Ruger m77 mkii accuracy problem

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farmer1911

New member
Hello all, I have a stainless lamanite stock ruger that I enjoy to shoot. It is chambered in 270win with the stock pencil thin barrel. It is my first deer hunting gun I bought about 12 yrs ago off the shelf new. Since then the best groups I could manage are at best two to 2.5 inches. Shot everything from 110gr to 140gr in various brands of ammo. I started rolling my own for it and still can barely get any better. I am pushing a 140gr horn btsp at 2700fps out of a win case, imr4831 powder. I settled on this one because the groups were the best, 2". I have the barrel free floated, and the action bedded. The action pops out with a slight nudge, so I suspect that it isn't tweaked or jammed in when it is tighten down. Any insight is appreciated. Thank you in advance..
 
I experienced accuracy issues with a new rifle purchase not long ago.. After trying alot of things with my handloaded ammo it turned out to be the scope. Have you tried a known good or new scope?
 
Have you experiemented with torque on the action screws? Front screw is supposed to be very tight, inside trigger guard (side where the floodplate connects) should be snug and the outside trigger guard screw should be tight but not as tight as the front screw.

Are groups stringing ?
 
I went from a junk Simmons prostaff to a vortex crossfire. The scope hasn't moved any in the rings, and I figure that it is holding because the groups don't move off of zero, as in the groups don't go from one end of the target to the other. I guess I haven't experimented with the screws in the action yet.
 
The MK-II's have a pretty hefty standard contour barrel. They made a few compact's and carbines over the years with thinner barrels.

Ruger's can vary greatly, some shoot very well, others may never do any better than yours. Most Rugers shoot better fully bedded just like they came from the factory. Although I've seen some guys make them work free floated.

And the screws must be tightened just right due to the angled action screws. Leave the 2 that hold down the trigger guard and floor plate loose, then tighten the angled action screw. Get it TIGHT, then tighten the others just tight enough so they won't back out during recoil. If the other screws are tight 1st, then the action can't move into place.
 
Thanks for the replies guys, yes I mostly use this rifle for deer. I can shoot out to 500 yards where I hunt, so I would like to be able to. I've taken it out to 600 yards with paper before, but I wouldn't shoot a deer that far. Seems to be the general consensus that the action screws play a big role. I will check fhem again and see what's going on. I'll report back with what I find out.
 
Screws are tight in the order as stated. Front lug screw is good and tight, other two are snug. This thing is throwing me for loops. I don't want to give up on it; it's my favorite rifle. How much play should be in the bolt? If I have a round chambered, I can just barely push the lug end of the bolt and it moves just slightly..
 
I have the same rifle, and purchased it within a year of yours. They, quite possibly, may have been from the same production run.

Mine has been a great performer.
However... some testing that I did with shims indicated that the barrel needed to be in contact with the ill-fitting stock. It didn't like to be free-floated, at all.

Advice given above, about the action screws, is sound.

One thing that affects performance of my rifle is copper fouling. If significantly fouled, accuracy falls off. But if squeaky clean, accuracy is mediocre.
It needs a little bit of copper fouling to shoot best (8-10 rounds, or so), and then stays there for a few boxes of ammo.

My barrel also hates moly coating or Lubalox (on Win/Nosler 'Combined Technology' bullets). Nothing with moly or Lubalox has ever shot worth a crap from that barrel -- even though the barrel really likes standard (non-CT) Nosler Ballistic Tips and Partitions.



I know you said you want to keep trying. But if you ever get fed up with the rifle, send me a PM. I'd be interested in adding it to my stable, and figuring out how to give it new life.
 
Sorry to burst your bubble, but it won't be for sale. I like it too much.... it is a beautiful gun that j bought myself, my first. I will try the shimming of the barrel for contact, an old timer said to use wax paper, I will try that. I only shoot jacketed bullets anyway, no lubed. Also, these are all 5 shot groups.
 
I agree that the "pencil" barrel may need some contact to settle it's vibration patterns. I wouldn't be too concerned about putting some fore end pressure on the barrel with the laminate stock. The other alternative(or maybe in addition) is one of the "Decellerator" rubber rings on the barrel. This thingie cut my Vanguard 257 Wby groups by almost 50%.
 
First three shots are always around the two inch mark. The other rounds following suit. I could try the rubber deal, I have seen a few of those.
 
How's the trigger on that rifle? Mine was too heavy, and a softer spring fixed that. I had a gunsmith do it, and if I'd known how easy the swap was, I'd have done it myself. Real easy to do, but you need the right new spring.

I had two scopes go bad on that Ruger while working up reloads. New scopes. Never hurts to try another scope when things aren't going right.
 
I have a pre MkII 77 in 6mm that was my Dad's bought new in 1983 or so.:confused: It had always been a problem child with factory and handloads. About 10 years ago I glass bedded the action and the barrel free floated all the way. This totally solved my problem. It will do sub 3/4" 5 shot groups at 100 yds.
 
Trigger is nice to me. Around 3-4lbs I would say and a very crisp release. I can't afford another scope just to try, otherwise I would. I'm going to try the forend trick a little and see where that goes.
 
COL

In reading over the posts in this thread there is no mention of cartridge length, and the distance your bullets are seated from the lands. In some rifles, that can make significant differences in accuracy of hand loads.
 
"I'm going to try the forend trick a little and see where that goes."

That's the least expensive option. Use something that won't absorb moisture and just slightly thicker than the gap about 1-2" back from the fore end tip. You don't want to apply a lot of pressure to begin with.
 
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