Handgun, position-sensitive powders ?

[Nevada Ed]

This was just brought up on one of the threads.

I can see with a long 38 or 357 case, where a 45% volume load
of powder in a case, might cause a problem.

Usually I will use a light load of FAST powder for a target load
but most of my factory or +P loads will have a 80% or compressed load of powder.

What powders have you found that cause a problem in the 38 & 357 cases
that give poor ES, chrony readings and poor target accuracy, in your loads?

In my 38, SR4756 was a powder that did not work out well
and it spiked in full loads with the 357 Magnum.

I also had "Smokey" loads with the 357 with 158 lead loads with HS-6 powder.

IMR4227 is also a looser in the small case, 38 special.

 

[Ivan the Butcher]

Clays (just plane Clays) is not position sensitive! My Cowboy Action load for 44-40 was 4.4gr of Clays. There was lots of room left over and some shots are close and low, but never a squib or pressure spike!

Ivan

 

[alwslate]

Some of the worst for position sensitivity in the .38 spl are Unique,SR4756 and PB. The least position sensitive powder I
have ever used in the .38 is the great long gone Winchester 452AA.

 

[WR Moore]

The effect of powder position took up a lot of gun mag space in the 1950's & 60's. The American Rifleman published an extensive article about it. IIRC, the major issue was velocity variation/alleged pressure spikes in target type loads in the .38 Spl. Apparently, if you have the $$$ to spend on ballistic lab pressure/velocity testing, you can find all sorts of interesting things to write articles about.

Again, IIRC, the only major outcome of all this was a very slight change in the suggested minimum load with Bullseye [Which may/may not have been related to the alleged "detonation" issue]. Dead minimum loads generally aren't all that accurate. I was once gifted with two boxes of the then new 210 gr lead SWC .45 ACP target loads (claimed 710 f/s) by Winchester. They didn't group as well for me as my handloads that went faster by some unknown amount. Out of curiousity, I pulled some bullets and reloaded the primed cases with the pulled bullet and my load of Unique. Accuracy was much better.

I later figured out that the problem was my follow through not being as good as those who shot at the National Matches.

 

[scooter123]

SR7625 is extremely position sensitive. Enough to that you can feel a small difference in the recoil with 45 ACP that is dependent on the position prior to firing. In the 38 special it was a very accurate powder but I found that if the barrel was pointed down prior to firing I would get 400 fps on a chronometer and if I had the barrel pointing straight up I would get 700 fps. Yeah a 300 fps swing in velocity dependent on barrel position Odd thing is the accuracy was very good and both positions shot to the same point of aim. Note, I was working up a light training load for a young lady who was a bit recoil shy. Ended up working up a 750 fps load using Unique that did not have enough variation to be worrisome.

 

[jeeps]

Unique is not position sensitive. Many and me use Unique in the 45/70 for that reason with no filler needed. 14 grn. of Unique and 405 grn. hardcast bullet with less than 25 fps from high and low fps over chronograph.

 

[STORMINORMAN]

I have never noticed any "powder position sensitivity" in any handgun loads... In rifles I can understand the concern and the concept.

Cheers!

P.S. Neither do I load any minimum or "bunnyfart" loads... Or any that are +P+, etc.