I have owned this rifle for the last 30 years and it has started misfiring about 10% of the time with different primers. The firing pin indention looks ok to me. I pulled the firing pin assembly and it looks good with no rust or grit. I oiled it and reassembled but this changed nothing. Any ideas? Should I replace the firing pin spring and would this increase the trigger pull?

on a ruger, you can change the spring, and while it COULD make opening/cocking harder, it should have little effect on the trigger pull.

have you changed anything, especially on the ammo - do you notice this with a certain brand or box or lot of shells, or, if you roll your own, have you changed anything in your process or setup?

After removing, and inspecting under magnification, the firing pen, cleaning out the bolt body, cleaning "everything" -- well, i'd likely throw the bolt body and springs, and everything else into an ultrasonic cleaner, just water and a couple drops of dawn soap - put back together --

i'd be worried, likely in the order
debris in the bolt
broken firing pin tip
something changed in the ammo -- i would suspect either overly resized ammo, or the primer is seated too deep
THEN i would replace with an OEM spring, preferably from ruger, but i'd settle for Wolfe

Do what Jeff said, but to answer your question about trigger pull; no.
I have had many Ruger 77s, including one dog leg 308. Never had a problem.
It is one of those issues above. Easy to troubleshoot.

I have seen bad springs in numerous Ruger 77's. Frequently, three or four coils at either end of the spring would be collapsed. A new spring always fixed the problem. Regards, Bill

As I've related hereabouts recently, my buddy bought a used Ruger 9.3x62 and I volunteered to sight it in for him to avoid his getting a flinch. However, it misfired on my first three attempts.

Though oil got it going, I looked at the spring and decided it was on the skimpy side compared with our 98 Mausers. I understand someone in the US makes a heavier spring that would fit but think getting stuff like that out of the country may have been a bit tricky back then.

Thanks a lot for your comments. I only shoot reloads but I have changed nothing in my reloading methods or supplies. At this same time I have used these primers in other rifles without issue. I was just wondering what the best guess on a course of action from here. I use this rifle for hunting so a 10% chance of a misfire is a pretty big concern. So you would think the firing pin spring would be the highest percentage course of action. It all looks good but removing the spring and firing pin feels over my pay grade. Thanks

I hear ya.. after doing it a couple million times, it's pretty easy and muscle memory. The first couple times can be exciting.

B1878
Were you shooting rounds in new, previously unfired brass ?

Id go to basics...try it with factory ammo before anyting else.

Agreed. The spring could have lost power over 30 years. Also check to see if the bolt handle is contacting the stock anywhere.

quote:

Originally posted by Duane Wiebe (CG&R):
Id go to basics...try it with factory ammo before anyting else.