Ruger 77 misfires

[northernbill]

I have an older(tang safety) Ruger M-77 carbine RS(I think) that is chambered in .358 Winchester. I bought this rifle about fifteen years ago, and it has never been totally dependable. Back when it was new to me,on rare occasions I would get a misfire, the primer would be dented, not quite as deep as the successfully fired rounds. Now the problem seems to be getting more pronounced, about one out of five rounds is a misfire. I have had it to three gunsmiths and nobody has any idea what the problem could be. Let me start out by saying it's not ammo related. I have tried two different boxes of older factory ammo and six different handloads all with different primers, so I think this rules out the ammo. I have tried three different firing pin springs, the last one was a heavier spring coulpled with a new lightweight titanium firing pin, so I think this rules out firing pin/ and or spring. The inside of the bolt where the pin/spring go has been THOROUGHLY cleaned, and only very lightly lubed. A headspace problem has occured to me, so I tried some handloads that I only sized the neck on. This should in effect should have been a fireformed case for my rifle and my rifle only, but I still had misfires. The last gunsmith I took it to said it seems to have a light primer strike when he dry fired it, and I have to agree. It doesn't SNAP like my other bolt guns. I hope someone has some fresh ideas. If I can't figure it out, how is Ruger with problems like this. I'm very leary of sending my guns to their manufacturer after being burned bad by Remington.

[gunnut69]

Ruger customer service has been great the few times I had dealings with them. They really want to keep the consumer happy as well they should. It seems as if you're pretty sure it's a light strike and have covered the major bases.. Have you checked firing pin protrusion? I'm certain you have so wonder if there might be something dragging or slowing down the strikers fall?? The culprit may be the trigger sear or perhaps its housing. Also check to be certain the cocling cam is rotated completely out of the way when the bolt is in the locked position. If it is not the striker via the cocking cam on the firing pin assembly will strike the bottom of the cocking cam at the ear of the bolt body and draastically slow the fall of the striker.. I haven't seen it on Rugers but the mainspring can also kink and rub the inside of the bolt body which may inhibit its function.. Surface wear should tell the tale.. I am not especially a fan of titanium firing pins. Is the debt on the misfired primers on center??? These are usually very reliable weapons and cause little trouble. I have one in 7mmRemMag that is wonderfully accurate and has been as reliable as death.

[mcwoodduck]

I had a similar problem with a Remington 700V.
Finally I took the bolt apart and cleaned the inside.
there was all kinds of gunk in the bolt and on the firing pin that kept the firing pin from going fully forward.  Some primers went click some went bang.
I then took apart the bolt from my M77R  with the tang safety I got as a Christmas present in 1982 in 308 and cleanind it too.
have not have any problems since with any of the bolt guns.  Once a year they get a full tear down firing pin clean.
Not too hard to do.

[charles p]

Don't have a Ruger but I soak and stir my 700 bolts in a mixture of very hot water and degreaser.  All the oil and dirt comes out, then I apply Remoil or graphite, depending on the temperature.

I once had a problem with condensation freezing my firing pin shut.  I think the combination of too much oil and vey cold air caused condensation to form inside when the rifle came out of the warm truck, and the condensation probably froze, making the firing pin unreliable.  Since cleaning my bolts regularly, and avoiding almost all lubricants, the problem has disappeared.

[northernbill]

An obstruction inside the bolt, be it dirt,grease,too much oil, whatever, was my first thought. The inside of that bolt is crazy clean.

[mcwoodduck]

An obstruction inside the bolt, be it dirt,grease,too much oil, whatever, was my first thought. The inside of that bolt is crazy clean.

Great minds think alike.
If it is not the crud in side the bolt then give Ruger a call.
I have sent a few guns back to ruger for different things.  Everytime they have fixed what ever the problem was.
First one was my 308 77 with a cracked stock, they replaced the stock and returned it in a week.
2nd was a Single six bisley I wanted a 22 mag cylinder for it, they do not offer that, replaced the main spring and one grip pannel they said has a crack (I cant find it) sent all the parts back.
The third gun is a red label 20 ga that the barrels came detached.  Ruger fixed it and so far shoots great.  Not sure what happened as I lent the gun to a friend for dove and he returned it with the barrels loose.
If the spring on the bolt is weak, or the firing pin is damaged they will replace them. 

[gunnut69]

I'd check for the interference or short striker first. No service department is fast today so it could take awhile..

[Nobade]

First thing I do is check the pin protrusion. It should be around .055". Then strip the bolt and measure end shake on a GO gauge. It should be no more than .003". If these are in spec, put the bolt back together and figure out where the interference is. Does the bolt have some shake with the striker all the way forward? If not, it has a problem. BTW, titanium firing pins are not a very good idea. They cause problems. The factory pins are very reliable and work for many years.

[STUMPJMPR]

You said it is a Re-Chamber.  Did you check the head space?  I have heard of people having problem's with the .35 Whelen in H&R's.  The standard firing pin protrusion on the H&R's proved inconsistent at best.  The 35 caliber guns have a very small shoulder for the cartridge to head space against.  If it is off a little bit it could allow the cartridge to sit too far in the barrel and the firing pin not hit hard enough.  

[gunnut69]

I re-read the original post and it appears this was not a re-chamber.. The Rugers had a problem with a run of 35 Whelans having misfires but I've not heard anything about the 358 Win.. The part about the the dent not being as deep on the misfires piqued my interest. I still am wondering about firing pin protrusion. Another thing would be the endshake measurement. Too much bolt shake would allow the bolts rearward movement to absorb the strikers energy. Of course one would thing the neck sized only brass would have fixed this pronlem.. The only remaining item would be drag somewhere in the strikers movement area..

[Luckyducker]

I think you need to look to see if a scope mount screw it too long (had this problem with son's tikka, as he had the screws in wrong holes) and  is prohibiting the bolt from fulling closing, as this can and will cause mis-fires.  You may even have to remove the scope mounts and fire the rifle to see if it still mis-fires.  That is the only thing that I can think of that you haven't ruled out.  Let me know if this was useful information.  Thanks, Dennis

[Mckie Hollow]

I have a friend that had the same gun, same caliber, same problem. He traded the gun off. Don't know if He ever did get it fixed before the trade.

[flintlock]

Why would you put up with it for 15 years and not simply send it back to Ruger???

I've sent a Blackhawk back to them and they were very good about repairs, even put
a new blue job on it for no charge...

My M-77 did that once, I cleaned it and put a new firing spring in it and it hasn't done it since...

Send it back to Ruger, they know their guns and can better trouble shoot it than you can...

[northernbill]

I spoke to the folks @Ruger and explained the problem. It's on its way there now. I'll update later, thanks for all of the input.