Oversized M1 op rods
- Thread starter Anthony_Slipp
- Start date
I have 3 of them sitting on my desk, I won't sell them because they are out of specs. The tip is bigger like you said, all 3 of them are out of shape, the angles are off a bit, and the metal seems softer, feels like they need an other heat treating.
i have one but with the relief cut and oversized piston.it seems on mine that
that is not the original piston.when i removed the grime/cosmo there were
solder (silver solder?) traces behind the piston.
it wasn't round a bit oval.i used emery cloth to sand it down--the metal is
soft--it will reduce to .526.a lathe would probably do a better job and make
it nice and round...
p.s. the piston is also longer than a standard one...
that is not the original piston.when i removed the grime/cosmo there were
solder (silver solder?) traces behind the piston.
it wasn't round a bit oval.i used emery cloth to sand it down--the metal is
soft--it will reduce to .526.a lathe would probably do a better job and make
it nice and round...
p.s. the piston is also longer than a standard one...
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Op rods can be re-pistoned with an oversize piston in order to use them with a worn gas cylinder. This is kind if a back-asswards way of solving a worn piston/gas cylinder relationship problem. Before working the piston down, it might be worthwhile to look for a gas cylinder with a worn/oversize bore. They are around.
Re-bending op rods to fit a rifle correctly is an arcane art which needs a lot of patience and trial and error to bend and fit the rod with both the gas cylinder and bolt which is to be used. I've re-bent 3 of them in order to make them usable. This isn't a task for the faint-hearted, but is do-able with a rigid vice or floor press to hold the rod while you bend it. I don't know what the heat treat specs are on the op rods, but they are quite soft as evidenced by the wear patterns that you see on the lug which engages the receiver, the interior bolt cammming surfaces, and the 2 hooks which engage the op rod catch.
All US GI op rods are marked with both the drawing number and the initials of the manufacturer.
Re-bending op rods to fit a rifle correctly is an arcane art which needs a lot of patience and trial and error to bend and fit the rod with both the gas cylinder and bolt which is to be used. I've re-bent 3 of them in order to make them usable. This isn't a task for the faint-hearted, but is do-able with a rigid vice or floor press to hold the rod while you bend it. I don't know what the heat treat specs are on the op rods, but they are quite soft as evidenced by the wear patterns that you see on the lug which engages the receiver, the interior bolt cammming surfaces, and the 2 hooks which engage the op rod catch.
All US GI op rods are marked with both the drawing number and the initials of the manufacturer.
That's a 1950's vintage Springfield rod which has been re-pistoned. Piston max OD is .526, min is .525. It is important that the piston not be out of round. Replacement pistons are available from Brownells.
The Kuhnhausen Shop manual on the M1 and M14 rifles is the most comprehensive technical reference available. It goes into great detail on the inspection and re-conditioning of op rods, incl piston replacement, and all other components. I've used it as my guiding light for the past dozen yrs or so and highly recommend it to the serious Garand/M14 wanker. Brownells sells it for $44.95; money well spent.
Some very good info here, thank you everyone for posting. Does anybody know where these came from though? Would these have been counterfeit or production of some other factory? Regardless of where they came from, I think I will stay away from these particular op rods and continue my search for a suitable unit. Having said that, would someone be kind enough to tell me if there is a source of op rods somewhere?
try numrich or gun parts corporation.i used them once for parts,not oprods but they probably
have them in stock.shipping,export fee and duty will cost you.it's 35 bucks for thye export
fee,shipping will be not too bad but the box has a huge parts description on it and i can almost guarantee you will get charged duty and brokerage from can. post.
oh btw,there may be a 100 dollar limit on purchases...
