Accuracy Issue with M88 :(

[Crazy.kayaker]

So days before my 2 week hunt my primary rifle develops an accuracy issue. 100 yards 4" + groups with an ammo that usually gives me 5 rounds under a quarter. Rifle is an M88 from 1965 topped with a Bushnell Elite 3200 on Burris low rings. Ammo is the Federal Blue Box 150 Grn. I did change the rifle from medium to low rings and had to tighten the screw that holds the barrel down to the stock as it some how came loose. I'm just wondering could the screw getting loose then being re-tightened have disturbed the way the rifle sits in wood stock and put new pressure points on it so that it no longer can shoot the ammo it use to properly or could it be something else? The scope ring/mount change over is solid as I've already double then TRIPLE checked it. Gonna be taking my 270 on my trip and missing my 308 unless I can fix it before Saturday. Any advice would be appreciated.

CK

 

[buffdog]

Accuracy issue

You checked the scope and rings, but did you check to see if the bases were tight?

Are you using the same ammo as you used before? Not brand of ammo, but the same lot number. In other words, did you buy a new box of ammo to shoot, even though it was the same manufacturer.

When the maker sets up a line for ammo, they run it by lots. When they change a component, say bullets or primers, they then classify it by another lot number. They will test it, usually for pressure, to make sure it is safe, but some do not accuracy test their ammo. Any component change can affect accuracy.

However, in your case, I would suspect the fore end tension created by the screw. Tightening it up will create more pressure of the barrel on the fore end, and this is where I would look first for the problem. Since this screw is located about halfway up the barrel, and screws directly into the barrel, any extra tension on it could cause inaccuracy.

You might also check for a loose recoil block. Remove the butt plate, insert a screw driver, and check to see that the bolt holding the recoil block into the stock is tight.

 

[RR]

Make sure the rear stock bolt for the stock adapter/recoil lug is tight
In fact I would glass it in as well as retighten the bolt. Free float the barrel.Glass bed the chamber area of the barrel and make sure there is clearance on the rest.Before you tighten the action screw make sure the action is tight to the recoil lug.

 

[Crazy.kayaker]

Last time I had bought ammo for the rifle was over 9 months ago so I'd say no to the lot # till just now. I forgot to mention the first round would go right were I wanted it the other rounds would be the ones that scattered around. 1st would be on the vertical about 2" high at 100 yards right where it's suppose to be and the 2nd and on would be high low left and right.

As for the base that was included in the checking to make sure everything is locked down tight.

I know any extra tension will cause inaccuracy which is why I'm here to find out how I can fix it for my trip since I don't have the money to glass the rifle if I want to afford my hunting trip. So glassing the rifle is not an option at this time.

I have an older rubber recoil pad I'll have to remove but I'm on it. (checked it out and it was 99% tight only got a 1/10 of a turn)

I'm willing to try almost anything to save a rifle that's won me over $300 in shooting contests with people that laugh at how ugly the M88 is. Kept me in lots of ammo.

 

[blargon]

I don't have the money to glass the rifle if I want to afford my hunting trip. So glassing the rifle is not an option at this time.

Just use LePage epoxy from canadian tire. $8 should cover it. I would say it was the additional pressure on the barrel from tightening the screw that is the issue.

 

[buffdog]

glass bedding

Just use LePage epoxy from canadian tire. $8 should cover it. I would say it was the additional pressure on the barrel from tightening the screw that is the issue.

Another way is to use Devcon Plastic Steel. It is a two part mixture, like epoxy. Take some Plasticene, make a small roll like a long cigarette, unscrew and take the barrel/action out of the stock, and put one roll of the Plasticene one each side of the front mounting screw hole, about 2 inches each way, or about 4 inches long total.

Remount the barrel/action in the stock and gently tighten down the front action screw until you feel a fair resistance. Then disassemble again, and you should have a hollow about 1/8 in deep or so, and about 4 inches long with Plasticene "dams". Coat your rifle barrel with a release agent (such as Pam) and make sure you coat the threads on the screw. Mix some Devcon, put the screw in the forestock, apply the Devcon, keeping it out of the screw threads, then assemble the rifle, screwing the barrel down until it is snug.

Let it sit for at least 4 hours, then disassemble. Remove the plasticene and trim the pad. You might also drill out the hole for the screw, but keep it close to the size of the screw.

You now have a bedding pad for the barrel. You are going to have to experiment with fore end pressure by tightening or loosening the screw, to give the best results.

A Brownells Accuragel bedding kit costs about $20. Get the AccuraGEL, not the AccuraGLASS, as it is thicker to work with, and does not run as much.

However, as a first option, without any work on the rifle, I would try loosening the fore end screw about 1/4 turn at a time, then firing a group. You might be lucky and find a "sweet spot", and not have to do further work on the rifle.
.

 

[loooongshotz]

So days before my 2 week hunt my primary rifle develops an accuracy issue. 100 yards 4" + groups with an ammo that usually gives me 5 rounds under a quarter. Rifle is an M88 from 1965 topped with a Bushnell Elite 3200 on Burris low rings. Ammo is the Federal Blue Box 150 Grn. I did change the rifle from medium to low rings and had to tighten the screw that holds the barrel down to the stock as it some how came loose. I'm just wondering could the screw getting loose then being re-tightened have disturbed the way the rifle sits in wood stock and put new pressure points on it so that it no longer can shoot the ammo it use to properly or could it be something else? The scope ring/mount change over is solid as I've already double then TRIPLE checked it. Gonna be taking my 270 on my trip and missing my 308 unless I can fix it before Saturday. Any advice would be appreciated.

CK

Owning an M-88 as I do I can testify to the barrel (forend) screw being a source of headaches. You will have to loosen it of and tighten it a bit at a time until it re-groups where it used to.

While I suspected that the 88 could be glass bedded I wasn't sure, and frankly I didn't think of it, is the rifle will out-shoot 90% of the bolt guns I see at the club. However the advice will be taken to heart.
Thanks buffdog.

 

[shortaction]

It is likely the screw in the forearm. Had this same problem with a Model 88 that someone had tried to free float the barrel.

There is a recess in the stock surrounding the sling screw and the barrel screw. I just used liquid fiberglass and put a little in front of the screw and behind it and put some waxed paper over the barrel cut out where the screw goes and set the barrel, receiver down in the stock and used a wood clamp just at the front of the receiver to squeeze the barrel down into the liquid fiberglass and let it set up overnight. Took it off next day and threw the waxed paper away and put the screw in. Shoots like a dream now with everything I feed it.

Good luck.

 

[Crazy.kayaker]

Thanks for the idea's on what to do to get my rifle working properly again. I'm not gonna have time to do the fix before my hunt so I'll be using my 270 for sure. But once I get back I'll be getting my favorite rifle working again. Would be nice to see if after it gets bedded if I can shoot something heavier then 150 grn bullets.

 

[Huntsman]

Forend screw. I had the same problem with mine until used 242 Loctite. I proceeded to Loctite all scope mounts/rings. I was able to get clover leafs with Rem 165CL and 42grs Varget. Now I am shooting 150gr CL and 46.6grs Varget and getting .730" groups (3 rounds). All cases are neck sized Rem. brass & WLR primers.
Best bet is tighten everything and as mentioned, work the forend screw until groups improve. Good Luck