Schuetzenman
01-08-2002, 11:15 AM
Most Garands come to us functionally ok. All three that I’ve purchased from CMP were fine and I've seen at least a half dozen others that also worked perfectly straight from CMP.
Accuracy is another thing. My CMP rifle produced 4.5" groups out of the box. I purchased Jerry Kuhnhausen's book called "The U.S. .30 Caliber Service Rifles". This is the most complete book on match conditioning and repair that I know of. In fact the completeness of the book may be its weakness. For low-level accuracy improvement that I think that most owners are looking for, one needs to read through a bunch of info to sift out the data. To try and distill it down for you here are the four biggest things that you could do yourself to greatly improve the accuracy of your rifle.
1. Loose Gas Cylinder assembly.
2. Op-rod is rubbing on the barrel, stock or front hand guards.
3. The action is not held tightly enough in the stock.
4. The rear sight aperture needs to be tight in its slot.
There are many more problems that need addressing for ultimate accuracy, but these four will usually bring the rifle to under 2 MOA accuracy. This is sufficient for most applications even including Service Rifle competition. Granted your rifle will be using up all the tolerance on the 10 ring but in theory a possible score could be fired with only a 2 MOA capable Garand.
Number one, the gas cylinder assembly. This commonly is going to be loose. Grab the gas cylinder assembly and try shifting it from side to side. If it rocks back and forth it needs tightening. To do this take a 1/8 to 3/16 inch flat faced punch and lightly peen the sharp edges on each side of the splineway slot at 12:00 on the barrel. Remember the word "LIGHTLY". It doesn't take much to make a big difference in a rather loose gas cylinder’s fit to the barrel. Next you peen one edge of each of the 5:00 and 7:00 o’clock slots. Peen the edge closet to the gas port on each of these splineways. Once again remember the word "lightly". Now try and get the gas assembly back on. You may find that you will need to cushion the front of the assembly with a piece of two-by-four. Take a mallet or hammer and hit the wood to drive the assembly back on to the barrel. Drive it on enough that the cylinder lock threads are well exposed. I then take the Cylinder Lock and use it to crank on the gas assembly. By the way, the Cylinder Lock should time up between 5:00 and 8:00. If it turns on further you might want to find another one. (I went to a gun show and brought the rifle with me to find a replacement, much better than trying to mail order one because its a crap shoot as to how it will fit.) I found two that worked. One came up at about 6:30 and the other stopped just short of 5:00. To use this one I will probably have to ream the seating surface, but that's a more in depth story. Back to the "no custom tools accuracy improvements".
The Cylinder Lock should snug up against the 45° shoulder of the barrel. Also there are three types of cylinder locks early WWII, what came on my rifle is beveled at the 12:00 top front edge towards the muzzle. These locks are soft steel and will get loose from shooting. Next is the "intermediate style", it is almost the same as the early type but does not have the top edge beveled. This edge is squared off and looks like a big figure eight. The last style is the hump toped or large toped Cylinder Lock. The intermediate and the hump top models are hardened metal and both should hold up under extensive shooting. Ideal hand tight would be for the lock to turn on to 5:30 and then a Cylinder Lock wrench would be used to bring to 6:00 alignment. All of this is designed to keep the Gas Cylinder assembly snugged up and not flopping around on the barrel. It's nice if your front sight isn't swinging through 10° of arc each shot. Ok that takes care of that topic.
Number 2, the Oprod is rubbing on the stock or Hand guards. The fix is to make things so they don't. Look for worn areas in the Parkerizing of the front hand guard ferrule, the front hand guard spacer, the lower band and the stock ferrule that has the front sling swivel attached to it. Look for rubbing on the Oprod as well. Burnished spots indicate contact. Any contact with the Oprod can cause poor accuracy. If the lower band is loose, prick punch marks on the band section of the barrel can tighten the fit of this up so that it won't rock. Don't get carried away with the punch marks. Do one set all around the barrel and then try the lower band for fit. (Assuming that it was loose, not all are.) The Hand guard spacer is the metal strip inside the front Hand guard. Look to see if the Oprod is rubbing on it. Mine didn't. Kuhnhausen shows how to make a forging fixture to put a "V" shape into it to create clearance between the hg. spacer and the Oprod. If you aren't hung up on looks a round nosed punch applied to the points of rubbing contact can bend away the metal to create clearance. If the rod is rubbing the front Hand guard ferrules filing some clearance on the inside edge can get you past this. Of course you take off the Parkerizing finish. But if it was rubbing hard, it's probably already gone. Try a stovetop reparker job on some of the small parts if you want to take care of the removed finish problem. For the stock ferrule filing is also the quick fix method. The long way is to remove it and cut away the wood to slide it over in the groove then epoxy bed it back. You may also find that the rod is rubbing in the stock channel. Wood removal is the fix. Add finish back to seal the wood as needed. Remember you are trying to prevent anything from bumping the Oprod while it cycles.
Last item, the receiver is not tightly pulled down into the stock. Two major causes in a service grade rifle are, the stock shrunk or it’s not the original stock and or the lugs on the trigger guard are worn. To have a service grade rifle that you can compete in the John Garand matches you can't epoxy bed your action or unitize your front hand guard. That and the reason that I'm trying to keep it simple is why I haven't gone there in these discussions.
The lugs on the trigger guard can be a major player in loose receiver / stock fit. Look at the little round pegs that are just below the pivot point of the trigger guard in the trigger assembly. These are supposed to be full round, no oval shape or flat on top. My service grade CMP rifle does have worn lugs. I found out just how worn when I put another trigger group in that had perfect lugs on the trigger guard. I almost couldn't latch down the trigger guard! Makes a noticeable difference in the accuracy of the rifle. Replace the trigger guard only or peen the lugs to flare them out again to tighten up the fit.
Last thing is the rear sight aperture. Grab it with your fingers and try and wiggle it up and down and side to side. Did it move noticeably? If not you’re good to go, if it did you need to find a replacement that is tighter or peen the aperture. This is not an easy thing because it is hardened. Much easier to just try different apertures until you find a snug one. If it’s too tight, good! You can stone it down to get it to fit.
If you do all that you will probably be at or less than 2" groups with the rifle. If you see the groups wandering as you shoot long strings, (guns heating up) you might want to spend the $70 bucks to send the barreled receiver and the Oprod and gas assembly into Cryo-Accurizing in Ogden, Utah. I frequently mention these people, (no I don't get a commission), because the process really works! Especially, the new Tri-lax process. It really does take about 50% off of an average rifles groups. If you have a bench rifle that shoots one hole groups anyway, forget it, how do you take 50% off of perfection? But for those of us that shoot service rifles it always works that I've seen. I have done 7 or 8 rifles and all have improved to the degree advertised. Their full address is:
Cryo-Accurizing
2250 North 1500 West
Ogden, Utah 84404
Email: rwbrunson@earthlink.net
Phone: 801-395-Cryo, Fax: 801-399-4000
The first one I tried and this was before Tri-lax was a Remington 700 BDL in .30-06. It was always good for two shots in about 1.5" at 200. Then the third shot would be off by about 4 inches and the fifth shot could be any where on the target by about a foot off from the first two shots. Very predictable. Once the rifle cooled off, it was back to the first two shots point of impact. Cryo treatment fixed this. Now it shoots about a 1.5" group at 200 yds. up to 10 shots in a string if you do your part. Well I think that's enough reading for this one post. I’ll supply photos at a later date of some of these features and techniques.
Accuracy is another thing. My CMP rifle produced 4.5" groups out of the box. I purchased Jerry Kuhnhausen's book called "The U.S. .30 Caliber Service Rifles". This is the most complete book on match conditioning and repair that I know of. In fact the completeness of the book may be its weakness. For low-level accuracy improvement that I think that most owners are looking for, one needs to read through a bunch of info to sift out the data. To try and distill it down for you here are the four biggest things that you could do yourself to greatly improve the accuracy of your rifle.
1. Loose Gas Cylinder assembly.
2. Op-rod is rubbing on the barrel, stock or front hand guards.
3. The action is not held tightly enough in the stock.
4. The rear sight aperture needs to be tight in its slot.
There are many more problems that need addressing for ultimate accuracy, but these four will usually bring the rifle to under 2 MOA accuracy. This is sufficient for most applications even including Service Rifle competition. Granted your rifle will be using up all the tolerance on the 10 ring but in theory a possible score could be fired with only a 2 MOA capable Garand.
Number one, the gas cylinder assembly. This commonly is going to be loose. Grab the gas cylinder assembly and try shifting it from side to side. If it rocks back and forth it needs tightening. To do this take a 1/8 to 3/16 inch flat faced punch and lightly peen the sharp edges on each side of the splineway slot at 12:00 on the barrel. Remember the word "LIGHTLY". It doesn't take much to make a big difference in a rather loose gas cylinder’s fit to the barrel. Next you peen one edge of each of the 5:00 and 7:00 o’clock slots. Peen the edge closet to the gas port on each of these splineways. Once again remember the word "lightly". Now try and get the gas assembly back on. You may find that you will need to cushion the front of the assembly with a piece of two-by-four. Take a mallet or hammer and hit the wood to drive the assembly back on to the barrel. Drive it on enough that the cylinder lock threads are well exposed. I then take the Cylinder Lock and use it to crank on the gas assembly. By the way, the Cylinder Lock should time up between 5:00 and 8:00. If it turns on further you might want to find another one. (I went to a gun show and brought the rifle with me to find a replacement, much better than trying to mail order one because its a crap shoot as to how it will fit.) I found two that worked. One came up at about 6:30 and the other stopped just short of 5:00. To use this one I will probably have to ream the seating surface, but that's a more in depth story. Back to the "no custom tools accuracy improvements".
The Cylinder Lock should snug up against the 45° shoulder of the barrel. Also there are three types of cylinder locks early WWII, what came on my rifle is beveled at the 12:00 top front edge towards the muzzle. These locks are soft steel and will get loose from shooting. Next is the "intermediate style", it is almost the same as the early type but does not have the top edge beveled. This edge is squared off and looks like a big figure eight. The last style is the hump toped or large toped Cylinder Lock. The intermediate and the hump top models are hardened metal and both should hold up under extensive shooting. Ideal hand tight would be for the lock to turn on to 5:30 and then a Cylinder Lock wrench would be used to bring to 6:00 alignment. All of this is designed to keep the Gas Cylinder assembly snugged up and not flopping around on the barrel. It's nice if your front sight isn't swinging through 10° of arc each shot. Ok that takes care of that topic.
Number 2, the Oprod is rubbing on the stock or Hand guards. The fix is to make things so they don't. Look for worn areas in the Parkerizing of the front hand guard ferrule, the front hand guard spacer, the lower band and the stock ferrule that has the front sling swivel attached to it. Look for rubbing on the Oprod as well. Burnished spots indicate contact. Any contact with the Oprod can cause poor accuracy. If the lower band is loose, prick punch marks on the band section of the barrel can tighten the fit of this up so that it won't rock. Don't get carried away with the punch marks. Do one set all around the barrel and then try the lower band for fit. (Assuming that it was loose, not all are.) The Hand guard spacer is the metal strip inside the front Hand guard. Look to see if the Oprod is rubbing on it. Mine didn't. Kuhnhausen shows how to make a forging fixture to put a "V" shape into it to create clearance between the hg. spacer and the Oprod. If you aren't hung up on looks a round nosed punch applied to the points of rubbing contact can bend away the metal to create clearance. If the rod is rubbing the front Hand guard ferrules filing some clearance on the inside edge can get you past this. Of course you take off the Parkerizing finish. But if it was rubbing hard, it's probably already gone. Try a stovetop reparker job on some of the small parts if you want to take care of the removed finish problem. For the stock ferrule filing is also the quick fix method. The long way is to remove it and cut away the wood to slide it over in the groove then epoxy bed it back. You may also find that the rod is rubbing in the stock channel. Wood removal is the fix. Add finish back to seal the wood as needed. Remember you are trying to prevent anything from bumping the Oprod while it cycles.
Last item, the receiver is not tightly pulled down into the stock. Two major causes in a service grade rifle are, the stock shrunk or it’s not the original stock and or the lugs on the trigger guard are worn. To have a service grade rifle that you can compete in the John Garand matches you can't epoxy bed your action or unitize your front hand guard. That and the reason that I'm trying to keep it simple is why I haven't gone there in these discussions.
The lugs on the trigger guard can be a major player in loose receiver / stock fit. Look at the little round pegs that are just below the pivot point of the trigger guard in the trigger assembly. These are supposed to be full round, no oval shape or flat on top. My service grade CMP rifle does have worn lugs. I found out just how worn when I put another trigger group in that had perfect lugs on the trigger guard. I almost couldn't latch down the trigger guard! Makes a noticeable difference in the accuracy of the rifle. Replace the trigger guard only or peen the lugs to flare them out again to tighten up the fit.
Last thing is the rear sight aperture. Grab it with your fingers and try and wiggle it up and down and side to side. Did it move noticeably? If not you’re good to go, if it did you need to find a replacement that is tighter or peen the aperture. This is not an easy thing because it is hardened. Much easier to just try different apertures until you find a snug one. If it’s too tight, good! You can stone it down to get it to fit.
If you do all that you will probably be at or less than 2" groups with the rifle. If you see the groups wandering as you shoot long strings, (guns heating up) you might want to spend the $70 bucks to send the barreled receiver and the Oprod and gas assembly into Cryo-Accurizing in Ogden, Utah. I frequently mention these people, (no I don't get a commission), because the process really works! Especially, the new Tri-lax process. It really does take about 50% off of an average rifles groups. If you have a bench rifle that shoots one hole groups anyway, forget it, how do you take 50% off of perfection? But for those of us that shoot service rifles it always works that I've seen. I have done 7 or 8 rifles and all have improved to the degree advertised. Their full address is:
Cryo-Accurizing
2250 North 1500 West
Ogden, Utah 84404
Email: rwbrunson@earthlink.net
Phone: 801-395-Cryo, Fax: 801-399-4000
The first one I tried and this was before Tri-lax was a Remington 700 BDL in .30-06. It was always good for two shots in about 1.5" at 200. Then the third shot would be off by about 4 inches and the fifth shot could be any where on the target by about a foot off from the first two shots. Very predictable. Once the rifle cooled off, it was back to the first two shots point of impact. Cryo treatment fixed this. Now it shoots about a 1.5" group at 200 yds. up to 10 shots in a string if you do your part. Well I think that's enough reading for this one post. I’ll supply photos at a later date of some of these features and techniques.