New(to me) M1 Garand Rebarreled to .308Win(7.62 NATO)

[alamogunr]

Per the title, I just acquired an M1 Garand that has been rebarreled to .308 Win. When I say "rebarreled", the description does not include that word. It says "mfg by Springfield Armory in April, 1942 with Criterion 5-18 .308 barrel".

My first question is: Can I use information in the BruceB thread concerning the M1A? If not, any information about reloading for this rifle would be appreciated. The description also includes a note that the "magazine has plastic insert to allow for either 7.62 NATO or .308 Winchester ammo to be used". This confused my because I could not understand why the use of either would involve the magazine. Does this mean that enbloc clips can or cannot be used?

I haven't really sat down and examined the rifle or compared it to the other Garand that I have had for a few years. I haven't done any reloading for the .30-06 Garand yet but don't expect the .308 to not have unique requirements.

Any insights would be helpful and appreciated.

[country gent]

I rebarreled a garand to 7.62 / 308 some years ago using a med heavy douglas blank. Yes you still use the enblock clips if its still a full garand. BM59 conversions used an m 14 mag I believe. The block mentioned is in the front of the mag well to compensate for the difference between length of 307 and 30-06. I never put one in mine and it feeds and functions fine. On garands with this conversion I would really recommend the use if a sled clip for single loading. the shorter case losses some drag slowing the bolt when chambering and the sled may help with this.

Loads for the m1A M14 are good use loads designed for the service rifles. Remember that the garand was not meant for powders slower than 4320, The old stand by in high power were 4895 and 4064.
My match duplication load was LC match case fed fold medal primer 41.5 grns 4895 IMR ad a hornady 168 grn bt hp match bullet, this load duplicated LC M852 both velocities and zeros in my rifles. Start low and work up for safety reasons.

[alamogunr]

Thanks! That answers my first questions.

[bob208]

I barreled my one m1 to .308 years ago when 06 brass was hard to get and .308 was every where. the block was to keep some one from trying to load .30-06 in a converted rifle. I did not put in the block and have not had any trouble at all. I use load specs. for the m14.

[Outpost75]

RL15 and Varget are also good powders for the Garand in either cal. .30 or 7.62mm.

[alamogunr]

RL15 and Varget are also good powders for the Garand in either cal. .30 or 7.62mm.

I have a 8 lb jug of DP85, which is supposed to be close to Varget. Would it be suitable if I started somewhat low and worked up to be sure it actuated the bolt? I also have H4895.

[Outpost75]

No clue on the DP85.

Being a surplus powder and knowing nothing of its origin, age or conditions of storage I would avoid it and use only new, fresh powder. H4895 is OK.

[9.3X62AL]

Something sits cross-wise for me here. If the rifle was rebarreled in 1942, keep in mind that the 308 Winchester/7.62 x 51 was not in existence until c. 1952. I would be sure of your chamber length before proceeding. "308" may be its nominal groove diameter--NOT its chamber spec.

[country gent]

Im thinking this is a CMP / DCM rifle assembled and the barrel replaced with a new criterion barrel ( criterion is a division of Krieger Barrels) The CMP/DCM has rebuilt some of the rougher garands by mixing matching parts and barrels. The Springfield Armory referred to may be the original armory not todays manufacturer.

Criterion wasn't there in 1942 either so this is another reason for my thoughts.

Look over the paper work if any and see if the CMP / DCM logo shows on it or is mentioned. Also a lot have been done by gunsmiths over the years. I also believe some VFWS have used the insert to convert to 308. 308 blanks are easier to find now than 30-06.

[dh2]

I was told years ago that many M1 grands was rebarreled to the 7.62 by the army in the transition to the M14, but have never done any research on it.

[Gtek]

Here is a little information for you I don't use the spacer block in my 308 Garand guys. The firing pin does not have any form of spring action or retention between fully retracted and fully extended. The firing pin is retracted by bridge in lower receiver about the time the extractor contacts rear of rim before bolt rotates into battery. Nothing will (should not) occur using only 308/7.62x51 ammunition, although there have been reports of an occasional slam fire in a single feed scenario.
THE DANGER IS IF ONE WERE TO INSTALL A CLIP FULL OR A ROUND OF 30-06!!!!!! The neck will seat with exposed cartridge in an open breech and the potential for an inertia fire is very real. Your gun, your face, your loved one, your call.

[alamogunr]

Im thinking this is a CMP / DCM rifle assembled and the barrel replaced with a new criterion barrel ( criterion is a division of Krieger Barrels) The CMP/DCM has rebuilt some of the rougher garands by mixing matching parts and barrels. The Springfield Armory referred to may be the original armory not todays manufacturer.

Criterion wasn't there in 1942 either so this is another reason for my thoughts.

Look over the paper work if any and see if the CMP / DCM logo shows on it or is mentioned. Also a lot have been done by gunsmiths over the years. I also believe some VFWS have used the insert to convert to 308. 308 blanks are easier to find now than 30-06.

The rifle arrived with a CMP hang tag. I'm not in the shop so I can't quote what is on it. Stock has CMP eagle cartouche embossed. A little faint and I almost missed it.

[Sailormilan2]

CMP has converted many Garands to .308 Win. Basically a simple conversion, since it only involves changing the only the barrel. CMP even sells Criterion barrels alone, for those who want to change their rifles.
Since it's chambered in .308 Win, you can safely fire Military Surplus 7.62x51 NATO ammo in it.
The .308 Garand will have slightly less recoil than a standard 30/06 Garand. But will probably be more accurate.
As was stated, it really doesn't need the spacer in the mag well to function. The spacer only serves to prevent loading 30/06 ammo in the magazine.

[Digger]

Have one of the "tankers" in 308 ...
Really enjoy using it on occasion with my cast.
Been quit a while tho ..will have to start over, working up.

[bob208]

it was the navy that went with the .308 grand. it was cheaper then buying m14 rifles. h&r did the work. if the barrel was good the rifle got the sleeve which some times came out. if the barrel needed replacement the new barrel was chambered in .308.

[Adam Helmer]

Per the title, I just acquired an M1 Garand that has been rebarreled to .308 Win. When I say "rebarreled", the description does not include that word. It says "mfg by Springfield Armory in April, 1942 with Criterion 5-18 .308 barrel".

My first question is: Can I use information in the BruceB thread concerning the M1A? If not, any information about reloading for this rifle would be appreciated. The description also includes a note that the "magazine has plastic insert to allow for either 7.62 NATO or .308 Winchester ammo to be used". This confused my because I could not understand why the use of either would involve the magazine. Does this mean that enbloc clips can or cannot be used?

I haven't really sat down and examined the rifle or compared it to the other Garand that I have had for a few years. I haven't done any reloading for the .30-06 Garand yet but don't expect the .308 to not have unique requirements.

Any insights would be helpful and appreciated.

Alamo,

I think perhaps you should have asked your questions of the Seller of your rifle??

Adam

[alamogunr]

Alamo,

I think perhaps you should have asked your questions of the Seller of your rifle??

Adam

He is a dealer and sells almost exclusively to collectors. He has always treated me fairly but does not claim to know anything beyond collector value. I'm probably one of a small group of customers that only buy what I can shoot.

Besides, I've learned everything I wanted to know from previous posters. They have been very generous with their knowledge.

[country gent]

Alamogunr,
Your rifle sounds like a fine piece of equipment to work with. It should be a very accurate reliable rifle, but may need a little break in. If your rifle was on of the cmp assembled ones the cmp armorers are pretty good from what I have seen. You may be surprised how well it performs.

The navy converted were done mostly in the armories and selected fir the conversion from what I have been told. The Navy also accurized these rifles for their teams. The Garand was a fine rifle in both calibers. I believe Patton labeled it "the Finest battle rifle ever produced"

[Alstep]

I was told years ago that many M1 grands was rebarreled to the 7.62 by the army in the transition to the M14, but have never done any research on it.


The Navy did the early conversions, as they didn't want to spend the money for M-14's. The 7.62/.308 conversions shot really well, the Navy team used them for many years with great success.


I had several M-1 that I rebarreled to 7.62/.308 and shot highpower service rifle competition for many years with it. Standard load was 41.5 gr IMR4895, Sierra or Hornady 168 or 173 bullets in LC brass. The heavier bullet would be good to 1000 yds, the 168 up to 600, they would loose stability & tumble at long range. Since the 7.62 is about 1/2 inch shorter than the .30 cal, as the throat wears you can seat your bullets out longer. Lots of little advantages of the 7.62 over the .30 in the M-1 Garand.

Load the clips just like the 30 cal. You don't need any spacers or gadgets. For rapid fire, just drop in an empty clip, load your 2 rounds & let the bolt slide forward. Advantage is you don't have to drop the magazine like the M-14. After you shoot your first 2, the clip flies out and you just push your 8 round clip in and continue. Saves you a few seconds that can be better spent concentrating on your position & natural point of aim, sight alignment & trigger control.

You're gonna love that M-1 in 7.62! Earned my Distinguished & Presidents with mine, (that was over 30 years ago).

[alamogunr]

Kind of a resurrection here. I would like to find a book on the Garand so I can learn more about disassembly and reassembly. It has been almost 60 years since I did anything with the Garand in ROTC. Those rifles must have been almost smooth bore with all the cleaning we had to do without ever shooting them. I can't remember if we did any disassembly or not. I suspect we did not.

For some reason I keep getting emails from Scott Duff publications. Are there better ones?

[Der Gebirgsjager]

There are plenty of books that show the disassembly of the M1 including those by Scott Duff, Bruce Canfield, and even The Gun Digest Book of Firearms Assembly/Disassembly, Part IV Centerfire Rifles, by J.B. Wood (one of the best, least expensive, and probably easily found on the internet), and a diligent search might even turn up the U.S. Army Training Manual or a replica thereof. Start with e-bay.

[Ford SD]

Per the title, I just acquired an M1 Garand that has been rebarreled to .308 Win. When I say "rebarreled", the description does not include that word. It says "mfg by Springfield Armory in April, 1942 with Criterion 5-18 .308 barrel".

My first question is: Can I use information in the BruceB thread concerning the M1A? If not, any information about reloading for this rifle would be appreciated. The description also includes a note that the "magazine has plastic insert to allow for either 7.62 NATO or .308 Winchester ammo to be used". This confused my because I could not understand why the use of either would involve the magazine. Does this mean that enbloc clips can or cannot be used?

I haven't really sat down and examined the rifle or compared it to the other Garand that I have had for a few years. I haven't done any reloading for the .30-06 Garand yet but don't expect the .308 to not have unique requirements.

Any insights would be helpful and appreciated.

I have a 308 and a 30-06 M1 Garand and also a M1A Clone (308)

and Yes I have shot Cast in the 308 M1A Clone ... 400 cast loads with out cleaning ... then got rained on and had to clean it ... No Lead

Yes Use Bruce B thread.... just be aware that your barrel is prob a 1/10 twist

Bruce B was using a 1/11 twist so his velocities / accuracy node will be higher than yours ....

So do not try to acheve his velocity (less 180 +- fps) ....
Best results will be with dacron and one of the powders Bruce B tried

I would use a heavy cast bullet and Look for less than 1950 fps ... Just stop when you get good accuracy (with function)

And if your rifle went through a recent rebuild it might need a bit of working in

[bob208]

those are the ones I use. have not found any better.

[alamogunr]

There are plenty of books that show the disassembly of the M1 including those by Scott Duff, Bruce Canfield, and even The Gun Digest Book of Firearms Assembly/Disassembly, Part IV Centerfire Rifles, by J.B. Wood (one of the best, least expensive, and probably easily found on the internet), and a diligent search might even turn up the U.S. Army Training Manual or a replica thereof. Start with e-bay.

Thank you for reminding me. I've had the J.B. Wood book for a long time. I just looked up the M1 in it. I also found a big NRA book among my gun books that also had instructions for many arms including the M1. I need to be more attentive to what is on my shelves.

[Sig556r]

I've seen one that still chambered in orig 30-06 but was fitted with a breech sleeve to accommodate .308/7.62 round. The loading chamber has a block that will not allow a 30-06 cartridge. Ingenious, yes...safe, not sure.

[SOFMatchstaff]

I have two Garands in 7.62, both navy trophy rifles. The barrels are marked 7.62 and AMF with installation dates. They shoot very well with GI ball ammo and my match loads, without the use of any spacer block, IMR4895 and 4064 , 173 gr ball or 168gr bthp. the hang tags were marked grd 2, match prepped with the serial Number inscribed on the trigger . Just shows the difference between a govt conversion and a later civvy or CMP job. I have several receivers that I thought of barreling with the Criterion tubes, but dont need to now..

[country gent]

If by breech sleeve you mean the little bushing the navy used to convert to 308. This sleeve was pushed into the chamber with a light coating of red Loctite. They did work and saved replacing a lot of barrels.. It had the neck shoulder of a 30-06 on the outside to git in the chamber and the neck shoulder of the 308 inside to set correct headspace.

This little bushing creates a long throat from the rifling. It also is dependent on the fit in a given chamber to maintain concentricity. I have see rifles converted with them and while they are safe. accuracy isn't quite as good as the ones rebarreled.

Several times on the local range we have found 308 brass with no neck shoulder left when a members rifle had the bushing pulled out with a fired case under extraction. A few years ago these chamber inserts were being sold in several magazines.

[edp2k]

The Navy did a lot of testing with these 308 bushings in 30-06 Garands and concluded that they were a huge problem,
since the experienced a lot of the bushings ejecting with the brass, and neither knurling nor anything else they tried
could guarantee (in their tests) that the bushing would always stay put.

The Navy then abandoned the bushings and rebarreled all guns that had the bushings and all future 308 conversions got a new 308 barrel.

[Bob Busetti]

Just as an aside, back in 1967 I was going through gunners mate school in the Navy. If I remember correctly the Navy conversion consisted of a chamber insert to allow the use of the 7.62 round & the plastic spacer in the magazine. Both items were handed out like crazy in case the chamber insert came out. The plastic spacer was not a problem. However once in a blue moon the chamber spacer would come out. When it came out on the range you put another one on a 7.62 round & slammed the bolt closed, them fire the round and it would tightly seat the insert. As a matter of fact I still have one of the chamber insets some where in my stuff.

[derek45]

.... The description also includes a note that the "magazine has plastic insert to allow for either 7.62 NATO or .308 Winchester ammo to be used". This confused my because I could not understand why the use of either would involve the magazine. Does this mean that enbloc clips can or cannot be used?.....

The M1 Garand magazine, and follower, is internal, and stays in the rifle.

Here's a pic of my M1, which is 30-06 and has no spacer.

https://i.imgur.com/vg03A58.jpg

here's a pic I stole from google, showing the 308 spacer

https://s3.amazonaws.com/mgm-content/sites/armslist/uploads/posts/2017/09/27/7377900_02__308_special_cmp_m1_garand_640.jpg

https://i.imgur.com/La4m45q.jpg

https://i.imgur.com/qcbUvbF.png

[W.R.Buchanan]

Alamo gunner: You can find so much info by Googling "M1 Garand .308" that you will never be able to read it all.

Virtually everything there is to know about Garands is contained in American Rifleman Archives.

The CMP has been doing .308 conversions for many many years. My Garand came from the guy who refurbished all the surplus guns for Arlington Armory in the mid 1990's. He offered .308 or .30-06, in either Full Length or Tanker models. $400.

He re-did about 25,000 guns and he told me @20 % were .308's.

My standard .308 load is 45 gr of IMR 4895 with a Recycled M80 Ball 147 gr.FMJBT bullet .

Randy