I have a 98 that has a 3 position Gentry safety and an after market firing pin spring and a Timney trigger. The rifles safety is nicely fit and functions flawlessly as does the trigger. Since this rifle was completed I've had 2 instances where the rifle failed to fire, both times the firing pin fall felt light and there was a dent on the primer but only half or less as deep as the normal dent. I re-inserted the problem round and both times they fired the second try. This is 2 failures out of maybe 50-60 rounds.
Where could this problem lie?

quote:

Originally posted by Snellstrom:
I have a 98 that has a 3 position Gentry safety and an after market firing pin spring and a Timney trigger. The rifles safety is nicely fit and functions flawlessly as does the trigger. Since this rifle was completed I've had 2 instances where the rifle failed to fire, both times the firing pin fall felt light and there was a dent on the primer but only half or less as deep as the normal dent. I re-inserted the problem round and both times they fired the second try. This is 2 failures out of maybe 50-60 rounds.
Where could this problem lie?

Gunk or metal chip in the bolt, gets between pin & bolt body? I have had this happed on 2 different rifles. 1 old mauser 1 out of the box new Win 70?

In some cases the relieving of the receiver for the new bolt handle is insufficient just barely allowing the firing pin to fall. In a few instances the primer is not hit hard enough.

Check the action to see that the firing pin is falling freely and not partially obstructed by lack of complete closure of the bolt.

This isn't necessarily the cause but a possible cause.

If the overtravel adjustment is set too tight the sear drags on the way down. Overtravel cannot be set to "0" and still have the trigger work properly. Bill

If the safety and set up were functiong "properly," you would not have had 2 misfires. Based on my experience, I would say the trigger has nothing to do with the problem. I am with Vapo and the very first thing I would look at it firing pin protrusion. It needs to be between .055-.065". It could of course be something else, but my experiences have show this to be the cause far and away the nost often.

Is this with a Gentry cocking piece?I have only used Gentry cocking pieces on M700s, and all of them had to be fit, as they came quite long. This is a perfectlty acceptable way for him to produce them, as that way they could befit to just about any bolt out there.

This is one place that routinely trips up "Brownells Parts Changers." There is a world of difference between between someone with an FFL who buys parts from a catalog, screws them together, and proclaims himself a "gunsmith," and someone who intimently knows wgat is going on in a gun and can verbally explain, and draw, all of the components and how they relate to each other. Some jobs are OK for shadetree guys to do, and some are not. Safeties should be left to the professionals.

Knowing some about those Gentry safeties, I would have to say there may be a problem with the shroud relationship to the bolt body. As Vapo said, there may be a problem with the bolt not closing fully. Remember the problem they have with the timing?

quote:

Originally posted by Marc_Stokeld:
If the safety and set up were functiong "properly," you would not have had 2 misfires. Based on my experience, I would say the trigger has nothing to do with the problem. I am with Vapo and the very first thing I would look at it firing pin protrusion. It needs to be between .055-.065". It could of course be something else, but my experiences have show this to be the cause far and away the nost often.

I would look a everything between the trigger and the firing pin. Something is causing the intermitten misfire and it isn't firing pin protrusion. If there were a problem with firing pin protrusion then it would happen with a lot more frequency that twice in 50-60 rounds.

Too tight of overtravel screw settings have caused their share of ignition problems. People set the screw too tight which causes the sear to drag on the way down resulting in a slow or retarded release. The sear has to drop cleanly, without any interference every time.

I would look at the safety and the trigger.

Thank you everyone for the list of things to check.
I am doubtful too that it is firing pin protrusion because the rounds that fire without a hitch are dented very pronounced and the 2 that didn't fire were a substantially lighter strike.
Thanks again everyone for all the suggestions.

you don't know until you check it. I have seen rifles that seemed to hit the primer just fine and then they would start to throw in the occasional and random misfire. The next trigger pull would show what looked like a good primer hit and plenty deep. Until you check the firing pin protrusion you do not know if it is fine or not.

Thanks Mark
I will have that checked as well then.

Here is a rare cause of what you described, but, it happened to me.

The firing pin is just a few hundreds inch too short.

A friend pulled the firing pin from my bolt and we compared it to another Mauser firing pin. There was the problem.

When it was at another shop being blued they must have swapped firing pins with another Mauser. All it needs it to be is a fraction too short.

Garrett