Quoted:
I did not say I had a problem. I asked of this is a potential problem.

Gas Cylinder Locks for Garands.
From: R. M. "Gus" Fisher
EMAIL:
Date: 23 Mar 1999
Time: 08:05:18


Comments
Ever wonder why it was common for people to use/demand the late style gas cylinder lock with the "hump" on the top for NM Garands? The answer is: All of them were hardened and they almost never broke. However, that's only part of it. There are two styles of the earlier lock without the hump. The first was soft (and broke a lot) and the second was the first hardened style. OK, how do you tell the difference? The first style has a chamfered (angled) edge around the forward (towards the muzzle) top edge. The second has a square corner in this area AND is marked with an "M". THESE ARE THE GOOD ONES and every bit as good as the later "hump" style lock. I replace the first style lock on ALL Garands that are going to be shot, no matter if they're service grade or NM, to ensure the lock will outlast the barrel. The early style locks belong on correctly dated original rifles or ones people are restoring. (I make no judgement calls on people who want to "restore" a rifle.) BTW a correctly fitted lock will hand screw between 6 and 8 O'Clock against the gas cylinder shoulder on the barrel for service grade rifles. On NM rifles, they should stop at around 4:30 to 5 O'clock and be torqued down. If your lock doesn't match these specifications, I suggest you find a new lock so the gas cylinder doesn't loosen up quickly. This would cause your front sight to be in a different position after each shot and BOY will that mess up your group!

Re: Loose Gas Cylinder-How to peen?
From: Mike Gingher
EMail:
Date: 06 Jul 1999
Time: 14:23:31


Comments
Philip - One other problem a loose gas cylinder can cause is short stroking,or a failure to feed. Not enough gas pressure to drive the po rod all the way to the rear and the bolt does n't pick up the next round. There other problems that can also result from ar be compounded by a loose gas cylinder.

Here is my way of peening, others might do it differently. 1) Break rifli into three main groups and field strip the barrel and receiver group. 2) Remove the gas cylinder and upper hand guard from barrel. 3)With the gas port up look at front end of barrel,there are keyways at 12 o'clock on the opposite side of the barrel from the gas port and also at 5and 7 o'clock. I peen the inside edege of the keyways (splines)at 5 and 7, the sides of the keyways nearest the gas port. I also peen heavyer ( don't know if this a real word, but you get my meaning) to the rear toward the receiver. I then turn the barrel over and peen both sides of the keyway at12 o'clock. 4) Replace the upper hand guard an the barrel then install the gas cylinder. Note- use a brass lead or plastic hammer to drive the gas cylinder on to the keyways. I drive the gascylinder on untill it clears 1/2 to2/3's of the gas cylinder lock threads, I then use a special tool to tighten the gas cylinder to its proper location. Note - Padded jaws on a medieum crecent wrench will work if used carefully. When I near the proper location for the gascylinder I back the lock off 1/4 turn and look into the front end of the cylinder, I want the gas port in the barrel to be as near to the center of the hole in theside of the gas cylinder as I can get it without taking the lock past past 6 o'clock.When I am close I bring the lock to 6 o'clock and stop. This method does not open keyways to the rear of the cylinder and helps keep the cylinder tight. 5) I then clamp the cylinder in padded vice jaws and install the gas plug using a special tool or a square shanked screwdriver specialy ground to fit the end of the gas plug.I use the square shanked screwdriver so that I can tighten the gas plug with a crecent wrench on the shank of the screwdriver. Once installed in this manner the gas cylinder seldom comes loose and does not need to be removed from the barrel. Cleaning can be done using a 50 cal.bore brush and patch holder attached to a cleaning rod section or a pistol rod. Note - I put a slight bend in the rod near end used as a handle for ease of use. Kind of long but hope it helps, if you have any questions email me at [email protected] Good shooting - Mike