I've been having issues with my custom Ruger 77 MarkII in .35 Whelen misfiring. The builder assured me (and I believe him) that my chamber is at minimum specs so the rifle's headspace shouldn't be an issue. I've researched this on other forums and it seems that Ruger+.35 Whelen+Rem brass often equals misfire. I'm going to start neck sizing only my brass and hopefully that will solved the problem but I also want to replace the firing pin to eliminate that variable.

I was looking on Brownells site and they have Wolff Blitzschnell firing pin spring in 24Lbs and 28Lbs, Ruger factory is 21Lbs. Which one should I go with? Any disadvange with going with the stiffer one? Thanks

A stiffer spring will increase the effort for bolt lift. I had a heavier spring decrease accuracy of a target rifle. We assumed from the harder impact. Might have been something totally different. In a hunting it shouldn't be an issue many use a heavier spring in a Mauser to decrease lock time.

Your smith says it's minimum headace, so necksizing wouldn't help... but I would ask him to use the headspace gages, once more, as uhman error being what it is, it COULD be off.

if you like, go with the 24#, as the 28 is a bear, as paul said, to lift...

try this... load up 10 rounds...
take them to the range and bring a bottle of clear nail polish (this is the easist thing to use for these, though blue painters tape can work)
if you have any misfires, sit them aside for now.

put a PIN POINT on the shoulder, at the junction of the neck and shoulder on the misfired ones.

let it dry 20 mins, and recycle through your gun.

if they all go BANG there's a misfit somewhere between the reamer, the gages, the chamber,the reloading dies, and the brass, as you have a headspace issue.

jeffe

I know there's a headspace issue but I believe that it's with the brass no the rifle. It appears that the Rem .35 Whelen brass are slithly undersize and can slip forward a little more than they should, that's why I'm hoping that neck sizing once fired brass should solve the problem. Thanks for the tip.

Steve,

Headspace can't be just a brass issue, since headspace is the amount of space in the chamber that the cartridge can rattle around in - it's the gap between the breech face and the case head.

True, your issue might not be headspace, but if you can resize your cases too much, for instance, you can indeed have a headspace issue in a chamber that's in spec. One way that might occur is to use different makes of sizing dies and shellholder, then follow the sizing die adjustment instructions. Your gunsmith is testing the chamber only, and generally not looking at the case head to shoulder measurement of your cases.

If you're shooting factory ammo, then your gunsmith is likely right, but handloaded ammo opens other possibilities.

Jaywalker

the problem with your rifle is mainly caused by the combination of a narrow shoulder, shallow shoulderangel and a relativly heavy hammer/fieringpinn.
For a given spring a heavier fieringpin will result in a slower but still as heavy an impact, when the cartridgesshoulder is not consistent enough as on the 35 wheelchair , this will make the case more suitable to absorb the impact, by simply beeing forced a litle into the chamber.

The most effectiv way to solve the problem is to reduce the weight of the hammer/fieringpinn, and keep the original spring. This will result in a higher fieringpinn speed, the same resistance on the boltlift and the same load on the triggermecanisem, but with less tendency for the case to absorb the impact.


In the old days Schultz & Larsen always used a heavier spring on rifles in calibers 30-06 and 9.3x62 than on all other calibers. Today after reducing the hammer/fieringpinn weight by 70% it is possible to have constant ignition with a 30%weaker spring, without any variations regarding calibers.

So the solution with less disatvantages is a lighter fieringpinn

At the advice of my gunsmith, I installed a 24# Wolff spring in my M-98 to decrease lock time. It is most definitely stiffer to cock. It DID decrease lock time. Is it more accurate? Well, not so sure about that...

If you decide to change, I would definitely NOT go past the 24# spring... JMHO, YMMV.

MKane160

Jorgen, your idea of a lighter pin make sense. I can see the "sharper" blow of a lighter pin for a better ignition, like a quick jab instead of a heavy punch. I'll have to look into that.

I bought the Brownells kit for my M77mkII with the 20% reduced trigger spring and 24 lb striker spring. The net result (other than the previously mentioned bolt lift increase) was a very noticable INCREASE in trigger weight. Way too much IMO, so I pulled it. The lighter trigger spring is nice, the heavier striker spring isn't in my one experiment. Maybe a better trigger job could take some of this effort out...all I have done is polish mine thus far.

I was thinking about the Tubb Speedlock system. With a lighter pin and a new same weight spring I would get the "sharper" blow and the new factory weight spring wouldn't increase bolt lift.