Early vs. Late M40A1's

[DstRflMn645]

I've seen of M40's that were converted to A1's and they have a short bolt shroud/plug, I've also seen M40A1's with the longer bolt shroud. My question is when the older/original M40's were upgraded to A1 configuration were the bolt shrouds replace or were these only on the newer receivers?

John

 

[Jrb572]

@USMCSGT0331 will probably know

 

[Skunk]

Parts got replaced as needed on the individual guns. As the years passed, there probably wasn’t much rhyme/reason as to which guns had short or long bolt plugs, flat safeties, etc.

 

[corsairpilot62]

Tagging in for interest.

 

[cplnorton]

Most of the pics that you look at of the A1's till the mid 90's have the short shroud. But I would never just classify one or the other as really being correct. If a part was serviceable it continued to be used. If it was worn it was replaced. A lot of M40A1's were rebuilt multiple times.

But an interesting fact that I don't think I have seen online, but I found in the Marine docs on the M40A1. When a M40A1 went in for rebuild, technically the Marine docs state to replace the bolt everytime you replaced the barrel. So it was supposed to be a new bolt and a new barrel combo. Now did that always happen, no. Sometimes they didn't replace the bolt. But when I asked for clarification on why this was done to a 2112, he explained to me that a worn bolt on a new barrel M40A1 only have about half the service life of when you replaced the bolt and barrel together.

So a lot of M40A1's were rebarreled especially leading into the 90's. So it's quite possible a lot received new bolts as well with the new barrel. So it's something to consider.

Usually a lot of the late 90's and M40A1 GWOT pictures you see, the bolts have the long shrouds. But they started to build new M40'as in the 90's all the way into 2002. So that could be why as well. Which all the Charlie and Echo receivers would have had long shrouds.

It used to bother me seeing a long shroud on a M40A1, but unless you are going for a really early looking build it woudln't bother me at all anymore. Especially when most M40A1's saw several barrels.

After seeing the Marine build docs on the M40A1, I feel much different about this. In fact if you see my M40A1 which looks like it came from a Marine Armory, it has a long shroud and I would not change it.

 

[Skunk]

I took these pics aboard MCB CAMPEN in 2005, rifle serial 224313. That bolt plug is the long version and polished blue. They used what they had to keep rifles in service.

 

[cplnorton]

This is what I find is incredible Skunk. Your scope 1114, was sold by the CMP in 2017. I love anytime I can identify a rifle or scope serial while in service. Especially when you can identify where they were used or who used them!

Here's when your scope was sold, I wonder who owns it now.

https://cmpauction.thecmp.org/detail.asp?id=4229&n=USMC-10x-Unertl-Sniper-Telescope-1114

BTW your rifle 224313 was initially built in Sept 1977, so basically one of the first M40A1's built, and was rebarreled in Aug 1995. So that might be when it picked up the shroud. But no way to know for sure.

I LOVE these original in service pics! Thanks for sharing!

 

[Redmanss]

Mid 90s and on, short bolt shrouds were rare on an A1. I only remember one or two in our platoons, and both my guns had long IIRC. 224343 (95-96) and 168820 (99-01).

 

[Skunk]

This is what I find is incredible Skunk. Your scope 1114, was sold by the CMP in 2017. I love anytime I can identify a rifle or scope serial while in service. Especially when you can identify where they were used or who used them!

Here's when your scope was sold, I wonder who owns it now.

https://cmpauction.thecmp.org/detail.asp?id=4229&n=USMC-10x-Unertl-Sniper-Telescope-1114

BTW your rifle 224313 was initially built in Sept 1977, so basically one of the first M40A1's built, and was rebarreled in Aug 1995. So that might be when it picked up the shroud. But no way to know for sure.

I LOVE these original in service pics! Thanks for sharing!

I’d buy #1114 if I knew where it was at.

 

[Skunk]

In 1995 (date on the book) the rifle had scope #1650.

 

[cplnorton]

1650 was sold by the CMP as well. It looks pretty much like a fresh rebuild with the USO mod.

It's so neat to actually tie these serials to a rifle.

https://cmpauction.thecmp.org/detail.asp?id=3529&n=USMC-10X-Unertl-Sniper-Telescope-1650

 

[Modoc]

Would it be safe to draw the conclusion that the Replacement bolts and shrouds used in the late 90’s and early 00’s DIDNT’T have the stupid J-lock that the Civilian Remington 700’s did? Or did the armorers remove the locks and weld up the shrouds?

 

[cplnorton]

I've never seen a J loc mentioned in the Marine Docs. Likewise I've never seen one on M40a1 I have torn apart. I really don't think they were used.

 

[Modoc]

I've never seen a J loc mentioned in the Marine Docs. Likewise I've never seen one on M40a1 I have torn apart. I really don't think they were used.

It doesn’t surprise me. Something to stick it to the Civilian market, but waived for others. I’d love to replace my j-lock shroud, but am not interested in PTG parts.

 

[Random Guy]

I will only add that when the USMC/PWS started ordering new M700 receivers from Remington, I think they were ordered with new bolts as well. I understand the first such order was in 1992 and these were the 99 “C” prefix M700 receivers that were built into M40A1s. Obviously all those bolts would have the long shroud as well. My 2cts.

 

[DstRflMn645]

Modoc,
Check this company out.

Gun Repair Center

gunrepaircenter.com

Select rifle parts and Remington 700, then go to page 9 I believe

John

 

[DstRflMn645]

Thanks everyone for the replies, I've narrowed down when they replaced short with the long shroud. A friend of mine had a '67 40-X, 308 that was a short shroud, he bought a 700 ADL in '73 and it was a long shroud.

John

 

[Random Guy]

Thanks everyone for the replies, I've narrowed down when they replaced short with the long shroud. A friend of mine had a '67 40-X, 308 that was a short shroud, he bought a 700 ADL in '73 and it was a long shroud.

The date was 1968 when the long shroud was introduced...here's some history that shows a lot of changes in 1968-69:

An Official Journal Of The NRA | Remington's Model 700: The First 50 Years

The Remington Model 700 is 50 years old, and continues to be a very popular rifle.

www.americanrifleman.org

• 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.

• During acceptance testing of imported rifles by the Australian government, the firing pin was eased down on a round in the chamber and the end of the bolt shroud then struck with a hammer. Since the end of its cocking piece protruded from the bolt shroud when the firing pin was in its forward position, the Model 700 failed that test. Remington took care of that detail in 1968 by increasing shroud length by about 0.265 inches.

• Also in 1968, the sear, which was originally a one-piece design, was changed to the two-piece design of the Model 721 after company attorneys decided it was in infringement on a patent held by Winchester. Controlled by the safety, the left side was called a safety cam while the right side served as the actual sear by engaging the trigger connector. It was changed to a one-piece design in 1974.

• The thumb tab of the original safety lever was square in shape but changed to a more rounded shape in 1969. During that same year the bolt handle was swept a bit further back but as hunters began to complain about getting their trigger fingers rapped when shooting a rifle chambered for one of the magnum cartridges, it was changed back close to the original angle in 1974.