I'm going to add an adjustable gas plug to my DCM M1 Garand. I see that there are several different ones out there. Do y'all have any suggestions for which one to consider. Is there one I should avoid?

Mine is currently as-is from CMP.

Begs the question: why? Plenty of Garand-compatible ammo out there, not to mention ease of handloading same.

I've got an urge to experiment.

I've got a couple of loads-- one a hunting load with 165 grainers and a target load with 150 grain FMJ's. These aren't hot loads, but from what I understand, I can tune the rifle by adjusting the gas.

Garandgear.com has a gas cylinder plug that works with all reasonable loads. Commercial ammo and military ball. No adjustment needed. Read about it on their website. I have one and it works.

Nice looking wood! I haven't got an adjustable gas plug but I seem to remember talk of the Shuster gas plug.

I'm looking for one that is adjustable. At least I think I do. From what I understand, you can dial in tighter groups. It also lets me experiment with a wider range of bullets; I can adjust the amount of gas so that the op rod is not at risk and the action is cycling with an optimal amount of pressure.

http://www.schustermfg.com/m1a-adjustable-gas-plug/

Why, why screw with a good thing?

Well, it's really easy to unscrew. The Schuster plug comes factory set to vent most gas so the action will not operate. Directions say to start by closing or screwing in the plug 1/4 turn at a time until the action functions. I installed one in mine and have it set so it functions slower than normal even with mil spec ammo. Theory is that slowing it down protects the operating rod. My gun has been totally reliable after adjusting.

Mine too.

Like having the option to adjust for heavier bullets/loads without hammering the op-rod.

Still have the original plug if I ever want to re-install it.

I got the Schuster. Haven’t used it. I have A box of Remington 150’s through it with no problems.

I can see why. A Garand is a fine rifle. I love to hunt with mine but with the stock gas setup you have to be careful with ammo and at that you're limiting performance. I want to get one of these adjustable gas plugs too. If you're worried about keeping it original just keep the old stock parts in a safe place and if you ever want to put it back in original condition you've got the parts right there. That way you can hand load hotter ammo and different weight bullets without worrying about damaging the op rod.

Thanks all! I'll probably order the Schuster after I dig out from Christmas.

This is the one I'd try. Been wanting to for years but haven't gotten around to it. I'd rather not have to make adjustments. Just screw in and go. They're a good company to deal with too.

Just my 2 cents....

I have used the Garandgear plug fairly extensively ( about 5 rifles), and like the concept. Also the fact that you are not tied to one load and have to readjust if you change loads.

The only warning I have is to occasionally clean the chamber in the ported plug, as it will slowly fill with carbon and you lose the pressure reduction, but the same happens with the plugs that work by venting.

And carry the issue plug in the buttstock. My kid's M1 did not cycle150 grain Remington CoreLokts with the non-adjustable plug in place. I still like the idea of not bending an op-rod so the trick plug stays in.

I load H-4895 for mine. Supposed to mimic the Garland load.

+1......... Didn't feel like messing with variables so I just run one IMR-4895 G.I. Equivalent load to keep things as they were meant to be. Use regular 150 gr. FMJ for paper punching and just substitute some Nosler 150 gr. Accubonds for hunting use. Both bullets shoot well and I feel better knowing my load is M-1 compatible without having to adjust things. Guess I just don't trust my op rod to anything but a standard M-1 load.

Update:

I finally got the Garand out with some test rounds to see if the Schuster plug was worth it.

We're Sneaking In

Bottom line: It took 6 rounds to get the plug dialed in, going from fully open and closing it a quarter turn per round. I then turned it on my gong at 200 yards and rang it 24 for 24.

Is it better?
Or, could you do the same with proper Garand ammo?

Hay people that is the gas screw, not a plug. It is not necessary for any loads factory or military below 180 grains! The M1 rifle was developed in the mid 30's for M1 ball ammo that is 173 grain bullet. M2 ball didn't appear until late 1939. Op-rods were made from 4140 steel and don't bend as alleged in the online forums. All commercial hunting ammo either 150, 165. or 180 are safe even Superformance. After market gas screws are not needed.

The answer is yes, sort of.

When I got my Garand 20 years ago, I was just starting to reload. I meticulously followed the instructions from the CMP-supplied American RIfleman article and never had a problem. I've never really strayed from that, loading 150 grain FMJ for plinking and 150 and 165 grain SP for deer hunting.

I'd never try to push the envelope with this rifle, but I would like to see what I can do accuracy-wise. What I understand to be true is that the gas port adjustment allows you to tune the rifle to the load. It all may be hokum, but if I can squeeze some extra accuracy out of this old girl, I'm all for it. We have a 450 yard option from our bench, and I'd like to stretch her out a bit.

I figure this is adding a little extra control to the mix. I can now try a load with the action not cycling at all and see if it changes the group.

the key to garand accuracy ... bedding. also make sure the foreend hardware set up properly...

accurate loads are well known. if you don't get good results... its something else. something to watch for...where does the rifle eject the cases?

should be 1 o'clock give or take a little. a well set up rifle will put them in a small area.

4895 and 4064 work well. no use trying slower powders to make a magnum out of it.

The October 2018 Handloader has an article by John Barness where he researches some M1 Garand loads with various powders. He listed 48 grains of Varget with a 150 grain Winchester Power Point. The listed 3 shot group is .88". That is the load I use in my 1903A3. I will say I have shot at paper and I found the load to be accurate. I just shot and didn't pay much attention to group size other than I can see where John got a .88 group. That load was nicely accurate in my 1903. I have yet to shoot it in one of my Garands.

kwg

I have the garandgear and my accuracy is really nice. I LOVE shooting that gun.

Pretty stock!

I have since shot this load in 2 of my Garands. I did bump it up to 48.4 grains just to get it over 2700 fps. I shot it at the same time I was shooting some HXP ammo I got from the CMP. The recoil from the 48.4 grains of Varget was slightly less than the recoil from the HXP and did not throw the brass as far as the HXP. The accuracy was similar. I do not have a chrono so I don't know the exact speed of the 150 grain Hornady FMJ. All in all I think it's a great load and I will try and dial in the accuracy at some point in the future. I know that Varget is difficult to find right now so I have considered trying IMR4320 or Accurate 2520.

kwg

I load my own ammo and as was said above, 4064 and 4895 are top powders for the M1 for 150, 165 and 180 grain bullets. Don't load it hot.
I also use 3031 for my loads with 220 grain RN bullets and it's worked flawlessly and I used it to kill elk and bears in the past. 220 gr Bullets chronograph at 2370 FPS with 42.7 grains. Those are very deadly when used on all the game I ever shot with them, most of which was shot between 30 and 150 yards.
I have had mine since about 1980. I glassed bedded the receiver. Other then that I have not done anything to deviate from GI specs and I have never needed to.

I just killed my 2020 Antelope buck with it a few weeks ago. Still works perfectly.

Instead of messing with the gas system I plan to bed my receiver according to established protocols over the winter. With previous Garands it paid off. GI-level loads with 4895,4064, and Varget and 150 Sierra fmj's and sp's group nicely as it is- sub 2moa. If a good bedding improves it a bit that will be the icing on the cake I'm looking for. (Recent CMP Special, WWII action with new Criterion barrel + new stock. So not mucking with a pristine original example.) I have 9 other .30-06's with which to shoot heavy bullets/loads out of if I choose to. No sense in beating a Garand or spending money on aftermarket gas systems if I don't have to.

good tag line. have you heard this variation? you can lead a horticulture but you can't make her think. dorothy parker

The trick gas plug does make sense in a user Garand that may have to eat road food and like it.

I looked at it like insurance. It does not affect the appearance of the gun at all. I have mine slowed down, its now a fun gun that may/will be shot with different loads, some probably hotter than mil spec. A plus is that it does not eject as vigorously and the spent brass piles up closer. You can store the original plug and a wrench to adjust the Schuster plug in the buttstock with no problem, so you can make adjustments if needed.