Thread: Pierced Primer

Another first for me, had one the other day when whipping outside to bang a magpie over. Had been a good load through the winter with no pressure signs. Am wondering is this temp related? Using 2206h. Although a different container from load development.
From the gunsafe to firing(2 shots)was all of 5 minutes but it was high 20's outside.
Thinking I should run a couple over the chronograph and check speed?

Pretty heavy ejector marks there, better back it off a few grains.

Pissin' hawt.

Never known 2206H to be very sensitive. So that load really didn't have any of the same pressure signs in winter? No ejector stamps, no cratering or pierced primers? What primers btw? CCI 200's?

I can model this in GRT or QuickLoad to give you an idea of what pressure you're running into. I'll need to know how much powder, what projectile, the OAL of a loaded round, the barrel length, and what speed you're getting.

Hi Charley, have a look to see if you have'nt pushed the shoulders a wee little to far back during the last resizing.

a/ Excess Pressure
b/ Excess Head spacing
c/ Sloppy Firing Pin in its hole and maybe assisted by weakened spring.

If those are ejector plunger hole marks I would look at excess pressure first.

Both those cases have clear ejector stamps on them unless your blind.

Primers are a bit square on the edge but not too bad.

You getting up there but not in the extreme. I’d back the load off a touch.

Excess pressure

Originally Posted by Dicko

Both those cases have clear ejector stamps on them unless your blind.

Primers are a bit square on the edge but not too bad.

You getting up there but not in the extreme. I’d back the load off a touch.

Nah, not blind mate. One eyed at times maybe....
@charliehorse with the blanked primer one shit may have gone back thru the firing pin hole. Pay to strip your bolt and check.

Thanks for that pointing that out @Dicko.....well aware. Where I was thinking was has the temp caused the pressure spike(is that a thing?) Was not getting stamps previously with this load. @Pommy try and rustle that info up for ya but may well be irrelevant considering. Thanks @zimmer on the firing pin hole

definately a thing....if you develope a load in hot conditions it will be fine in cold....the otherway around can be dangerous.

Greetings Charlie Horse,
Whatever the load is is FAR too hot. The ejector hole marks mean that the elastic limit of the brass has been exceeded and the brass is flowing back into the ejector hole. In .308 Federal cases are very heavy and need the loads cut compared to others but don't know about .22-250. AR2206H is probably a bit quick for the .22-250. I wouldn't be surprised to find that the primer pockets have expanded as well. It would pay to check case length and neck thickness as well.
Regards Grandpamac.

Yep hot load there. Powder burning rates for the same powder can vary by lot number that is why they should never be mixed.

I think we get a bit carried away on the effect of temp on pressure stability. The limited dat I have seen suggests you need to be well above 40c to see effects or leave your ammo exposed to heat, for example sitting out in the sun at the range, on the dash of your car in the sun, in a very hot chamber for a while before firing etc.

In my .22/250s I always used slower powders like 2209 or WW760 but you can get away 2208 and 748 burn rate powders

Thanks for the info guys, back to the drawing board by the looks.

Anyone recommend a powder to use with 75g ELDM?