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ShooterAZ
07-22-2012, 03:49 PM
I went to the range today and had an interesting thing happen. I took my SBH 44 and Contender with multiple barrels including 44 Mag. Here is what happened. For the 44 I brought two loads: 8.7 gr Unique and 18.9 gr 2400 loaded with the RCBS 250 Keith type. I sized to .430 and lubed with BAC. My alloy was 20/1.

I started out with the Unique load with both pistols in 44 and after 20-25 rounds I checked the barrels. It was leading in both guns...not very much, mainly the first 1/2-3/4" of the barrel. I thought to myself uh-oh something went wrong. I cringed as I loaded up the 2400 loads thinking things were going to get much worse.

Much to my surprise... The 2400 load cleaned the leading out from the previous Unique loads, and the barrel was left bright & shiny like a mirror! What gives? Just when I thought I had the whole slugging/casting/sizing thing figured out...this happens. I surely would have thought the higher velocity load would have leaded more.

OK... so what happened? Is the Unique load just not fully obturating? Does this boolit like higher velocity? My first inclination would be to bump the Unique load up to say 10 grains? Am I right? This had Shooter a bit confused today. Both loads shot were quite accurate BTW.

Thanks...ShooterAZ

geargnasher
07-22-2012, 03:55 PM
Pressure curves and soft alloys, interesting game isn't it? The Unique might not be making quite as much pressure as the boolit likes to keep the seal, or it might be skidding when it hits the lands and getting some gas cutting. The 2400 gives a more gradual acceleration which is friendlier to the soft boolit as it grips the rifling.

Gear

ShooterAZ
07-22-2012, 04:16 PM
Thanks Gear. I have been using this same alloy in 45 ACP and 38 Special with excellent results. I must say that I have become a fan of the softer alloys. This was my first attempt with the RCBS 250K. It is a good boolit, very accurate. I will try bumping the Unique load up a bit and see what happens. If that doesn't help, I have a winner with the 2400 load.

geargnasher
07-23-2012, 04:02 AM
I've shot more three inch groups than not at 100 yards with a Model 29 and a 4MOA red dot (tough to shoot sub-dot groups unless you draw the right sized dark circle to shoot at!) using 16:1 alloy and a 429421 hollow point powered by a medium dose of 2400. Zero leading. Lots of other philosophies work too, though, so don't think a gas-checked LBT WFN made from water-quenched wheel weights or straight linotype at the right speed and the right twist won't shoot tiny groups at a very long range too, in fact further than the softer stuff much of the time. Lots of ways to skin that cat.

Gear

44man
07-23-2012, 07:23 AM
I agree with Gear.
The initial thump of Unique is too much for the alloy. It might get worse if you increase the charge. Just because it has a lower overall pressure you are applying it more suddenly.
Soft lead does not mean you will get leading, it is what you do to the boolit. Your indications are boolit skid.
The .44 works just fine with WD WW metal.
I am in the camp that the faster powder, lower pressure loads need an even harder boolit then a full power hunting load.
High pressure loads that must use a fast powder like the 9mm or so, need even harder.