LORDIE JIM!!!
Let's just stick with this thread for the results on your milsurp brass fire forming!
Instead of 3 different threads.
Make it easier on you.
Thanks for getting all the brass info summarized here.
Let the 500 Bateleur thread incubate until hatch date.

No chance to get to the range today.

OK, I pulled the bullets from the fire forming loads and will decap and anneal the case necks and shoulders, then reload them and fire-form them.

Fire-forming load: 90.0 grains of IMR-4831 that has been sitting for 20 years and needs to be burned, and some Hornady .338/250-grain RNSP bullets seated backwards, nose in case,
and an F215 primer.

Trim the result to 2.647" minimum, and no more than 2.650" allowed as a tolerance,
though usual max brass is 2.657" for the 49-10.
Compare that fire-formed milsurp brass to the civilian stuff that is 131.45 grains H2O gross after fire-forming and trimming as above.
No resizing after fire-forming to be consistent.
That will tell how much difference in milsurp versus civilian case capacity for the 49-10.

10-4 Ron... I'll let the 500 Bateleur thread incubate and 500 AccRel thread live on its own...

Lord Jim,
And then there were six milsurps left, and one civvie, waiting on the shelf to be fired tomorrow:

and

The 6 milsurp and one CIV case looked like this after fire-forming:



There was a case mouth crack/split of a single milsurp case:





I got carried away on trimming so two were too short by a few thou, before I got the trimmer set correctly, and the one defective case was a loss:



Had to reconsider the procedure:
Initial fire-forming may not fully sharpen the shoulder, so I am just comparing the 3 milsurps that made it to full length to the one civilian case that Jim sent.
I had to FL size them to uniform the necks and case mouths. Then trimmed.

Before fire-forming the milsurps averaged 2.726" long and weighed 341.6 grains. After blowing out they were 2.697" long.
The one civilian case was 2.719" long and weighed 330.9 grains. After blowout it was 2.685" long.
Maybe the harder milsurp brass does not quite form as completely as the civilian brass???
Minimal difference if any, on the order of 1 grain of water as you will see below.

They were all decapped and sized to .338 Lapua Magnum, reloaded with new primers, powder, bullet, and fired.
Then FL sized in 49-10 dies and spent primer left in place.
Then trimmed.

3 milsurp, average, length: 2.648", weight 345.0 grains, gross water capacity: 127.4 grains
1 civilian case length: 2.648", weight 333.2 grains, gross water capacity: 128.2 grains

They will all get a little bigger after a full pressure 49-10 load.


There is no significant difference in the milsurp versus the civilian Lapua-made .338 Lapua Magnum cases, except for the brass properties/hardness.

I have fire-formed over 150 civilian (Lapua-made) .338 Lapua Magnum cases to 49-10 and had only 1 similar neck split as the one out of 6 milsurp cases.

I fire-formed one new PRVI-made .338 Lapua Magnum case and it split much worse, despite the obvious factory annealing of the new brass, so I fire-formed no more of those.

10 of the Hornady .338 Lapua Magnum cases fire-formed without defect, and they also showed good annealing of the new brass from the factory.

My annealing of the milsurp cases may not have been as good as the Lapua (or Hornady or JCI) factory annealing on the civilian cases.
Also the milsurp cases were "once-fired," used cases, from high-pressure military spec ammo
that showed cratered, flattened primers and ejector marks on the base of the brass.

FWIW.

Jim,
I'll return the 4 pretty cases that formed to 49-10 with the sample of JCI blank basic cylindrical, and keep the 1 milsurp failure and the others that I have cut in cross section or trimmed too short.
Mail to you tomorrow.

Using the blank basic is looking better all the time.
I am saving that for 500 Bateleur.
I still like the civilian Lapua brass for the 12.7x68/49-10, but blank basic cylindrical would be a snap there too.
Will get more when JCI makes it in 2013.

Hey Ron,

Why not keep one or two of the formed milsurp 49-10s for future reference along with the split case and two sectioned cases.

quote:

3 milsurp, average, length: 2.648", weight 345.0 grains, gross water capacity: 127.4 grains
1 civilian case length: 2.648", weight 333.2 grains, gross water capacity: 128.2 grains

They will all get a little bigger after a full pressure 49-10 load.

This is very good to hear. Looking at the photographs and from your capacity measurements the overall dimensions and wall thickness of the Lapua milsurp brass and Lapua commercial brass must be identical as they drop out of the factory case forming machine. The weight difference must be due to a slightly different composition of the case material.

I lost one Lapua milsurp case due to a split neck when running the cases through my Hornady Custom 338-500 Neck Sizing Die so that’s two cases out of about 80 so at this rate that’d be maybe 5 cases out of the 200 Lapua milsurp cases purchased – I could live with that failure rate if need be. need to pick up one of those electric turn-table annealing machines because I really don’t do a uniform job by hand.

Looking at the Jamison/Captech Intl price list, their 338 Lapua formed brass costs less than Lapua, Hornady, Norma, and Nosler brass so their Lapua cylinder brass is a no-brainer – it’ll be the best brass to use for the 49-10 as well.

quote:

Originally posted by capoward:
... need to pick up one of those electric turn-table annealing machines because I really don’t do a uniform job by hand.

Me too.
The case that cracked got a little more heat than the others as you can see the color change farther down the case,
as well as greater blackening/soot at the neck, and that was before the soot from the powder smoked the crack.
I could have damaged that case myself.
Gotta spin the case in the flames to make it more uniform too.

Hey Ron,

Your package arrived yesterday afternoon and I had a chance to open and peruse the contents. The J/CI cylinder brass is awesome! And thanks for the fire formed brass; I'll compare to some of my hydraulic formed brass tomorrow.

Jim,
Glad you got it.
We are going to have to anneal JCI basic after it is necked down also.
You saw my latest annealing technique on the 400 Whelen thread, thanks for noticing.
I don't think the JCI blank basic has been annealed, but it is great as is for necking down to 12.7x68/49-10.
It should be annealed after necking it down.
Old wildcatter saw:
Anneal after necking down.
Anneal before necking up.