Lower band repeatedly breaking??

[JB0311 Find all posts View Profile Close JB0311]

I have an m1 that the lower band keeps cracking along the pin hole,iv replaced it three times and after abit of shooting it cracks again. Has anyone else had this issue?

[RDS Captain Find all posts View Profile Close RDS]

Never had that problem. Are the lower bands USGI or Asian repros from Wayne Machine? What type of pin are you using? Roll pin or solid pin.

[David Milisock Find all posts View Profile Close David Milisock]

I see what looks like an odd fit, also a solid pin. The fit does not seem square.

[JB0311 Find all posts View Profile Close JB0311]

I’m not sure of the make of the lower bands they came from numerich gun parts,the first two I used a role pin,this last one I tried a solid pin. The fit was very tight and looked good each time until shooting about 50 rounds through it,under recoil it begins to crack and bend. The rifle has a aluminum beded stock perhaps it’s not tight enough in stock so there’s excess pressure where the band contacts the stock?

[jak Staff Sergeant Find all posts View Profile Close jak]

Is there enough play between both hand guards and the lower band ? Also, when you install the pin make sure the hole in the band and the slot in the barrel are perfectly lined up. Being off just a bit can damage the band.

[JB0311 Find all posts View Profile Close JB0311]

SThe front hand guard is loose enough to rattle abit and the rear is tight to the band with about a 1/8 inch gap between rear hand guard and receiver. Also made sure it was lined up perfectly both times I replaced it.

[TJT Gunnery Sergeant Find all posts View Profile Close TJT]

Is the band fitting tightly against the locating shoulder on the barrel? Is the band loose? If loose, peen the barrel lightly with a prick-punch where the band sits. You want a tight fit of the band on the barrel. If it has to be lightly driven into place, so much the better. A loose lower band is also not conducive to good accuracy. You want about .032 (1/32") clearance between the front of the receiver and rear hand guard, and about the same fore-and-aft clearance of the front hand guard to the rear ring of the gas cylinder
Jon

[Smokey Sergeant Find all posts View Profile Close Smokey]

The hole for the pin looks elongated. I'm wondering if the stock fit is wrong, and the band is actually taking the recoil of the barrel and action. Maybe consider building up the recoil shoulders in the buttstock to stop this. You could get some metal shims and put those over the shoulders first to see how much "gap" you have, and if that fixes the problem. Need to make them slightly thicker than the elongation damage to the band.

[TJT Gunnery Sergeant Find all posts View Profile Close TJT]

Good call on that one Smokey. To the OP-- there should be about 1/32" clearance between the front of the stock ferrule and the face of the lower band. When properly set up, the stock ferrule should impart slight DOWNWARD pressure on the lower band but no forward pressure. Show us a pic with the butt stock in place.
Jon

[JB0311 Find all posts View Profile Close JB0311]

Is this the recoil shoulder of the stock if so there is definitely a noticeable gap I don’t recall on garands iv worked on before but it’s been like ten years

[JB0311 Find all posts View Profile Close JB0311]

I believe that is the culprit.it definitely only happens after several shots and there is noticeable hammering on the stock furel as well.so I either need a new lower band and stock or to shim the current stock there.

[Smokey Sergeant Find all posts View Profile Close Smokey]

Took another look at the first pictures, the hole is being elongated in a manner I would expect if the band is being hammered forward towards the muzzle. This would happen if it were being slammed against the front ferrule, with the weight of everything but the buttstock doing the hammering. Do you have another buttstock that might fit properly?

[JB0311 Find all posts View Profile Close JB0311]

I do not but plan to get a set from Dupage trading. It was intended for a match rifle. It’s been rebarreled and aluminum beded before I bought it. It’s just odd that whoever beded it didn’t understand where the recoil is supposed to impart on the stock. Definitely turned me off to beded m1s the accuracy was good for about 50 shots each time I replaced the band but degraded quickly after that.i don’t think it really needs a beded stock

[jak Staff Sergeant Find all posts View Profile Close jak]

The gap between the rear receiver legs and the stock looks excessive. The whole barrel/receiver assembly is getting slammed backward as you fire the rifle breaking the lower band.
As Smokey said, try different stocks and see if the problem goes away.

[JB0311 Find all posts View Profile Close JB0311]

Ok thanks for the help.ill update after I replace stock and band.