"Event" today shooting my 10mm DE

[calpoly93]

I was shooting me Delta Elite today for the first time in several years today, when I experienced and "event", I thought I'd get some input on.

The loads were from yesterday, and were WIN 180gr TC bullets, on top of 6.4 gr. N340, with a WLP primer in mixed brass obtained online years ago from one of the surplus vendors. Loaded on a progressive, each charge visually checked. As I loaded the magazine, I noticed the round I was loading at that moment was nickel plated, and a very good looking cartridge overall. I admired its concentricity(sp?) and beauty as I inserted it into the magazine, second from the top, thinking how great it would be to buy 1,000 of brand new nickel-plated brass.

First shot: nice load. Milder than the AA #9 loads from earlier, but definitely more than a target 45 ACP.

Second shot (the lone nickel load): I got a bit of stinging powder in the face, and noticed very mild recoil.

I immediately checked to see what happened, cleared the gun and saw something drop as I locked the slide back. Then I heard something rattle in the gun. The rattle was the case, minus the head, falling out of the chamber. The object I saw prior, was the case head, separated like a button off your shirt! (see pic). Next round in the magazine was flipped 180°.

It wasn't an overload (I used N340 since the charge takes up so much of the case), and there was nothing that would have indicated something was wrong on the outside of the case, like damage or bulging. But it looks like the head was "unscrewed"?...Any thoughts/comment would be appreciated...

BTW gun seems to be completely fine.

 

[critter]

I used to own a Colt DE in 10mm and am an experienced (and I thought careful) reloader. I had a similar 'event' with the 10mm that I have never been quite able to explain fully.

I have decided that 'high horsepower' and semiauto are not very compatable. Sold the 10mm and have gone to revolvers (FULLY supported rounds) for hunting, etc requiring horsepower.

Gland you and the gun are intact. Hope you get it figured out.

 

[Striker Fired]

The case is a Federal h/s I bet. The older two piece type(at least they look two piece.

 

[Blue68f100]

It looks like an unsupported case blow out. Was the round loaded a 10mm and not a 40?????

Hows your OAL? Is the bullet contacting the lands?

 

[Bush Pilot]

You can probably salvage that case with superglue and a bulge buster from Lee.

 

[243winxb]

10mm - 180gr - N340

It wasn't an overload (I used N340

Looks like a maximum load @ 6.4gr. Note that a .8 gr increase only produces 65 FPS more, in the data. Different Component = Different Pressure Plus brass of an unknow history. I see more KABOOM in your future. Of the powders listed, you seem to be using the fastest one. http://www.lapua.com/view_reload_tables.php?relodata=6&relocaliber=24&lang=en&siteid=products

 

[calpoly93]

"Note that a .8 gr increase only produces 65 FPS more, in the data"
Yes, that is an interesting attribute of that component combination...

I was using data that indicated a Max. of 6.9gr. (don't have it in front of me, can't tell you the source off the top of my head) and I was looking for a mid-range load.

Looking at the VV site, they show 6.5gr., but I think you hit the nail on the head, "Brass of an unknown history"... I think the brass was at the end of its (apparently) long life. I wonder if that would have prevented this from happening...

Using anything buy virgin brass, I will be staying at the bottom end of data from now on, and going to AA#9 or N350.

 

[Jitterbug]

I only use NEW yellow Starline for maximum loads in 10mm, MY used brass is then segregated and sorted by times fired, and thereafter loaded with minimum cast bullet target loads only.

With Jacketed bullets I go new brass only, especially in 10mm.

I just tossed a batch of 7 times fired brass into the scrap bag. One time fired mild factory then 6 times fired mild target.

Never will I use brass that I didn't fire or know the history of.

I know someone else will chime in and say the use "range" brass or whatever all I can say is good luck with that...any brass I leave on the range is well, well used and truly scrap.

 

[Nick93]

Seems that case is an old balloon cases from federal ... just saying

 

[calpoly93]

Critter - thanks for the response, I tend to agree. I find myself shooting revolver more frequently these days!

Striker Fired - yes Federal! I am unfamiliar with "older two piece", could you fill me in?

Blue68f100 - I will check when I get home, as I recall, the curve of the bullet profile started at the edge of the case, so I believe I am off the lands.

Bush Pilot -

Jitterbug -You have a very good procedure! I will look into starline brass as well.