M40a1 build guide

[gregv]

Re: M40a1 build guide

Got my rifle back from GAP about a month ago. They did a fantastic job! Just got the scope mounted today, so I thought I would share a few pictures. I wish I was a better photographer, but here is what I have.

Greg V

 

[kft101]

Re: M40a1 build guide

Beautiful rifle, Greg. GAP definitely does awesome work.

Is that a return stock?

And you should post the pics in the official M40A1 picture thread too:
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=3571926

 

[Deleted member 10043]

Re: M40a1 build guide

She's nice!

 

[gregv]

Re: M40a1 build guide

No, not a return. I bought it from a guy here on The Hide about a year ago.

Thanks for the link, I'll get some pictures up over there soon.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kft101</div><div class="ubbcode-body">Beautiful rifle, Greg. GAP definitely does awesome work.

Is that a return stock?

And you should post the pics in the official M40A1 picture thread too:
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=3571926</div></div>

 

[totenkopf]

Re: M40a1 build guide

super nice!!!!

 

[totenkopf]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Emilio</div><div class="ubbcode-body">This one?

</div></div>

yes, also from a production source, Unertl 10xs were chromed (corrosion resistance) first before coating...as you can see (as did my scope) the "silver" color is showing through. Most of the scopes I saw or used at Quantico in the 80s had very little original finish left.
M

 

[M40_A1]

Re: M40a1 build guide


Beautiful stick there, Greg!

 

[mwhite]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg V</div><div class="ubbcode-body">Got my rifle back from GAP about a month ago. They did a fantastic job! Just got the scope mounted today, so I thought I would share a few pictures. I wish I was a better photographer, but here is what I have.

Greg V

</div></div> That is a nice rifle greg, did gap build all of it for u,, including getting the scope for u, r did u all ready have it.

 

[mwhite]

Re: M40a1 build guide

Does anyone know if uso made another run of the mst-100, r going to make another batch of them.

 

[kft101]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mwhite</div><div class="ubbcode-body">Does anyone know if uso made another run of the mst-100, r going to make another batch of them. </div></div>

USO just made a batch of them recently. Last year, I think.

That was supposedly the last run they were ever going to make. Of course, they've had about two or three "last" runs so far.

These scopes are real work intensive to get made and a specialty item for USO. You can call them and ask, but they've specified in the past that unless it's worth their while, quantity-wise, they have no plans to make any more.

Of course, these scopes do come up for sale every now and then, on this board as well as other listing and auction sites.

 

[M40_A1]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kft101</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mwhite</div><div class="ubbcode-body">Does anyone know if uso made another run of the mst-100, r going to make another batch of them. </div></div>

You can call them and ask, but they've specified in the past that unless it's worth their while, quantity-wise, they have no plans to make any more.

</div></div>

...and, the more people who call or express interest, the more likely they would say, "Hhhmmm. It might be time to make another run." Considering the slow sell of the last batch, though, it might take considerable interest to make it happen again.



<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: totenkopf</div><div class="ubbcode-body">yes, also from a production source, Unertl 10xs were chromed (corrosion resistance) first before coating...as you can see (as did my scope) the "silver" color is showing through.</div></div>

The final layer is black chrome. Considering the porosity and poor corrosion resistance a thinly plated hard chrome underplate would provide, it's more likely you were seeing bare steel, or perhaps a nickel underplate. Copper is another possibility, but you'd know it if you saw it. Otherwise, black chrome relies on oil to provide improved corrosion resistance.

 

[savagepc.223]

Re: M40a1 build guide

nice

 

[rlm8541]

Re: M40a1 build guide

Can anyone help...I am in need of an original "Unertl" base and rings "Brazed" for my M40A1 build.....I know they are going for big bucks and I am willing to pay as well.
Last set I saw went for $550. Not surprising as most were cut in half at the RTE shop when the A1 was taken out of service.
Also looking for an "Original" take off or replacement "wooden" M40 stock....Please help the needy...lol Thanks men!

 

[mwhite]

Re: M40a1 build guide

Dont know about original unertl base and rings,,, but u might try gap r uso,, uso had some bases that was for the mst-100 like the unertl base, texas brigade armory r maybe iron brigade armory, just to name a few

 

[rlm8541]

Re: M40a1 build guide

Thanks mwhite......Yeah, Ive had conversations with them in my hunt for the originals. Im not sure why Im being so anal about this build....I have an original "T" series Unertl, 6 dig 700 action, M40A1 take off stock with matching bottom #'d metal. I have a Hart barrel blank on order (8 weeks delivery) and I have a 2112 buddy of mine building it for me on his off time at the PWS shop at Quantico.
Just wanting to build is as absolutely correct as I possibly can get it.
Guess I just need to suck it up and order a set from GAP or TBA I suppose.

I really appreciate the response partner!

Oh, I am also building an original M40....Already have the Green Redfield and original 40X base and rings, 6 digit receiver.....Need to find an original M40 wooden take off.....The hunt continues!

 

[TheChad-->]

Re: M40a1 build guide

What is the difference is a factory Recoil lug and an afermarket one?
Thanks

 

[mwhite]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChadUSN</div><div class="ubbcode-body">What is the difference is a factory Recoil lug and an afermarket one?
Thanks</div></div> After markets one sometimes are thicker than the factory.

 

[gregv]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mwhite</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg V</div><div class="ubbcode-body">Got my rifle back from GAP about a month ago. They did a fantastic job! Just got the scope mounted today, so I thought I would share a few pictures. I wish I was a better photographer, but here is what I have.

Greg V

</div></div> That is a nice rifle greg, did gap build all of it for u,, including getting the scope for u, r did u all ready have it.</div></div>


mwhite, sorry about the late reply. I have been away for a bit. Anyhow, I sent GAP my 6 digit receiver, bolt, trigger, mag box, etc. along with the stock, which I bought here on S.H. GAP provided the barrel and put it all together, including markings and finish. I installed the scope and mount myself. I bought the mount from a S.H. member and got the scope from USO out of their last run.

 

[TWOMANATTACK]

Re: M40a1 build guide

I am no expert on building these rifles, however I have spent a day or two carrying, cleaning and employeeing the M40A1. I am going to try to only post pics that I know for fact are USMC SPEC rifles or USMC issued rifles. Most of this info is from from memory and I will need help getting all the details correct.
Because this post is so long and has become difficult to search, I am going to post a 1 STOP post for those gathering parts. I will put up pictures of the parts as much as possible. Please PM me with photos and parts info that I may have forgotten. All details that should be considered will be posted. I will also start adding notes to show where you can buy some of these parts. I will update this list for people looking to gather them. There are alot of well informed people out there that have good information to add to this list, please PM me with that info so I can relay onto this.

<span style="font-weight: bold">M40A1 USMC SPEC SNIPER RIFLE PARTS GATHERING CHECKLIST</span>

Remington 700 6 digit clip slotted action and in the proper serial number range 168,179 thru 322,769 some later ones will have letter prefix. LEFT or RIGHT handed action (if you dont believe me PM me).
*Some of the rifles @ horno had a pic rail and rings. The top of the receiver was milled and the rail was recessed into the slightly milled reciever. I saw a couple other rifles at the school house like this. I have researched this heavily and got some answers. I have also seen a couple of pictures of other 8541s with their M40A1s and rail system. What I understand through my research is that some units and school houses were outfitted variants to the M40A1 depending on the units mission or to gather end user feedback. PM me for more info or if you have pictures of your M40A1 with a pic rail system.

Remington trigger tuned and milled (.240 from the front, .290 Heigth) to fit modified M40A1. This modification was clean and milled, not hacked up garage work. Older actions should have tall flat safety lever and dual sear. Newer actions or actioins with replaced triggers will have round safetly lever 1 piece sear.

BDL Mag boxes were used and tack welded to the receiver

MCMILLAN STOCK M40A1 HTG NON STIPLED Forrest camo.
MCMILLAN STOCK M40A1 HTG NON STIPLED Smear pattern. Glass bedded no pillars. True M40A1 USMC spec rifles will not will not have a bipod on them

1.25" Witchita sling swivels

Winchester M70 Bottom metal. This bottom metal will have to be modified to fit the stock properly.

Pachmayer .6 brown basket weave butt pad

Unertl Lugged scope base and rings (upside down style) simrad caps on alot of MUESOC units rifles in the 90's. Slotted type scope mount screws. Redfield mounts early ones.

Barrells can be spec SS taper Schnieder, kreiger, hart, HS precison, atkinson + others. Barrells should be stamped RTE-P. and BLACK OXIDE finish(There were some very early barrells that were stamped differently)
<span style="font-weight: bold">*barrel crowns will vary ! ! !</span> I have verified this. My issued rifles were the same crown as in the picture. Newer rifles with replaced barrells can and will different crowns!!! I was stationed in 3 different STA platoons on 2 different bases, toured the RTE shop in the 90's and every rifle that I remember had the more square cut crown. Besides real time experience with these rifles, I also verified this with 2 different SNCOICs from the RTE PWS shop. They gave me the spec for the more square cut in case anyone wants thier clone to have the same barrell crown as the rifle they carried.

Recoil lug is modified stock remington lug. 2deg taper

Unertl 10x scope USMC SNIPER marked
US OPTICS MST-100 10x
Unertl T-series 10x

MRT SLING 1907 NM sling

 

[JaneDoe]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TWO MAN ATTACK</div><div class="ubbcode-body">
Recoil lug (*NEED ANSWERS ON THIS ... WAS THIS A modified stock REMINGTON part?)
</div></div>

TMA, in looking at the photos of my issued M40A1 before I had one built for myself, the recoil lug appears to be the same thickness as the factory Remington lug. It is definitely not as thick as a Badger or DD Ross lug. I would assume that the Precision Weapons Shop ground the factory lug so it was squared to the action and re-installed it. I wish I would have taken detailed photos of my issued weapons.

 

[long-shot]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tim8654</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TWO MAN ATTACK</div><div class="ubbcode-body">
Recoil lug (*NEED ANSWERS ON THIS ... WAS THIS A modified stock REMINGTON part?)
</div></div>

TMA, in looking at the photos of my issued M40A1 before I had one built for myself, the recoil lug appears to be the same thickness as the factory Remington lug. It is definitely not as thick as a Badger or DD Ross lug. I would assume that the Precision Weapons Shop ground the factory lug so it was squared to the action and re-installed it. I wish I would have taken detailed photos of my issued weapons. </div></div>

If I'm not mistaken the recoil lug is a factory unit that was tapered slightly (2 degrees?).

 

[popeye089]

Re: M40a1 build guide

Here it is again, bottom metal. I thought about being stingy but I don't need it. From What I see on NRA Museums shots this is spot on. Including the rounded button. I may be wrong but it is nice looking

[size:14pt][color:#000099] [

 

[firesniper27]

Re: M40a1 build guide

do you want to smooth out the barrel befor applying the parkerizing or the ceracoat?

 

[firesniper27]

Re: M40a1 build guide

I am also wondering about the triggers I have the old style with the bolt lock and the newer style with the round safty witch is the correct trigger for the forest camo pattern?

 

[SDWhirlwind]

Re: M40a1 build guide

If you built your M40A1 on an older 6 digit receiver like the Corp did to the first ones using receivers from M40's needing rebuilt then the tall flat safety is correct. If a newer C, E or G receiver than the round knob would be correct. I am sure some of the older safties were eventually replaced but it would depend more on action SN then stock color as some of the older receivers had stocks broken etc and ended up in the newer forest camo at some point.

Also if you have a stainless barrel which they all had then you cannot park it, parkerizing only works on Chrome Moly steels. The Corp used a Black Oxide type of finish although I am not real familiar with exactly how it is applied. It didn't hold up very well from what I have heard/read.

 

[M40_A1]

Re: M40a1 build guide

Some additional information which may be of value to incorporate into your summary post:

3-5 lb trigger pull

recoil pad glued and screwed (epoxy)

13.5" length of pull

"sniper fill" in stock

bolt release filed to no less than .060" (as well as the trigger housing milled) to fit modified Winchester M70 trigger guard

tabs on follower filed down to create 5 round magazine capacity

sling swivel anchors: 1/4" x 3/8" x 2" to 2 1/2" long cold rolled steel embedded in the stock (during manufacture) from 1 1/2" to 2" from each end of the stock to place swivels at 2" to 4" from the ends of the stock. Wichita swivel studs are 7/32"-40 threads, and the stock with embedded anchors was drilled and tapped by Quantico.

bedding was Devcon steel in 1991

bedded out to about 1 3/4" forward of the receiver under the rear of the barrel

lots of evolutionary variation on placement of serial numbers on parts

crown spec given to me by Quantico in 1991: .050" deep, .200" out from edge of bore, then 45-degrees out (leaving about 1/16" to 1/8" lip)


Don't sweat long firing pin shrouds or round safeties unless you are doing a perfect, "first out of the shop in 1979" build, as even at that time the long shrouds and round safeties were on the market as replacement parts by Remington.

No "smoothing" of the barrel. The rougher, the better the durability of the oxide (hot blue). Finish was glass beaded prior to immersion into the salt bath. When I made my build twenty-one years ago I supplied my gunsmith with a 40 pound can of Oxynate 84 in exchange for his bluing my parts with it. I don't know for a fact Quantico used this Brownell's product, but it is the go-to stainless hot blue (oxide) on the market:
http://www.brownells.com/gunsmith-tools-...d-prod1103.aspx

 

[firesniper27]

Re: M40a1 build guide

thanks for the info I think im just going to use my 40x trigger I had it milled to spec . I guess I will sell the old one wich is also milled to spec and has duel sear and square safty.

 

[firesniper27]

Re: M40a1 build guide

what finish is used on the barrel on in the post above by two man attack on the bottom of his post?

 

[grunt0311]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">what finish is used on the barrel on in the post above by two man attack on the bottom of his post? </div></div>

The correct finish on the M40a1's is a black oxide. Not too many people do it today. Most people get theirs duracoated or some sort of other finish.

 

[firesniper27]

Re: M40a1 build guide

I will ask my smith about the black oxidizing when I get my barrel done thanks for the info.

 

[firesniper27]

Re: M40a1 build guide

still have any of the MRT 86 slings avalable?

 

[firesniper27]

Re: M40a1 build guide

what are the specs for this barrel crown?

 

[SDWhirlwind]

Re: M40a1 build guide

Just about every spec used on the M40A1 is listed in the first few pages of this thread and was the reason it was started. First page, second post by Longshot with all the pics, crown spec at bottom of second post and a img link to a pic of how it should look!!!! Those specs confirmed by George at GAP on second page concerning crown, 45 degree bevel and .090 deep!

 

[M40_A1]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">what are the specs for this barrel crown? </div></div>

Which crown? There were several variations. The specs I gave were direct from Quantico in 1991.

 

[firesniper27]

Re: M40a1 build guide

I was refering to the one Two man attack has on the bottom of the post on this page

 

[M40_A1]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">I was refering to the one Two man attack has on the bottom of the post on this page </div></div>

I see.
I'd like to have that spec too. When I did my build in the early 1990s I originally based my crown on a photo of one of the early M40A1s from the early 1980s with an Atkinson barrel, and that crown looked just like the one in Two Man Attack's post. But then when I got some real measurements to work with from Quantico (the specs I gave) I had it recut to a known rather than leave it just based on guess work from a photo.

The crown in the photo looked like it had an outer ring cut straight down to the recessed surface, but the shadowing seemed to indicate the recess had a very slight conical taper to the bore. I've always been curious if the recess was flat, or slightly tapered, and I hope Two Man Attack's specs will answer that nagging question for me. So, please, Two Man Attack, would you be willing to provide those for us?

 

[firesniper27]

Re: M40a1 build guide

dose anyone know where I can get a mrt sling from the 70s or 80s?

 

[TWOMANATTACK]

Re: M40a1 build guide

The following barrell crown spec was provided by a Marine Corps 2112 of the RTE Shop. The crowns varried over the years depending on the 2112 that cut them.

".075 deep and at a 45 degree angle to leave an approximate final width of .750 at the widest portion of the crown"




I have seen USMC issued M40A1 rifles cut to the M40A3 crown recess. I even own one with that crown. HOWEVER, between 1990-1998 ALL of the M40A1s that I carried, cleaned, saw at the school house or was otherwise responsible for had the much more square cut crown recess. Again, I can only speak from practical experience or about rifles that I had real time experience with. As the M40A1 rifles were rebarrelled for units like PMO after the A3s were issued to STA platoons they had the A3 crown. So either crown is correct. AGAIN I can only speak on what I had practical experience with.




<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 10Xview</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">I was refering to the one Two man attack has on the bottom of the post on this page </div></div>

I see.
I'd like to have that spec too. When I did my build in the early 1990s I originally based my crown on a photo of one of the early M40A1s from the early 1980s with an Atkinson barrel, and that crown looked just like the one in Two Man Attack's post. But then when I got some real measurements to work with from Quantico (the specs I gave) I had it recut to a known rather than leave it just based on guess work from a photo.

The crown in the photo looked like it had an outer ring cut straight down to the recessed surface, but the shadowing seemed to indicate the recess had a very slight conical taper to the bore. I've always been curious if the recess was flat, or slightly tapered, and I hope Two Man Attack's specs will answer that nagging question for me. So, please, Two Man Attack, would you be willing to provide those for us?</div></div>

 

[firesniper27]

Re: M40a1 build guide

so the barrel in the picture isnt relly square it is tapered its just deceving? also what finish is on that barrel? iI like the grey look

 

[M40_A1]

Re: M40a1 build guide

Thanks, Two Man Attack. I got that spec. But I (and I think firesniper) thought you meant you had the spec for the more square cut crown. Thanks for clearing that up and giving a rundown on the time frame. It would be great if a timeline for the various crowns could be made, but then maybe there was no clear cut evolution. Interesting, because everything I knew in the Corps had very specific parameters (You know, the right way, the wrong way, and the Marine Corps way).

Do you remember if there was ANY taper to the recess on those flatter cut crowns you saw?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">so the barrel in the picture isnt relly square it is tapered its just deceving? also what finish is on that barrel? iI like the grey look </div></div>

The crown with the 45 degree spec appears to be the one in the link that doesn't open automatically (at least on my end), specifically:

 

[firesniper27]

Re: M40a1 build guide

I was refering to the picture of the barrel above the link that goes to this picture or is that the same barrel?

 

[M40_A1]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">I was refering to the picture of the barrel above the link that goes to this picture or is that the same barrel? </div></div>

Two Man Attack will have to answer that for you to be certain, but to my eye they look nothing alike. The crown in the upper photo (with the grey areas) has a distinctly squared shoulder, and the linked crown with the model holding it has a distinct 45 degree shoulder which reflects the specs he provided.

 

[TWOMANATTACK]

Re: M40a1 build guide

The cuts are comepletely different. One of the barrells has is 0.90" depth and the other is 0.75" depth. Both specs call for a 45 degree cut, but barrell lenght and the 2112 building the rifle would determine how "square" the cut would look. Hope the following pictures and explanation helps. The owner of GA Precision had posted some pictures of used USMC issued barrells that had been removed from the M40A1s at Quantico. They have since been deleted. Perhaps he can repost them to show the variance in the crowns?

Crown:

45 degree .090" deep

".075 deep and at a 45 degree angle to leave an approximate final width of .750 at the widest portion of the crown" The 45 degree was not critical so some looked more "square cut than others."

 

[M40_A1]

Re: M40a1 build guide

Thanks again, Two Man Attack.

I'm still not seeing anything close to a 45 degree angle in that one crown. Maybe more like a standard 11 degree cut with a .075" deep rim. I understand that photo was from Celtic Rifles originally.

Were those GAP photos in this thread originally, or elsewhere?

 

[firesniper27]

Re: M40a1 build guide

well hopfully ga percition can repost the barrel pics so we can see the diffrent varriations of the barrel crowns

 

[mwhite]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">well hopfully ga percition can repost the barrel pics so we can see the diffrent varriations of the barrel crowns </div></div> The crown on mind looks like the one on page 22 on gregs gun.

 

[firesniper27]

Re: M40a1 build guide

chad do you know the spec on the crown on your barrel?

 

[mwhite]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">well hopfully ga percition can repost the barrel pics so we can see the diffrent varriations of the barrel crowns </div></div> On page 11 and 13 of this thread there r a couple of pictures of different barrel crowns, but u might have already seen them.

 

[firesniper27]

Re: M40a1 build guide

Did anyone find any pics of the diffrent barrel crowns or specs for the square crown?

 

[firesniper27]

Re: M40a1 build guide

dose anyone have any 80's slings?