1978 Ruger M77 Changing POI , Tumbling Rounds

Tangers can be made to shoot.

My 1974 300 WM barrel would shoot 1.5-2". Mine did well with 150 TSX/TTSX before I changed the barrel.

Good suggestions so far above. This is how I worked mine out.
Clean it really well.
Float the barrel if needed.
Front action screw at 60 inch pounds, rear action screw at 40 inch pounds, middle screw-just snug enough it won't come out (if not bedded, you may not be able to snug it up this much, but front should be a little tighter than rear if you can't get them like above).
Rifle basix sear-best $40 for a tanger ever spent. Ruger triggers are pretty stiff.

I have since replaced the barrel and stock and shoots like a different rifle. But with the above, the right loads, it shot an inch.
With the new sear, my 308 win shot very well also.
 
I'll try to pick up some different rounds and see how it behaves. I was a little worried about shooting it more, it was behaving so erratically.
I guess the jacket may be seperating from the bullet as it leaves the gun ? I can see how that would throw the rounds everywhere, and why the jacket itself would stick in the paper once it got to the target.
The jacket sticking to the paper suggests to me that the bullet came apart after leaving the muzzle, so while in flight. This isn't uncommon with fast twist bores. But your rifle probably isn't fast twist. You can confirm this with a ball bearing handled cleaning rod and a bore brush. When the bullet comes apart inflight it doesn't always have enough energy to pass through a paper target with cardboard backing. This suggests to me that the barrel could be rough. Or the rifling is very sharp. This is why I suggested a tough bullet. Ballistic Tip aren't extremely expensive and and have extruded jackets. These jacket tend to be thicker and tougher than typical cup and core bullets. You could try some JB bore polishing compound or Flitz on a jag with tight fitting patch. Work it back and forth completely through the barrel but not completely out. I use a bore guide. Do about ten passes and clean out the bore (solvent to get the polish compound out) and try shooting it again.
 
The bad accuracy reminds me of fire forming 32 Winchester Special with 30-30 loads. All over the place, but we did not even check the the targets. I gave up and stocked up on 32 win spl brass with the right head stamping. How do your fired brass cases compare to the unfired rounds?
If the bore is smooth to a dry patch, you really need to check the bore size and the chamber. Sometimes rifles get alterations, that do not get marked on the barrel. Take the stock off and check the bottom of the barrel for markings.
 
Definitely should shoot that ammo without issue. Like all of AZShooter reply. A friend's 7mm Ruger tang was all over the place. He was pulling his hair out when he discovered a burr on the crown. He had a smith recrown the barrel and the issue was resolved. Hope you discover your issue.
 
This suggests to me that the barrel could be rough. Or the rifling is very sharp.

I'm not ruling out some rust mid barrel that isn't easy to see, but if *too sharp* of rifling could be causing this I'd actually suspect that first.

A friend that used to shoot competitions looked at the bore before I shot it and was going on and on about how crisp the rifling was. It looks pretty crisp and distinct to me too, but I'm a pretty casual shooter. I've never actually broken in a brand new barrel so maybe part of the problem could be there ? I assumed this rifle was shot some back in it's day, but that may not be the case.
Still I think there's more going on here than just a barrel that needs to be broken in, but maybe that's a part of it ?
 
I'll try to pick up some different rounds and see how it behaves. I was a little worried about shooting it more, it was behaving so erratically.
I guess the jacket may be seperating from the bullet as it leaves the gun ? I can see how that would throw the rounds everywhere, and why the jacket itself would stick in the paper once it got to the target.
You might try taking a Q-tip and very lightly inserting it into the muzzle crown till the cotton is just inside. When you remove it, there should be NO white fibers sticking to the crown. You can also try lightly running the Q-tip around the muzzle. If there is a burr on the crown, it will catch the fibers. This doesn't definitively eliminate the crown as the source of the problem, but will give you some confidence that the crown is at least smooth and not burred and shredding bullets. However, it still may not be concentric with the axis of the bore and may need to be re-crowned. Re-crowning is not a big job for any competent gunsmith and usually not a great expense.
 
I'm not ruling out some rust mid barrel that isn't easy to see, but if *too sharp* of rifling could be causing this I'd actually suspect that first.

A friend that used to shoot competitions looked at the bore before I shot it and was going on and on about how crisp the rifling was. It looks pretty crisp and distinct to me too, but I'm a pretty casual shooter. I've never actually broken in a brand new barrel so maybe part of the problem could be there ? I assumed this rifle was shot some back in it's day, but that may not be the case.
Still I think there's more going on here than just a barrel that needs to be broken in, but maybe that's a part of it ?
I wouldn't over think it. If your friend shot competition I'd assume he knows what a good bore looks like. The bore could be undersized or over sized. Take a look at the cases and check the primers for signs of pressure. If the primers look fine then I'd just give it a really good cleaning and try some different ammo. You don't even have to lap the barrel like I described with JB polishing compound. Just buy a good new copper bore brush and give it a good cleaning. Don't fret about it too much at this point.
 
I have since replaced the barrel and stock and shoots like a different rifle. But with the above, the right loads, it shot an inch.
With the new sear, my 308 win shot very well also.
Appreciate the advice. It will be a bit before I can mess with the rifle again, but I'm making a list of everything in this post. I'll start with all the easiest ones and work my way up from there.

I considered just keeping the action and building a better rifle off it too. I'm kind of torn there because I love the gun just the way it is. It's pretty sleek, not too big or small, not too heavy and real classic looking. I'd love to make it cooperate and shoot some whitetails. But if I can't make it shoot I think the next step will be a new barrel and stock, and probably a better gun in the end.
 
I "think" that you ought to forget this "piece of junk" rifle and sell it to me; cheap!!! I've got a number of these rifles in the safe, and...............they all shoot well without too much work to get them to shoot. First and foremost I read that you bought new rings for this rifle, did you purchase Ruger rings or something aftermarket like Leupold or another brand. I have a brand new set of Leupold rings in the basement that say they fit the Ruger 77 action but they do not, these rings will not tighten up on the integral bases in the action. Also I am assuming that this rifle is a flat top and not one of the earlier "round" top Ruger 77s. If the rifle is a round top then there a possibility that you have a few more variables then just rings fitting the integral mounts, then you will have scope bases that screw to the top of the receiver that are tapped into the receiver. Also torquing the action screws properly is important. The factory specs are 90-95 inch pounds on the front action screw, 30 inch pounds on the rear action screw, and.....just enough pressure on the center screw (in front of the trigger guard) to hold the magazine box up against the bottom of the action. For me I only tighten the front action screw to 75 inch pounds because I just fear stripping out that from screw, and I have never had any issues. Over tightening the center screw can cause a problem with accuracy, however not to the level that you have written in the original post. Based upon what you have written, I suspect that you have either an ammunition problem or there is a scope issue/mounting issue. I do not know the history of this rifle, so cannot comment on the barrel as it "could" be shot out and ought to be slugged out to figure out bore diameter. What I can comment on is that if the bullets are not piercing paper. I have never seen any 30-06 jacketed or cast bullet that would not punch holes through a piece of paper. I know ammo can be difficult to find right now, but if this were my rifle I would be looking for some different ammo before I did anything else. Also read in one of the replies that Ruger 77s were noted for their bad barrels, I believe that Douglas barrel made there barrels for Ruger as well; I suspect that some would question the quality of Douglas barrels??? If you have an older Ruger 77, I strongly suggest changing the firing pin spring as they "do" get weak over the years, and they "will" give you a PITA/FTF problem. One would never think that both rifles would give the same problem as the same time, but they did. I have been using Wolffe 24 pound replacement springs with very good results. This has nothing to do with your accuracy issue, just trying to prevent a nightmare that I had on a hunting trip one year. What I usually will do with my Ruger 77s is to glass bed them four inches in front of the recoil lug, use two layers of .010 thousandths pipe wrap tape (Brownells) from that four-inch mark in front of the receiver out to the end of the barrel to free float the barrel, and then pillar bed the rear action screw. I don't pillar bed the front action screw because I do not believe there's enough material between that front screw and the action to make a difference. Over the years I have done this to at least five or six 77s and it improved their accuracy to MOA with all the rifles, and....they were in 30-06. I suspect that living in Texas you have a number of resources for a gunsmith. I have a gunsmith in Plains, Montana, Dennis Olson, who likes to work on Ruger 77s if you are looking for someone to work on your rifle for you. Good luck with figuring this out, it really is not a fun date when something like this happens.
 
I "think" that you ought to forget this "piece of junk" rifle and sell it to me; cheap!!! I've got a number of these rifles in the safe, and...............they all shoot well without too much work to get them to shoot. First and foremost I read that you bought new rings for this rifle, did you purchase Ruger rings or something aftermarket like Leupold or another brand. I have a brand new set of Leupold rings in the basement that say they fit the Ruger 77 action but they do not,
I appreciate the Tips. I believe this is a flat top.
I did buy brand new Ruger Rings when I mounted the second scope.
I will add your advice to my list !
 
I appreciate the Tips. I believe this is a flat top.
I did buy brand new Ruger Rings when I mounted the second scope.
I will add your advice to my list !

Great I hope that you figure this out. Please let us know what's going on when you figure it out. There's some really great folks on this forum, everyone is here to help out.
 
Appreciate the advice. It will be a bit before I can mess with the rifle again, but I'm making a list of everything in this post. I'll start with all the easiest ones and work my way up from there.

I considered just keeping the action and building a better rifle off it too. I'm kind of torn there because I love the gun just the way it is. It's pretty sleek, not too big or small, not too heavy and real classic looking. I'd love to make it cooperate and shoot some whitetails. But if I can't make it shoot I think the next step will be a new barrel and stock, and probably a better gun in the end.
Let me know if you want to get rid of the stock! I have a 1976 tang safety in 270. Stinks the issues you are having. Maybe i got lucky, but i bought one with a cracked wrist. Repaired the stock and shoots consistent 0.75 MOA. It shot some ammo ok, but shoots the federal 150 gr round nose really well. You may try some monolithic barnes LRX, ttsx, nosler E-tip or similar. I had some crazy things happen in a 26 nosler with a rough throat. Jacket separation, 12" groups at 100 yds etc. With the 127 LRX 0.5-.75 MOA. If it tumbles with monolithics i would definitely trash the barrel.
 
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