.243 blown primers

[myponga]

My mate has a .243 sako, and his load is 38.5grns of ar2209 with 100grn nosler partitions, and sdated 1.6mm off of the lands. The primers blow out.so he reduced the load to 37grns and the same thing happened. This is with Winchester primers,yet with federal primers its fine. Any one got any clues?

 

[rscott5028]

The question is whether it's due to the firing pin shape/protrusion or pressure.

If I'm not mistaken, Winchester primers tend to run hotter than Federal. And, Federal primers tend to be softer material and more sensitive.

If those are even true assumptions, then it would seem that he's hovering around MAX pressure with the Win primers.

The great thing about safe reloading practices is that it doesn't matter. You simply back down to a safe level and work up slowly whenever you change components and including using new powder lot numbers.

-- richard

 

[Broz]

Hole in the primer from the pin or completely blown out of the case?

Either one I say it is too hot of a load. But a sharp, or pin with a burr, could pierce a primer if you are just getting a pin hole.

Jeff

 

[davewilson]

a firing pin spring that's too weak can also cause this.

 

[myponga]

Thanks for the replies guys, yeah the primer is completly out of the primer pocketthis is a starting load for this powder, according to the adi handloaders guide.

 

[Broz]

Thanks for the replies guys, yeah the primer is completly out of the primer pocketthis is a starting load for this powder, according to the adi handloaders guide.

Man, the only thing I have ever seen that done this was a very hot load. Like 5 gr to much. I would be for backing it off and checking velocity. Or maybe someone here could run it on "quick Load" for you.

So after fired and the primer is blown out,, I take it the pocket is swelled and will no longer hold a primer. That could only be very excesive pressure.

Jeff

 

[rscott5028]

Surely the scale has been calibrated and cross checked....

 

[Broz]

Surely the scale has been calibrated and cross checked....

Excellent point!!

 

[roninflag]

i use 37.5 grain of varget with an 85. is ar2209 the same as varget?. no matter you are using too much powder.

 

[myponga]

Yeah we compared his scale with mine, and they show identicle readings. The primer pocket has expanded and primers sit loosley. The strange bit is he tried this exact loading in the past and there was no signs of high pressure.

 

[Broz]

Well for what ever reason ( hot powder lot?) it is a very over pressure load. Maybe it was close before and a new powder lot pushed it over the edge. I would not shoot one more. Back it off and start over working up slowly is my advice.

Jeff

 

[britz]

I would seariously consider using a different powder or a different bullet. I have no experience with that powder brand. However, I have had a similar experience using Hodgdon's loading data and a 22-250 switching to a 60 grain pill. I used a medium load to start with since I had maxed out the powder with no problem and a 55 grain bullet. First shot blew my primer out, stretched the case. Idiot me didn't realize that the case had blown out yet so I had shot an additional 2 rounds with the same result. I didn't realize until the 3rd shot actually blew the ejector plug back in the bolt face of my Savage rifle.

moril is that the charts arent always right for every rifle/bullet/powder combo.

and yes, i did pull my head out of my rear since then.

 

[yawn]

AR2209 is H4350

 

[Barstooler]

How many times has he reloaded the brass??? The 243 is famous for case stretching even after the first reload. Do the rounds chamber hard/tight?? If so it could be the neck is too long and he is jamming the bullet into the throat which is pinching the neck/bullet and creating extra pressure.

Simple case trimming could fix this or he could rechamber to 243 AI that essentially eliminates case lengthening issue in the 243.

Barstooler