M1 Garand cycling issue

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Ramzzz

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So I finally got my M1 in 30-06 out to the range and I am having an issue (i think). My goal is to have a reliable 100ish yard range plinker using the minimum amount of powder to reliably cycle the action. Accuracy is not a major concern. I tried 3 rounds of each charge weight. It would reliably pull out the spent brass and chamber the next round as per previous tests. It would throw the brass around 4 or 5 ft at 47g and about 10ft with the 50g load.

The issue I am having is the bolt is not coming back far enough to lock and to eject the en bloc under the lower charge loads. It is not until i use the 50g load that it reliably locks the bolt back and spits the en bloc out (it only spits the block up about 1 inch before it starts to fall back to earth). From what I have read, lots of other guys loading for the Garand are getting great results with much lower amounts of powder.

47g did not lock back the bolt once.
48g did not lock back the bolt but the bolt face bumped up against the back of the en block on 1 of the 3 rounds.
49 grain locked the bolt back and spit the en block up once but the other 2 times the bolt face bumped up against the back of the en bloc before it could eject upwards.
50g cycled ok. The bolt locked back and the en bloc was ejected upwards with all 3 rounds.

The max powder weight is 51.5g as per CamPro data but shouldn't the Garand cycle fine with much lower charge weights? It seems to me like mine is very gas hungry when most of the other garands i've read about are over gassed with modern powders.

It came from TNA with a new Criterion barrel a few years ago so I am assuming it was put together by a competent person. All seems fine when cycling the action manually on the bench with dummy rounds.

I field stripped it and thoroughly cleaned and lubricated everything before the testing. The op rod piston is in spec but I have no gauge to check the gas block. The op rod/bolt assembly passes the tilt test with flying colors. It moves back and forth like butter.

I am using 147g Campro projectiles with H335 as per Campro's loading data on OAL and charge weights. I plan on using 4895 in the future but I have 8lbs of H335 that I would like to use up eventually.

I was thinking about maybe trying a different (softer) operating spring or new op rod and gas block. Worst case scenario i could enlarge the gas port on the barrel a few thou and repeat the test. These results do not seem normal to me but I could be out to lunch.
 
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I just checked the M1 G information out in the Hornady manual and H335 is from 36.9 to 46.4 for 150 grs. I haven’t used H335 but I would suspect at top load cases should be 7 to 10 feet out and clip flys out well. Does sound like a gas issue. You should be using data meant for Garands as 50 grs should be over max for Garands. Powders I use and have had success with are H and IMR 4895 and Varget depending on what is available. Some of the fellows that build them will likely give more info.
 
Snider shooter said:
I just checked the M1 G information out in the Hornady manual and H335 is from 36.9 to 46.4 for 150 grs. I haven’t used H335 but I would suspect at top load cases should be 7 to 10 feet out and clip flys out well. Does sound like a gas issue. You should be using data meant for Garands as 50 grs should be over max for Garands. Powders I use and have had success with are H and IMR 4895 and Varget depending on what is available. Some of the fellows that build them will likely give more info.
Click to expand...

The first round of testing I did I started at 43 grains and it wouldn't even cycle the action enough to pick up the next round. It had enough to pull the spent brass out and that was about it. No way would mine cycle at 37g in its current form although that would be great if it would.
 
H335 in my experience is an efficient powder in gas guns (although have only used it in .223 and .308) - I've not used it for a Garand.

Looking at the Hornady manual for Garands, and having used their data for a couple of M1s, I concur with Snider shooter - you have a rifle issue, not a powder issue.
 
Problem solved. After some more investigation, the gas port on my barrel was undersized at .067. The gas ports on Garands came in 3 different sizes between .077 up to .1065 So i opened it up to .085 and voila...she cycles beautifully on 39 grains.
 
Good to hear. I would rather have a lower safe charge than going over max for the rifle. Op rods aren’t cheap anymore. Hornady manual has a separate section dealing with Garands using proper powder and bullets. Sierra has a good section pertaining to gas operated rifles worth the read.
 
A .30-06 Garand which is within spec will always cycle reliably with a 150gr bullet using 48gr IMR4895 or 48gr IMR4064.

Doing the tilt test to rule out a binding op rod is a good first move. Next to check is the op rod spring which has a min/max length of 19.75 - 20.25 inches. Avoid the longer Wolff op rod springs or cut them back to proper length.

After that it's the gas system to check for short stroking. First check the gas plug. If there is a crack on the inner face it will leak gas. The valve must be fully seated to prevent gas leakage. Sometimes the valve has to be cleaned of accumulated gunk to make sure it's fully seated. The gas plug must be kept tight when shooting.

Location of the gas cylinder in relation to the gas port is important. It must allow the gas port in the barrel to appear in the corresponding "window" of the gas cylinder. The lock can be adjusted or other locks trial fitted to achieve the proper location for the gas cylinder on the barrel.

The gas port should be clear of carbon build up. For a .30-06 barrel, a #47 drill bit (.0785) can be used as a clean-out tool, and a #46 bit (.0810) can be used as a maximum gauge. A # 45 bit (.0820) can be used as a "no-go" gauge.

The op rod piston diameter can be miked to make sure it is a minimum .525.

The interior diameter at the front of the gas cylinder can be checked with plug gauges to discover an excessively worn cylinder. A .528 gauge is "GO". A .532 gauge is "NO-GO".

There are no commercial gauges available to check the outside diameter of the barrel around the gas port. Gas can leak here, so it's necessary to find a cylinder that works by trial and error.
 
purple said:
A .30-06 Garand which is within spec will always cycle reliably with a 150gr bullet using 48gr IMR4895 or 48gr IMR4064.

Doing the tilt test to rule out a binding op rod is a good first move. Next to check is the op rod spring which has a min/max length of 19.75 - 20.25 inches. Avoid the longer Wolff op rod springs or cut them back to proper length.

After that it's the gas system to check for short stroking. First check the gas plug. If there is a crack on the inner face it will leak gas. The valve must be fully seated to prevent gas leakage. Sometimes the valve has to be cleaned of accumulated gunk to make sure it's fully seated. The gas plug must be kept tight when shooting.

Location of the gas cylinder in relation to the gas port is important. It must allow the gas port in the barrel to appear in the corresponding "window" of the gas cylinder. The lock can be adjusted or other locks trial fitted to achieve the proper location for the gas cylinder on the barrel.

The gas port should be clear of carbon build up. For a .30-06 barrel, a #47 drill bit (.0785) can be used as a clean-out tool, and a #46 bit (.0810) can be used as a maximum gauge. A # 45 bit (.0820) can be used as a "no-go" gauge.

The op rod piston diameter can be miked to make sure it is a minimum .525.

The interior diameter at the front of the gas cylinder can be checked with plug gauges to discover an excessively worn cylinder. A .528 gauge is "GO". A .532 gauge is "NO-GO".

There are no commercial gauges available to check the outside diameter of the barrel around the gas port. Gas can leak here, so it's necessary to find a cylinder that works by trial and error.
Click to expand...

I’m not a Garand guy at the moment, but I had to save this post for sound info in the future.
 
purple said:
A .30-06 Garand which is within spec will always cycle reliably with a 150gr bullet using 48gr IMR4895 or 48gr IMR4064.

Doing the tilt test to rule out a binding op rod is a good first move. Next to check is the op rod spring which has a min/max length of 19.75 - 20.25 inches. Avoid the longer Wolff op rod springs or cut them back to proper length.

After that it's the gas system to check for short stroking. First check the gas plug. If there is a crack on the inner face it will leak gas. The valve must be fully seated to prevent gas leakage. Sometimes the valve has to be cleaned of accumulated gunk to make sure it's fully seated. The gas plug must be kept tight when shooting.

Location of the gas cylinder in relation to the gas port is important. It must allow the gas port in the barrel to appear in the corresponding "window" of the gas cylinder. The lock can be adjusted or other locks trial fitted to achieve the proper location for the gas cylinder on the barrel.

The gas port should be clear of carbon build up. For a .30-06 barrel, a #47 drill bit (.0785) can be used as a clean-out tool, and a #46 bit (.0810) can be used as a maximum gauge. A # 45 bit (.0820) can be used as a "no-go" gauge.

The op rod piston diameter can be miked to make sure it is a minimum .525.

The interior diameter at the front of the gas cylinder can be checked with plug gauges to discover an excessively worn cylinder. A .528 gauge is "GO". A .532 gauge is "NO-GO".

There are no commercial gauges available to check the outside diameter of the barrel around the gas port. Gas can leak here, so it's necessary to find a cylinder that works by trial and error.
Click to expand...

Great info. Thanks for posting.
 
Snider shooter said:
Good to hear. I would rather have a lower safe charge than going over max for the rifle. Op rods aren’t cheap anymore. Hornady manual has a separate section dealing with Garands using proper powder and bullets. Sierra has a good section pertaining to gas operated rifles worth the read.
Click to expand...

Yes it is very nice to have a reliable rifle using lower charge weights. Cheaper to load, less(ish) recoil, brass lasts longer, etc.
 
I had a similar problem with my Garand back in 2002 when I rebarrelled it. I must have tried at least 20 different loads that all "short stroked" for lack of a better term. It turned out to be that the "gunsmith" who rebarrelled my rifle, only screwed it on hand tight. I sent the rifle to Dlask , got it done properly and never had the problem again.
 
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