I have a new Winchester Model 70 rifle in 375 H&H.  It has been back to Winchester once for problems with the extractor, and I really do not want to send it in again (they damaged the front sight while it was there).  I think this rifle must have been put together by the FNG, because it had the extractor problem as well as a spare pin rolling around in the action.  I found the spare pin after it jammed up the trigger.

Anyway, I have had a couple of failures to fire.  Both times this happened the firing pin made a shallow strike in the primer.  I rotated the bullet and then it fired.  You could see two primer hits, one shallow and the other typical.  Can anyone suggest what would cause this?

I have put about 60 rounds through the gun so far, 45 of them handloads.  Both of the failures took place with the handloads, using Rem 9.5M primers.  I load the primers with the RCBS hand tool.

I have also experienced some primer cratering with some near max loads.  There are no other pressure signs.  I am not sure if this is related.  Neither of the failures to fire had cratering.

Thanks for any suggestions.

Now you've learned your lesson!! This is why you buy Remmys!!!!  

First, looking at your post, it's very unlikely you have a weak spring or bad firing pin, since you have a NEW rifle.

What this sounds like is, you may have a problem with the reloads.
Since you haven't had a problem with factory ammo, this is a strong indication that it isn't a rifle problem.

Your first step is to buy and shoot some more factory ammo.
If it fires all the factory ammo with no problems, shoot some reloads.

If it shoots the factory ammo fine, but has problems with the reloads, you'll have narrowed the problem to something you're doing wrong during loading.

What you have to do at that point is determine just what you're doing wrong.

If the rifle has problems with factory ammo too, just return the rifle to Winchester for a proper repair.
It will likely be nothing you can fix, and attempting to do so may void the warranty.

As to what might have caused the light hits on the reloads, one possible cause is failure to clean out the primer pocket and/or failing to fully seat the primer.

Another would be failure to properly resize the case.

I guess a key question is, how experienced a reloader are you with with this type of caliber?

Thanks raf.  There was a fair amount of gunk in the bolt.  I'll order some new parts and give that a shot.  I guess I could pull apart another Model 70 and compare it's parts to the bolt and pin on this one.

dfariswheel:  I think there is some possibility that I could have a bad spring or pin, as I have already determined that the rifle was defective in at least two respects.  Perhaps I got a short action spring?  I am actually using handloads rather than reloads, with new Rem brass.  I did not resize; perhaps that is part of the problem?

I do not think it is a failure to properly seat the primers, as the light primer hit is visible.  It definately makes a shallower dent than a regular strike.  Even after the problem shells were fired, the first strike looks shallower (I rotated the shells so that the two strikes are slightly offset).

I will order some factory ammo next time I get something from Cabelas or Midway.  The local shops really want an arm and a leg for this caliber.

IIRC, during both trips to the range, the light primer strike was one of the first few shots I fired.

Thanks for your help guys.

hickboy:  

Quoted: I have put about 60 rounds through the gun so far, 45 of them handloads.  Both of the failures took place with the handloads, using Rem 9.5M primers.  I load the primers with the RCBS hand tool.

I think I know what's wrong with your handloads. You're not seating the primers in the primer pocket. You need to PUSH the primers deeper into the primer pocket. The firing pin has expended all of its energy moving the primer assembly into the primer pocket rather than setting off the priming mixture and going "bang."

I fired 18 shots (all handloads) on Saturday, and had one more weak primer hit.  I have ordered new small parts and factory ammo, and will make sure that I am paying extra attention when seating the primers during the next round of reloading.

The one that failed this time, after the first strike but before I fired it the second time, actually felt a little more deeply seated than the average primer.

Maybe my Winchester rifle is just rebelling because I am using Remington brass and primers?

I had the same problem with a winchester 94 ( new gun also ).

What solved it was i had to use winchester primers.

Go figure

Shitcan the Remington primers, had the same problem with a 454 Casull and cured it with cci primers
after first replacing the mainspring ,cussing,kicking , screaming etc........   You couldnt beat me into using remington primers again.

Thanks for the input guys.  I was looking through my Speer reloading manual and they had a lot of the same suggestions.  The manual indicated that the problem is most likely a failure to seat the primers properly, as dfariswheel and warlord suggested.  Maybe I was just paying too much attention the '24' DVD when I was seating the primers.

I was thinking of loading up a box of these primers in brass for a few different rifles (this 375, a 300 Mag and an '06) and firing them (without bullets or powder) to make sure that the primers are not the problem.  It is a cheap way to eliminate one (unlikely) possibility.  Is there a reason I should not do that?

I went back out yesterday, and fired 18 handloads with no misfires.  I had one cratered primer.  Almost all of the cratered primers have been with Swift A-Frames and warm loads.  I think I will stick with the 260 grain Accubond.