M1 Garand

[Johnw...ski]

Any one know anything about the gas cylinder plugs on the M1 Garand?

I know the old style was solid verses the new which has a spring loaded valve.
It seems to me the pressure in the gas cylinder would keep the valve closed so I don't see the benefit. I have read the solid plugs will give better groups.

My rifle is an early model, SN 255XXX with the newer plug, I also have a solid plug I am thinking of trying.

Does anyone have any experience with this? What are the positives and negatives?

John

[Jack Stanley]

John ,
The valve on the newer one is meant to vent some of the pressure when launching grenades . When the launcher is attached it opens the valve the correct amount for using grenade launching blanks which are indeed different that salute blanks .
For use with Ball ammo the solid plug will work just fine . In the time I've been fooling with Garands , I've seen just one vale that was cracked but it didn't seem to affect the performance of the rifle . Could it leak ? well yeah , the more the valve is opened the more chances there are to get debris in it and cause it to leak . Could it break ? yep , it has more parts than the solid . Is it a big thing to fret about ? no , but it does give you a mission to take the rifle out and fire it to see which you like best :-D

Jack

[Johnw...ski]

Thanks for the answer Jack, that makes perfect sense, but that brings up the question, why do they make adjustable plugs?

John



John ,
The valve on the newer one is meant to vent some of the pressure when launching grenades . When the launcher is attached it opens the valve the correct amount for using grenade launching blanks which are indeed different that salute blanks .
For use with Ball ammo the solid plug will work just fine . In the time I've been fooling with Garands , I've seen just one vale that was cracked but it didn't seem to affect the performance of the rifle . Could it leak ? well yeah , the more the valve is opened the more chances there are to get debris in it and cause it to leak . Could it break ? yep , it has more parts than the solid . Is it a big thing to fret about ? no , but it does give you a mission to take the rifle out and fire it to see which you like best :-D

Jack

[NuJudge]

The new adjustable plugs are made so one can use powders that are slower than what the Garand was designed for, venting excess cylinder pressure, and preventing bending of the Operating Rod. The Garand was designed around 3031-4895-4064 speed powders. Rifles such as the FAL have adjustable gas systems, but the Garand does not.

The original Garand solid plugs never go bad.

The popet valve ones made late in WWII for use with grenade launchers and continuing through the end of production do go bad eventually, venting when they are not supposed to.

[dominicfortune00]

As I understand it, the adjustable ones are for people who want to try different powders(slower or faster than IMR 4895) in reloaded ammo in a Garand.

Reloaded ammo with too big of a pressure wave peak can bend the op rod.

The adjustable is set, or can be set so that it cycles the action using M2 ball ammo, any pressure over the M2 levels would be vented to prevent damaging the rifle.


Unless you're going to try to work up a load using different powders or bullet weights, you probably don't need one.

[Jack Stanley]

In addition to letting you use slower powders , the vented plugs allow you to try heavier bullets . If I remember right the military had a 173 grain FMJBT , with a vented plug you might be able to use hundred and ninety grain match bullets very effectively .

Jack

[smokemjoe]

I pushed the plug out on one of mine, now shoot 17 Grs. 4759 and 200gr. bullets, run the bolt by hand, no leading in the barrel port, better groups,got a single shot mag. block and no more M1 thumbs, Had 3 smashes in 2 weeks, got a B square scope mt. on it. Works great. Joe

[NickSS]

One thing about the adjustable plug is that you can tune them so that the empties just fall in a nice pile. I usually use 4895 or 4064 and 168 gr HPBT match bullets. Before I put an adjustable plug in the brass went frontwards and to the rear. So I had to hunt a considerable area to pick it up. I put in a Shuster adjustable plug and slowly closed the gas bleed hole until the brass was reliably ejecting and it is all landing about two feet to the right rear os where I am shooting from. Makes a pile about two feet in diameter. Also softens the recoil and lowers wear and tear on the oprod.

[Johnw...ski]

So as I understand it the solid plug may help grouping. Does this mean that with an adjustable plug there is a trade off with accuracy?

So far this year I have shot almost 1000 rounds of 173 gr. FMJBT bullets with
60.0 gr. of H4831SC using the issue spring loaded gas plug with no ill effects other than the op-rod spring seemed to have gotten tired but all was well after I stretched it 1-1/2 inches.

This load has been extreamly accurate out of my rifle and I am wondering if the solid plug would help.

When this lot of bullets runs out shortly I plan to use the Hornady 150 gr. FMFBT with about 58.0 gr. of H4831SC. I am still working on the final load for this bullet and am close accuracy wise to the 173 gr. bullet at 200 yds. so far.

[bruce drake]

Nope, The adjustable gas plugs (mine is a Schuster) allow you to use slower powders or heavier bullets. It also allows me to tweak the load where I can dial the load into the rifle. I've seen noticeable improvements in the accuracy of my Garand with a given load. It's another variable for the handloader to deal with besides bullet weights and powder charges.

If you want to focus on one less thing, than go with the older plug. The schuster plug is different than the older valved plug which as they mentioned correctly before was designed to shoot blank charges of very fast powders to launch grenades.

[tejano]

I pushed the plug out on one of mine, now shoot 17 Grs. 4759 and 200gr. bullets, run the bolt by hand, no leading in the barrel port, better groups,got a single shot mag. block and no more M1 thumbs, Had 3 smashes in 2 weeks, got a B square scope mt. on it. Works great. Joe

I have had a Garand for several years, but I have not shot it as much as I do my other weapons. However, I did come real close to getting an M1 thumb the first time I took it to the range. I am left handed, but have always shot rifles right-handed. I load with my stronger left hand and keep my right hand on the operating rod handle just in case. Yeah, I know that is not the way I have seen it done in movies, but it seems to work. Or, is it just heresy?

[Jack Stanley]

Being left-handed myself , you would think my thumb is half gone form the problems folks blame on the Garand bolt . While I'm feeding mine , I've noticed that the bolt cannot come forward untill your thumb lets go of the ammo . So , I'll hold it down completely untill I'm ready to get the thumb out of the way ..... and then , do that quickly .

Jack

[PatMarlin]

Never hear of the garand thumb. Could you explain that some more?

I bought mine earlier this year and have not fired it yet.. :roll:

[NickSS]

M1 thumb comes from incorrectly inserting a loaded clip. The right way is to set it in the rifle in position. Put your thumb about midway down the length of the cartridges and push it into the rifle smartly until it stops at the bottom. Then in one fast motion pull your thumb and hand away from the action. The bolt will release and slam forward chambering the first round 9you may have to bumb the op rod handle to get it going. The wrong way is to do the same thing but then be tentative about geting your hand out of the way. This will result in the bolt slamming shut with your thumb still in the action. The resulting mangled thumb is known as M1 thumb. If you are unsure you can place your fingers of your right hand alongside the action and hold the oprod to the rear while seating the clip. That way your fingers will block the oprod from closing until your thumb is out of the way. When loaded properly there is no problems and you can get of at least four clips in one minute of aimed fire. My own record is 38 rounds in a minute.

[45 2.1]

You get M1 thumb only once (or at least you should). If you get it twice, you will probably sell the rifle. Takes a long time to heal also. BTDT while trying it right handed. I'm left-handed though and developed my own method of rechargeing. Roll the rifle to the left, insert clip with left hand and push home while pad of left hand is on right side of rifle blocking the operating rod handle. Once it locks withdraw fingers, then hand and let slam shut. No mangling that way.

[waksupi]

If you want an advanced course in sore thumbs, get yourself a Hakim, and not pay attention when loading. Those are like blunt guillotines, travelling at 1100 fps.

[B747]

Also, keep in mind that the Garand has a floating firing pin that will at the very least make an indent mark on the primer if you release the bolt from all the way back.

I've had a slam-fire on mine even with a CCI #34 military style primer with the hard shell is supposed to help prevent that. When single round loading I now drop the bolt from about half way closed to keep bolt closing speed down.

A slam fire is always a bad deal --- if it occurs out of breach lock, really bad things will happen.

Wally

[PatMarlin]

All right... thanks!

[garandsrus]

My belief is that M-1 thumb normally comes from not having the bolt locked all the way to the rear, while thinking that it is.

The bolt will remain open when it is behind the follower, but it is in fact not "locked". It can come loose very easily, slamming shut. The bolt "locks" about another 1/4 to 1/2" to the rear.

A "Single Load Enhancement Device" or SLED is a great way to load the Garand single shot and worth way more than the $10 or $15 they cost. You put the SLED (which is a modified enblock clip) into the rifle and it stays put until you remove it, which is also very easy. Then, you just snap a round in the clip. When you are ready to shoot, just pull the op rod back and let it go. The round will chamber. This is especially useful for left handed shooters when using coats, shooting gloves, slings, etc.

The SLED does load the round from a clip, so the op rod is going the proper speed.

John

[sundog]

I am a southpaw and I love the Garand. The SLED is essential for me for high power as far as I'm concerned.

[pincherpartner]

I'm another southpaw too, but instead of the sled for single loading I . . .
Cup the palm of my hand over the rear sight
Hold onto the op rod with my trigger finger
Release the follower with my middle finger
Move my finger out of the way and let the op rod close the bolt

It's very easy to do, doesn't cost anything and looks more professional than those people trying to wrassle with the beast.


It's a method that was mentioned in the "Precision Shooting with the M1 Garand" book by Roy Baumgardner. The book is also a pretty good source for tips and some interesting stories about the Garand.

[TNsailorman]

Back to the "slamfire" mentioned earlier. The M1 has a free floating firing pin but it has built in safety features that normally preclude the firing pin sliding forward and setting off a primer without the trigger being pulled. If an M1 does fire as it is closed, there is either a problem with the ammo or worn parts(usually a worn hook on the firing pin or it is broken). I do recommend harder primer cups on the M1 such as the CCI #34 Military primer or a regular LR CCI for those who worry about this, but that is just a precaution. It has been my experience that if the primer pocket on reloads has been deepened with a primer pocket uniforming tool such as the Sinclair, you don't have any problems even with the sensitive Federal primers unless there is a problem with the firing pin hook. I have been shooting Federal primers in my GI brass for many years and have yete to experience the dreaded "slamfire". My experience anyway.

[WineMan]

I enjoyed the information Bill Ricca provided here:

http://www.billricca.com/lockscrews.htm

wineman

[Johnw...ski]

I got out to the range today with my garand and plenty of loaded ammo. The load was 60 gr H4831SC with a 173 gr. military match FMJBT and BR2 primers.
I have been having very good success with this load.

I had the origional gas plug with the valve in it that came with the rifle, a solid gas plug from U.S. Armory, and a Schuster adjustable gas plug from Midway USA.

I shot 3 shot groups at 200 yards, here are the results:

Origional plug with valve: 2" group
Solid plug: 4" group
Adjustable plug, screw turned in 1/8 turn at a time
until rifle functioned +1/4 turn: 3" group
+3/8 turn: 5" group
+1/2 turn: 6" group
+5/8 turn: 2" group
+3/4 turn: 3" group
+7/8 turn: 3-1/2" group
+1 turn: 1-3/8" group
+1-1/8 turn: 2" group
+1 turn: 1-1/2" group
Origional plug with valve: 2-1/4" group


This was done shooting at a standard military 12" 200 Yd target using the standard rear sight and a 22mm globe front sight with a .105 ghost type insert from a bench with front and rear bags.

This proves to me that the adjustable gas plug can be a real advantage.

John

[Meatco1]

I think everybody needs to discover the joys of "Garand Thumb" on their own.

I certainly learned my lesson well while in Basic, 1963.

Never forgot it!!!!!!!!!!!

Richard

[eka]

Richard that reminds me of a story an old Marine vet from Korea was telling me. He made it all the way through basic without getting the thumb. On the day of graduation he smashed it. He said he stood in formation with blood dripping off his thumb and wasn't about to say anything about it. He said nothing was going to hold him up from leaving that place. His name was Richard too.

[Meatco1]

eka:

I think most of us old timers who were originally issued Garands, have somehow managed mash our thumbs at least once. Some, who were a little slow have done it twice.

The lesson is usually painfull enough for most of us to remember for the rest of our lives!

Johnw Ski:

That is good information you posted. I installed a Schuster a few months ago, but haven't had the time to test yet.

I'm using a different powder & bullet combo (WW748 & Rem 165 gr Core-loc), but will go with your proceedure when I do test.

Thank you,

Richard

[sg5054]

When you load the enbloc clip start your first round on the right side and fill the clip. You will finish with the last round on the left (high) side. By doing this it will keep your thumb nail from snagging the inside of the reciever and breaking the corner of your nail. Also, when you load the clip make sure your rounds are fully seated in the clip. I load 7 and then press the tips against the bench top to make sure theya re seated. Then install the 8th. No need to hit them just press.

When you load the clip,
1. pull the op rod back and see that it is locked fully to the rear.
2. take the clip and place it on top of the follower. The bolt will not release until the clip is fully inserted.
3. place the right side of your hand against the op rod lever, palm against the side of the stock and thumb on top of the clip.
4. push the clip straight down until fully inserted with your hand still holding the op rod.
5. all in one motion,smartly flip your thumb up and out as you remove your hand from the op rod.
6. the bolt will release from its locked position and may close completely into battery or may only move forward and catch the first round. If it does stop at the first round just give the op rod a tap with the heel of your hand to close it. You want it to close smartly don't gently lower it into place.
7. If you want to load single rounds get a SLED clip from Midway USA. Trying to load single rounds by placing them in the chamber is risky business.

Practice the loading moves above at home by locking the bolt back and going through thhe steps above. Just push the follower down while holding the bolt like you would load a clip and flip your hand (see #5).
You get your thumb smashed if you get lazy or careless.

Have fun. These rifles are a gas!
1 SA 6-42
1 SA 12-53

sg5054:-D

[PatMarlin]

Great instructions.

I'm going to archive them... :drinks:

[Doug Bowser]

The reason the military refitted all the M1 rifles with the vented gas plug was the Grenade Launcher. With the solid gas plug, the op-rod would be damaged.

Doug Bowser

[Ricochet]

Also, keep in mind that the Garand has a floating firing pin that will at the very least make an indent mark on the primer if you release the bolt from all the way back.

I've had a slam-fire on mine even with a CCI #34 military style primer with the hard shell is supposed to help prevent that. When single round loading I now drop the bolt from about half way closed to keep bolt closing speed down.

A slam fire is always a bad deal --- if it occurs out of breach lock, really bad things will happen.

Wally
I've found that my "new" PSL puts very deep dents in #34 primers. I've seen many fired cases from older guns that had no deeper primer dents. Haven't yet had a slamfire, but I would load with no other primers, and think it especially advisable to only let the bolt close on a live round when pointed in a safe direction.

[Meatco1]

Ricochet:

On my 1943 Springfield using what's considered a "soft" primer (Federal) I get a noticeable, but small primer indent. In the 40+ years I've been shooting this rifle, I've yet to have a "Slam fire".

I guess all these old warriors all different!!

Respects,

Richard

[Linstrum]

My first Garand puts dents in the primer when live rounds are cycled through and ejected by hand. I thought at first it was the firing pin doing the denting but I discovered that it is the ejector plunger that puts in the dent as the cartridge is stripped from the en bloc. I bought another bolt and the new bolt doesn't put dents in. I compared the heights of the ejector plungers and the one that dents primers seems to be about 0.005" longer. Never had a slam fire in any of my Garands using regular CCI, Federal, or Winchester large rifle primers. I use military primers now, though.

I certainly agree with Ricochet, I think it is darned good practice to only chamber a round with the muzzle pointed in a safe direction with any autoloader, especially old military types. Back ten years ago one of the guys who worked at my wife's gun store told me he had a close call with an old 1911A he had never fired before, he loaded a full clip in and when he let the slide loose to chamber the first round it slam fired and went full auto. The unexpected recoil of seven rounds firing full auto raised the muzzle up and the last round went through the bill of his baseball cap. "Live and learn" took on new meaning for him, especialy the "live" part!


rl457

[PatMarlin]

Oh my lord.