I'm looking at a Mark X in 375 H&H that chambers factory ammo fine (Federal w/ 300 gr. Nosler) but won't close on a GO gauge. I've read some discussion on AR about tight minimum headspace tolerance being a good thing for belted magnums, but have also read that headspace below minimum can put excessive strain on bolt lugs and recesses - which could be a bad thing on the Zastava action. What do you think?

quote:

Originally posted by Ratltrap:
I'm looking at a Mark X in 375 H&H that chambers factory ammo fine (Federal w/ 300 gr. Nosler) but won't close on a GO gauge. I've read some discussion on AR about tight minimum headspace tolerance being a good thing for belted magnums, but have also read that headspace below minimum can put excessive strain on bolt lugs and recesses - which could be a bad thing on the Zastava action. What do you think?

If it closes on factory ammo but not on a "go" gauge you are fine. Because of sloppy tolerances on belted ammunition, I will on occasion set headspace like this. Again, as long as it closes on factory brass you are fine. Zastava actions are plenty tough to handle this.

I wouldn't be afraid of it as long as I chambered as a test, every round I load or buy to hunt with.

I'd also use it as a bargaining chip for a somewhat lower price.

or, frankly, one could have a n-g rather than g gage... look CLOSE

jeffe

Yes, that is a deal breaker.

Hand reaming the chamber a couple thou can't be a deal breaker......Reamers aren't plentiful but aren't that hard to find either!

Seely Masker once told me, "...Richard, you set the headspace when you close the bolt on a loaded round...". Once you have fired cases, you should be able to handle it by setting the dies for those cases. It does make a nice bargaining chip on the dicker though. If I wanted the rifle, I make the deal.

Rich
DRSS

I bought it.

I'm with you on the price negotiation. The guy was really surprised when the bolt didn't close. I'm sure he thought I was trying to pull a fast one on him - until we checked the gauges on his Mark X 7 Mag.

Sounds like the worst case might be renting a reamer. I make it a habit of running my hunting ammo through the action before I take it into the field anyway, but I'll have to pay particular attention to this gun.

Personaly I wouldn't touch that chamber (with a reamer).
BM brass that comes close to max length on the belt is a scarce as hens teeth, with the majority being .003-,005 under max (max belt length is .001 under min recess depth).

This would NOT be a deal breaker for me! When I was at the Colorado School of Trades, our instructor, Dick Kroeckle always told us to chamber belted cartridges using the "GO" gauge as a "NO-GO" gauge. His reasoning was that all of the ammunition makers made the belts too short and chambering the barrel using the "NO-GO" gauge would automatically build in excessive headspace. I have always chambered magnums using this method and have NEVER had anyone come back to me saying they couldn't chamber a round. As far as I'm concerned, you have the best situation with this particular rifle.

I would rather trust a headspace gauge over loaded ammo,factory of not. Why do you think they make gauges for? Try another gauge just to be sure its not a faulty gauge as well. This can happen also,don,t assume anything! They go accordingly. van

I have a 7mag that my smith chambered like that. Domestic brass chambers fine, but Norma brass doesn't. It's about 4 thou longer (at the rim) than domestic brass.

Check it with Norma brass, and if it chambers, I would expect you are good to go. FWIW, Dutch.

Got to the range with the gun after work yesterday and it's a shooter , so I'm going to leave the chamber as is for now. After a fouling shot, it put 4 of those factory Federals into less than 1.5" at 100 yards. I hope to do a bit better with handloads, but if not, that's OK too. I'll keep the domestic brass issue in mind, but with 40 rounds of unfired and another 40 of once fired Winchester brass on the shelf it may be a while before it sees any imported brass.

Now I just need to get out and find that nice lookin' bruin I saw last summer.

As long as you use brass that has be "tested" you will not have a problem. As siggested by some earlier posts most US made BM brass will be "short" speced. I have stopped a chamber as much as .006 and out of a box of 20 rounds 3 or 4 will chamber, and usually all will chamber before the bolt will close on the "go" gauge.

www.duanesguns.com

If the bolt will close on your ammo there is nothing unsafe about it.
Reaming by hand is just fine to bring it into spec. Not a deal breaker to me.