41 Keith testing.......

by Gunner , St Louis, Sunday, July 02, 2023, 16:49 (509 days ago)

I started the 41 Magnum/230 gr Keith plain base bullet/1,000 fps experiment this morning with the first test loads.

First……building the loads, as most Keith users will have found out, the Keith has a big shoulder, and some chambers don’t like it when loaded to full length OAL for a cartridge. My experience is no different, using regular 41 Magnum brass, loaded rounds will not seat fully in several guns. Solution??? Trim the brass!!! Since I am not using max pressure loads whacking a little off the top is a minor thing, in this case I trimmed the brass back to 1.200” from the normal 1.285”, this will allow the final load to chamber in any gun.

As I no longer have a 414 Supermag I used the die set from that barrel for this. No issues, as expected, until I tried to crimp, which should not have been an issue, but for some reason the RCBS crimp die will not crimp, felt like the crimper was hitting the top of the bullet shoulder. Since I am a 41 Mag freak, have plenty of dies/parts in the cabinet, next I tried a Dillon, it worked, then remembered why it was in the cabinet in the first place, I do not like the style of crimp it does, more of a press in than roll in. Next die was a Lee Factory crimper, it produced a good roll crimp and onward I moved.

Winchester 231 powder charges of 7.0, 7.5 and 8.0 grains were chosen, using a Reddington 10x powder measure to speed up the process. Any help is welcomed when using a Rock Chucker press to build loads. Final dimension was set at 1.601” oal.

Range time……the Shooting Chrony was set at 10ft from muzzle, 5 rounds of each load was fired over the sensors with a short pause between loads to allow for cooling. Worked out as I was chronographing other guns as well, after a bit of time I shot another 5 rounds of each load over the chronograph to eliminate variables as 5 is good but 10 is better when it comes to shooting over chronographs. Below is the average and spread for each load using my 4 5/8” Ruger Blackhawk……..

7.0 grs 952 fps 36 sd
7.5 grs 1009 fps 20 sd
8.0 grs 1054 fps 18 sd

While my goal was 1,000 fps the 8.0 gr load felt a slight bit better with very little burnt powder flakes left over, though all three loads were very smokey, plain base bullet problem, a gas check version would be nice, the price jumps way up for that option, so for now I will stick with plain base. Side note- for you longer barrel 41 Mag owners just add 35 fps per inch to come close to what the load will do in your gun.

Next step……load more of the 8 grainer loads and start bench testing

Gunner

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41 Mags rule, Baers rock!