Smokeless for Black

[PJ Hardtack]

The current issue of 'Handloader' magazine has an article by John Barsness on big bore Brit rifles. He discusses his experience with smokeless in the .450/.400 using 5744:

"The boys at Western Powders have a formula for finding a starting load with 5744: 1) fill a case with 5744 to about where the base of a seated bullet would be; 2) weight the powder and 3) use 40% of that powder charge.
The formula resulted in a charge of 23 grs, producing a muzzle velocity of around 1,000 fps. Since 1,400 fps was the goal, I divided 1,400 by 1,000 and multiplied 23 by the result (1.4), a technique that can be used with any single-base smokeless powder. The resulting charge of 32 grs matched the velocity of the black powder load with slightly better accuracy. The only problem was that the 5744 load shot about 10" higher at 100 yds."

If you have any issues with this information, spare me your invective. Contact the magazine. I'm just messenger.

I found the formula I use with 5744 in 45-70 and 50-70 in an article by Ross Seyfried - 40% of the nominal BP charge. That extrapolates to 28 grs. I've upped this to 30 grs and got no benefit accuracy wise, just a tad more recoil. Unlike Barsness's experience, these 50-70 loads shoot into the same group at 50 and 100 yds as my BP loads.

[rickk]

The velocity was obviously measured by matching the bullet speed with a 1963 Yamaha 350 and reading the speed off the speedometer.

[w44wcf]

PJ Hardtack,
Sounds right to me. Thank you for the info.

A bit of history........
The older 40% rule was originally adopted with the advent of DuPont No. 1 bulk smokeless back in the mid 1890's. 28 grs of that powder duplicated the performance of 70 grs of b.p. It also filled the capacity of the case.

IMR4198 is very close in burning rate to DuPont No. 1 Bulk Smokeless and 5744 is close in burning rate to 4198.....just a tick or 2 faster.

w44wcf

[PJ Hardtack]

rickk

"Contact the magazine. I'm just the messenger." I'm sure John Barsness would like to hear from you.

I've got a chrono that has been out of the box twice - once to prove that it works and once to prove that ammo companies and reloading manuals lie.
Game continues to drop and targets get hit where I want. Life is good .....

[Rafe Covington]

Thanks for the information, it will come in handy for me.

Rafe

[rickk]

Not picking on you at all PJ H... just being sarcastic in general. 

Rick