nksmfamjp
Well-Known Member
- Joined
- Jan 5, 2004
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- 3,200
I thought I posted this somewhere else, but I did not.
First:
The formal instructions
bulletin.accurateshooter.com
Found this reference for starting charge weight.
gundigest.com
My cases I'm forming are new Starline 270 Win to 300 Sherman….So, I
Annealed new Starline brass
Expanded to 338 cal
Ran through the FL die with bushing 0.002" under neck diameter. Sized until bolt would close with a moderate force. Too heavy for hunting or Benchrest.
Anneal again
Put clay in primer cavity. Filled with titegroup to just spilling over. Weighed that charge at 57.8gr. 1/10th was ~6 gr.
Prime with large rifle primers
Made ladder from 6 to 15gr in 1gr increments using Titegroup
fill with 2 1/2 min Cream of Wheat to about 1/2 full neck
Cap with 1" square of TP pressed in with a punch
Shot the ladder.
Results:
6-7 gr….CBTD not fully achieved. About 0.001" short; shoulder shape about 90% formed; case length 2.480"
7-10 gr….CBTD at max; shoulder shape not fully formed; Case length about 2.480"
11-15 gr….CBTD at max; shoulder shape 98% or better; case length varies 2.480" down to 2.474" at max
I am making final loads at 11 gr. Otherwise recipe is same.
Necks are 0.050" shorter than spec. I wonder how that will affect accuracy. I prefer the neck length were bullet diameter long. I think they will be short of that.
Resulting case will be about 70-75gr h20, I think. I'll measure today and share result.
First:
The formal instructions
How to Fire-Form Brass without Bullets « Daily Bulletin
Many of our Forum members shoot an improved 6mmBR cartridge. This might be a 30°-shoulder 6mm BRX, or a 40°-shoulder 6mm Dasher, or the 6mm BRDX, which is very similar to the Dasher, but with a slightly longer neck.
Found this reference for starting charge weight.
The Ins and Outs of Fireforming Cases
A catch to choosing a rifle chambered for an Ackley Improved round is obtaining the brass to reload. Luckily, fireforming cases — shooting them in the Improved rifle — is a quick and easy way to procure plenty of brass.
gundigest.com
My cases I'm forming are new Starline 270 Win to 300 Sherman….So, I
Annealed new Starline brass
Expanded to 338 cal
Ran through the FL die with bushing 0.002" under neck diameter. Sized until bolt would close with a moderate force. Too heavy for hunting or Benchrest.
Anneal again
Put clay in primer cavity. Filled with titegroup to just spilling over. Weighed that charge at 57.8gr. 1/10th was ~6 gr.
Prime with large rifle primers
Made ladder from 6 to 15gr in 1gr increments using Titegroup
fill with 2 1/2 min Cream of Wheat to about 1/2 full neck
Cap with 1" square of TP pressed in with a punch
Shot the ladder.
Results:
6-7 gr….CBTD not fully achieved. About 0.001" short; shoulder shape about 90% formed; case length 2.480"
7-10 gr….CBTD at max; shoulder shape not fully formed; Case length about 2.480"
11-15 gr….CBTD at max; shoulder shape 98% or better; case length varies 2.480" down to 2.474" at max
I am making final loads at 11 gr. Otherwise recipe is same.
Necks are 0.050" shorter than spec. I wonder how that will affect accuracy. I prefer the neck length were bullet diameter long. I think they will be short of that.
Resulting case will be about 70-75gr h20, I think. I'll measure today and share result.
