Posted by: Cash is King
Fire forming belted magnum brass to load .340 Weatherby or .458WM subsonic loads. - 02/08/17 09:48 AM
Preamble:
With the exception of .378, .416 and .460 Weatherby... all belted magnum brass uses .300 H&H as the original parent case... at least to the best of my knowledge.
My goal is to convert odd lot brass I have to brass I can use.
H&H brass will be fire formed to .340 Weatherby... all others will be used to load 730 gr. .458 pills in a .458WM.
I will not share specific charges (lots in internet opinions out there... simply Google "fire forming with Cream of Wheat"). I will say that I am using a much lighter charge than many... and still tweeking that charge. I am using Clays powder and whatever primers I happen to have the most of. Not that important.
Step 1
Prime brass, charge with a light load of a fast pistol powder, add Cream of Wheat or old used walnut tumbling media (small scoop full), stuff/pack a 1/2 sheet of toilet paper on the top and shoot in a .340 Weatherby, .458 WM.
Neck expanding and removing neck (sawing it off) has been tried. Seems to help mitigate splitting. See 3rd and 4th row in the back of pic).
Cream of Wheat or old used walnut tumbling media (small scoop full) may not be necessary... Testing just primer, powder and toilet paper method as well. 2-9-2017 EDIT... THIS DOES NOT WORK WITH A LIGHT CHARGE!!! Will try again with a heavy charge.
Below are the pills I am loading. About 1.7" long (.45 acp brass for scale). Cartridge overall length will matter, but seating depth is irrelevant (i.e. any brass length from 1.8" to 2.5" will work with these pills in a .458 WM or .458 Lott). Think breech seating (like the big guns by US Navy), although this is actually case seating and not breech seating).
Pills can be bought from Matt's Bullets, for around $0.50 a pill http://www.mattsbullets.com/index.php?main_page=product_info&products_id=319
Step 2:
After picture:
Step 3:
Trim (below splits (if splits are present)) and load. I may also try a mini chop saw like many folks use for a .300 Blackout case fabrication from .223.
I will post pictures of this once I get it completed. As well as a video/audio of 730 gr. pills being launched (with a can).
FYI... I have already fired these pills in a .45-70 with a .458 Lane can. They are VERY VERY VERY quiet. Impact is HUGE. Can of Copenhagen for scale.
Why abandon the .45-70? The powder column is too short (or at least VERY short) after the pill is seated 1.1"... plus I happen to own a 1:10 twist .458WM. 1:10 should stabilize these 2 ounce fishing weights very well.
Conclusion:
IMHO... The name of the game in subsonic is to launch the biggest projectile possible below the supersonic crack. This is the goal of this project. Sub MOA accuracy is secondary.
Edits and more pictures to follow.
With the exception of .378, .416 and .460 Weatherby... all belted magnum brass uses .300 H&H as the original parent case... at least to the best of my knowledge.
My goal is to convert odd lot brass I have to brass I can use.
H&H brass will be fire formed to .340 Weatherby... all others will be used to load 730 gr. .458 pills in a .458WM.
I will not share specific charges (lots in internet opinions out there... simply Google "fire forming with Cream of Wheat"). I will say that I am using a much lighter charge than many... and still tweeking that charge. I am using Clays powder and whatever primers I happen to have the most of. Not that important.
Step 1
Prime brass, charge with a light load of a fast pistol powder, add Cream of Wheat or old used walnut tumbling media (small scoop full), stuff/pack a 1/2 sheet of toilet paper on the top and shoot in a .340 Weatherby, .458 WM.
Neck expanding and removing neck (sawing it off) has been tried. Seems to help mitigate splitting. See 3rd and 4th row in the back of pic).
Cream of Wheat or old used walnut tumbling media (small scoop full) may not be necessary... Testing just primer, powder and toilet paper method as well. 2-9-2017 EDIT... THIS DOES NOT WORK WITH A LIGHT CHARGE!!! Will try again with a heavy charge.
Below are the pills I am loading. About 1.7" long (.45 acp brass for scale). Cartridge overall length will matter, but seating depth is irrelevant (i.e. any brass length from 1.8" to 2.5" will work with these pills in a .458 WM or .458 Lott). Think breech seating (like the big guns by US Navy), although this is actually case seating and not breech seating).
Pills can be bought from Matt's Bullets, for around $0.50 a pill http://www.mattsbullets.com/index.php?main_page=product_info&products_id=319
Step 2:
After picture:
Step 3:
Trim (below splits (if splits are present)) and load. I may also try a mini chop saw like many folks use for a .300 Blackout case fabrication from .223.
I will post pictures of this once I get it completed. As well as a video/audio of 730 gr. pills being launched (with a can).
FYI... I have already fired these pills in a .45-70 with a .458 Lane can. They are VERY VERY VERY quiet. Impact is HUGE. Can of Copenhagen for scale.
Why abandon the .45-70? The powder column is too short (or at least VERY short) after the pill is seated 1.1"... plus I happen to own a 1:10 twist .458WM. 1:10 should stabilize these 2 ounce fishing weights very well.
Conclusion:
IMHO... The name of the game in subsonic is to launch the biggest projectile possible below the supersonic crack. This is the goal of this project. Sub MOA accuracy is secondary.
Edits and more pictures to follow.