Accuracy is Gone?

[squirrel_hunter6]

I have a Marlin Model 60 that is scoped with a 4x Tasco. I used to easily  to shoot groups that were about 1" at 50 yards. Now the gun is shooting groups that look like a horizontal line with a small cluster in the middle! I had never cleaned the gun so I thought that may be the problem. I cleaned it and cannot tell any difference.  

Any Advice would be appreciated. Thanks.

[jh45gun]

Make sure you use a cleaner that takes out lead fouling and check your mounts to the scope to see if they are loose. WIth a 22 having soft lead if the shells are properly lubed or plated a barrel should about last forever. Some folks hardly ever clean the bores if they are shot with good ammo. I did have pistol lead up once on me badly as I had the shells in the truck and the lub melted off the bullets and I did not realize it. I cleaned the gun and took chuncks of lead out of the barrel so in some cases they can lead up.  Also check the crown and see if it got nicked up if it did it will not shoot as well either and you may have to recrown it.

[ron haralson]

Good suggestion about the possible muzzle damage. Possibly you could also have a stock bedding problem, and sometimes as simple as stock screw tension.
                                                        ron

[jh45gun]

Forgot to add something obvious check all the scope screws ect make sure they are all tight. Jim

[Charles/NM]

I place a washer between the front screw lug and the stock to free float the barrel of model 60 Marlins.  You need to be sure the washer doesn't bear on the side plates or it will push them up and bind the bolt.  Found that out the hard way at a silhouette match.  It sounds like your stock may be bearing on the side of the barrel.  That will cause all sorts of weird results.  Free floating the barrel and mag tube will help solve that problem and make your rifle a lot more consistent.

[squirrel_hunter6]

First off, I would like to thanks everybody for their input. I got the gun brand new about 5 years ago and I guess that I have put about 5,000 rounds through it. I used to get good 5 shot groups that were about the size of a quarter at 50 yards with a solid rest. The gun shooting weird is a new occurence.

When I took the gun apart to clean it, I thoroughly cleaned the barrel. So, there shouldn't be any chunks of lead or anything like that in that barrel.

I am guessing that the muzzle crown is the place in the barrel where bullet exists. I looked at the muzzle real close and I could just make out a slight indentation where the rifling ends. I think that I may have done this when I was cleaning the barrel.

The barrel isn't free floated. The stock touches the barrel in various places but it has always been this way and I used to get what I would consider good groups.

I think that the scope may be to blame. The front objective sits on top of the rear sight. The scope continually slides backwards, ever so slightly. Since I sighted it in for hunting season back in September, I would say that it has moved about 0.5 inches. I am using the Tasco rings that came with the scope and I have tightened them up as much as possible. Can somebody recommend a set of rings that won't slide?

Well, maybe it's a combination of things.

[Keith L]

It sounds like the scope combo is the problem to me (sliding is not good).  I use Leupold rings and bases on most of my guns.  I don't know if they make them for a Marlin 60.  And if the scope is a Tasco packed with rings in a plastic blister pack on a hook at Walmart the scope may be suspect also.

I have had lots of trouble with the current run of Chinese Tasco scopes.  I have a couple of the old Japanese Pro class and World Class scopes that are fine.  I don't know what to recommend for a low end scope that will work well with your Model 60, perhaps others can help.  

Life is to short to wrestle with all the problems that come with poorly performing scopes.  Good luck.

[greenjeans]

I use the Leupold weaver base rings from Wal-mart and have neve had a problem. They fit standard Weaver bases. Noticed yesterday that they also have them for grooved mount rimfires. Great rings for the $.

[ironglow]

Pull the scope...try it with irons and see if the problem is still there, although I would strongly suspect that it needs to be recrowned.
 
   When you replace scope, use good rings...I prefer Millet; they grip tightly and you can adjust almost any amount of lateral zeroing with the ring locking screws.
 
   Then a dab of Locktite at all points where the scope or rings can slip helps...

[hillbill]

if you want to stay with your current scope and mount combo you might try shimming inside the rings on the bottom part of the rings with a thin piece of paper or tape. lay the shim material in the bottom ring and trim to fit with a razor blade, reassemble scope and rings and recheck the zero. the shim material should add enough diameter to the scope to tighten everything up and stop the slideing around.just be sure to do both rings the same amount and be carefull not to use anything tooo thick or you may crush the scope if you tighten the rings too much. good luk!