Load work up help

[Charlie Two Tracks]

I am trying out loads for my GP-100 6 in. using MiHec mold 359-640. This test was with the wide hollow point not the pentagon one.
I am using AA#9 with this test.
The alloy is 9# of WW, 9# of pure lead and 1/2 lb Tin.
The BHN tested at 9.8 with this mixture.
The loads I tested were: 13.0 grains, 13.4 grains and 13.6 grains.
There was a bunch of young boys show up with their dads just after I got there and I just tested those loads. It is a nice day here and I can go back out when there is more room at the range. It only has 3 stations.
The best group was at 13.4 grains. 4 holes were touching at 25 yds and the other two were 1/4 inch away. The 13 and 13.6 were spread out much more.
There were only 6 rounds fired from each load. Is that enough to concentrate on just the 13.4 load or do you have to run a bunch of each load first? Also, I have no idea on how well the HP worked. Should a guy concentrate on the accuracy or how well the HP mushrooms? Or is it a happy medium? I have a 20 mile trip to the range so I am trying to figure out as much as I can in the reloading room. Sure wish I could walk out the back door and shoot. Maybe someday I'll get a place like that.
Oh ya. There was just a trace of leading on the forcing cone when I was done. None in the cylinders. The boolits were sized at .360 and lubed with Carnuba Red. .360 was used so I can also use it in my SP-101 which has had the cylinder reamed to .358........

[ChuckS1]

I'd be happy with the 13.4 group if you're just target shooting. Personally, I never placed much on hollow point expansion, especially with wheelewight alloy. I figure any expansion is just an added bonus. As for testing, I usually test 10 rounds, but that's just me. I think 6 gives you a pretty good idea.

[USSR]

Charlie Two Tracks,

I have that mould, as well as several other of Mihec's hollowpoint moulds. IMHO, the key to having a HP that mushrooms and does not fracture is, keep the antimony down and the tin up. If I were you, I would alter your alloy to 12# pure, 6# WW, and 3/4# tin. This gives you an alloy with essentially the same BHN as the alloy you used, but it gives you an alloy which is much more malleable. Again, just MHO.

Don

[williamwaco]

Charlie,

You are frightening me.

How much does that bullet weigh?

I have blown the forend off a Thompson Contender with less than your lowest load of AA No.9 using 158 gr SWC.

The same load required removing the cylinder from a S&W M-19 and driving the cases out with a cleaning rod and a small mallet.

Please watch closely for pressure signs.



.

[Charlie Two Tracks]

the 359-640 dropps at 160 grains. Max. published load is 13.7........... You need a very strong crimp and magnum primers. No sign of any pressure problems at all. You don't want to use AA #9 for light loads.

[btroj]

I use 13 to 13.5 of WC820 with the same bullet in my Marlin. My lot of WC820 is very similar to AA9. Shoots great in the rifle. Sort of tough to shoot in the GP100, ogive sits in the throats jut enough that loading it is tough.

[Charlie Two Tracks]

I really don't know what I am going to do with this load but I have the mold.............. ya gotta do something with it. The coyote get killed pretty dead with the LEE 158 RNFP but......
like I said, I have the mold and the boolits look awful good when they are loaded. I would like to have a nice expanding round........ just because.

[Jim]

.....The loads I tested were: 13.0 grains, 13.4 grains and 13.6 grains............

Charlie, I'm curious. Was there a reason you skipped 13.2? Not callin' you out, I just noticed the gap in the sequence, that's all.

[Charlie Two Tracks]

Ya, there was a reason. I had the boolits loaded up in 1/10 grain increments but just as I got ready, two dads and their sons showed up. There are only 3 stations at this range, it is the holiday weekend for the boys, the weather is going to get real cold and windy, so I just hurried up the test. I shot the 13 grain and it didn't lead so I went to the 13.4 and then skipped to the 13.6 to see if it would lead at the higher pressure. There was already a guy in station 3 so I wanted to let the boys shoot with their dads. At least I know there should not be any leading problems with any of the loads.