357 crimp problem

[broham]

I am loading 158gr semi jack hp made by Zero for a gp100 357. The press is a Lee classic turret. The dies are their carbide 4 die set. I seat the bullet to the crimp groove(on these bullets it's barely even an indentation more like a scored area) and crimp in the factory crimp die. It seems like some of the rounds get a good firm crimp and some I can actually spin the bullet in the case. There is no bullet movement in or out just spin. I might get 5 to 10 like this every 50 to 75 rounds. In the past I single loaded them and they shot fine I just can't figure out why this is happening. Brass is Win and this is maybe the 3rd time they have been loaded.

 

[IDriveB5]

Have you trimmed your brass? Some may be longer than others.

 

[REB]

Have you trimmed your brass? Some may be longer than others.

+1

 

[ReloaderFred]

There is some variation is wall thickness, even within the same brand of brass. If your sizing die isn't sizing the brass enough, or your expanding plug is at the maximum diameter, it's going to show up when you seat the bullets. You can check this by pulling the loaded rounds out of the press after the bullets have been seated, but before they go into the crimping die. If it's a sizing or expanding problem, you'll discover it at this point.

Hope this helps.

Fred

 

[Steve C]

One other thing may be causing this lack of bullet grip by the case besides what Fred mentioned. You could have a batch of bullets with a few ones that are of smaller than standard diameter. Its most likely what Fred described with thin walled cases but if you do not mix case brands and segregate by manufacturer then its more likely the bullet diameter. I have read before that some people have got the wrong diameter from a bullet producer. A few bullets sized at .355 (in 9mm dies) could cause this. If you have any of these loose bullet rounds, pull the bullet and check its diameter or if you don't have calipers or micrometer then try loading a different bullet in the offending case and see if its loose too.

If you don't segregate your cases then Fred's probably right.

 

[243winxb]

broham
Quote:
"found that if I don't bell the case at all and just seat the bullet it sits nice and tight" Quote

the powder-thru-expander Lee die/expander button that bells the case should measure .355" or smaller (not the belling part)when measured with a micrometer. If your is bigger get a new one or make it smaller using a lathe or emery paper.

 

[rcmodel]

+1

Your expander portion of the stem is too big.

We just had a long discussion about exactly the same problem a couple days ago.

http://www.thehighroad.org/showpost.php?p=4772155&postcount=13

rcmodel