M14 Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
I've been doing some load development for a new to me M1 Garand. It is a beautiful 1945 Springfield Armoury. I'm getting a consistant issue of having two distinct groups within a single 5 shot group. It seems like almost every load I try will have 3 rounds in one "group" with the other 2 rounds in another group usually about 3 inches apart. The separation is mostly verticle although some have a bit of lateral in them as well. Some of the loads look very promising with 3 and sometimes 4 rounds in a group of an inch and even less, then 1 or 2 rounds in another nice tight group but 3 inches higher or lower. Looking for some clues as to what may be causing this. Due to the range being busy and my spotting scope not very good I haven't determined if its the first or last rounds that are spread either. I have checked the receiver/stock fit and it seems nice and tight with no play. As well I don't think it is the shooter as I shoot other rifles with similar sights on the same trip to the range with nice 1 1/2"- 2" groups. I should add shooting is done from a solid bench with a good rest.
 

·
Registered
Joined
·
60 Posts
I get that with changes in my position or loss of focus on the front sight.

It was driving me nutty during initial load development in my match Garand. Basically the rifle was accurate enough to show me problems with my shooting that I never noticed in my other rifles that weren't as accurate.

If you don't have the problem with similar rifles, maybe the rear sight is moving? Also are you single loading each round or loading from a clip? Some Garands throw the first shot in a clip. Some are picky about consistency in loading the round and not touching the op rod after the round is chambered.

If the rifle isn't bedded and match prepped, it might just be that the action is shifting a little and you can't tell. Could also be that the op rod is rubbing somewhere. If your front handguard isn't loose, it could be changing POI as the rifle warms. Also if your rear handguard is contacting the receiver it can affect POI as the rifle warms up.

That sort of a stream of consciousness approach...I'll bet somebody else has a more structured approach to the problem.

Good luck sorting it out.

-J.

PS, try 10 or even 20 shot groups. It may just be that your 5 shot groups are showing a trend that isn't real. If you get two clear groups with 20 rounds, then you have a mechanical problem. If you just get a 3" or 4" group with no subgroups, then that's just your rifle's level of accuracy.
 

·
Registered
Joined
·
4,248 Posts
Need alittle more info
At what distance are you shooting?
Are you shooting off a bench?
How is trigger guard lock up? When you close the gaurd does the gaurd stop hard before it closes or does it go all the way down then snaps shut?
USGI Stock or commercial?
Is the front handguard tight or is there slight back and forth movement?
Grab the rear aperture, can you make it move or is it secure? Even alittle movement can effect accuracy?
Ggrab the gas cylinder, can ypu make it rotate or is it secure? Even a little movement can affect accuracy?
 

·
Registered
Joined
·
6 Posts
Discussion Starter #4
OK, here is what I have so far. Shooting is at 100yds off a sturdy bench at the range I belong to. The stock is USGI marked with a refurb number. The milled trigger guard goes right down and latches without much resistance. I can't detect any movement between stock and receiver though. Front hand guard has some movement fore and aft. Rear handguard is tight to the receiver, I can't slip anything in there. The gas cylinder has some side to side play. The gas cylinder lock up isn't until about 8 o'clock. The rear sight is tight, slight side to side movement if I push on it but minimal. So from this where to start? I can easily remove the rear handguard and sand a little off the back end to give some clearance there, but what do I do about the gas cylinder? Can the Garand gas cylinder be shimmed like an M14? Not sure I'm going to replace the trigger guard at this time.
 

·
Registered
Joined
·
532 Posts
OK, here is what I have so far. Shooting is at 100yds off a sturdy bench at the range I belong to. The stock is USGI marked with a refurb number. The milled trigger guard goes right down and latches without much resistance. I can't detect any movement between stock and receiver though. Front hand guard has some movement fore and aft. Rear handguard is tight to the receiver, I can't slip anything in there. The gas cylinder has some side to side play. The gas cylinder lock up isn't until about 8 o'clock. The rear sight is tight, slight side to side movement if I push on it but minimal. So from this where to start? I can easily remove the rear handguard and sand a little off the back end to give some clearance there, but what do I do about the gas cylinder? Can the Garand gas cylinder be shimmed like an M14? Not sure I'm going to replace the trigger guard at this time.
Lots of problems.

1. Trigger guard should close with a good amount of resistance. That's what gives the rifle it's lock up to the stock. If the wood is compressed in their two options are available. New stock or glass bedding. Nothing else will last for any amount of time.
2. Rear handguard needs to be at least a credit card width from receiver. Yes you need to take it off and file it down.
3. Gas cylinder needs to be taken off rifle and the splines on the barrel need to be peened. This can be done with a ball peen hammer or a socket normal 1/4 inch and hitting on the socket to peen the splines.
4. Garands if you bench rest them make sure you rest them on the stock not near the front handguard. Does all sorts of weird things when you do that. Other than testing loads I do all my shooting in Prone with good tight sling.
5. While you have stock apart good time to do tilt test see if it's rubbing anywhere.
6 If you are using surplus M2 ball expect flyers. This stuff is minute of man at 100 yards. It happens
Good luckGI1
 

·
Registered
Joined
·
4,248 Posts
Forget about the gas cylinder lock, fix the other issues they are hurting the rifles accuracy.
Loose lock up and a loose gas cylinder are the biggest factors
 

·
Registered
Joined
·
6 Posts
Discussion Starter #7
Thanks for the help. I will post results when I can get the tweaks done. I'm going to try and do one fix at a time and see what the improvement is from each one.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #8
Ok finally got a chance to tackle things tonight. I sanded the rear of the handguard to give clearance from the receiver. I used the socket method to tighten the splines for the gas cylinder no wiggle anymore. In finally getting to this though I think I found the major problem. I hope I'm wrong but I think I have a bent op rod. Its been a long time since I've had a Garand and I can't find ny pics that show it. So here's the question should the op rod have an up/down (verticle plane) offset about half way down? I tried the tilt test while I was at it and it binds up about an inch back from lock up. Thanks for the help given to date.
 

·
Registered
Joined
·
4,248 Posts
How hard is op rod binding with tilt test,, can you shake it to close or easily push it forward?
A Op Rod slightly binding isnt going to throw accuracy off that much so I doubt this is affecting .
Are there run marks on rod or stock so you can see where it is rubbing?
 

·
Registered
Joined
·
6 Posts
Discussion Starter #10
OK I feel a little stupid. The more I look at it the bend in the op rod it has to be part of the design. Its just too perfect, not a bow. I played around with the tilt test and found that it worked perfectly when out of the stock. I looked for rub marks on the op rod and stock and with a little sanding here and there I have it pretty good. Binds just slightly before full close and needs just a little help to get out of lock up. I think I'm ready for the range. Hopefully Saturday. I will report back with accuracy now that the gas cylinder is snug and the handguard isn't touching the receiver.
 

·
Registered
Joined
·
3,005 Posts
And the rear of the gas cylinder should not be pressing against the front handguard.
It's ok if the front handguard has a little movement and can touch the gas cylinder, but not for the gas cylinder to have pressure against the handguard.

Jay Kosta
Endwell NY USA
 

·
Registered
Joined
·
1,584 Posts
A quick and easy temporary fix for the loose triggerguard is to cut two shims from a soda (or beer can depending on your preference) that fit under the trigger housing area. You should have a definite resistance during the last 1/2 inch of travel and lockup. Unless you plan on shooting in J.C. Garand matches (illegal modification), this should improve the rifle's intrinsic accuracy as the action WILL move under recoil with a loose lockup even though you don't feel any movement by hand.
BTW, double shims might be needed when you said it seems to have little resistance at lockup. This should help until you glassbed or replace the stock.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #13
After a long delay I finally got out shooting yesterday. Using the same load as before groups were what I would call better. While overall group size wasn't any better due to 1 flyer in every group the remaining 4 rounds (I was shooting 5 round groups) were better. Instead of 2 rounds being nice and close over here and 3 rounds being nice and close over there. Now if I could just get rid of that flyer. Thanks for the help so far.
 

·
Registered
Joined
·
79 Posts
It's not uncommon for the first round out of each clip to be slightly out of the main group. And the tilt test is WAAAAAAAAY over-rated. I have 4 M1's. 2 pass the test and 2 don't. Of the 2 that don't, 1 of them is the most accurate shooter of all, and I'm talking about a 2 MOA rifle.
Jon
 
1 - 14 of 14 Posts
Top