's a few M240 range cards in there, I'm too lazy to pull everything back out and retake the photo, so ignore those.

 

[wadebrown]

This is incredibly wrong. XM3 receivers were stainless S prefix Remington 700's, not 40X. My platoon had 4 of them and I own 2 originals (one of which is one of the four rifles my platoon had in Fallujah). I also have the entire USMC XM3 serial number list. Not just the few dozen the CMP received, I have the complete USMC serial number list. All XM3's are 700's with an S prefix, none of them are 40X.

Here's my XM3 with a real 6 digit M40 from 1966, both are 700's:

The one we had from DARPA when I worked the OneShot program for Lockheed was a 40x, at least that was the model designation on the receiver.

 

[USMCSGT0331]

The one we had from DARPA when I worked the OneShot program for Lockheed was a 40x, at least that was the model designation on the receiver.

Then it's some kind XM prototype or a completely different rifle. IBA produced some other rifles that were supplied to the government around the same time, such as the XM1 and XM33. I bet you did see some rifles built on 40X receivers, but whatever you saw wasn't one of the 52 issued USMC XM3's. I have all 52 serial numbers, every single one is an S prefix 700. I wish you had a camera with you back then, sounds like you got to see some cool prototypes and other rifles!

 

[RGStory]

If anyone has a copy of FMFM 1-3B that was published between October 1967 and August 1969, please post it here. If such a publication exists, it would help narrow down when this name change occurred.

Is this what you are looking for? Proposed 1968. It was posted on Sniper's Hide a few years ago.

 

[USMCSGT0331]

Is this what you are looking for? Proposed 1968. It was posted on Sniper's Hide a few years ago.

That would be it, I figured someone here would have that information! The Vintage Section never fails to impress. I clicked the attachment, but it's only 9 pages long, so I can't see anything past the table of contents. Hopefully there's a complete file somewhere, if anyone has it, please post it.

 

[pmclaine]

Wouldnt the clip slots have been much different on 40X production from M40 production?

The M40 has a detailed/designed clip slot.

The standard Remington clip slot I generally see on 5 and 6 digit receivers I have bought is just a square slot at the rear of the receiver lacking the "tits" to position the clip and lock it in place.

I think the work on the detailed clip slot significant enough to define the M40 as altogether different than a 40X.

 

[Random Guy]

My understanding of 'clip slots' (Remington made M40s) vs 'lug slots' (USMC made M40A1/A3/A5 rifles):

The 6 digit M700s/M40s made in 1966-1969 had clip slots with the small oval cut-outs or "tits" at the ends to facilitate top-loading via 5-rd stripper clips. My assumption that was how the old 40-X receivers were also machined in the 1960s. Moreover, decades later, the two M40 commemorative rifles (the SSA and Chuck Mawhinney versions) were both machined based on Remington's M40 drawings that were dated 1969. These have the oval "tits" to facilitate clip loading, and thus are 'true' clip slots. (see first pic as an example, and 4th pic shows a typical US 5-rd stripper clip of 30-06 with the small roundish 'nubs' on the sides - hence the need for the small oval cut-outs to allow the stripper clip to fully slide down into the rifle)

In contrast, the USMC machined "lug slots" on the C, E and G-prefix replacement receivers that they got from Remington circa 1992, and into the late 200Xs/early 201Xs, for the M40A1/M40A3/M40A5 rifles. These 'lug slots' lacked the 'tits' as that additional machine work was not needed. The lug was to simply support the scope rail, not to facilitate top-loading via 5-rd stripper clips.

My replica M40A1 was made down at Quantico where they machined the C-prefix receiver, and you can see in 2nd pic that the 'Lug slot' does not have the oval 'cut-outs' that you see with the original 1960s era clip-slots. An MOS 2112 explained to me the 'lug slots' were cut at the rear to be just shy of allowing a Unertl M40A1 scope mount to fit-in - and they then hand-filed the back side of the rear lug on the scope mount (see white arrow in pic #3) - just enough so that the scope rail would be a tight fit - and not have any lateral movement. Not sure about the specific process re later M40A3/A5 lug slots and the DD Ross and BO scope rails, but that was the process in the 1990s when they were making M40A1s w/ Unertl mounts.

Many folks use the term "clip slots" in the context of the USMC-built M40A1, A3 and A5 rifles, but I think "lug slots" is more technically correct for the C, E and G prefix receivers that the USMC armors machined. It's only the original 6-digit M40s that have true "clip slots." That's all I know.

Re last pic - Interestingly, the T44E4/M14 with a 20-rd detachable magazine was designed in the late 1950s with a clip slot to facilitate loading via 5 rd stripper clips, but I doubt that feature was used much given easy mag changes. That said, one can see the small 'nubs' on the sides of the stripper clip that requires a small clearance cut. Again, on a scoped M40A1-A3-A5, no need to machine fancy clip slots - when just a simple lug slot will do...

 

[RGStory]

That would be it, I figured someone here would have that information! The Vintage Section never fails to impress. I clicked the attachment, but it's only 9 pages long, so I can't see anything past the table of contents. Hopefully there's a complete file somewhere, if anyone has it, please post it.

See: https://www.snipershide.com/shooting/threads/fmfm-1-3b.6937854/

I have a original copy of the entire manual that my father gave me. He was a sniper in Vietnam in 1968-69. It is FMFM 1-3B "PROPOSED" FIRST DRAFT, dated Feb 1968.

He only posted once, but hopefully he is still around and can get that to you.

 

[pmclaine]

My understanding of 'clip slots' (Remington made M40s) vs 'lug slots' (USMC made M40A1/A3/A5 rifles):

The 6 digit M700s/M40s made in 1966-1970 had clip slots with the small oval cut-outs or "tits" at the ends to facilitate top-loading via 5-rd stripper clips. My assumption that was how the old 40-X receivers were also machined in the 1960s. Moreover, decades later, the two M40 commemorative rifles (the SSA and Chuck Mawhinney versions) were both machined based on Remington's M40 drawings that were dated 1969. These have the oval "tits" to facilitate clip loading, and thus are 'true' clip slots. (see first pic as an example, and 4th pic shows a typical US 5-rd stripper clip of 30-06 with the small roundish 'nubs' on the sides - hence the need for the small oval cut-outs to allow the stripper clip to fully slide down into the rifle)

In contrast, the USMC machined "lug slots" on the C, E and G-prefix replacement receivers that they got from Remington circa 1992, and into the late 200Xs/early 201Xs, for the M40A1/M40A3/M40A5 rifles. These 'lug slots' lacked the 'tits' as that additional machine work was not needed. The lug was to simply support the scope rail, not to facilitate top-loading via 5-rd stripper clips.

My replica M40A1 was made down at Quantico where they machined the C-prefix receiver, and you can see in 2nd pic that the 'Lug slot' does not have the oval 'cut-outs' that you see with the original 1960s era clip-slots. An MOS 2112 explained to me the 'lug slots' were cut at the rear to be just shy of allowing a Unertl M40A1 scope mount to fit-in - and they then hand-filed the back side of the rear lug on the scope mount (see white arrow in pic #3) - just enough so that the scope rail would be a tight fit - and not have any lateral movement. Not sure about the specific process re later M40A3/A5 lug slots and the DD Ross and BO scope rails, but that was the process in the 1990s when they were making M40A1s w/ Unertl mounts.

Many folks use the term "clip slots" in the context of the USMC-built M40A1, A3 and A5 rifles, but I think "lug slots" is more technically correct for the C, E and G prefix receivers that the USMC armors machined. It's only the original 6-digit M40s that have true "clip slots." That's all I know.

Re last pic - Interestingly, the T44E4/M14 with a 20-rd detachable magazine was designed in the late 1950s with a clip slot to facilitate loading via 5 rd stripper clips, but I doubt that feature was used much given easy mag changes. That said, one can see the small 'nubs' on the sides of the stripper clip that requires a small clearance cut. Again, on a scoped M40A1-A3-A5, no need to machine fancy clip slots - when just a simple lug slot will do...

This thread....

https://www.snipershide.com/shooting/threads/remington-700-dbm-opinions-from-guys-that-put-them-in-and-use-them.6976379/page-2

Picture from LRI half way down the page shows the no frills Remington square clip slot on my 5 digit receiver.

I be guessing that was typical for commercial sales.

The "tits" version is a copy of what was made for the Springfield 03, which was used by Winchester, which the military wanted on the M40, which we should probably all thank Mauser for.

 

[Isaiah's Blacksmith]

It is all in the stock. Clip slots at that time were based on the stock and magazine. The M40 particular clip slot was for an ADL stock (plain stock) with 5 round BDL magazine. We all know it was drilled for mounting receiver sights. So, again. It was just an offering by Remington in general. You could have ordered the same rifle from the custom shop at that same time for commercial purchase. Or you may have walked into a Coast-to-Coast hardware store to find a R700 with a similar stock, magazine, and clip slot for sale.

 

[Isaiah's Blacksmith]

Here is a stock with square clip slot and iron sights

Remington fans...interesting old 700

I picked up a rather interesting Remington 700 today, one I've never even heard about (much less seen). Its an early model gun in .243, with a 5-digit serial number. The chambering caught my eye first, as I'm always looking for short action 700's, but the low serial number really got me ...

www.24hourcampfire.com

 

[USMCSGT0331]

It is all in the stock. Clip slots at that time were based on the stock and magazine. The M40 particular clip slot was for an ADL stock (plain stock) with 5 round BDL magazine. We all know it was drilled for mounting receiver sights. So, again. It was just an offering by Remington in general. You could have ordered the same rifle from the custom shop at that same time for commercial purchase. Or you may have walked into a Coast-to-Coast hardware store to find a R700 with a similar stock, magazine, and clip slot for sale.

I don't understand how a clip slot is based on the type of stock. Having the cut match the type of clip being used, absolutely. Matching it to a type of stock, that's something I've never heard of. Hell, you can have a clipslotted single shot receiver with a solid stock. It can't be used, but the type of stock doesn't change the clip slot's design.

I'd really like to know how "the M40 particular clip slot was for an ADL stock." Please explain to me how that clip slot design was specifically for that specific stock. And how that same clip slot was also used with other types of stocks during that same time period.

Even if clip slots were based on stocks, this type still wouldn't have been based on the ADL stock. The M40 type clip slot was a hold over from the original 40X test rifles, so it would have been based on one of those stocks. The 40X rifles at the time were typically in a heavier target stock:

This is just getting ridiculous

 

[Isaiah's Blacksmith]

That is just the way Remington described the plain ol' BDL stock for the M40. Remington's words not mine. They had their own company language.

 

[Isaiah's Blacksmith]

I found it. It was in Remington language a sporter type stock with cheek rest "ADL type for 5 round BDL magazine". Page 157 One Round War. There was nothing special or magical with the clip slots. They were standard based on the magazine based on the stock those magazines went into for iron sighted rifles. The square clip slots were for ADL blind magazine stocks back then and I posted a good example above. The whole 40x bug-a-boo was that these weapons were made in the custom shop. To meet deadlines they basically went with a R700 varmint with some minor exceptions explained on page 157. And since you brought up single shot. Yes, Remington would of made you a single shot clip slot rifle if that is what you wanted. The Marines ordered the clip slots and then promptly made them useless by mounting a scope base over it and Remington knew it, of course. They actually contributed to some problems with the scope base coming loose that means not only were they not necessary they actually contributed to accuracy problems in country in those elements. Thus, the reason for the lug slots was explained above by @Random Guy

 

[pmclaine]

I found it. It was in Remington language a sporter type stock with cheek rest "ADL type for 5 round BDL magazine". Page 157 One Round War. There was nothing special or magical with the clip slots. They were standard based on the magazine based on the stock those magazines went into for iron sighted rifles. The square clip slots were for ADL blind magazine stocks back then and I posted a good example above. The whole 40x bug-a-boo was that these weapons were made in the custom shop. To meet deadlines they basically went with a R700 varmint with some minor exceptions explained on page 157. And since you brought up single shot. Yes, Remington would of made you a single shot clip slot rifle if that is what you wanted. The Marines ordered the clip slots and then promptly made them useless by mounting a scope base over it and Remington knew it, of course. They actually contributed to some problems with the scope base coming loose that means not only were they not necessary they actually contributed to accuracy problems in country in those elements. Thus, the reason for the lug slots was explained above by @Random Guy

So were the "mil spec" clip slots only adopted after the mil started buying Remingtons or perhaps specific only to the mil rifles....all commercial sales getting the square cut?

Are there commercial rifles out there.....other than clones like the MaWhinney or SSA.....that have the detailed clip slot?

I have only seen the detailed clip slot done by peeps building clones from a custom builder or the two replica commercial rifles.......all "au natural" clip slots I have seen are the plain square cuts.

Perhaps I need to get out more....

 

[Mister Ridge]

So were the "mil spec" clip slots only adopted after the mil started buying Remingtons or perhaps specific only to the mil rifles....all commercial sales getting the square cut?

Are there commercial rifles out there.....other than clones like the MaWhinney or SSA.....that have the detailed clip slot?

I have only seen the detailed clip slot done by peeps building clones from a custom builder or the two replica commercial rifles.......all "au natural" clip slots I have seen are the plain square cuts.

Perhaps I need to get out more....

Do you mean specifically on the 700 or also the 40X/40XB?

 

[USMCSGT0331]

I found it. It was in Remington language a sporter type stock with cheek rest "ADL type for 5 round BDL magazine". Page 157 One Round War. There was nothing special or magical with the clip slots. They were standard based on the magazine based on the stock those magazines went into for iron sighted rifles. The square clip slots were for ADL blind magazine stocks back then and I posted a good example above. The whole 40x bug-a-boo was that these weapons were made in the custom shop. To meet deadlines they basically went with a R700 varmint with some minor exceptions explained on page 157. And since you brought up single shot. Yes, Remington would of made you a single shot clip slot rifle if that is what you wanted. The Marines ordered the clip slots and then promptly made them useless by mounting a scope base over it and Remington knew it, of course. They actually contributed to some problems with the scope base coming loose that means not only were they not necessary they actually contributed to accuracy problems in country in those elements. Thus, the reason for the lug slots was explained above by @Random Guy

FFS, what you just posted about the ADL stock is in a separate paragraph from the clip slot. No where at all does Senich say anything about a specific clip slot being based on a specific stock or for a specific stock. It's just a standard fucking 40X fucking clip slot. It was also used with other stocks. It's not "all in the stock," the stock didn't determine the clip slot type.

And the clip slot contributed to the scope base coming loose? The clip slot causing accuracy problems? WTF is this shit? This is one of the fucking dumbest things I've ever heard.

When I take my original M40 to the range, it shoots half an MOA at 100 yards, I've even posted pics of it here before. Amazingly, the clip slot on my original M40 doesn't seem to cause any accuracy issues. And it sure as hell doesn't make the scope base come loose. But what do I know.

I'm done with this thread, this is just getting fucking retarded.

 

[pmclaine]

Do you mean specifically on the 700 or also the 40X/40XB?

Either....was the square cut a commercial offering until the mil came along and wanted the detail cut?

 

[Mister Ridge]

Either....was the square cut a commercial offering until the mil came along and wanted the detail cut?

Hmm, that I'm not sure about. I do know that variants of the 40X were produced with the detailed clip slot because it was needed by NRA High Power shooters but I can't say what came first.

 

[Isaiah's Blacksmith]

I'm just waiting for somebody to come out with the box of mil spec stripper clips designed just for the USMC M40, lol. Seriously, no other modern rifle has gone through so much speculation than the so-so original USMC M40/700. Do any of you even own an SKS .

 

[Isaiah's Blacksmith]

FFS, what you just posted about the ADL stock is in a separate paragraph from the clip slot. No where at all does Senich say anything about a specific clip slot being based on a specific stock or for a specific stock. It's just a standard fucking 40X fucking clip slot. It was also used with other stocks. It's not "all in the stock," the stock didn't determine the clip slot type.

And the clip slot contributed to the scope base coming loose? The clip slot causing accuracy problems? WTF is this shit? This is one of the fucking dumbest things I've ever heard.

When I take my original M40 to the range, it shoots half an MOA at 100 yards, I've even posted pics of it here before. Amazingly, the clip slot on my original M40 doesn't seem to cause any accuracy issues. And it sure as hell doesn't make the scope base come loose. But what do I know.

I'm done with this thread, this is just getting fucking retarded.

And you're not in Vietnam having to deal with it's shortcomings.

 

[five 0]

Hmm, that I'm not sure about. I do know that variants of the 40X were produced with the detailed clip slot because it was needed by NRA High Power shooters but I can't say what came first.

From the American Rifleman article Remington 700 first 50 years.
A magazine charging notch in the front of the Model 721 receiver bridge was carried over to the design of the Model 700 receiver, but it was eliminated in 1966.
The REMINGTON MODEL 720 has the detailed clip slot as used on the 40X centerfires.

 

[Isaiah's Blacksmith]

Hmm, that I'm not sure about. I do know that variants of the 40X were produced with the detailed clip slot because it was needed by NRA High Power shooters but I can't say what came first.

Government is a waste of taxpayer money. Of course the civilians came first

 

[wadebrown]

Then it's some kind XM prototype or a completely different rifle. IBA produced some other rifles that were supplied to the government around the same time, such as the XM1 and XM33. I bet you did see some rifles built on 40X receivers, but whatever you saw wasn't one of the 52 issued USMC XM3's. I have all 52 serial numbers, every single one is an S prefix 700. I wish you had a camera with you back then, sounds like you got to see some cool prototypes and other rifles!

The one I had in hand was taken off the pallet that was supposed to be headed back to Iraq at Remington after they had repaired it. What I heard was that IBA transferred the repair contract over to the custom shop at Remington. The rifle came with the full XM3 kit as spec'ed by DARPA. The OneShot program was strongly associated with the XM3, DARPA could not be wrong so the sighting system had to go with the XM3. Prior to the main test I tested the rifle that Remington supplied us and it misfired about every other shot and had a trigger that was absolute crap. I disassembled the bolt and found a bent firing pin that was causing the main spring to ride the interior of the bolt, so I replaced the firing pin and dropped in a trigger I had on the bench and things were better. Things were not great still misfired so in went a new Wolff spring, which reduced the misfires but they never went away but I had to get the gun on a plane to the big island for three weeks of testing.

I was surprised Rem had not test fired the rifle before it was headed back into theater, the problems were apparent within a few rounds. We always fully
tested our UAVs before sending them off to theater, I always figured the customers absolutely needed them to work out of the crate and the back and forth transit was expensive and chewed up the calendar.

I was not at all impressed with the rifle we were given, but it was a replacement for one of the two XM3's that were transferred to Lockheed as a part of the OneShot contract those two rifles were never deployed I was told they were part of the original XM3 contract. It would not surprise me that DARPA kept a few of the first articles of production, a pretty standard practice, I assumed that is where the two original XM3's with complete kit except for the night vision, we got came from. They both shot like shit, could not maintain better than 2 MOA with actual fresh M118LR ammo, that is why we got the third rifle via Remington that I was told came out of the repair channel. I do not recall the model designation on the original XM3's

Of course since Lockheed had corporate rules did not allow any employees to handle firearms as a part of their work assignments I claimed to have done all of this on my own time to my manager. What would an employee of the largest defense contractor need to handle firearms. I had a lot of fun working/playing at Lockheed even with the infinite rules that exist in a large org like that, I also worked with some great people for the most part, I was lucky.

That about sums up my recall which is not perfect, except I remember being surprised that the XM3 I shot so much was built off a 40x as I knew it was spec'ed on a 700.