Alternative Calibers for the Garand

[bdrake]

The USPS reported that my Garand receiver and Barnett 7mm Mauser barrel arrived last week for Tim to work on when he gets the time. I'm more than comfortable knowing it will return some time this summer with the great quality that I've heard about on several other rifle forums. I'll get to do the finish chambering after Tim pulls the old barrel and mounts that new custom barrel on it and then mails it back to me for reassembly.

First post on this forum but I've been reading on the forum all evening and its been rewarding already for my other garand knowledge as well.

Bruce

[jbkf1003]

7mm Mauser Garand? Sounds interesting. What made you decide on that?

[ordmm]

The USPS reported that my Garand receiver and Barnett 7mm Mauser barrel arrived last week for Tim to work on when he gets the time. I'm more than comfortable knowing it will return some time this summer with the great quality that I've heard about on several other rifle forums. I'll get to do the finish chambering after Tim pulls the old barrel and mounts that new custom barrel on it and then mails it back to me for reassembly.

First post on this forum but I've been reading on the forum all evening and its been rewarding already for my other garand knowledge as well.

Bruce

As a firm believer in "alternative" calibers for the M1 Garand please keep us updated with details of the build. The 7mm Mauser is a great cartridge.

Greg

[bdrake]

7mm Mauser Garand? Sounds interesting. What made you decide on that?

It actually was a gift from a fellow shooter. Its my first 7mm cartridge as well so I'm looking forward to the new challenges.

Bruce

[Old Guard]

As a firm believer in "alternative" calibers for the M1 Garand please keep us updated with details of the build. The 7mm Mauser is a great cartridge.

Greg

I really Like the 7mm mausers, they have a very long history, and make a fine sporting weapon..I would believe it to shoot like a soft- 308w round in garand...Should be nice...

[majbdrake]

Tim has returned my 7mm Mauser Barnett Barrelled receiver on Saturday. Looks great and its timed perfectly. Now I just need to run the finish reamer into the chanber to close the deal. I just wanted to let people know about the fast-turn-around time. (I'm bdrake but for some reason I've lost the password to the account so I created another.)

The rifle went right back together with just a bit of relieving of the stock and upper handguard to deal with the heavier barrel profile. By Saturday night it was back together and sitting on the shelf awaiting the time with the reamer.

Bruce

[majbdrake]

Oh, and starting load will be a 140gr Remington Soft Point over 40gr of IMR4895 so I'm confident it will be a soft shooter but hopefully a X-counter for rifle matches.

[ordmm]

As said before, please update with any info you care to share.

Greg

[Old Guard]

Oh, and starting load will be a 140gr Remington Soft Point over 40gr of IMR4895 so I'm confident it will be a soft shooter but hopefully a X-counter for rifle matches.

That Bullet choice sounds good for 7mm mauser load

[majbdrake]

That Bullet choice sounds good for 7mm mauser load

Its what my local gunshop had on hand and it is in the middle of my preferred 130gr and 150gr Sierra Matchkings so I figured I'd give them a try. They are also 25% cheaper than the Sierra so if they are good, I'll stay with them until the X-s drop out of the black.

Bruce

[Old Guard]

Sounds like a plan, I know that round will surprise most folks when i comes out of a good barrel..Mine is a nos star Barrel..

[timshufflin]

So who's reamer did you use for the 7mm? Did it come out good as far as reaming and then showing headspace was met with gauges?

[majbdrake]

So who's reamer did you use for the 7mm? Did it come out good as far as reaming and then showing headspace was met with gauges?

Tim,

I used a PTG Finish Reamer as you know the reamer companies don't make a pull through reamer in 7mm Mauser.

Here is how I did it for your own knowledge but I'm sure its not economically feasible for you to offer it as a regular basis unless the customer knows it will cost the time and effort.

I received my barrel back from you last week and put a call out to www.reamerrentals for the reamer. It arrived 2 days ago and I proceeded to work on the chamber.

I placed the barreled receiver vertically in my bench vise with the front receiver ring protected by a piece of old leather (boot tongue in my case.)

The adapters needed to hand-chamber a Garand with a barrel mounted is to use a set of 3/8 socket extensions, (2" and 4"), a 3/8" universal swivel socket, a 3/8" 8-point socket and a socket wrench.

I slipped the reamer into the short chamber after I dipped the reamer into a cup of metal cutting oil, then added the 2" extension then the universal swivel and then the 4" extension. With the extensions added, the socket wrench with the 8-point socket is fitted to the square end of the 4" extension.

The angle of the extension is about 20-30 degrees off center from the reamer due to the requirement to clear the closed back of the receiver. It also clears the back of the receiver with enough room for you to operate the wrench without wrapping your knuckles. With the universal swivel, the concern about the offset angle of the force used to turn the reamer is negated and the reamer stays true to the chamber (With the understanding that it would never be as true as a lathe-cut chamber). The reamer was plenty sharp enough to cut the chamber with the hand pressure applied as it was turned.

Here is the time factor. I started with twenty 1/4 turns of the wrench with additional oil added at the halfway mark to prevent any issues with chips in the chamber than took the reamer out and cleaned both it and chamber out.

I would then slip the stripped bolt into the receiver and then measure with the headspace gauges. I would then repeat this process of cutting, cleaning and gauging for about 3 hours. I lowered the number of twists of the reamer with each successive time I would do the cycle until as the bolt slowly moved further forward and finally seated into the receiver's lug points and met the headspace gauge requirements.

I then reassembled the rifle and bolt and did several function checks for loading and ejection of the new cartridge with a couple of dummy cartridges I made up. Everything did as it was supposed to do so I took it to the gun club last night for a test fire.

I fired 14 shots total at 100 yards. 6 single fire and one full clip of 8 to verify the ability to rifle to load and eject a full clip.

Here is the current issue with the rifle. The stock gas port was cut for standard .079" 30-06 port size. It doesn't cycle with a 40gr IMR 4895 and 140gr bullet.

I'm going to take it apart tonight and run a drill into the port to move out to the 7.62 NATO (.106") port size and try again later this weekend (hopefully tonight).

Now for the good part. Before the rebarrel, this old girl would be lucky to pull 5MOA at 100 with quality 30-06 loads. Now. 14 shots fired - 2MOA. And this with having to break firing position after every shot to eject the empty and cock the hammer. It shoots a little low for the original sight settings but it will be easy to build a data book with repeated firings at the various ranges.

Another good thing is that the rifle isn't bedded or even match prepped yet so there still remains a lot more potential to coax out of it.

Bruce

[timshufflin]

I actually don't know that reamer companies don't make pull throughs for 7mm mauser, I've never checked. It seems like the difference between 7mm and 7.62mm wouldn't be so drastic as to make a smaller rod for pull through available. 7mm = .275" and there is a pull through reamer for .270. Can anyone educate me on if the math is the problem or if it's just that nobody has a 7mm pull through.

[ordmm]

Bruce,,,,Appreciate the update! Please follow-up with gas port size and ongoing range reports. This info is very much appreciated!

Greg

[majbdrake]

Tim,

I think they just haven't built one as the demand isn't there to stock one on a regular basis. I can see 270 having a pull through reamer as I've seen 270 Garands before. I've even seen a 243 Garand before but I've never seen a barrel in 7mm Mauser.

Greg, I may be able to get to the range this weekend but my gas cylinder is a very tight fit on the new barrel so it takes a bit of tapping with a rubber mallet to seat and unseat right now. That's a plus right? ;)

Bruce

[ordmm]

Not a gunsmith, but as others have said....tight is good. Block of wood and a mallet usually gets it seated.

[majbdrake]

I went and cleared the gas port of brass shavings from the singleshot operation on Thursday (it seems like the port must have been rough enough to shave enough lead off the bullets as they went by to close off the port completely) and reamed the port out to .095 and now The Heretic is working and functional.

I'm going to have to relook 40gr as the primers are flattened more than I would like. I may drop down a grain or two o see if the rifle functions without flattening the primers. The bullets definitely go where they are supposed to go but the brass ejection goes from 11 to 3 o'clock during firing and the clip does eject when empty.

On 3 of the 4 clips of ammo I fired this evening, the bolt would ride over the 8th round causing me to have to manually pull the bolt back for that last cartridge. More studying and more review of Kuhnhausen's book on that little issue I am sure.

[Old Guard]

Drake, thanks for you follow-up,, you Might have to chamfer the gas port if it still is shaving enough bullets to stop up the port? But you did open up the port..Flattened primers...

[majbdrake]

The port was blocked from the original gas port hole size. The old hole was .072" and yes I opened up and chamfered the port and after firing 4 clips last night there was no evidence of shaving bullet jacket material after I opened the port.

Yes I have flattened primers with the new port size. When it was firing in single shot mode last week, I had less primer flattening but this is more for my personal choice on the cartridge cases as the primers were not cratered or pierced.

Now I wonder if Tim could pull these replies from this thread and place it in another thread so that we could continue this conversation but without blocking the original intent of the thread which was about Tim's turn-around time on his work.

Bruce

[ordmm]

Now I wonder if Tim could pull these replies from this thread and place it in another thread so that we could continue this conversation but without blocking the original intent of the thread which was about Tim's turn-around time on his work.

Bruce

New thread would be great. Think alternative chamberings for M1's could be of interest to many.

Greg

[majbdrake]

Thanks Tim for shifting this over to another thread. I didn't expect you to make it a sticky though! I'll try to upload some photos of the brass soon as well.

Bruce

[ordmm]

Bruce, Sounds like your moving right along. Once you set the gas port size have you considered using a gas screw like the Shuster for final tuning? Also, it appears there are no issues using the 7mm round in enblocs?

Greg

[majbdrake]

Greg,
I've already decided that I'll be using a Schuster plug on this rifle as the GI plug makes all the gas to go back a bit more than I like. Ejection pattern is everywhere currently and I'd like to tune it down to a nice pile of empties on the ground. Luckily, I already had one on the parts bin for this rifle when it was a 30-06.

The 7mm Mauser (7x57) cartridge loads and feeds fine through the clips. Its like the happy medium in case lengths between the 30-06 (7.62x63) and the 308 Win (7.62x51). There is no need for a spacer block in the magazine well like what is normally seen in a 308 Win conversion.

I think this will be a project to get her shooting well. I owe you all some photos when I have some free time around evening schedules for the kids.

Bruce

[majbdrake]

Good afternoon shooting today!



I installed a Schuster Gas Plug and the Champions Choice polymer stock the other day and finally got to the range to dial it in.



Same load as before - 40gr I4895 and a 140gr softpoint gave me a 3MOA grouping at 100 yards with no stock bedding/lugs and with just a hasty sling slung over a concrete bench.

Next trip, I'll try to do a ladder test to see how minimal powder loads for function tests with the .095 gasport operate and to see if a lighter load is the sweet spot to drop it below 3MOA.

Considering I regularly shot 6MOA with the rifle's last barrel, I am very happy so far with the progress this rifle is making.

Bruce

[majbdrake]

1414

Here is a photo comparing 3 Garand clips loaded from left to right with 30-06, 7x57 and 308 win.

Bruce

[ordmm]

Bruce, thanks for update!

[majbdrake]

Glad to provide you with it. I wouldn't have been able to do this project without Tim's assistance in swapping the barrels out in such a quick manner.

Bruce

[majbdrake]

1429
38.5gr of IMR4895 is the best of a ladder test from today. I went from 40gr down to 38gr in .5gr increments. The target was shot on a SR-1 Reduced Highpower Target at 100 yards.

[majbdrake]

1435
200 rounds of 7x57 all staged for the next trip to the range/match.

[ordmm]

Am looking forward to the range report. The release of the $125. receivers by the CMP might create some interest alternative caliber and configuration rifles. Thank you for the update.

Greg

[majbdrake]

I'm heading to a 200/300 reduced distance rifle match on Saturday with the boys and wife in tow. The boys to shoot their ARs as Juniors, me with The Heretic and my wife to photograph us all for her scrapbooks.

I hope to be able to post my results and a few photos of me with the rifle in action by Sunday.

Bruce

[timshufflin]

I'm very curious if anyone has a Garand in .458 Win mag. This is about the only round worth me trying right now. I'd kind of like to do both rounds that the late Mr. McCann did.

[centurion20000]

Forgive my amateur design thoughts and maybe looking like a lunatic, but it looks like you'd have to develop custom versions of these parts.

Op-Rod (which you're already a wizard at)
1489

Gas cylinder (to allow for heavier barrel)
1488

Gas Cylinder Lock
1490

Lower Band

On the back end ...
Bolt
Cartridge Lifter
Extractor

And of course a heavy garand barrel for .458 Win Mag



Interestingly enough once you get that done you can replicate all of the win mag calibers (.264, .300, 338, wildcats to death) as it looks like the 84mm OAL is the limiting factor.

1491


For capacity you'd have to machine those two ridges I pointed out on the 35 whelen thread at the front of the receiver. I went out and bought some 35 whelen and I can see where the receiver needs machining and it's not much (and certainly wont compromise the receiver strength)

Have you tired putting 300 / 458 win mag rounds into an en bloc clip to see how they fit?


1492

Some reference links

http://olegvolk.livejournal.com/608143.html


Another one is the web archive link to McCann's page .... you might be able to crib some from there.
[You could also buy the design papers off his widow perhaps]

Oddly enough the earlier versions of his page go into slightly more detail on the construction than the later archived versions.

http://web.archive.org/web/20081017054647/http://www.mccannindustries.com/rifles/458garand/458garand.html

Good luck Tim. I'll buy one :)

[Punch The Clown]

Tim, just take a scrap barrel and bore the chamber for the .458. Not with a chamber reamer. Just end mill or drill it. You should be able to check feed issues without building a custom gas system-yet. If the receiver needs to be modded you'll know right away. Same for the bolt and other internals. It'll work Bro. I just know it.

[centurion20000]

Oh here's another one for the idea pile.

375 Ruger (85mm OAL)

And apparently people are making wildcats out of it ... 30/375 (There's your ultra long range 30 cal Garand with 300 Wby performance and 4000+ ftlb ME)
300 Dakota is another weird one you can throw on the pile too.
338 Campfire (338/375R)

$auto$

And apparently someone's necked the 375 Ruger up to .416 and is shooting that too.

After seeing some more research apparently if you wildcat the 375 Ruger (neck up or down), you've basically reinvented the XXX Newton (30, 35, etc)

Lothar-Walther got back with me saying the might be able to do a .375 custom barrel. Also they stated that if you wanted just a .30 blank you can order one and wait for them to do a run of Garand barrels.

Still .... lots of interesting possibilities.

[majbdrake]

1504
I haven't been able to take it to a match as I'm waiting for a spinal fusion surgery on my neck next week but I was able to get the rifle to the range Saturday to put the loads over the chrono and zero the rifle for later this year. 2650fps with 38.5gr of IMR4895 and the 10 round string pretty much kept them in the black.

[ordmm]

1504
I haven't been able to take it to a match as I'm waiting for a spinal fusion surgery on my neck next week but I was able to get the rifle to the range Saturday to put the loads over the chrono and zero the rifle for later this year. 2650fps with 38.5gr of IMR4895 and the 10 round string pretty much kept them in the black.

Hope all goes well with your surgery and your back 100% in shortest time possible!

Greg

[ordmm]

Took a look at the ballistic graph on the .458 Win and then compared it to the graph for the 450 Marlin. The 450 might be worth looking into. Looks like existing mags could be used...which I'm thinking means existing receiver config of the BM14 could be used. If you go to this site and scroll down you'll see a pic of the 450 rounds in a mag. Here's a link to source of pic: http://www.ar-10-rifles.com/index.php

1506

[majbdrake]

Good Lord. An elephant gun....

[centurion20000]

IDEA ....
http://img.photobucket.com/albums/v236/Centurion20000/1%20%20%20Garand/20141019_123720_zpsc8bda95c.jpg

Compared to 30-06 / 35 Whelen ... 375 Ruger
http://img.photobucket.com/albums/v236/Centurion20000/1%20%20%20Garand/20141019_144643_zps61bd0dde.jpg


Another ultimate round you could rechamber a Garand in ....
416 Ruger
http://i221.photobucket.com/albums/dd107/cstmgolf/100_1911.jpg

405gr at 2500+ fps

[majbdrake]

Took the "Heretic" Garand to a 100 yard NRA Reduced Course Garand/M1A Match last week for its first match. She didn't disappoint as it shot well enough for me to take 2nd place behind a double lugged M1A. With a little more tweaking, I may even beat that guy the next time I bring the Heretic to a match.

Bruce

[Old Guard]

Took the "Heretic" Garand to a 100 yard NRA Reduced Course Garand/M1A Match last week for its first match. She didn't disappoint as it shot well enough for me to take 2nd place behind a double lugged M1A. With a little more tweaking, I may even beat that guy the next time I bring the Heretic to a match.

Bruce

Good news, Its working very well now? OG.

[Punch The Clown]

Original Garand T3e1 in .276 circa 1929.

http://i369.photobucket.com/albums/oo140/Stumedic/Garand_t3e1_sn_1_1929_zps7evsa2we.jpg (http://s369.photobucket.com/user/Stumedic/media/Garand_t3e1_sn_1_1929_zps7evsa2we.jpg.html)

[musketjon]

Come on Bruce, you know the rules. Pictures or it never happened.
Jon

[kwg020]

I would really like one in .270. But there are other priorities. I just think it would be a screamer.
kwg

[centurion20000]

358/375 Ruger would actually fit perfectly and be a 35 magnum caliber (no gas/no major barrel mods). 5 shot (tight packed clip). 358/375 Ruger is basically a reinvented 35 Newton. Wider boldface needed but same COAL as a 30-05

It's ballistic capabilities are; 250 grain at 2850 to 2900 fps. Or the great 280 grain Swift A-frame at 2650 fps.

It's a wildcat but it would make one heck of a moose/kodiak rifle.

And all you need is a reamer and the go/no-go gauges and an adjustable plug.

[centurion20000]

What is the widest rim that the M1 Garand bolt face can accomodate at 60+ kpsi?

30-06 family
Rim diameter .473 in (12.0 mm)

375 Ruger
Rim diameter .532 in (13.5 mm)

[Shug]

What is the widest rim that the M1 Garand bolt face can accomodate at 60+ kpsi?

30-06 family
Rim diameter .473 in (12.0 mm)

375 Ruger
Rim diameter .532 in (13.5 mm)

Ruger bolt would have 1.27x the bolt thrust on it as the 30-06 bolt, assuming the same pressure in kpsi. But that is theoretical; real world might be very different because the physics behind bolt thrust are more complex than just a linear relationship to surface area and chamber pressure.

Some real world stuff that would need to be taken into account if you're actually engineering a rechambering:
- Coefficient of static and dynamic friction between the cartridge wall and chamber wall
- Stress/strain curves for plastic deformation of wall brass and modulus of elasticity for same
- Pressure curve the cartridge as a function of time
- and lots of other phenomena

[centurion20000]

So has anyone given any thought to a BM=59 or a Garand perhaps chambered in 277 Fury?

135 gr at 3000+ feet out of a clip or a 20 round M14 mag sounds like one interesting sleeper rifle.

https://en.m.wikipedia.org/wiki/.277_FURY

2952


Basically it's a 270-08 with a steel baseplate so it can handle 80K PSI and correct me if I'm wrong but the Garand receiver is about the strongest out there (see Hatcher's Notes).

277 Fury Wiki Quote



The .277 FURY or 6.8×51mm,[3] (designated as the .277 SIG FURY by the SAAMI[1]) is a centerfire rimless bottlenecked rifle cartridge announced by SIG Sauer in late 2019. It utilizes a hybrid three-piece cartridge case that has a steel case head, brass body and a locking washer that mechanically connects the two to support a chamber pressure of 80,000 psi (551.6 MPa).

Specifications
The cartridge uses a case that is the same length and diameter as the .308 Winchester.[7] Each cartridge case consists of a stainless steel base coupled to a brass body via a locking washer.[8][9] Stainless steel has a significant higher yield strength than brass, allowing the engineers to use higher Maximum Average Pressure (MAP) chamber pressure levels.[10] Bullets are either 135 grains (8.7 g) "match grade" or 140 grains (9.1 g) "hunter tipped".[9] The SAAMI warns that Maximum Average Pressure levels greater than 65,000 psi (448.2 MPa) may present increased risk of unsafe cartridge case or firearm rupture and thus require cartridge case and/or firearm designs that depart from traditional practices (materials, construction, and other design criteria).[1][11][12]

The .277 FURY SAAMI (voluntary) Maximum Average Pressure (MAP) chamber pressure of 80,000 psi (551.6 MPa) enables a 135 grains (8.7 g) projectile muzzle velocity of 3,000 feet per second (914 m/s) from a 16-inch (406 mm) barrel.[1][7] It also means that the .277 FURY should only be chambered in small arms that are capable of handling the accompanying bolt thrust safely.

Performance
SIG Sauer claims that the cartridge has performance superior to the 6.5mm Creedmoor, exhibiting 6 to 9 feet (1.8 to 2.7 m) less bullet drop at 1,000 yards (914 m), while delivering 20–25% greater energy.[9]