Garand barrel/gas cylinder fitment issue

bbman25 · March 2, 2013, 09:05 PM

ive been working on a rifle to use for re-enacting, and i found a barrel online that is tapped at the muzzle to use a set screw to fire blanks (and still be able to shoot live ammo), rather than using a pops adapter or another uglier looking one. the rifle I used for the build also required a new gas cylinder, it was heavily pitted and the previous owner put alot of rounds through the rifle, and the cylinder is just pretty beat up in general.

so anyway, i got this barrel online, and the gas cylinder as well (new old stock, came from greece)
and I test fitted the cylinder on one of the other garands. it was a snug fit, but a good snug. not a "pound on it with a hammer" snug.
when i went to test fit the cylinder on the tapped barrel, it didnt even make it past the threads. actually, it didnt go over the threads at all. the cylinder lock didnt thread either.
to confirm that it was the barrel with the issue and not the cylinder, I tried locks and cylinders from 2 of my other rifles, all with the same issue.

the barrel is an SA USGI barrel, 1960's dated.

were barrels and gas cylinders/locks ever "fitted" to each other, or are all the parts supposed to just work flawlessly with each other? i am a bit confused here. i can tell the barrel has been used before, there is residue near the gas port, the rifling shows some wear, along with other general wear one would find on a barrel. my dad got the lock to thread but it was rough. he suggested chasing the threads, but that wouldnt solve the issue of the cylinder not fitting. its almost as if the channels in the barrel were not machined deep enough. I feel it is noteworthy to mention, the other barrels i have appear to have tooling marks on the silver area that the cylender fits over, as if it was machined down using a lathe. furthuring my confusion, as the tapped barrel has no such marks.

I was thinking i could find a gunsmith to take a look and try to fix this (does anyone know of any good ones near bethlehem/allentown PA?), Id rather not risk ruining any parts.

lmccrock · March 3, 2013, 06:40 AM

Did you ask on the CMP M1 Forum? More M1 experience there.

Orlando · March 3, 2013, 08:25 PM

I have installed NOS barrels on some of my builds and when installing the gas cylinder they had to be driven on with a block of wood and hammer. They fit very, very tight.
You are just used to worn out barrel splines and gas cylinders sliding on easily

March 2, 2013, 09:05 PM	#1
bbman25 Member Join Date: February 15, 2012 Location: PA Posts: 36	Garand barrel/gas cylinder fitment issue ive been working on a rifle to use for re-enacting, and i found a barrel online that is tapped at the muzzle to use a set screw to fire blanks (and still be able to shoot live ammo), rather than using a pops adapter or another uglier looking one. the rifle I used for the build also required a new gas cylinder, it was heavily pitted and the previous owner put alot of rounds through the rifle, and the cylinder is just pretty beat up in general. so anyway, i got this barrel online, and the gas cylinder as well (new old stock, came from greece) and I test fitted the cylinder on one of the other garands. it was a snug fit, but a good snug. not a "pound on it with a hammer" snug. when i went to test fit the cylinder on the tapped barrel, it didnt even make it past the threads. actually, it didnt go over the threads at all. the cylinder lock didnt thread either. to confirm that it was the barrel with the issue and not the cylinder, I tried locks and cylinders from 2 of my other rifles, all with the same issue. the barrel is an SA USGI barrel, 1960's dated. were barrels and gas cylinders/locks ever "fitted" to each other, or are all the parts supposed to just work flawlessly with each other? i am a bit confused here. i can tell the barrel has been used before, there is residue near the gas port, the rifling shows some wear, along with other general wear one would find on a barrel. my dad got the lock to thread but it was rough. he suggested chasing the threads, but that wouldnt solve the issue of the cylinder not fitting. its almost as if the channels in the barrel were not machined deep enough. I feel it is noteworthy to mention, the other barrels i have appear to have tooling marks on the silver area that the cylender fits over, as if it was machined down using a lathe. furthuring my confusion, as the tapped barrel has no such marks. I was thinking i could find a gunsmith to take a look and try to fix this (does anyone know of any good ones near bethlehem/allentown PA?), Id rather not risk ruining any parts.

March 3, 2013, 06:40 AM	#2
lmccrock Senior Member Join Date: April 23, 2007 Location: Red Rock. TX Posts: 820	Did you ask on the CMP M1 Forum? More M1 experience there.

March 3, 2013, 08:25 PM	#3
Orlando Senior Member Join Date: May 2, 2009 Posts: 352	I have installed NOS barrels on some of my builds and when installing the gas cylinder they had to be driven on with a block of wood and hammer. They fit very, very tight. You are just used to worn out barrel splines and gas cylinders sliding on easily