M1 ,cast loads and less spring

[RU shooter]

Has anyone played around with cutting some off the recoil spring and stretching it back out to regular length so that lighter cast loads can be made to function fully ? Seems to me as easy as the op rod and bolt move that if the spring has less resistance you could get away with a lesser pressure load and maybe still function.

[oldhickory]

You're much better off getting an adjustable gas cylinder plug. They're under $40.00.

[RU shooter]

You're much better off getting an adjustable gas cylinder plug. They're under $40.00.
If I understand the adjustable plug, They are designed to lower or bleed off excess pressure correct? If that being the case how would it be better with lower pressure cast loads. I would if anything need to amplify or boost pressure to get functioning and I dont think they make anything that does that yet. I know the cast loads I have tried already function as is but was wanting to see if by having less spring I could lower that level even more .

[Gtek]

NO,NO,NO PLEASE NO! The spring should be 19.00" to 20.25" free. Unkinked and straight.
The spring is the heart of this weapon. It slows the bolt through cycle, bolt contacts rear of rec during such. Also req'd pressure to strip round and return bolt to BATTERY. An out of battery discharge will ruin your day. This weapon on the right day with soft primers this can occur. John C. Garand designed this weapon to operate in a given pressure and burn rate to control dwell timing and survival of metal parts. The plugs / orifice control are designed to lower to correct levels with faster powder / higher pressures. Please stay in the envelope,
Gtek

[oldhickory]

If I understand the adjustable plug, They are designed to lower or bleed off excess pressure correct? If that being the case how would it be better with lower pressure cast loads. I would if anything need to amplify or boost pressure to get functioning and I dont think they make anything that does that yet. I know the cast loads I have tried already function as is but was wanting to see if by having less spring I could lower that level even more .

The one I have can be adjusted from fully open to fully closed and should work with about any boolit and any reasonable powder charge. I really-really wouldn't clip the spring.

[Rich/WIS]

If the oprod spring is not strong enough it will not be able to strip rounds from the clip. This is a common problem with M1s, I had to replace the spring in mine. Also, although it doesn't show as a lube point in many diagrams the spring needs to be GREASED, not oiled for proper function. The only CB loads I have used were with a RCBS 308-165 SIL, 36 grs was shortstroking but 37gr was fully reliable.

[cabezaverde]

Adjustable plugs are on sale at Midway this month. Just ordered one.

[madsenshooter]

I don't get the adjustable gas plug craze. As the guys state above, they're meant for bleeding off excess gas when you decide to use slow burners for jacketed loads. There's no reason to have one for cast boolits. Even a case full of WC860 or something like that will not generate enough port pressure that one would need an adjustable plug. Anyone trying to use one with cast is spinning their wheels, in my opinion. That said, I own one, it only gets used for jacketed loads of slow burners where the load exceeds 50gr of powder. In my opinion trying to use one with typical cast loads is just throwing another variable into the cycling equation.

[mroliver77]

I dont use one for cast but adjust for jacketed to where I get reliable function and just a bit more. The Garand has plenty of extra oomph on the system that beats up the parts. If I were in battle I would run it as designed. For plinking and paper shooting I keep it to a minimum.
I agree that lowering the spring pressure could result in a failure to fully strip and chamber a round. This could lead to a bad day.
If anything leave the gas plug open and cycle by hand. Then you can shoot all the wimpy loads you want.