Blown primers

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barktwid

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I fired my .22 hornet at the range today. The barrel was cleaned and free of obstruction. The load I was using was 12grns of Lil' gun and a 40grn speer bullet with new rem. brass and a win. small rifle primer. This was not the first time I fired this load but it was the first time in sub 0 temp and at 100yards. When I ejected the spent case I noticed that the primer was missing. I checked the bore for obstruction again and fired again. The primer fell out of the case. I checked the bore and, of course, I fired again. The third case seemed normal and the 22 I fired after that seemed normal also. The groups were about 3" so I will not use this load again but I am stumped as to why the first two RANDOM rounds would do this but not the rest. I have been reloading since I was 16 so that is about 16 years and I have never had a missfire and only one split case. This load was 0.5 grns less than max and again the bore was clean and clear. I am fairly new to the hornet and lil'gun powder.
 
I don't think so as I weigh every charge and the level of the powder is easy to see in the hornet case. I also mix up all my reloaded rounds so that I fire them in a totaly random order. I am stumped.
 
It could be a lot of different things, did you measure the case length? My dad had this happen and the problem was a few cases that were way to long, this is with brass he had used many times and not trimmed, but it could also happen with new brass.
 
I measure and trim all my brass but I never measured and trimed this new batch as I never had a hornet case holder for my trimmer. I'll measure it tonight and let you know.
 
Thanks, I would be interested to see what you find. Dads was with a .30-06, we never even found the primer and it left a ridge on the case head almost like a mini belted mag. The bolt had to be hammered open using a piece of wood. I still have the case I could measure it again to see how much over max case length it was. Don't even want to know what C.U.P was achieved that day.
 
No the two that blew the primers were 0.020 and 0.015 under max case length, It was only there second firing. There is no question the cases over pressured but the bolt was not hard to open. If it would have been any thing bigger than a hornet I probably would have quite shooting.
 
How old is the brass? The primer pockets may have gotten over sized over time.
"...left a ridge on the case head almost like a mini belted mag..." That's a whole different issue. Headspace, over charged, etc.
 
Brass was fired once before, There is no signs of presure other than loose primers, Bullets were .025-.030 away from the rifeling.
 
What kind of scale do you use? Is it in good repair? Do you check your zero against scale weight checks? Is the scale on a good solid surface? Does it get rocked as you operate your press? Is it possible you did not zero the scale prior to that reloading session? Is it possible that it got knocked out of zero sometime during the loading process?
 
VERY odd. It's virtually impossible to get too much lil-gun into a Hornet case; at 12.0 it's probably quite compressed already. I generally run 13-13.5 grains of lil gun behind a 35 grainer, and at that amount it's pretty much flush with the case mouth. And I have brass that's been fired more than 10 times with this load.

I wonder if maybe you got the wrong powder into those cases somehow? 2400, or H110; that would certainly be a stiff load.

Or maybe you have an old lot of lil-gun; there was a recall not tooo long ago (though that should have affected all rounds, not jsut the first few)
 
The scale is tip top and always checked. As for the powder Lil'gun is the only ball powder I have on hand at this point.

I am thinking that perhaps I did not get all of the gun oil out of the barrel the last time I cleaned it and that the cold temp thickened it up making it harder for the bullet to pass through. I might not have noticed this when I looked through the barrel. If this is not it I am at a loss.
 
I've done alot of shooting / reloading in cold weather.

My guess - brass and action shrinkage.

I've seen the primers in my M-14 just hanging there after inspecting the brass in -15c.

Try RELOADING in -15c and see if the primers take any force to insert!!!!
 
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