what were you shooting out of it?

only thing i ever heard of bending an op rod was "hunting loads"

well its hard to say for sure but 8-16 rounds could have caused the problem especially if the powder was too fast or too slow. Garands need a power with a burn rate somewhere near IMR 4895.

\i have read some guys who use 150 coreloks in their garand without damage and it sounds like you may have been using such a round. Remington doesn't recommend you shoot corelocks out of a garand either-way.

While it doesn't help you now my .02 would be get the op rod fixed or replaced and stick to HXP o Garand specific factory or handloads, or get a adjustable gas plug)

were you shooting the garand ammo while using an adjustable gas plug?

There aernt any members on the CMP forum that have the jig to check Op Rods that I know of
It would have to be sent to Columbus Machine
I would get to excited yet, dont even know if that is whats causing short stroking
A Op Rod can slightly rub and not cause any problems. His could have been rubbing all log
The OP needs to check the things I listed first

i dont recall any problems with it with the corelock ammo. i remember the gleeful PING as the en block ejected, I'm 99% sure it happened on its own and i didnt have to cycle it.


op rod test will slide to about 85-90% on its own, then hangs up. you can operate it manually to the full length of the channel.

Did you do the tilt test with the trigger assembly removed?
If not hit will hit and hang up on the hammer.

Couple of months ago, I had a problem with the op rod rubbing on the stock where the handle goes through the slot in the stock. This rifle had worked fine before, but I guess the wood started swelling over time, and the op rod started rubbing on the stock, so when I discovered that, I simply sanded it down.

It too me awhile to figure this out, since the rifle was passing the tilt test. It wasn't until I was slowly inserting the trigger guard with my other hand on the stock in the area of the op rod that I realized what was going on.

Op Rod has to rub real darn hard to cause short stroking unless other parts are close to being out of spec
You never answered me, did you do the tilt test with the trigger group installed??
If you are THE BOLT WILL RUB ON THE HAMMER when sliding rearward .

sorry, been away from this topic a bit. no , i didnt tilt with the trigger installed, but i will try it.

thanks,

OP, are you using grease or oil on the rifle? Using oil instead of grease can cause damage very quickly to the oprod.

There are three general causes of the condition described by the OP.

1. Insufficient gas impulse being delivered to the oprod. This can be caused by a fouled gas port, an undersized or worn oprod piston, gas leakage from excessive wear to the cylinder, a leaky "poppet" on the lock screw and/or the ammo.
2. Excessive binding in the operating system. The description of the OP of his "tip test" results indicates that there isn't sufficient binding to be the cause.
3. A fouled chamber which would create friction on the fired case.

I have hunted for years with Remington Core Lokt ammo in M1s. It is highly unlikely that this ammo would cause any damage to the rifle. I would start with a detailed cleaning of all of the gas system components, the barrel and chamber followed up with a more detailed examination of the gas system. The piston should be concentric and a minimum of .526 OD. A quality micrometer will determine this. A gas cylinder gauge will be needed to check it for wear on it. I would replace the gas cylinder lock screw with a WW2 "solid" to eliminate that as a problem. I've heard that a belted .338 magnum case can be used as a poor man's cylinder gauge. When I was actively performing I&R for veterans organizations in MO I always kept a good supply of spare parts on hand. Good luck. These things can be challenging but in the long run easily corrected once diagnosed and a great opportunity to learn more about the actual function of your rifle.