M-1 Garand help, piston

[rojocorsa]

So the the piston of the M-1s oprod seems to be very subtly scraping against part of the gas tube wall. It's very fine, with no resistance and can only hear it if you manipulate the op-rod slowly.


What's the deal---is the weapon forgiving of this, or is something wrong with my piston? I'm aware that there is a place that fixes op-rods and pistons and all that, but it's nice to save the time and money--however if it needs to be fixed by them, so be it. I might even sell this gun down in the near future; I want to make sure the buyer gets it in good working condition.


Thanks--

M-1s are not usually my thing, other than the basic general stuff.

I'm aware that the piston itself needs to be a certain diameter across the board, but I don't have calipers for that. Anyway, the point is that this gun moves without any real resistance--I wonder if it would work fine anyway. I figure that it's a military weapon, so it will be overgassed and with looser tolerances.


ETA: I'm positive that the oprod isnt bent; it will pass the tilt test and slide with just gravity. Interestingly enough, the slight scraping sound doesnt happen if the GI gas plug is off the tube at the end. It's a little weird.

[shotcaller6]

Good ears! How is the accuracy?

[rojocorsa]

Here is a group I shot with the weapon this past Saturday, using HXP surplus.

The target is the standard 8" bull @ 100yds, for reference. I put two clips through a very hot weapon. After the 1st clip, I let it cool. I think what you're looking at there way my second clip.

[littlejake]

The piston doesn't effect accuracy; but does effect function. You say you are certain your OP rod is not bend (a common condition on the Grand.)

And, you do not hear the noise with the gas plug is removed.

IMO, this falls into, "if it ain't broke, don't fix it."

[rojocorsa]

I'm 100% sure that the rod isn't bent. It doesn't bind or snag up, there are no discernible gouges or anything like that.

The only thing I hear is that slight chalky sound around the first two inches of rearward travel, but even then it's no real resistance. It's probably a non-issue. I just wanted to be careful about it.

Thanks
Rojo

[me109g4]

Probably hearing the op rod spring. in the tube not the piston. As to using calipers to measure the piston diameter, dont. Use a micrometer, since the total run out on the piston is around .001 calipers just dont cut it for accuracy.
Since the gun functions and passes the tilt test, dont mess with it.

[6mmintl]

group does not look too bad, maybe just some worn/loose parts/center band/handguards/etc.

Bring it over to redwood city and we can go thru it "With the Manual".

[rojocorsa]

group does not look too bad, maybe just some worn/loose parts/center band/handguards/etc.

Bring it over to redwood city and we can go thru it "With the Manual".

Thanks, PM sent.

[pro-nra]

My thought is if it passes the tilt test, no function issues, piston is not scratched up and passes minimum measurement with a mike leave it alone.

It is smart to have at least couple of known good op rods as spares for situation like this. I try to have at least two of every easily replaceable parts for my M1s.

[rojocorsa]

Took it down to 6mm in Redwood City.

The weapon is good to go! Looks I'll be hanging on to it for a while and I'm definitely gonna shoot it. Learned a lot about what makes M-1s tick.

Thanks again 6mm!