M40a1 build guide

[Turk]

Re: M40a1 build guide

<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: SDWhirlwind</div><div class="ubbcode-body">
As for "accuracy suffers" how many factory rigs or custom actions nowdays use a welded in mag box to enhance accuracy???</div></div>

For that matter, how many factory rigs or custom actions use a welded recoil lug? Leave it to the Marines to try anything to squeeze every posible ounce of accuracy out of a sniper rifle!

Yes, you are absolutely correct about a BDL magazine dropping out through the floorplate if not somehow secured. I thought that went without saying. Of course, that being the case, they could have simply used easily removable, modified ADL magazines, but they didn't. I wonder why.



</div></div>
They didn't weld the lug or the box for accuracy!!! Stop w/ this misinformation! The lug was welded to make it easier to line it up on the rebarrel, and the box had to be welded in to keep it from falling out. No "voodoo" there! And as far as not using the ADL mag box, not all the receivers they used had the hole to screw in the box.

 

[mwhite]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">can someone tell me when you get your action clip sloted dose that include the little angle cutout on the side of the recever? </div></div> yes, and drill the holes on the other side for iron sights.

 

[mwhite]

Re: M40a1 build guide

Dennis do u have to change anything by going with the shorter shroud, mind has the longer one.

 

[SDWhirlwind]

Re: M40a1 build guide

No Sir, fits same as the longer one. Only difference is appearance!

 

[firesniper27]

Re: M40a1 build guide

do you know of anywhere that has the usmc drawings for the trigger guard and floorplate modification?

 

[Rainier42]

Re: M40a1 build guide

Firesniper27 ... Page 23 above has an excellent description of what you need to do for the trigger guard modification; page 2 shows a photo of the modified trigger; page 16 shows a trigger guard before and after; page 20 shows good photos of an unmounted action; page 22 shows/tells you how much to trim from trigger.

 

[firesniper27]

Re: M40a1 build guide

I saw all that I was just wanting to know if someone had the usmc spec drawing like how they have the one for the clipslotting gap says they have one on the m40a1 video

 

[Rainier42]

Re: M40a1 build guide

Which video ... do you have a link?

 

[firesniper27]

Re: M40a1 build guide

if you go to youtube search m40a1 it is the ga percition video it says on the video that the floor metal is modified to usmc drawings

 

[M40_A1]

Re: M40a1 build guide


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">Stop w/ this misinformation! The lug was welded to make it easier to line it up on the rebarrel, and the box had to be welded in to keep it from falling out. </div></div>

I owe everyone here an apology.

I'm sorry that I correlated the welding of the recoil lug to accuracy. I was trying to make a point that the Corps sometimes does things that differ from common custom gun building methods, but I was wrong to make an analogy based on something I didn't really know to be the case. If anything good came of this, it is that we now have the reason for the welding of the recoil lugs, and it makes perfect sense. Thankyou, Turk (Though, now I am wondering why they stopped the practice).

The M40A1 is the reason I am even on this forum. I have learned tons from members' posts in this thread, and I have information I am glad to share as well. It is certainly NOT my intention to start or perpetuate any misinformation. I need to be more careful.

As for my comment that welding the magazine was done partly for accuracy, I did not pull that one out of a hat. Sometime during my research around 1990 when I did my build I got that information from someone that I felt was a reliable source, and the principle behind it made perfect sense to me. It's akin to the reason clearance must be left between as many of the parts as possible so they do not touch and change the harmonics of "the system" from shot to shot.

However, having now gone back over all of my notes I see that I did not make a notation regarding this, and consequently cannot remember which source it was that told it to me. So, for what it's worth, I have no way to back it up. Really, though, for the purpose of a build guide it doesn't matter. The M40A1's had welded magazines, so that is how a build should be done.

 

[firesniper27]

Re: M40a1 build guide

the magazine box was welded to the recever so it wont fall out when the floorplate is opened

 

[M40_A1]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">the magazine box was welded to the recever so it wont fall out when the floorplate is opened </div></div>

This has already been established as a reason, maybe even the only reason. Thankyou.

 

[Rainier42]

Re: M40a1 build guide

10X ... no apologies are necessary, the purpose here is to help one another and you've already been a big help to me. We all receive info from different sources and it is no always accurate.

Followup question for you ... would you know what tools were used to notch the trigger? Any step-by-step directions on doing this.

thnx,
Rainier

 

[SDWhirlwind]

Re: M40a1 build guide

The Corp used a mill to do the triggers. My guess though is a dremel was the 'winner' with most of these so called 'clones'!

 

[M40_A1]

Re: M40a1 build guide

Thanks, Rainier.
George at GAP gave the cut dimensions for the trigger housing about half way down page one of this thread.

 

[Rainier42]

Re: M40a1 build guide

Jerry ... Very nice!

 

[firesniper27]

Re: M40a1 build guide

I didnt see that I may have missed it I was talking about a spec on how much to mill out the trigger guard

 

[Jerry W Hudson II]

Re: M40a1 build guide

Here's a picture of mine done by GAP

 

[Jerry W Hudson II]

Re: M40a1 build guide

 

[Turk]

Re: M40a1 build guide

That floor plate looks different; kinda like it was modified on both ends??

 

[Rainier42]

Re: M40a1 build guide

Turk ... not my rifle but it is Win M70 bottom metal. Does look to be correct and it is a GAP build. Do you have photos of something that looks to be different?

 

[M40_A1]

Re: M40a1 build guide

The TG looks post-'64, and the FP looks pre-'64 (or at least the hinge) to me.

 

[Turk]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rainier42</div><div class="ubbcode-body">Turk ... not my rifle but it is Win M70 bottom metal. Does look to be correct and it is a GAP build. Do you have photos of something that looks to be different? </div></div>
Before

And after

And if in fact if that box is welded; the welds need to be a lot more sloppy!

 

[Rainier42]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rainier42</div><div class="ubbcode-body">Turk ... not my rifle but it is Win M70 bottom metal. Does look to be correct and it is a GAP build. Do you have photos of something that looks to be different? </div></div>
Before

And after

And if in fact if that box is welded; the welds need to be a lot more sloppy!

</div></div>

They look very similar to me. Differences really come down to who manufactured the bottom metal and some of the milling performed. Not sure it matters.

Again, GAP built that rifle and, from what I can tell, they do one of the best M40A1 repros which includes welding the box magazine. What makes you assume the weld is sloppy since one of the photos posted by the owner shows a damn good install?

 

[Turk]

Re: M40a1 build guide

Similar yes, exact no. Look at the shoulder on the hinge; one is round, other flat. As far as the welding; I guess you misunderstood. The ones I have seen in the past in the RTE shop were sloppy compared to the on the one you are referring to. If you really want to get in to specifics lets talk about the finish!

 

[M40_A1]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">Similar yes, exact no. Look at the shoulder on the hinge; one is round, other flat.</div></div>

Precisely. The post-'64 Model 70 hinge shoulder is left round, and the shoulder on the pre-'64 hinge was ground with the floorplate attached, making it "flat" (actually a slight convex curve).

Ditto on the finish. No black oxide is my biggest beef with most of the builders. (Not saying the builds don't look good- just not 100% "right")

Not to nitpick, but for the sake of those doing builds, the E-prefix M40A1s I've seen did not have the two holes drilled and tapped in the side of the receiver. Were there variations in the E receivers in this regard? Or did GAP drill and tap them?

 

[Turk]

Re: M40a1 build guide

GAP certainly makes one of the best clones! I am guessing they were probably drilled for authenticities sake. What is crazy is that the barrels were not plugged during the "black oxide" process; in effect voiding the warranty of the HS precision barrels. So if you are a civilian and you want an exact replica you are screwed if it doesn't shoot. Also seems like that bottom metal is wider?

 

[Jerry W Hudson II]

Re: M40a1 build guide

Look at the picture on page 13 closely of the trigger guard and floorplate

 

[Turk]

Re: M40a1 build guide

Sorry, looks like pix are gone.

 

[Jerry W Hudson II]

Re: M40a1 build guide

The "E" prefix receiver I used for my build was manufactured in 1997-1998. I have a MRT 5-95 marked sling for it as well. The scope base and rings are a recent reproduction made by USO. Now if I could just fine a damn MST-100 for it.....

 

[Jerry W Hudson II]

Re: M40a1 build guide

This is the picture I was referring to. I know it is of a real USMC M40A1.

 

[Turk]

Re: M40a1 build guide

Not a combination you see often; digital camo and a M40A1.Btw, you just missed a USMC Unertl on fleabay!

 

[M40_A1]

Re: M40a1 build guide

Mr. Hudson, did your receiver have the screws in the side when you originally bought it?

I'm seeing E6247002 in DFA, vol.5 having the screws. That receiver is clip slotted, I assume by IBA, but was not an M40A1 clone, so I doubt they would have felt the need to drill them themselves.

Then, I am seeing E6704836 with the Marines at Pendleton having no holes. So, I have to wonder if Remington stopped providing those holes somewhere between your serial number and that one. Of course, sometimes there's a long transition period.

I agree. GAP makes the best looking builds I have seen. I've never heard a complaint and I hope to send my next build over to them. I just wish they could find some way to make black oxide an option.

 

[Jerry W Hudson II]

Re: M40a1 build guide

No rear receiver holes when I bought it. GAP put them in there when my receiver was clip slotted. I have been told it is correct to have them with my serial number, and I have been told it is not correct to have them with my serial number.

 

[M40_A1]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jerry W Hudson II</div><div class="ubbcode-body">I have been told it is correct to have them with my serial number, and I have been told it is not correct to have them with my serial number. </div></div>

Sounds like the crown debate. I know I have seen at least one "E" without the holes, but I trust George as he made the trip to Quantico and had a 2112 working in his shop who should know. It seems to be one of those things that could go either way and be "correct". Thanks for the information.

Your build turned out really nice. Thanks for sharing the photos. Are you going to throw some glass on it and try it out in the mean time until you find your MST? I'll bet you're itching to try her out.

 

[Rainier42]

Re: M40a1 build guide

Which is the correct Remington trigger for a build?

 

[Jerry W Hudson II]

Re: M40a1 build guide

Old style solid back/shoe

My bottom metal is post 64 all steel construction

 

[Jerry W Hudson II]

Re: M40a1 build guide

As you can see in the photo above the two M40A1 actions at the bottom of the picture are both 6 digit "US" marked receivers with rear holes drilled and tapped in the rear of the receivers. While you cannot see the serial number on the top M40A1 action in the picture, you can see that it is not "US" marked and has the rear holes drilled and tapped in the rear or the receiver.

 

[Jerry W Hudson II]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">WILLIAMS DOSENT MAKE THE TWO PEICE BOTTOM METAL ANYMORE I DON'T THINK </div></div>

Williams emailed me back yesterday two piece all steel construction post 64 Winchester bottom metal will be available again April 2013.

 

[mwhite]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jerry W Hudson II</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firesniper27</div><div class="ubbcode-body">WILLIAMS DOSENT MAKE THE TWO PEICE BOTTOM METAL ANYMORE I DON'T THINK </div></div>

Williams emailed me back yesterday two piece all steel construction post 64 Winchester bottom metal will be available again April 2013. </div></div> Jerry r u getting a williams bottom metal like the one on page 3 of this thread, that one looks great,

 

[Rainier42]

Re: M40a1 build guide

Some interesting info regarding the A1 from Gus Fisher, a retired 2112. The second and third pages are worth reading:

http://m14forum.com/bolt-action/82023-m40a1-project-2.html

 

[Turk]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rainier42</div><div class="ubbcode-body">Some interesting info regarding the A1 from Gus Fisher, a retired 2112. The second and third pages are worth reading:

http://m14forum.com/bolt-action/82023-m40a1-project-2.html </div></div>
I could be wrong but I think Fisher was doing the gas guns, and Cook was building the bolt guns?

 

[Rainier42]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rainier42</div><div class="ubbcode-body">Some interesting info regarding the A1 from Gus Fisher, a retired 2112. The second and third pages are worth reading:

http://m14forum.com/bolt-action/82023-m40a1-project-2.html </div></div>
I could be wrong but I think Fisher was doing the gas guns, and Cook was building the bolt guns? </div></div>

Not sure ... maybe I'll write him.

 

[M40_A1]

Re: M40a1 build guide

Now that's a name out of the past! Thanks for sharing, Rainier.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">I could be wrong but I think Fisher was doing the gas guns, and Cook was building the bolt guns? </div></div>

I know Gunny Cook was working on the bolt guns in the early 1990s, but MGySgt. Fisher was the one to whom I was referred for Unertl questions, though I'm not sure why.

 

[Raven 6]

Re: M40a1 build guide

I can tell you MGySgt. Fisher knows an M1A inside out.

 

[Turk]

Re: M40a1 build guide

Gunny Cook is at Barrett. He put together a M40A1 for me at the RTE shop. Nicest person you could ever meet. His picture is in one of the "Death from afar" books.

Rainier42 did you happen to notice the welds on the box in the thread you posted? That's the "sloppy" I am talking about. Not quite as clean as the GAP rifle is it?

 

[M40_A1]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">Gunny Cook is at Barrett. He put together a M40A1 for me at the RTE shop. Nicest person you could ever meet. His picture is in one of the "Death from afar" books.
</div></div>

Awesome. I'd love to see that one. I'm curious what kind of crown he put on yours. I used the spec he gave me, not quite as deep as some of the others I've seen here. He was very gracious to take some time out to talk with me, and his help was invaluable considering this was before I had internet, pre-DFA, and the M40A1 cult had not yet been born (McMillan grudgingly made the stock for me). Vol.1 is where his picture is.

 

[Rainier42]

Re: M40a1 build guide

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">Gunny Cook is at Barrett. He put together a M40A1 for me at the RTE shop. Nicest person you could ever meet. His picture is in one of the "Death from afar" books.

Rainier42 did you happen to notice the welds on the box in the thread you posted? That's the "sloppy" I am talking about. Not quite as clean as the GAP rifle is it? </div></div>

Turk ... yes, did notice. Also, note there are a couple of pics showing that the recoil lug has been welded to the receiver. Not sure why he did that.

 

[Turk]

Re: M40a1 build guide

Probably wanted to do it old school. I don't remember those welds being that big; but I guess each one is unique.

 

[Rainier42]

Re: M40a1 build guide

Posted this question in the gunsmithing section as well: Anyone know what the specs for the M40A1 chamber should be. Spoke to the gunsmith I am going to use for my metal work (Bob Green here in York, PA) he mentioned there were options regarding the actual chambering. Have read some use an 852 reamer(?) and is based on Ferderal match 168gr. Would appreciate any input you all might have.