Garand Adjustable Gas Plug

[Boberama]

If I get an adjustable gas plug can I shoot full power .30-06 in a Garand, for example, 180 gr at 2700 fps?
Does the plug sacrifice any reliability? Any disadvantages ( I don't care about CMP match rules )?
I'm looking at a McCann or a Schuster, which one should I get? I may want to fire a variety of differnt bullet weights.

 

[HenryD]

I use a Schuster that I ordered from Midway and am quite pleased with it. It comes opened up so that too much gas vents through the plug, forcing you to set it up for your load. I adjusted mine so that it just cycles and strips off the next round with my lightest 150 grain commercial load. Stepped up to 165 and 180 with the plug still locked down and it runs fine with the Schuster venting excessive gas. I would readjust it again if I wanted to go higher just to be on the safe side. Make sure your Garand is in good shape and has the relief cut in the operating rod that corrects the weak point in the earlier Garand op rods.

 

[highorder]

Make sure your Garand is in good shape and has the relief cut in the operating rod that corrects the weak point in the earlier Garand op rods.

If you have an uncut Op-Rod, sell it and buy a cut Op-Rod.
The money left over from the sale of the first will buy you cases of ammo!

 

[skidooman603]

+1 to both above replies

 

[dmazur]

I'm looking at a McCann or a Schuster, which one should I get? I may want to fire a variety of differnt bullet weights.

I have both, and I prefer the McCann (screw-in inserts with different orifice sizes) because it is repeatable following disassembly.

Also, I have a small steel plate cut to fit the buttstock holes which has D&T holes to store the inserts. I've stamped reference numbers beside them, which can correspond to different loads.

As long as you follow the instructions, starting with the largest orifice and working smaller to determine which one is suitable, you can make a note of the orifice number and use that in the future for that load, instead of "working down". This saves time and ammo.

IMO, the Schuster is equally effective at protecting the op-rod, but doesn't lend itself to "swapping loads" as easily. You need to start wide open and slowly adjust the Schuster smaller until you get reliable cycling, each and every time you change. I haven't been able to count turns or clicks, though that is theoretically possible.

Users of adjustable gas plugs (gas cylinder lock screws) should be aware that these devices are in no way self-regulating, and that assuming a load/bullet weight is similar to another load/bullet weight is probably not a wise thing to do...

 

[Col. Plink]

I would also say readjust for each kind of load.

Henry, if you're Schuster is adjusted for your lightest load, it will cycle stronger loads but not vent any more and may put too much pressure on your op rod. Likely it is more closed than it needs to be for strong loads; I've heard it's best to open it all the way and then click it down on each shot till it reliably cycles. It may be too open to cycle the lighter stuff that way, but at least you can be sure you're not trapping too much pressure with the stronger stuff.

 

[HenryD]

Great advise Col. Plink and dmazur. It is best to adjust for each load. My current adjustment point just cycles reliably for Remington 150 (another click and it will not strip next round) and is much more reliable for commercial Remington 165 and 180 grain. I am satisfied with this current setup, but it is not for everyone.