Powder Residue on Case Problem?

C

Carl Bouge

Guest
I have a Sako 75 varmint in 22ppc. I use Lapua brass. I have turned the necks so a seated bullet measures .002 under the chamber diameter. The gun shoots great usually in the .2 or .3"s. The problem I am having and cannot figure out is when I shoot V133 powder in it, I end up with case powder residue blow back on the shoulder and sometimes even on the side of the cases. If I shoot Benchmark powder I have zero residue and everything looks perfect. I have played with the headspace and only I bump my shoulder back to where the bolt close freely but with a little tension. Cannot really bump it back anymore without making it hard to close the bolt. I cannot figure out why one powder does this and the other one does not??? I have about 6 lbs of the V133 laying around that I use to use in my 6ppc and would like to make use of it. Hoping maybe someone has ran into this problem before and can help me out.
 
How much are you bumping it back? It is possible that the web is not getting sized enough. It will give the same hard to close bolt.
Butch
 
Light load of N133?

Could it also be that you're running such a light load of N133 that it isn't fully expanding the neck and sealing the case? I would think if you can seal it with Benchmark then you could with N133 but I had to ask.
 
If the bolt gets tighter when bumping shoulders, you may be bulging the shoulder with a die that is to big. I am saying that if the bolt feels good
at .001 shoulder bump , but gets tighter with more shoulder bump, thats
a good place to look. Another issue is necks getting to long.
If you are using Lapua brass, but loading by a manual that
specifies Sako USA cases, you may not have enough pressure to seal
the shoulder and will get gase coming back on the sidewalls. Generally
a slower powder with not enough pressure will do this befor a faster.
Sako USA cases are lower capacity, so when using Lapua, The USA
loading specks can make sooty cases.
Look for a bright shiny line at the body shoulder junction.
 
I basically set the dies up where the die and the shellholder do not touch when ram is up, then go down in about 1/16" inch increments until the bolt closes with just a little tension and that"s where I set it, if I go down further it starts closing real easy.
I do not have a chamber gauge to see exactly how far I am bumping the shoulders back but I try to set it up to the minimal bump. It just seems funny to me the V133 does this and the Benchmark does not. I tried a wide range of loads with the V133 and does not make a difference. I have tried going over maximum to see if would seal case and make a difference but it did not.
 
Carl,
You better make a gizzy or buy a tool to check headspace. The way you are doing it could lead to casehead failure and a bad accident.
Butch
 
Butch,
I have got a Wilson headspace gauge ordered, I will see what it says.
Thanks Carl
 
Carl
Are you jamming the bullets with N-133?
For ha ha's measure the diameter of the fired necks on the 133 loads and compare to the BM loads.

When I use Viht in a 204R (huge jump to the lands)the necks of the brass will not expand consistently. Even when pushed hard.
 
Ok I measured the headspace I bumped the shoulder back .001 and loaded some more with the V133 and end up with same thing still has powder residue on shoulder and sides of the cases. I am lost! the loads shoot great. When I shoot the Benchmark powder the shoulder and cases are clean and bright. Guess I will stick with the Benchmark
 
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