Short stroking

[finloq]

Fired my M1 for the first time today. It would not eject or strip rounds. I created some light loads and assumed that was the problem (gas cylinder and port seem clean, op rod slides cleanly without spring-tilt test). I just checked the new stainless steel op rod spring that I had installed prior, compared to the USGI spring that was on the rifle, when I got it:
Stanless - 20 1/2"
USGI (used) - 19 3/8"

Loads:
147gr. in front of 47gr. IMR4895
168gr. in front of 45gr. IMR4895

Loads or spring?

With 3 clips fired, it cycled once.
When operated manually, no problem ejecting a spent round or stripping a new one and chambering it.

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[browningautorifle]

Insufficent gas or an undersized piston. Check the sticky in this forum for more info on mechanical failure.

[Ben Hartley]

[spring]
Stanless [sic] - 20 1/2"
USGI (used) - 19 3/8"
Loads:
147gr. in front of 47gr. IMR4895
168gr. in front of 45gr. IMR4895
Loads or spring?

Probably neither. First thing to check: is the gas cylinder lock screw tight, and is the poppet valve closing completely? Either of those will lead to a lack of action-cycling "ooomph." And guess how I know? Been there. (And I'm embarrassed to admit, more than once, too!)

Remove the gas cylinder lock screw (also incorrectly called the "gas plug"), clean the poppet valve thoroughly. Ensure it closes completely. Inspect the screw for cracks; if none are found, reinstall the screw -- tighten it down hard -- and try shooting 'er some more.

If you found cracks in the gas cylinder lock screw, they're not hard to find, and a lot cheaper'n operating rods or gas cylinders!

FWIW, I've never had a bit of problem with the Orion 7 stainless springs.

HTH

Ben Hartley

[finloq]

Probably neither. First thing to check: is the gas cylinder lock screw tight, and is the poppet valve closing completely? Either of those will lead to a lack of action-cycling "ooomph." And guess how I know? Been there. (And I'm embarrassed to admit, more than once, too!)

Remove the gas cylinder lock screw (also incorrectly called the "gas plug"), clean the poppet valve thoroughly. Ensure it closes completely. Inspect the screw for cracks; if none are found, reinstall the screw -- tighten it down hard -- and try shooting 'er some more.

If you found cracks in the gas cylinder lock screw, they're not hard to find, and a lot cheaper'n operating rods or gas cylinders!

FWIW, I've never had a bit of problem with the Orion 7 stainless springs.

HTH

Ben Hartley

Thanks, Ben. Well I put a piece of yellow coated wire up through the hole in the gas cylinder and used a bore light on the barrel and saw yellow; so the holes are lined up.
The gas cylinder is locked up tight. It looks like the poppet is closing completely, but I filled it with mineral spirits and pushed it open, letting the spirits drain through; then did the same with water and CLP. I can see no cracks in the cylinder lock screw. I'll post again when I have a chance to test it.
Oh, yeah. I hit all of the grease points before shooting, that's not it, but I'll keep trying.

[browningautorifle]

So you don't think it could be an undersized gas piston or over worn gas cylinder??? Why?

[finloq]

It very well could be the gas piston. I found a good deal on an HRA op rod that (according to the seller) gauges to spec. My SA op rod's gas piston is gauging at .521", I just don't trust my caliper. I understand that min spec is .526". I have the HRA op rod enroute anyway (along with an HRA trigger housing as well). If all of that fails, I will replace the gas cylinder.
By the by, the M1 is an 5,52 Mil. HRA with original (8/54) HRA barrel.
I know that being post Korean War (conflict, engagement), it is not worth, turning into a 'Correct Grade', but...what the hell?

[Ben Hartley]

Jim...

So you don't think it could be an undersized gas piston or over worn gas cylinder??? Why?

Of course it could, and most likely is the cause, if Finloq's posted piston dimensions are accurate. Seems to me, though, that looking at the simplest (and easiest to correct) conditions are to be preferred.

And for future reference, there have been many good reports about

http://www.columbusmachine.com/index.htm

...for repair/refurbishing M1 Garand operating rods.

HTH

Ben Hartley

[finloq]

Well...Occam's Razor!
It was the op rod spring. The first thing that I did upon receiving the rifle was take it apart, clean and grease it...and of course, replace the op rod spring with a new stainless steel (Sarco) spring.
Finally made it back to the range today with an used USGI spring on it and she cycled fine, although she 'short stroked' on the 1st round of the 1st clip (just to mess with me).
I have a new op rod piston being placed on an HRA op rod for me by Jim Swartz right now anyway.
Anybody remember that old, old song: Leave Well Enough Alone?
"Well, I'm old enough,
and, I know my stuff,
So, leave well enough alone."

[Charlie Xray]

I had a Garand doing that. It was my match rifle. I changed the op rod and the problem went away. Must have been a worn piston button?

CX

[finloq]

?
The old op rod worked when I put the USGI spring in.
I have replaced the Sa op rod with an HRA with a new button from Jim Swartz, now anyway.
I guess that I worked my way into restoring her (so to speak).
I have replace the SA with HRA:
Hammer, trigger, trigger housing, trigger guard, bolt, op rod, follower rod, gas cylinder.
Still need:
Front sight, bullet guide and stock set.
For some reason, I want to keep the IHC safety; maybe just to show that she has replacement parts?
In the end, I expect to have a nice $1100 rifle that cost me $1250.