M40a1 build guide

#701
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: whitetailnut</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mwhite</div><div class="ubbcode-body">Does anyone have some pictures of there m40a1 stock where the front wichita swivel is in the stock, (Looking on the inside). I want to see what it looks like on one thats done right so i can make sure i dont mess up. Thanks alot </div></div> Thanks for posting pictures, mind dont look like that, minds got a insert about the size of a nickel in front, thats the way i bought it from mcmillian.

DSCF0369.jpg
</div></div>
 
#702
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mwhite</div><div class="ubbcode-body">
Thanks for posting pictures, mind dont look like that, minds got a insert about the size of a nickel in front, thats the way i bought it from mcmillian.</div></div>

I don't know about that. I do know that the swivel on this stock can't be removed or at least it doesn't appear to be removable.
 
#703
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: whitetailnut</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mwhite</div><div class="ubbcode-body">
Thanks for posting pictures, mind dont look like that, minds got a insert about the size of a nickel in front, thats the way i bought it from mcmillian.</div></div>

I don't know about that. I do know that the swivel on this stock can't be removed or at least it doesn't appear to be removable. </div></div> Your swivel wont unscrew and come out. I can unscrew the stud out of mind but the insert stays there. your insert may be built in to your stock and cant see it. The insert in mind has got come out, for the wichita to work i would think.
 
#704
Re: M40a1 build guide

The insert is molded in and hard to really tell it is there. Wichita should screw out unless glued in. Might be rusted. On 1 I had I put some penetrating oil on and let it set overnight, then gently turned it loose just a bit then back tight etc a little at a time until it worked loose. Don't crank on it if tight and no lube or you will either twist it off or pull/strip threads on one or both pieces. Same with rear. They are both machine thread, 7/32 x 40 threads per inch, a real oddball thread and not the same as Uncle Mikes etc.
 
#705
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SDWhirlwind</div><div class="ubbcode-body">The insert is molded in and hard to really tell it is there. Wichita should screw out unless glued in. Might be rusted. On 1 I had I put some penetrating oil on and let it set overnight, then gently turned it loose just a bit then back tight etc a little at a time until it worked loose. Don't crank on it if tight and no lube or you will either twist it off or pull/strip threads on one or both pieces. Same with rear. They are both machine thread, 7/32 x 40 threads per inch, a real oddball thread and not the same as Uncle Mikes etc.</div></div> The swivel on the back has like a wood screw thread but i wont to change it to machine screw, the front insert on my stock is machine thread but not like the wichita swivel thread its smaller, so im going to have to take it out, may have to get someone to put the things in, cause i wont it to be right
 
#706
Re: M40a1 build guide

Uncle Mike's studs are like 3/16'x 32TPI. Some on HS stocks I have read are 24TPI instead of 32??? Haven't pulled one out of one of mine to confirm this however. Didn't know Wichita made a wood screw type thread back then??? Are they indeed Wichita's or perhaps the old Remington like used on the 40-X etc? They look similar.
 
#707
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SDWhirlwind</div><div class="ubbcode-body">Uncle Mike's studs are like 3/16'x 32TPI. Some on HS stocks I have read are 24TPI instead of 32??? Haven't pulled one out of one of mine to confirm this however. Didn't know Wichita made a wood screw type thread back then??? Are they indeed Wichita's or perhaps the old Remington like used on the 40-X etc? They look similar.</div></div> There wichita swivels, got them(2)from iron briage armory, and got one from wichita arms, the ones from IBA,, one is machined thread and one is for the wooden stock, they have both which every u would wont. wichita arms has both kind too.
 
#708
Re: M40a1 build guide

That's O.K., SDWhirlwind, I appreciate your willingness to help. So to be sure, the Marine Corps bottom metal has flat bottomed holes?

---------

The information I got from Quantico in 1990 regarding the steel inserts:

The sling swivel anchors are 1/4" x 3/8" x 2 to 2 1/2" long cold rolled steel imbedded in the stock from 1 1/2" to 2" from either end, placing the sling swivels at 2" to 4" (3" target distance).

You can verify the presence and roughly the position of the steel blocks with a magnet.

I'm curious, do all of the return stocks show the sling swivel hole from the inside of the barrel channel like that? I thought it would be better to avoid a hole open at the top to keep water from accumulating and rusting the threads.
 
#709
Re: M40a1 build guide

Hey, quick question:

whats the difference between the BDL and the ADL mag? Is there anyway to get the BDL to work? I know from reading this thread 50 times that the ADL will need to be ground down etc. but just wondering on the BDL.

If anyone has a spare ADL and spring/follower, I would be interested. Midway has em, just wanted something cheaper and not repo...(11 for box, 25 for follower, 7 for spring...)

Reagrds,
DT
 
#713
Re: M40a1 build guide

I am getting old and forgetfull but seems I read somewhere(this thread on thought) that the first M40A1 stocks came with a red Pachmayr recoil pad??? Can't find it now but was wondering if anyone else recalls this? I know the red is no longer made and McM currently uses brown. Anybody else recall???

Thanks.

Respectfully,
Dennis
 
#715
Re: M40a1 build guide

After a discussion with SD and a PM to Mr. Davis, yes the first color was red, however after discontinuing them, all future and fixes were done with the brown.
Chad
 
#716
Re: M40a1 build guide

I have a question about the MST-100 mount.

How are the rings attached to the base? They look like Redfield rings, but obviously are not secured like the Redfileds.

Thanks, Greg V
MST-100Mount008.jpg
 
#717
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg V</div><div class="ubbcode-body">I have a question about the MST-100 mount.

How are the rings attached to the base? They look like Redfield rings, but obviously are not secured like the Redfileds.

Thanks, Greg V
MST-100Mount008.jpg
</div></div>

The rings are attached either silver sodiered or brazed. I cant remember which way USO went with. I know they had a problem with one of them when they did the black oxide finish because the rings would break loose when you shot the rifle. They are copies of the Redfield rings.
 
#718
Re: M40a1 build guide

Thanks, I was just curious. I called USO and asked the same question, but the guy on the phone told me that they were machined as one unit. I could see that they weren't, so maybe I wasn't real clear in what I was asking.
 
#720
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Seth8541</div><div class="ubbcode-body">Found a 6 digit Rem 700 SA today at the gun show. .308 bolt face.

Ser#-102XXX

Great shape. Should I have grabbed it? </div></div>

HELL YEAH you should of grabbed it!! Been looking for one too. Great piece to start your M40a1 build. Serial number in the right range as well. Need to go back and get it NOW.
 
#721
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USMC Grunt</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Seth8541</div><div class="ubbcode-body">Found a 6 digit Rem 700 SA today at the gun show. .308 bolt face.

Ser#-102XXX

Great shape. Should I have grabbed it? </div></div>

HELL YEAH you should of grabbed it!! Been looking for one too. Great piece to start your M40a1 build. Serial number in the right range as well. Need to go back and get it NOW. </div></div>

It is part of a whole package. Rem 700 SA BDL 6MM $750.00. If you want it let me know. I can get you in touch with the guy.
 
#722
Re: M40a1 build guide

Serial Number IS NOT "in the right range" for an M40A1 nor an M40. Earliest SN used for an M40 was 168,179. Useable recievers from M40's were rebuilt to M40A1 specs.
 
#723
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SDWhirlwind</div><div class="ubbcode-body">Serial Number IS NOT "in the right range" for an M40A1 nor an M40. Earliest SN used for an M40 was 168,179. Useable recievers from M40's were rebuilt to M40A1 specs. </div></div>

That was my first thought when I saw it, but was unsure. Serial # ATB pretty low. Thanks for the info.
 
#724
Re: M40a1 build guide

I seen a 235,XXX(would have been a Sept 66 receiver) at the Rapid City, SD gunshow today as a complete rifle with scope. Don't remember the price but it was high enough that I had no interest in it. Was a 6mm Varmint Special barrel from late 71ish and a newer cut checkered stock from early 70's. Owner tried to convince me it was a "custom gun out of the Custom Shop as all the heavy barrels were built in the Custom Shop"!!! Guess I looked like I fell off a turnip truck or something.When he couldn't answer my questions about why there was parts from 3 different yrs over a 5 or so yr span he started to back peddle in a hurry on his "Custom Shop" sales pitch. Love gunshows and all the knowledge they contain!!!
smile.gif
 
#725
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SDWhirlwind</div><div class="ubbcode-body">Serial Number IS NOT "in the right range" for an M40A1 nor an M40. Earliest SN used for an M40 was 168,179. Useable recievers from M40's were rebuilt to M40A1 specs. </div></div>

You guys are right. Went back and reread the first page of this thread. Seth I didnt mean to lead you in the wrong way. I guess I got excited for the 6 digit action and didnt register the SN. Id like it buy it but I cant stand to pay the price just to tear it down and build to spec.
 
#726
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SDWhirlwind</div><div class="ubbcode-body">I seen a 235,XXX(would have been a Sept 66 receiver) at the Rapid City, SD gunshow today as a complete rifle with scope. Don't remember the price but it was high enough that I had no interest in it. Was a 6mm Varmint Special barrel from late 71ish and a newer cut checkered stock from early 70's. Owner tried to convince me it was a "custom gun out of the Custom Shop as all the heavy barrels were built in the Custom Shop"!!! Guess I looked like I fell off a turnip truck or something.When he couldn't answer my questions about why there was parts from 3 different yrs over a 5 or so yr span he started to back peddle in a hurry on his "Custom Shop" sales pitch. Love gunshows and all the knowledge they contain!!!
smile.gif
</div></div> Guess he found out right quick like that u new more about that GUN (and guns) than he did, dont u like it when someone trys to pull something like that. lol
 
#727
Re: M40a1 build guide

They are still out there at reasonable prices. Both of mine came from the Phoenix show in the last 4 months. Both were complete rifles. One is 266,xxx ADL in 6mm, the other a 321,xxx BDL in 22-250. The rifles were $400 each. The BDL looks like it was never fired. I do feel pretty lucky to get them, but it's not impossible to find em.
 
#728
Re: M40a1 build guide

Honestly though, its not like any civilian is going to get an action actually used by the USMC. When people talk about being in the right "range" all you mean is that they are close to the same time as the ones made. There a set number of serial numbers on a list of actions used so technically everyone serial numbers are out of spec in my opinoin. If you get a six digit action and have it stamped correctly I call it done for a clone build.
If you want to be a spec Nazi (i am myself, but also realistic) then you would have the action that matches your return stock but honestly I think everyone makes that compromise so IMHO get a six digit action and call it good.
 
#729
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: chad3</div><div class="ubbcode-body">
20.jpg


Hard to see, but its there. </div></div>

I cant see it. Is the taper from a side view, front view, or bottom view?

Thanks, DT
 
#730
Re: M40a1 build guide

Tapered sides from the front to the rear. When shot, in theory, this acts as a wedge holding the action from moving. At least that was the best way it was told to me.
Chad
 
#731
Re: M40a1 build guide

Aw, I think I got it. So, if you were looking down on the barrel, the sides of the taper would make the edges of an arrow pointing back at the action? In theory, wedging itself into the stock to keep it centered?

Top View:

Action

/ | \

barrel

Yes?

Reagrds,
DT
 
#732
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: D_TROS</div><div class="ubbcode-body">Aw, I think I got it. So, if you were looking down on the barrel, the sides of the taper would make the edges of an arrow pointing back at the action? In theory, wedging itself into the stock to keep it centered?

Top View:

Action

/ | \

barrel

Yes?

Reagrds,
DT </div></div>

D_TROS,

No. Like this:

t_403150100_1.jpg


A properly bedded stock will not need to have extra "anchoring" or "centering". You want the barrelled action to be able to be removeable from the stock. The taper will wedge down in the stock for easier action removal. Otherwise, the bedding will lock the action in the stock when it cures if you have the taper the other way. The same reason you don't want to bed a barrelled action above the 50% or half of the diameter of the action. You would not be able to remove the stock without damaging it.

I hope I explained this clearly.
smile.gif
 
#733
Re: M40a1 build guide

Your picture is just a red X. Please repost or email. I never had any problems bedding an action if you use a releaseing agent and tape on the recoil lug. Anybody else?

Regards,
DT
 
#734
Re: M40a1 build guide

Also wanted to say that I sent out money on Friday for a new Schneider Barrel, M40, 1:12, 6 groove, and Mr. Gary Schneider had it delivered to me by Wed the following week (this week). Now that is service.

Now I hope the thing shoots as good as his service!! ha
 
#735
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: D_TROS</div><div class="ubbcode-body">Also wanted to say that I sent out money on Friday for a new Schneider Barrel, M40, 1:12, 6 groove, and Mr. Gary Schneider had it delivered to me by Wed the following week (this week). Now that is service.

Now I hope the thing shoots as good as his service!! ha </div></div>

Ohh it shoots alright. They claim it holds MOA up to 10,000 rounds plus
 
#736
Re: M40a1 build guide

As i recall, the Sniper Rifles used in the 60's by the marines in vietnam, including by Hathcock and Mawhinney, were bought off the shelf from the PX in Okinawa. The Corps and the Army had cncelled their Sniper programs after Korea, just like after WW I and II. Wood stocks, satin blue actions and barrels, and Redfield scopes. Some had Unertls installed by armorers when they could find some. .308 and 30-06 both. That is how desperate things had gotten. They were used until unservicable. In that climate and conditions, that was a year or two.
The M1C's and D's and the Marine Springfield's were out of the system or worn out and gone by then.
if you are building a M40A1 you are pretty much building the weapon built in the 70's at Quantica for the Scout/Sniper Instructor program that didn't come into existence until the very late 70's and were designed and built in the mid 70's. the Unertl USMC Sniper 10X didn't hit the FMF until Nov/Dec of 82. I remember that because I was there and almost everybody else in the section was on leave, so i had to zero almost all the rifles in the Bn and then some.



 
#737
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Donttrytorun</div><div class="ubbcode-body">I remember that because I was there and almost everybody else in the section was on leave, so i had to zero almost all the rifles in the Bn and then some.</div></div>

I bet that was fun. I struggle zeroing this optic when I haven't picked it up in awhile. It's a little challenging!
 
#738
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: long-shot</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Donttrytorun</div><div class="ubbcode-body">I remember that because I was there and almost everybody else in the section was on leave, so i had to zero almost all the rifles in the Bn and then some.</div></div>

I bet that was fun. I struggle zeroing this optic when I haven't picked it up in awhile. It's a little challenging!</div></div>
It was harder than you think, because it was the first time we saw them when we were at the range. The 2112's went all over the world swapping out the rings and scopes from the Redfield 3x9's.
I think I did 5 of our 8, and a couple from another Bn in the same situation.
The Unertl had, as I recall, just a allen screw in the center of the turret knob, with no cap, to adjust the elevation and deflection, and you could do it at any range from 100 to 1000 yds. After you zeroed it that way, with no marks like on a standard, typical scope, you were able to use the elevation and windage knobs, and the fine tune below the elevation turret, for your range adjustment, compensation for altitude, ammo, and temp, and for windage and lead.
It took a little while to do it, but I was just out of the school and a sharp tack anyway, so I got it pretty fast.
After everybody came back we all went back to the range to adjust our own ourselves. To be honest, there wasn't much for them to move, because proper sight picture should be the same for everybody. they just moved a few inches or so at 500, so we could all shoot the spindle out of a spotter disk about 25% of the time. And that spindle was a little over .30", so we shot around 1 1/2 inch groups at 500.
i had two different guys I worked with as partners (we all had 2 that each were familiar with each sniper and could serve easily and comfortably with as a parnter) One was a big Cornfed guy about 3 inches taller than me, and the other was a little navajo indian. We all shot each others rifles without any change or adjustment. We could swap between us, even with the physical and height differences, and still shot the same zero, as any good shooter should.
That Unertl was very sophisticated, and very cutting edge at the time. It was designed and built to specs made by USMC snipers, and the USMC went specifically to Unertl, because of the relationship back in the 30's and 40's with the Springfield 03 Match and Sniper rifles of WW II. There was no open bid for the contract.
 
#739
Re: M40a1 build guide

Lots of greeat info in this thread!

I am in the middle of assembling a M40A1-inspired rifle and have a couple of questions.

For those of us not wanting to the clip-slot mount route, are the IBA one-piece 1" mounts the closest in profile and function to the originals? Are there any other options?

The SA I have for the base of this rifle is currently in a McMillan woodland camo A2 stock, which I am planning on selling to fund a HTG. Will I be giving up much functionality?

Thanks!
 
#740
Re: M40a1 build guide

To the people starting from scratch, there is no "other options." Its either an M40A1 or its not. Pricey, yes, but worth it. There really are no other options, thats why, when you can find one, the mounts are bringing $350+

Usually if one cant afford/find a return stock, they get a new one from Mcmillin. The A2 is not an M40A1 stock. Never was or will be, so the question of functionality is a moot point and the ergonomics/comparisons should be discussed/have been discussed in other threads. I would sell it and get a woodland stock and go from there if you want a "M40A1-inspired rifle."

Regards,
DT
 
#742
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: FLHX</div><div class="ubbcode-body">Can anyone clarify as to the length of pull measurement of the return stocks from McMillan. Was there a difference between the smear and woodland. </div></div>

I dont think that there was a difference between the two stocks. The both of them should be the standard lenght of pull which I think is 13.5".
 
#743
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: FLHX</div><div class="ubbcode-body">Can anyone clarify as to the length of pull measurement of the return stocks from McMillan. Was there a difference between the smear and woodland. </div></div>

I just measured the stocks I have. The woodland return is about 1/4" longer than the smear. So the difference is really negligible.
 
#745
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: FLHX</div><div class="ubbcode-body">Thanks KFT101.

What was the measurement, 13.5 and 13.25 inch? </div></div>

Yep, that's exactly it. Measuring from the middle of the trigger to the edge of the recoil pad, the woodland return was 13.5" and the smear 13.25". Add about 1/8" if you want to factor in the outward curve of the recoil pad.
 
#746
Re: M40a1 build guide

Anyone with experience with the original Unertl A1 mounts care to provide some info?

The repro mounts from USO that I have, and seen on others' builds, seem to have a real noticeable gap between the top and bottom ring halves with a Unertl or MST-100 scope mounted.

All the real M40A1s I've seen with the Unertl mounts have a very tight fit, where the ring halves are basically touching. Is there just a slight difference in the repro ring measurements, or do the rings on the original Unertl mounts sit closer together just because of the years of wear?

I ask because it seems like the current gap on the rings I have are just asking for something to get lodged in there and maybe fudge up the exposed threads of the screws. I know, probably will never happen, but I'm just a stickler like that.
 
#747
Re: M40a1 build guide

KFT101 I have both the USO repo mount and an original Unertl mount that I found at work with Simrad mount. I measured in 2 different spots on the rings. One is where the ring halves touch and the other would be top and bottom. The USO repo was smaller than the Unertl. On the USO it .088 at the ring halves and .063 at the top and bottom. On the Unertl it is .098 at the ring halves and .072 at the top and bottom. I hope this helps out with what you wanted.

But since you mentioned it I have noticed the same with the USO mounts having gaps between the 2 halves which is not good. All the actual M40a1s the mounts are not like that at all. Good question I hope this helps.
 
#748
Re: M40a1 build guide

@USMC Grunt: Thanks for the info. It's certainly an eye-opener. I didn't think to measure the repro mounts before sending them in for my builds. So the rings on the USO repro mounts are not even 9/10th of an inch in diameter on the inside, huh? Well, that certainly explains the gaps between them when mounted.

Is the difference in the inside ring diameters a combination of the top and bottom halves, or maybe just the top? I'm thinking of getting some real Redfield rings and swapping out the top halves, and see if it closes the gap any.

Also, SWEEEEEET find on the real Unertl mount and simrad cap. And can't beat the price! Haha. I read the thread on it and commented also. Whenever you get your milling skills up and running, I'm definitely in for two (and maybe more) of the A1 simrad caps when you make them.

Cheers.

Ken
 
#749
Re: M40a1 build guide

When I measured the 2 the rings were screwed together. Looking at the rings I measured top and bottom and then right were the 2 ring halves meet.

I also have 2 pairs of Redfield rings, 1 is the top screw and the other bottom screw. I measured the same way as I did the other 2 and found that the bottom screw is (measured from top to bottom) .080. The top screw is measured .083.

So I see that no mounts is actually 1" like they are suppose to be. Im sure that you could lap the rings for a better fit. I remember reading, I think that it was on here, that the USO mounts didnt have to be lapped but guess we could be wrong.
 
#750
Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USMC Grunt</div><div class="ubbcode-body">
I also have 2 pairs of Redfield rings, 1 is the top screw and the other bottom screw. I measured the same way as I did the other 2 and found that the bottom screw is (measured from top to bottom) .080. The top screw is measured .083.

So I see that no mounts is actually 1" like they are suppose to be. Im sure that you could lap the rings for a better fit. I remember reading, I think that it was on here, that the USO mounts didnt have to be lapped but guess we could be wrong. </div></div>

Hmm, that's interesting. Are your Redfield rings new manufacture, or old stock?

The real Redfield rings, as well as the USO repro ones, seem pretty thin already and do not look like they have that much metal to give, either for lapping or whatever.

By the way, what would the height be for the Redfield rings used in the A1 mounts, medium or high? Dual dovetail or regular, or either with the bottom cut off and soldered on? And anybody know how the rings were attached to the bases in the original mounts?
 
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