R77 acting funny--HELP!

[blackco]

I don't have a lot of specifics but here is what I know; My dad has a Ruger M77 heavy barrel in 22-250 and it has issues. The gun is out-of-the-box factory and I am sure the barrel is free floated. With a variety of hand loads and factories he has shot it gets ok accuracy (3/4 in @ 100yds). Here's the issue; if he shoots a long string, 10 or more shots, the gun seems to settle down and starts shooting into about 3/8in. If he lets it cool off the whole thing starts all over again. It is a consistant gun, it does the same thing and shoots the same with almost all loads he has put through it and it starts to settle down after 8-10 rounds shoot rapidly. He wants it for coyotes in eastern Oregon so he needs the first shot to count, but as he says; the gun likes to shoot hot.

If any of you folks who know LOTS more than me have any ideas I would be thrilled to hear them.

Thank you in advance for your help.

 

[Sendero_Man]

First, stay with best load. If it is shooting 3/4 moa, that is good for a coyote gun.

I would suggest to zero it at 200 yards. That way, he will hit any coyote out to about 350 to 400 if he holds on fur.

I wouldn't worry that it tightens after shooting it 10 shots. If he sights it in, so the cold bore shot counts, that is all you need to worry about if that is what he is after.

And, for PD hunting or similar, he'll know it will keep performing better.

the coyotes won't know that it shots better warmer.. /ubbthreads/images/graemlins/grin.gif

 

[James Jones]

Go back and double check the barrel channel and make sure that their is planty of cleariance , at least 2 buisness cards gap all the way around.
If the barrel is still acting the same with the barrel totaly free floated , the bedding correct , scope mounting all tight and in place then I'd say that the barrel has some stress issues and is probably a good cantidate for a cryo treatment.

 

[MachV]

Cut my teeth on a Ruger 243 that was just as you discribe,it grouped best hot. The first shot from the gun was always out of the group BUT it was always out the same place!! So I just sighted it in with the first shot and lived with it for years.There are a couple of things to try though to make it more consistant.
You/he might want to look into getting it pillar bedded by someone who knows Rugers.Shy of that the action screws can be adjusted to se if that helps.Loosen all the screws a little and rest it on the recoil pad muzzle up.Then tighten the front recoil lug screw as tight as you can get it.Then tighten up the back tang screw fairly snugg.The center screw is tightened only enough to hold it in,if this helps just locktight the center screw loose to keep it from moveing.Another thing to look for is that the back tang is freefloated in the stock....If it is hitting againt the stock on the back side it can cause irratic groups.