Model 25 won't hold zero

[Salvo]

My model 25T in .223 shoots tight groups, but it will not hold zero from one shooting session to the next. The elevation stays spot on, but windage typically changes from 1-3 inches at 100 yards.

I'll get it sighted in, go home, and the next day it will be shooting off to one side or the other.

I've tried various fixes... At first I suspected the scope, so I put another scope on that had worked well on one of my magnum rifles. No change.

Then I tried different rings, removed the savage bases and re-installed them with thread-locker and a torque driver to 20 inch-pounds.

Then I bought a new Nikon Prostaff P223 4-12x40, Leupold vertically split rings, and a picatinny rail. All torqued down to specs with blue thread-locker.

Then I glass-bedded the action. - Still no change.

Now I'm thinking that the barrel (press fit and with two pins) must be moving somehow. - I can't for the life of me figure out how else it could still be unable to hold zero horizontally.

Short of glass-bedding the barrel, do any other fixes or possible sources of the problem come to mind? The really frustrating thing about it is that the rifle shoots tiny groups, it is quite accurate.

Click image to see it larger
http://i239.photobucket.com/albums/ff206/arwatch/Firearms/Savage%20Model%2025%20-%20223/th_IMG_3764T_zps6cfa161c.jpg (http://s239.photobucket.com/user/arwatch/media/Firearms/Savage%20Model%2025%20-%20223/IMG_3764T_zps6cfa161c.jpg.html)

[JCalhoun]

Provided the movement is not shooter induced I cannot think of anything that you have not already tried. I'd call Savage.

[Salvo]

Yesterday I glass-bedded the barrel just ahead of the action for about four inches, and also up near the fore-end tip. The action is already bedded. - But there has been freezing fog for two days here, so I haven't had a chance to shoot it yet.

In theory, the combination of a bedded action and barrel should put a stop to any movement. I'll have to wait at least a few days though to find out if that fixed it. If it still shifts its zero when I try it out, the next step after this will be to re-crown the barrel.

I'm going to keep at it until it's fixed, I hate to send guns off but in the end, it may come to that. I'm taking my time, making one change at a time so that if and when I hit pay-dirt, I'll know what fixed it. It goes against my grain to pass off problem guns on someone else, so even if I decide to get something different, I'm going to fix it first.

Have my fingers crossed here, I'm going to be truly flabbergasted if it still shifts its zero after bedding the barrel.

Have no problem like this with my other rifles. It could be something about me and the stock, but I don't think so. Have no problem with a model 16 in .243 and a 17HMR with the same type of stock.

[DanSavage]

When your down to this level of accuracy it could be the wind,, it doesn't take much to move a .223 left or right a little. Try using wind flags if you already haven't.

[Salvo]

I go early and catch the morning calm, if it's windy I don't bother. The club is only five or ten minutes from my place.

The first trial with the barrel bedded, I fired four groups of five rounds. It behaved itself, shooting smaller groups than it had before. All groups were shooting into the same spot on the bulls-eye. - The real test will be when I go back again, am waiting for a break in the weather for that. Today it's sleeting and pretty windy, too.

I am very encouraged by the results so far. - Apparently the barrel has enough slop to move around in the receiver if not supported. Bedding the barrel was a lot quicker and easier than removing it, then putting it back on with thread-locking compound.

I should be able to report success or failure in a few days. - I think it's fixed but you never know until you give it a good chance to mess up.

[Salvo]

It was awfully cold and a bit windy today, but I thought I'd give it a chance. There was a 10 mph wind coming in from the right.

The gun shot very slightly to the right, and 1/2" higher than before.

As before, the groups were very good, less than 1/4" more often than not.