COW for dasher

[potatoe]

Does anyone use the COW method for dasher forming? I've only used regular FF for my brass but I'm getting kinda cheap lately. I'm thinking about using some pistol powder I got laying around to do this

 

[rifle50]

I use it with my brass......Have done 300 cases, and only had a small shoulder split in 1 case...That was the first hundred...I annealed the next 200 and never lost a case, and they BLOW to the TRIM length...I use a .257" mandrel to upsize the neck...neck with 6mm down to form the "False shoulder". Annealed after this step....Use 15 grains of bullseye, fill to bottom of neck with cream of wheat, NOT INSTANT and with small screwdriver stuff neck with some toilet paper.........I swab chamber every 5 rds or so with a bore mop and carb cleaner to keep chamber clean, then a blast of AIR after every shot as you can get some COW in chamber and next round will make small dent in case. Don't ask how i know?........I have a NEW HORNADY Dasher HYDRO FORMING DIE i have never used, NIB ...............Hope this helps........Carl

 

[letronshootit]

I am using COW method as well now and not fireforming with bullets. The first 100 6brx cases I did with the bullet jam method worked but the case casualty rate was not to my liking. Next 100 cases was COW method and I had zero case loss. Cost of brass, components, and barrel wear is the reason for using COW. I used Promo shotgun powder 10gr fill the case with COW and then 1/4 sheet tissue paper. I did the .257 neck expansion and 6br neck size down the neck until bolt will just close. Your powder load will have to be tailored to the Dasher of course, make sure it is such that deposits of cow are not collecting on the inside of the shoulder as one shooter described to me. It does take a good cleaning to get the COW out at the end of the session, I blew it out with compressed air every 5 shots and wet patched every 15. I am glad that 6brx and kin with Lapua cases are a long lived case, fireforming is a necessity for these wildcats and satisfying when done with no case loss.

 

[potatoe]

Thanks fellas. I just tried it and it worked. Also got a 1.550+ case which I never got with the bullet FF. Thanks!

 

[Phil]

What powder and how much was necessary????

 

[potatoe]

I used 8gr. W231.

The shoulder is not 100% sharp but very close and the shoulder measures with in .002 of my other FF case with the bump gauge. I hope all of them turn out this nice

 

[rifle50]

After 1-2 full load firings your shoulder will be sharp and filled out. After the COW treatment i load and shoot in a match....Glad it is working out for you........Is a pain but way to go and save bullets and barrel........Carl

 

[painless2]

I use the same method of the false shoulder but omit the COW!!!
Use 15 gr 231, pistol primer, paper towel plug, hold straight up and fire.
Never lost a case.
Tom