Blown Primers in New Trophy Hunter XP 7mm-08

[mlayne]

I picked up my new Savage 7mm-08 Trophy Hunter XP on Tuesday, spent Wednesday cleaning, torquing the action retaining bolts and scope mount screws, bore sighting the rifle and sending in my $75 rebate paperwork to Savage. Today I went by Cabela’s and picked up two boxes of Nosler 120gr Ballistic Tips and headed to the range to break in the barrel and zero the rifle.

I was cleaning between each round for the first 5 rounds when I noticed that in 4 of the first 5 rounds the primer had blown out. I found them in the magazine. On those rounds there was a slight burr about where the ejector pin would have hit the face of the case. Needless to say that ended my range session. Pity, as it was a Fine Soft Oregon Day with no wind a light drizzle and no one else at the range.

This is my third Trophy Hunter XP, having previously sprung for a 300 Win Mag and a 338 Win Mag. I’ve never had a problem with either of them. I’m suspecting improper head space or possibly bad ammo but I thought I’d ask if any of you have had a similar issue or have any ideas.

Thanks,

mlayne

[bigger]

Sounds like excessive headspace or overpressure, but I think overpressure would be less likely with factory rounds.

Was the bolt hard to open at all?

[mlayne]

Nope. Bolt was not sticking at all.

[mlayne]

I decided to send it back to Savage and let them figure it out. I suspect it will come back better than new.

[Zero333]

Should of bought a different brand of ammo.

My brother had a problem with a 7mm08 Trophy hunter xp where the bullets were tumbling out the muzzle and keyholing all over the place. Ended up being the ammo (Rem. 140gr Accutip). The bullets broke in half as soon as they flew out the muzzle. Rem. Corelokt factory ammo shot good and so did my handloads.

It is extremely unlikely you have excessive Headspace, but anything is possible. Next time tape 2 pieces of masking tape on the head of the cartridge (and cut them to the circumference of the head), then see if the cartridge chambers. If it chambers, try with 3 pieces of tape. if it closes on 3 pieces then it might be headspace or the brass has been sized too much at the factory. Ideally you don't want the cartridge to chamber with 2 pieces of tape on the head. But even if it chambers with 3 pieces of masking tape, it's not too bad and not dangerous. Each piece of masking tape is 0.002" thick.

I've found plenty of full length sizing dies when set up as per the instructions, end up sizing some brands of brass 0.004" to 0.005" smaller than a go-gauge. So this means many handloaders after full length sizing their brass end up with up to 0.008" of working headspace, which is double than it should be. And nothing bad comes of it.

I think it was the ammo (loose primer pockets) along with higher pressure due to little freebore in the chamber. Or just bad ammo, bad batch of brass with loose primer pockets.

[Robinhood]

I've found plenty of full length sizing dies when set up as per the instructions, end up sizing some brands of brass 0.004" to 0.005" smaller than a go-gauge. So this means many handloaders after full length sizing their brass end up with up to 0.008" of working headspace, which is double than it should be. And nothing bad comes of it.I've found plenty of full length sizing dies when set up as per the instructions, end up sizing some brands of brass 0.004" to 0.005" smaller than a go-gauge. So this means many handloaders after full length sizing their brass end up with up to 0.008" of working headspace, which is double than it should be. And nothing bad comes of it.

With the exception of having to retrieve the top half of a case from the chamber.

[Zero333]

With the exception of having to retrieve the top half of a case from the chamber.

After resizing those cases several times like that, yes the case could rupture.

About the OP's fear of excessing working headspace... If his chamber had excessing headspace, the primers would not get blown out. More than likely they would look flattened after being slammed back against the bolt face, if anything.

Chances are very likely it's the brass of the factory ammo he fired that had a problem with loose primer pockets.

[jfksc]

Should have fired at least one other type of ammo before you sent it back. I had the same thing happen with one type of ammo. Never happened before or after that box of ammo.