It's always been something with the Mauser from Hell.

I've had this sporterized K98 since 2014, and it's always been something going wrong. I finally got all the bugs worked out last year and got it shooting some of the best groups I've ever shot. I gave it to a local gunsmith to do one last bit of tinkering-- specifically to put a different safety on it, because the old one wouldn't fit under the scope.

I finally had it out this weekend to test it out for deer season. Ooops. I had 5 round left of one batch and 40 from another. I used the first 5 to test function. On the first three of those, I could not get a dent on the primer on the first try. On the second try each time, I had normal function. After I switched to the newer batch, everything was fine.

I just need someone to double-check my logic. Batch 1 was full-length resized. Batch 2 was neck sized. My guess is that somehow in all this, that started making a difference. Also, there might be a lubrication issue now. My solution to the latter will be spraying some brake cleaner into the hole for the firing pin and then following that up with a drop or two of very light oil.

Your thoughts are appreciated.

Please don't spray wash the bolt, disassemble it and clean it, avoid oil in my opinion. Reassemble and check firing pin protrusion, .065" to .070" is in the ballpark. Check the gap between the extractor hook and bolt face, should be just a few thousandths more than your rim thickness. If your ammo in batch 1 was sized a little too much' normally the mauser extractor should hold the rim firmly enough for headspacing and firing unless it is too sloppy and the cartridge is being driven forward by the firing pin to the limit of it's travel. The rim/extractor engagement was never intended to provide headspacing. The shoulder was designed to do that. Depending on the type of safety installed, you never specified, a striker safety requires possible alteration of the striker travel which could contribute to your issue and occasionally a trigger safety with an overtravel adjustment will push the sear up to bind the striker travel. Yes, Mausers are 'simple', but are engineered for all the beautifully designed pieces to work in harmony. Aftermarket stuff needs be installed by grumpy old men who fully understand the system. IMO.

Hard to say without looking. As for as inside the bolt far better to learn how to disassemble the bolt. Not hard, German conscripts could do it and they didn't have Youtube. You'll get all kinds of opinions but I like to LIGHTLY use a synthetic grease that doesn't change viscosity with temperature in there. Lightly meaning wipe off the excess leaving a thin film. Actually that firing pin spring is so strong it's not critical.

BTW a broken spring can result in intermittent functioning but I doubt that'a the problem.

Thanks. Y'all are probably right. However, this is the first outing after being at the 'smith. I don't want to go mucking about with his work until he's had a say. Y'all convinced me to send him an email and let him know what's up. He lives just a mile or two from the house. My guess is I'll drop off the rifle and he'll have it back to me one way or the other inside of a week. He and I are just getting to know each other, but he's been a sterling fellow to work with.

Could be that the shroud isn't fully screwed back into the bolt. Quite common to be one rotation short.

IMO we get grumpy from figuring out how to get aftermarket stuff to work on Mausers.

Not a chance the full length size bumped the shoulder too much?

That could very well be. However, the rounds in Batch 1 were not problematic when I used them the last time (prior to the safety install)

Having installed many safeties on Mauser actions to clear scopes, yes they can impede the firing pin. But instructions are pretty clear.

I was thinking the same thing. The shroud lock pin (if that's what it's called) can catch one turn short on some Mausers.

Check your chamber too. Take it back to the Smith and have him gauge it or make a Cerrosafe cast of it. Not a problem if you only load for that one rifle but good to know.