Crimping, Part 2

Crimping, Part 2

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Quote:
Originally Posted by ar15barrels View Post
Don’t assume that the bullet moved during chambering.
It could also have moved forward during extraction.
Sharpie on the bullet is also in order to see if you find rifling marks.

If the bullet was seated firmly into the lands, the barrel will hold on to the bullet and yank it from the case.
They call this “breech seating” in the benchrest world.

Breech seating with loads designed for a bullet to jump will cause elevated pressures.

I tried several different degrees of crimp with the lightest crimp showing the most movement and the heaver crimp the least. I didn’t see any signs of the bullet getting into the rifling. The extractions were slow so I wouldn’t have to chase the things around the room.

These were Rainier 250 gr TMJ’s, pretty soft, it was not hard for me to mash the bullet with the crimper.

I tried a Hornady XTP 240 gr HP with the “groove”. Very slight roll crimp, factory case. Feed fine, bullet didn’t budge. Of course doing the same thing with a 284 case – Jam. Duh.

We now know why I was jamming. Now, whether my high pressures using the 284 cases was caused by large rifle primers, too much powder, too little crimp, tilt of the earth on it’s axis or all of the above, (probably all of the above) I still don’t know.

And at this point I’ve already spent way more on 284 cases, trimmers, reamers, pilots, gas and range fees than I would have on the equivalent number of factory rounds.

Don’t get me wrong, I’ve learned a lot, I’ve had fun, people have been very helpful and I’ve had a excuse to buy tools, what more could a guy ask… well I haven’t picked up any chicks… but I’ve still had hours of entertainment.

But I think there’s a point where ya gotta say “Dude, just go buy some more factory rounds! They’re straight wall cases dude, you can reload them a bunch of times before they wear out! Let somebody else take one for the team. You’re not cut out to be methodical, you’re having a tough enough time figuring out what works with the factory cases!. You just want to save a little money and have fun, don’t suck the joy out of it by going in over your head!

Know what I mean?

The Hornady XTP

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No, about 2.1″ AOL. Just to where the groove in the bullet starts to hit the case. Don’t ask me why there, it just looked like a good spot, and it gives the roll crimp die a little something to work with.

Like I said, I’m winging this whole thing.

As far as the 284 cases, I’ve had no luck at all. I’ve sized them but I can’t get the case wall the right thickness. A .452 reamer takes to much and leaves a good size shelf down in the case. I’m sure there has got to be a way to make them work but I’m not patient enough.

I’ve just been reusing the brass from the factory rounds. Thank goodness for straight walls, the cases are holding up well.

Montana Gold has some .452 250 gr 45 Colt bullets for a reasonable price, I’ve been thinking about getting some of those, but so far between the Barnes X 250 and 275 gr HP bullets, the Hornady 230 and 240 gr HP bullets and the Rainier 250 TMJ bullets I,m just confusing myself trying to figure out the loads.

https://secure3.mooseweb.com/montana…/pricelist.tpl