6mmbr brass prep

Facts

Ok here are some FACTS that I found last night.
I am prepping some 220 Lapua brass. Oddly enough the box I received last month is the exact same lot as the one I got January last year. Lot P00406602, both from Sinclair.
Here is what I found about the primer pockets and holes.
Last year I bought a K&M primer pocket uniformer/reamer. It never quite seemed to clean up the pockets around the flash hole.
I have fireformed the cases last night I started to uniforming the primer pockets and noticed the same thing around the flash hole, a small roundish area that just didnt come clean and retained some to of the carbon.

Primer Pockets
I took a case and reset the uniformer to clean all of the carbon. About 2 cases later I had the same thing then again. A case that would not clean up right around the hole then a few more cases the same thing. I reset the uniformer for .0015 deeper using a feeler guage and started over most cleaned up but a couple didnt. Out of 30 cases I did 7 did not clean up completely which shows the primer pockets are not uniform.
Further some of the pockets had a lot of brass that came out of them and those 7 had very little. Some were actually so shallow that I really had to hang on to the case holder to keep it from coming out of my hand and there was a lot of difference in the amount of brass particles that came from various holes.

Flash holes.
When you examine them outside and inside the appear to be punched. they are concave on the outside in the pocket area and they are convex (raised) on the inside of the case.
Flash holes some were larger than others and some were slightly off round.
I used a K&M flash hole uniformer and out of the same 30 cases 6 holes were so small I really had to do a lot of twisting to get the reamer through the hole.
Looking at the brass on the table top under the holes some were worse than others.
These 6 were some that didnt clean up completely and some were from the ones that were completely clean.

Conclusion the primer pockets and the holes are not very uniform and in this lot they are punched and not drilled.
 
One more conclusion, Vern: So much for weighing cases. You might try after all is cleaned up uniformed in the primer pocket and flash hole (which don't affect case volume), but with all this going on, why assume everything else "down there" is consistent?
 
Thanks Charles, I think. If I understand what your telling me is to weigh cases but only after all the extra brass is removed?
I have often thought about weighing but never did just because of things like this. However weighing would be best done after all has been done AND then some kind of cleaning like sonic cleaning so that the cases are unaffected by the carbon inside.
 
Vern
Your findings mimic my own findings.
One thing though are you sure that is the lot# or could that have been the part#?
Lynn
 
Charles -
What is the weight of the case going to tell you?
If it will tell you the volume, I'd say yes weigh the cases. But they won't........


Lynn -
By the number he gave, it is obvious the Lot number. The part numbers go more like this "4PH6046" and the lot numbers as he gave (P00406602).


Happy Shooting
Donovan Moran
 
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Wow Vern, as I stated in my previous reply, I just prepped out 100 pieces of Lapua 6BR brass, and honest to God the flash holes were absolutely perfect. I checked these flash holes using a 10X loupe that we use at work to inspect defects in glass. I used a pin vise with a #53 bit just to make sure of size and to clean out any residue around hole. I used a small 1/8" bit to just smooth out inside of flash hole, just barely touching outside of hole. I have a small flash hole deburring tool but I don't want to take any chances of changing the flash hole diameter size. I use Wilson neck dies with bushings to size necks, in the past the Wilsons dies were larger then the flash holes, but they have changed this size and they now fit the flash hole perfectly. I recently prepped out some 22-250 Lapua brass and found the same problems with the depth of the primer pockets that you found with the 220 Lapua brass, which left an untouched area in the center of the primer pocket, I hope this doesn't happen with this 6BR brass, I won't know until I fire the brass a couple times then try to uniform the primer pockets.
Thanks,
Dave T
 
dmoran65 said:
Charles -
What is the weight of the case going to tell you?
If it will tell you the volume, I'd say yes weigh the cases. But they won't........
Click to expand...

My point exactly. I don't weigh cases, never have.

* * *

& by the way all, I don't believe "DaveT" is Dave Tooley. Somebody else with the same initials.
 
Lynn the part number is 4PH5013
LOT NUMBER IS P00406602
22 RUSSIAN BRASS
I know its not 6BR like the thread but its still Lapua and if one can have consistency problems then other calibers can too.
 
As a follow up.
I have done about 93 cases. 21 of the cases still have some sort of deficiency, uncut area right around the flash hole. There for 21+% at this point are not uniform.
I know we tend to throw away brass that does not measure up BUT Ill be danged if Ill accept a 21+% loss. When I pay almost $100 for a box of brass if I have to throw away almost 1/4 or 25% there is something wrong with that.
I am thinking about extending the cutter another 1/2 thou or so to get them to all clean up the same. Might be a little more or a little less. I dont know till I try it.
What do you think.??????????
 
Vern
Out here they now combine the 600 yard nationals with the 1000 yard nationals.We need 30 rounds for lightgun at each distance and 60 rounds for heavygun at each distance or 180 rounds.We usually bring the same amount for sight in and practice so 400 rounds is a good number.
If I lose 50% of the brass it still works for practice and sight in just not the actual record targets.
My uncle and his girlfriend have several alfalfa ranches in northern California near the Oregon border and they have a rodent that looks like a cross between a chipmunk and a ground squirrel that everybody calls "Squeaks". You can shoot out a barrel in no time as the fields are covered with these little things.A couple thousand rounds per trip is common.Do a google search for "Squirrel Wars" and you can see this is a yearly competition with lots of different categories.It is perfect fo0r any rounds that are not match quality.
Lynn
 
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