I am having trouble with a Ruger M77 Hawkeye in .35 Whelen. This is a brand new rifle - I installed a Timney trigger before firing it the first time. I also replaced the factory stock with a Hogue overmolded aftermarket stock.

I've done the same trigger replacement on other rifles without any trouble.

Everything works fine, except that 2 or 3 out of every 10 cartridges do not fire. The primers are dented, but there is no ignition of the powder.

I initially thought maybe I had a batch of bad primers, but I loaded another batch using different primers and still have the same trouble.

It seems to me that the firing pin must not be consistently striking the primer hard enough. Does that make sense?

Not enough firing pin protrusion
or
excessive headspace (in either rifle or ammo)
or
not enough mainspring tension
or
internal interference & drag on the striker
or
not enough striker fall (sear too far forward)
or
bolt handle not down all the way (stock interference)
or
???
Good luck, Joe

Excellent! I can start with the easiest of the possible issues and work my way up.

I hadn't thought of the fact that maybe the bolt is not closing all the way. Since I restocked it that's certainly a possibility.

Some of the other things it could be are probably less likely because it would have had to come from the factory that way (which is possible, but less likely than something that I caused when I replaced the trigger or restocked it).

Take yer bolt apart and make sure there aint no gunk in that thar chamber and sprang...

The easiest check you can make is to put the factory stock back on and try it. That should isolate it to a stock problem or a trigger/striker problem.

Also, one possible problem to add is a firing pin that is too large at the tip. I would doubt this on a modern factory rifle. My guess is that the striker is dragging spomewhere and slowing down.

I'm having the same problem with one of my Rugers. I hope you let us know how you solve your problem, so hopefully it will help me figure it out.

I've tried a variety of things, and it still does it sometimes. It improved by changing the brand of primers, but it still misfires sometimes. I sent it to a gunsmith, who checked the firing pin extrusion, and headspace.

KB

I'll definitely post an update and let you know how it goes.

I did take the bolt apart and cleaned it even though it was brand new (it had maybe 10 shots through it the first time I started trying to figure out what the problem was, and that was the very first thing I did).

I'll start by putting it back in the factory stock and seeing if I still have the issue.

I suppose it could be headspace, but my fired cases all look perfectly normal. I would think if it was a headspace issue I'd see some evidence on the head and/or primer, or some stretch marks on the body.

quote:

or
bolt handle not down all the way (stock interference)

This is my guess

Took it to the range tonight after restocking. First cartridge - "click."

Brought it home and took the bolt apart. I could tell as I was unscrewing the firing pin assembly from the bolt I could feel it rubbing on the inside of the bolt in certain places. It is clear to me that the firing pin is not perfectly perpendicular to the inside walls of the bolt and is binding in there.

So now the question is what to do about it.

I think a trip back to ruger (bolt) would take care of this. Call them first.



Cal301906

My guess is you have undersized brass.
Try the same everything with once fired brass and I'll bet you don't have a problem.
Don't make a huge rifle problem out of nothin.

Compare the primer indentations and the case lengths between the fired and unfired cases.
Add layers of scotch tape to the case head until you feel the lugs just touch.A difference will be easy to find. In spite of what they say a 35 Whelan has less shoulder and is a tad
touchr. Before someone bombs me I own one.

You might put the original trigger back in and try it...you will have to take the Timney out anyway or Ruger will put a new trigger on it, charge you for it and keep the Timney.

That way you will have a "before and after" comparison and know for certain if it is something wrong with the Ruger or the something with the Timney causing the HooHaw.

By the way...just about EVERY Mauser and clone will rub the spring somewhere as the spring is NOT centered on the firing pin. Check for the hole the firing pin runs through...sometimes there are burrs or rough spots in it. YOu can mike the firing pin and hole or have a gunsmith or machine shop do it...the same with the firing pin bore and a bit of reaming will solve that problem.

I would look at the sear, trigger, bolt and all the little nooks and crannies around those areas...the firing pin spring is usually strong enough to overcome most problems unless it is running in grease or has a LARGE burr someplace...look for bright spots that show points of wear.

A "slow" firing pin hanging up on a tiny burr can drive you up the wall by overlooking it...I've used magnifying lenses many times to find what looked like it wouldn't cause a problem, but DID...

J.D. covered all the "usual suspects".

Luck

There was a problem with new .35 Whelen brass not having the shoulder properly located.
Have you tried checked the shoulder location of your brass or loaded ammo?

You might take some primed 30-06 or .270 brass and see if your rifle will pop those primers.
If it does your .35 Whelen brass may be suspect.

I have a similar problem. It's a Ruger MKII with a Douglas 9.3x62 barrel. I went through the factory ammo, and/or fresh brass thing, then neck sized only to clear up the question of head space. I also had a gunsmith (not the builder) check headspace and firing pin protrusion, and he said it was fine.

He recommended changing primers from CCI to Fed or Rem, which I did, and it eto help. Neck sizing seemed to help too. By help, I mean the frequency of misfires was reduced, but not eliminated.

Obviously this is not a rifle that I can send back to Ruger. The gunsmith who made it has gone out of business or passed away, since I can't contact him anymore.

It has a Timney trigger, and sits in a Hogue stock. I have checked to see if the stock is touching the bottom of the bolt, and it appears to be clear.

Although I have reduced the frequency of misfires, it's still unreliable. When it fires, it's accurate, and handels well. I like the rifle, and sure would like to figure out how to solve this problem.

Seems to me like maybe we can fix two rifles with one solution. I have basically run out of ideas, and put the rifle aside for at least three months now. Perhaps soon I'll get it out to the range again. Until I have a better idea, I'm just going to continue working with the neck sized brass, and load development. While doing that, the frequency of misfires will become apparant, and maybe the remedy will also become apparant too.



Thanks

That is eerily similar. Mine is a Ruger MkII and is (was) in a Hogue stock with a Timney trigger. Even before I put it back in the factory stock it seemed to me that the bolt was closed all the way.

Also, I get a good "snap" when I dry fire it. No discernible issue until you chamber a round. And then maybe 20-30% of the time there is no ignition. Changing primers made no difference.

I truly think it is misalignment of the striker/firing pin assembly inside the bolt. It is dragging on the inside of the bolt and is not in perfect alignment with the hole the pin goes through on the bolt face. 70-80% of the time the misalignment does not slow it down enough to stop it from hitting the primer hard enough to fire, but the other 20-30% of the time it does.

I have replaced the cocking piece on the theory that if the cross pin holding the firing pin in the cocking piece is not exactly 90 degrees to the cocking piece the firing pin assembly will not be perpendicular to the inside of the bolt.

I also ordered a stiffer spring from Brownells and will install that when it arrives. Using the "bigger hammer" theory, maybe application of more force is called for.

It's a shame, because: A.) I love the caliber (and am about to head to Canada for black bear, where I would love to use it); and B.) when it does fire it seems to be a pretty accurate rifle.

Buffnut,


Check the bolt handle clearance by running a piece of paper under it ... should clear easily when it the bolt is closed.

Are you making your brass or is it new 35 Whelen brass?

If you're making it, you might try the following:

Instead of necking it up to 35 go to .366 (9,3) or .375. Then size it by starting long and adjusting the sizing die down until the bolt will just close. This will assure that your rounds are not going too far into the chamber thus giving you too long a headspace.

Had a similar problem with 338-06 and this is how I solved it.

Brand new Remington brass. I haven't tried any of the suggestions regarding the brass yet because I've convinced myself the issue is in the bolt.


However, I'm going to just neck size the fired brass I've accumulated so far and then see if I'm getting 100% ignition on those rounds.

I'm also going to try SR4759's suggestion and stick some primed .270 or .30-06 in there and see if the primers reliably pop.

If you suspect it it the bolt swap in the bolt of another rifle and pop the primers in some primed brass.
If you have headspace gauges for the .30/06 et al check it and shoot it if it gauges ok.