case pressure!!

[o1sick7]

here it goes. im new to reloading. i was at cabelas. wehre i get alot of my reloading needs. and they were all out of regular small pistol priomers. so the guy behind the counter said he had some cci 550 magnums. and that they would work fine in my 9mm. so i got home and called my friends dad he has been reloading his whole life. and he said he has never done this but dont see the problem. he has used magnum primers in non magnum guns. and it worked fine. so putting my trust in this man i loaded up some 150 rounds. and yesterday i went to the range and out of the first 5 shots 2 of the primers blew out of the case and one hit my glasses. and the other 3 had bulges in the primer. i took it to the raange tech. and he said it was due to the primer. any input on the subject?

 

[ChadTRG42]

Re: case pressure!!

Well, it's kind of obvious what's happened. It's a hot load. When you work up a load and shoot a max (or over book max) load with a standard primer, then switch to a magnum primer, things like this happen. The magnum primer has a hotter flash, so you have to reduce the powder charge to keep the same pressure as before. Magnum primers will work, but you have to off-set (reduce) the powder charge so you do not get pressure. Do not shoot any more of these rounds and discard them or pull the bullets. I would also recommend reading the into on reloading at the beginning of most reloading manuals. It's there for a reason.

 

[o1sick7]

Re: case pressure!!

they were mid range loads. i have never load to max. i dont need to set any speed records. i just like to shoot. and i have read the layman manual and the hornady, and i just ordered the lee. i just didnt know the mag primer would be that rough. i guess lesson learned.i only shot 5. and i also had to order a puller. brake them down and start over.

 

[Halfnutz]

Re: case pressure!!

Congratulations, Your're not Blind, Disfigured, or Dead.

If you don't see it in a reloading manual, it's prolly not in there for a reason.

 

[SuperSeal110]

Re: case pressure!!

Did you happen to look at the primer after the 1st round to make sure you weren't getting flat primer/ejector marks?

Obviously not if you kept shooting. Lessoned learned, hopefully...

 

[dragonjr45]

Re: case pressure!!

Never take the guy behind the counters word for it. Seems like some places will hire anyone these days. I had a guy at cabela's try to talk me out of the leupold I was getting ready to buy, and recommended the barska instead.... needless to say, my mind didn't change.

 

[Clark]

Re: case pressure!!

Over the last 12 years I have overloaded 19 Bagder, .223, .243, 25acp, 257 Roberts AI, 260, 270, 7mmRemMag, 32acp, 32sw, 32S&WLong, 32-20, 7.62x25mm, 7.62x39mm , 308, 7.62x54R, 8x57mm, .380, 9x19mm, 9x23mm, 357 Sig, 38 sp, 357 mag, 38sw, 40sw, 10mm, 10.4mm, 45acp, 45Colt, 452/70, .410, and 45/70.

But some are just a page of notes, but I have hundreds of hours invested in overloading 9x19mm handguns.

When I work up to the point of case bulge, primer pocket going loose, or primer piercing in 9mm, I sometimes back off from the threshold of trouble and work back with a magnum primer.

The effect of a magnum small pistol primer compared with a standard small pistol primer on pressure is ~ 0.7 gr of powder. That is, I reach the threshold of trouble with .7 gr less powder when using a magnum primer. The effect on velocity is less.

Most published loads for 9mm can be increased by ~ 4 extra grains of powder in most semi auto 9mm pistols, and the only problem is painful recoil. The lawyered up corporations that sell +P+ 9mm ammo are fairly safe with an extra grain or two.

What does it all mean?
The wrong charge might do it, but it would have to be a powder with a high density- speed product. Bullseye, Unique, AA#7, ect will not fit enough in the case. AA#5, HS-6, and 3N37 can make that kind of trouble.

 

[Fuzzball]

Re: case pressure!!

"they were mid range loads. i have never load to max."

Well, it wasn't the primer, as such. It was the combined effect of a previously established charge and a new, hotter primer. Used as they should have been, the mag primers would have worked fine.

What you just learned is that, in your weapon, "mid-range" with that powder and bullet IS a max load and using a hotter pimer sent it WAY over the edge. Explaining why EVERY book tells us to start low and only move up untill/unless....etc. <span style="text-decoration: underline">And then they caution us to reduce charge by 5 to 10% and retest if we change ANY component</span>. Seems you didn't do that!

Do those cautions make more sense now?

 

[ChadTRG42]

Re: case pressure!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: o1sick7</div><div class="ubbcode-body">they were mid range loads. i have never load to max. </div></div>
Out of curiosity, what was the load used and bullet?

 

[treebasher]

Re: case pressure!!

Holy bulging cases Batman!!

 

[918v]

Re: case pressure!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChadTRG42</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: o1sick7</div><div class="ubbcode-body">they were mid range loads. i have never load to max. </div></div>
Out of curiosity, what was the load used and bullet?
</div></div>

Yeah! Tell us the load.

 

[o1sick7]

Re: case pressure!!

i am using once fired brass. 5.5grn of hs-6 powder and a hornady xtp 124gn. topper. and it is 1.065 oal

 

[918v]

Re: case pressure!!

Do you own any other Winchester/Hodgdon powders... maybe like 231/HP38???

 

[o1sick7]

Re: case pressure!!

i have s ome unique. why?

 

[Clark]

Re: case pressure!!

I know that with 115 gr HS-6, the primer pierces at 10.8 gr.
A magnum primer with pierce and the case bulge at 11.5 gr.

Most 9mm pistols have ~ .190" feed ramp intrusion into the case support. The web of the case is ~ .160", leaving ~.030" of thin unsupported case wall. This is much better than most 40sw, 10mm, and 45acp pistols.

If o1sick7's cases did not guppy belly, and the primer fell out, then there must be good case support.
If his firing pin fit is better than my test gun's, then it looks like double charges.
12.5 gr HS-6 is all that will fit with a single compression of the powder.

 

[ChadTRG42]

Re: case pressure!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: o1sick7</div><div class="ubbcode-body">i am using once fired brass. 5.5grn of hs-6 powder and a hornady xtp 124gn. topper. and it is 1.065 oal </div></div>
Now you've got me baffled. That's actually a fairly light and under charged load. It is under the minimum charge weight listed by .9 grains. HS-6 is a slower pistol powder and needs to be kept at near max charges. So, you might have an under charge, which can also cause pressure. HS-6 powder has the highest charge weight in powders for the 9mm. I would look for a different powder for the 9mm.

 

[918v]

Re: case pressure!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: o1sick7</div><div class="ubbcode-body">i have s ome unique. why?
</div></div>

I'm wondering if you "thought" you used HS-6, but really used HP38. Or maybe you have a contaminated jug. I did that once: dumped the wrong powder into the wrong container after having disassembled some rounds.

 

[ChadTRG42]

Re: case pressure!!

I thought about the same thing. I am assuming you are using the stated powders and didn't mix or substitute the wrong powder in it's place.

 

[Clark]

Re: case pressure!!

Few powders have the speed-density product to get into trouble with the 9mm.

Many people think that a case full of Bullseye or Unique will make trouble for the 9mm, but it will not with 124 gr. Bullseye and Unique are just not dense enough. Only 6.4 and 7.3 gr respectively will fit, and they do not make much pressure.

HS-6, OTOH, is dense. 12.5 gr will fit. That can make real trouble.

 

[o1sick7]

Re: case pressure!!

I didn't know that powder could go bad. But I know that I didn't over charge. I always check o.a.l and o.a.d and charge every 5 pistol cases. It take forever but that's how I feel. Comfertable. What really gets me. Is it worked fine on some berrys 147grn's. [Same hs6] maybe its time to dip in to. The uniqe

 

[o1sick7]

Re: case pressure!!

My lyman says for the bullet that 5.3 is starting load and 6.0 is max load.

 

[flounderv2]

Re: case pressure!!

Did you hand measure every load on a scale or did you use an auto dispenser like the auto disk kits like on some lee progressive presses. If you used a disk kit to drop powder, I would venture to say you may have calculated your cc vs grains incorrectly. Just a thought

 

[o1sick7]

Re: case pressure!!

no i have a rcbs 5-10 and an digital. i usally use the 5-10 now that i got it back. i really dont know what happened. but i am just going to pull all of them. and check the powder. and if it is still dead on. i will just slap in some new primers and call it a day.