7.62 NATO problems

[mpmarty]

Howdy all:

I've got a problem and think I've found the cause.

Problem:
Once fired boxer primed military brass.
Cast 31141 H/P from new group buy (beautiful mold)
Once assembled the neck diameter is .341" and will absolutely not chamber in my Savage bolt gun.
Same rounds function perfectly in my Russian AK chambered for this cartridge.
boolits are cast of COWW + 2% tin and air cooled.
boolits are sized in a Lyman #45 in .309 GH&I dies lubed with 50/50 alox beeswax
One week after sizing the boolits mike at .312"
Original unfired rounds measure .333" at the neck.

Solution (I hope)

Resize boolits in a LEE push through .308 or .309" sizer which should reduce neck diameter of loaded round to .337 or so.

Thoughts? Comments? Suggestions?

Thanks for your input

Marty

[3006guns]

If I understand correctly, you're saying that your unloaded boolit GROWS .003" one week after sizing? Have you actually measured the boolit immediately after it comes from the sizing die, or just assumed it was correct? Trust me, it wouldn't be the first time a sizing die was marked incorrectly......I have one!

About the only other comment I can make is that the neck might expand somewhat, but usually the problem is keeping the neck from sizing our lead boolits DOWN when seating. I've never heard of one "growing", but maybe I just misunderstood your explanation.

[williamwaco]

I vote for the bullets being improperly sized ( or not sized at all ) before loading.

Check them out.

[MtGun44]

How are you measuring the boolits before loading? I tend to agree that some
sort of mismeasurement is likely.

Bill

[runfiverun]

at .310 boolits that size would make your brass .0155 thick.
at 309 they'd be .316.
if that's the case I myself, or gearknasher would buy that brass from you.
if you are talking about 308 brass.

[mpmarty]

at .310 boolits that size would make your brass .0155 thick.
at 309 they'd be .316.
if that's the case I myself, or gearknasher would buy that brass from you.
if you are talking about 308 brass.
give me an address and I'll give you a couple to measure and see if you want more.

[mpmarty]

OK problem solved if not completely figured out. Used some sizing wax and ran a boolit through a LEE .308 sizer and loaded it. VOILA! It fits and the bolt closes. Now I have to cast up some more (darn) and see what the Lyman #45 .309 sizer produces. I hope it is oversize and I can just order another G & H die and move on. The neck thickness of this military brass runs as high as .0155".

[Larry Gibson]

Resize the bullets you have but in the future let the bullets AC 7-10 days before intial size. lube and GC seating. This will allow for the alloy to "settle out" at size and hardness.

Larry Gibson

[kbstenberg]

MPMarty not to be a wet blanket BUT. Have you slugged your bore to see what dia. it is. I'm just asking if you may have an overly tight throat for the bore.
Kevin