9.3x62mm Fire Forming ?

[youngda9]

I got 100pcs of new brass for Christmas. I've prepped it for loading and want to use something on the cheap to form 50pcs for one rifle, and 50 for another. I was thinking 10gr-12gr of Unique and a 286gr cast boolit would be a good way to fire-form on the cheap.

I've read a lot about 10-13gr of Unique for 30-06 and smaller calibers. The 9.3 throws a much heavier boolit so I wanted to ask for some advice before proceeding. I don't have any lighter boolits to shoot in these rifles, that is what the 358's are for Any thoughts?

I'm tempted to just put normal loads in the brass, but then I don't really know if the data taken is valid if the results are underwhelming. I always segregate brass for different rifles and neck-size only for longer brass life and better accuracy.

I have Unique, H4895, RL-17, RL-15, H335, H322, H4320, 300-MP, and Accurate 2015 (too fast).

[Harry O]

I have fire formed a bunch (two or three hundred) of 9.5x57 Mannlicher-Schoenauer cartridges. I did it by full-length forming brass and cutting off the excess length. After priming the case, I put in a scoop of about 13gr of Red Dot or Bullseye. On top of that, I filled the rest of the case with filler (cream of wheat early on and plastic shotgun buffer later on). Then I pressed a block of paraffin wax onto the mouth of the case to seal it off. The paraffin wax must be warm to seal it without fracturing.

Then fire them. Works perfectly without wasting a bullet.

[haynk]

Not clear what kind of new brass you got for Christmas. If it is factory 9.3 x 62 I see no reason for not using regular loads, starting at the minimum of course. If it is 30-06 brass, Nonte's "Guide to Cartridge Conversions" directions say: "Trim to 2.48, expand neck to hold .366 bullets, fire form."

He also says 35 Whelen loading data may be used as a guide.

"Cartridges of the World" does not show any loads for the powders you have. It shows a 286 grain SP with 57 grains of 414 for 2500fps.

haynk

[youngda9]

It is PRVI 9.3x62mm brass. Thanks for the responses. I don't want to mess with cream-of-wheat. I have a bunch of cheap cast boolits that I'd like to use for this task.

[wmitty]

So you are expanding the new brass to fit the chambers and then neck sizing? I'd go with the Unique and start with 6 grains and increase in .5 grain increments until it was obvious the shoulders had conformed to the individual chambers. This should occur before you start having problems with leading if the 286 grain boolets are gas checked and well lubed.

[runfiverun]

initial fore forming is best done with pressure.
a full 50-55 k load is gonna press the brass out to conform to the chambers dimensions.
red-dot will give you 45-k easy enough, as would unique.
but to really get the square shoulders and such you need the higher pressure.

[youngda9]

Good point run. I'll just do a normal load using the H4895, 40+ grains with the 286gr cast boolit. Thanks for the responses.