group by on M40a1 barrels

Frank Green · Monday at 9:47 AM

So a couple of guys asked me about doing a group buy on M40A1 pattern barrels. Most guys if they want one they just order one.

So I'll throw it out there to see if there is any interest in a group buy and my thoughts on the two options.

The two options are but I only want to settle on one of each.

First is the contour....My 40a1 spec build I did the barrel contour to the A1 prints. Which is a .875" muzzle +/-.010". Breech length is 4" at 1.2" diameter.

I was given an original A1 barrel by Mr. Land. It was a used take off. If I recall correctly the muzzle is around .900". I'll double check tonight when I get home.

So that's the first question is the muzzle diameter. What would you guys want? .875" or .900".

2nd question.... number of grooves for rifling? Prints for all the A1 thru A3 barrels called out 4 groove, or 5 (which most likely means 5R but they never put the "R" on the prints. They still do that with the 6.5CM barrels and 300 and 338 Norma but the spec is 5R) or 6.

I'd prefer to do the 5R but give me your thoughts.

Later, Frank
Bartlein Barrels

I did mine with the 5R

RIGREG · Monday at 10:56 AM

Take my money!

I’m in for two.

My thoughts: .900 muzzle. (I’m not an expert, but to me, that is the M40A1 “look.”)
If I’m buying a Bartlien barrel, I want the 5R.

Guys who have take off stocks and other original parts may have other opinions. I’m essentially building new rifles on six digit receivers. New Smears, repro bottom metal and scope mount, commercial Redfield parts and scopes, etc. I just want them to look as correct to me, as possible.

Thanks for your efforts,
Greg

Belvedere · Monday at 3:28 PM

Same here. I’d be down for one @.9 and 5R. Would you be willing to do the rough finish?

Frank Green · Monday at 4:04 PM

Belvedere said:
Same here. I’d be down for one @.9 and 5R. Would you be willing to do the rough finish?

Rough finish as far as what?

Do you mean on the outside of the contour it's a rougher finish? The one take off that I have that is original isn't really rough per se. See the attached pic. It does have some turn lines on the o.d. but it's not horrible and yes... not as smooth as we turn them.

If the above is what your asking for.... we can just finish turn them and how they come out with a nice turn finish... then we just won't run them thru the polishing machine afterwards. They will get bore reamed, prelapped and rifled and out the door.

Or do you mean like rough chambered and threaded on the breech end type stuff?

Stevo86 · Monday at 4:20 PM

If memory serves me correct, when Schnieder started supplying barrels is when the rough finish started.

Stevo86 · Monday at 4:20 PM

Prior to that with Hart and all the others, the barrels were smooth finish

Belvedere · Monday at 4:26 PM

As Steve said the rough finish that Schneider used to do. Probably what you’re saying about not polishing them after contouring. Works for me. Thanks Frank!

kft101 · Monday at 8:39 PM

Maybe I missed it, but, umm… price?

Stevo86 · Monday at 8:48 PM

I’d be down for one Frank. Need to start collecting parts for an A1 for my son.

Frank Green · Tuesday at 8:46 AM

kft101 said:
Maybe I missed it, but, umm… price?

I haven't worked that out as of yet. Will do some sort of discount and time frame for them to be all done. I've got to run the pricing past Tracy first for the o.k. for the group buy.

I'll talk to him today. We have to be out for a bit driving today. I'll talk shop while we are driving.

AndyK · Tuesday at 10:02 AM

Great Frank,
I'll take one...
Andy

Coejro · Tuesday at 5:14 PM

I’ll take one for sure

5R and .875 is my preference, but I’ll take one whatever the final consensus is.

sgtsmmiii · Tuesday at 5:55 PM

5R and .900".

Frank Green · Wednesday at 8:20 AM

Coejro said:
I’ll take one for sure

5R and .875 is my preference, but I’ll take one whatever the final consensus is.

So far the consensus is .900".

Frank Green · Wednesday at 8:22 AM

kft101 said:
Maybe I missed it, but, umm… price?

So I talked to Tracy yesterday and the price is $380 plus the brown truck charge for shipping. Let's let this thread run for a week or so and to get a rough idea of how many we are looking at and will go from there to put the order together.

Later, Frank

Broc · Wednesday at 10:10 AM

Count me in for one as well.

Thanks Frank!

molonlave · Wednesday at 1:29 PM

Please put me down for two.

cplnorton · Wednesday at 7:00 PM

Just to add a little context. Frank's measurement of .875 +/- .010 is exactly the Marine Corps specs from their M40A1 blueprints I pulled from the archives. The blueprints of the barrel are dated 1999. By then the Marines were installing Schneiders on the M40A1.

I do have a original M40A1 takeoff barrel that is pre-Schneider that I know 100% came from a M40A1. When I measure it's muzzle it's right about .0925 on my digital calipers. The barrel I'm pretty sure is a HS Precision.

When I go back to the 1970's and the creation of the M40A1 program the specs on the Marine docs states its 1.18 that tapers .01159 per inch for 24 inches. If I'm doing my math correctly that puts it at .902 roughly.

I know I measured a M40A1 that was built in 1977 in Marine inventory and It was a fuzz over .900

I would say the early ones were the .900 and the later Schneiders were the .875, since that drawing shows it at .875 at the time of Schneider, but I have a take off Schneider that is .0902. So It really doesn't match that theory.

But anyways I guess when it comes down to it, either spec is correct. I can prove either one by Marine documents. So it will come down to personal preference. I don't need any barrels but if I would choose, I would likely choose the .900. But I don't have any skin in this game other than providing some context.

Random Guy · 2025-03-13T18:05:48-0400

FWIW, this replica was built ‘on-location’ using one of extra USMC barrel blanks that Gary Schneider would sell from time to time. (Back then the “Hobby Lobby” program was tolerated for 2112s seeking to maintain their skills, but it went away thereafter). I got the barrel maybe in 2017 or so, and Gary told me whenever he got an order from the USMC for M40(A5) barrels, he would make 5 or 6 extra barrel blanks for guys like me, who wanted to build a replica rifle. Mine came marked as seen here:

My Schneider M40A1 barrel appears a little fatter at 0.914”, so perhaps there is some variance?

As for that slightly rough machine finish on the surface of Schneider barrels, someone told me the USMC asked for that rough finish, as the subsequent camo paint would stick a little better. I can’t remember if that was Gary or a 2112 who said that, but that is what I was told years ago. Hard to photograph, but it’s a rough surface:

…So my vote is a 0.900” diameter barrel, 5R rifling.

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group by on M40a1 barrels

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