question about lee 356-125-2R

[rmatchell]

Ok so I have been working with my brother in law on casting and loading, and he has been doing well with both. I talked him into buying a 6 cavity 356-125-2R when one came up available on amazon and it has been nothing but trouble. It cast great looking boolits with our coww alloy and drops around 128 to 129 grains. We had to look around for a good powder for the weight, once we got the load down we still have fit issues in his guns. We started out sizing at .358 and lubed with lee nra formula they shot without any leading they just wont chamber all they way. When you chamber a round and remove it you can see an engraved band 1/16" up from the case mouth.

After seeing that I though we could try sizing at 356 to see if it would help and still no luck. So again we tried going down to 355 just to try it. Still no leading just doesn't fit the chamber. So i'm out of ideas for now, except finding a different powder to allow us to seat deeper into the case. Any help would be great, thanks in advance.

Oh and he has been using AA#7 and he is using them in a springfield emp and a sig P6 if that helps.

[ipijohn]

It looks like you need to seat deeper to keep it out of the rifling. My CZ's require a maximum overall length no greater than 1.070 to keep from engraving with that boolit.

[freebullet]

I use the same bullet. Your likely seating them too far out. To determine the seating depth for a given boolit I -
Insert a boolit in the chamber until it is centered and wedge a toothpick between the breech face and slide. Insert a dowel from the bore end and make a mark at the end of the barrel. Remove the boolit close the slide insert the dowel mark at the end of the bore. Now measure from the inside of the bottom mark on the dowel to the outside of the top mark. Seat yer boolits no more than .030" past that measurement with the 2r boolit. Make some dummy rounds and make sure they feed before loading any.

[Shiloh]

I use a case gage for seating purposes. I can seat longer for one thatn the other, and used to load that way. Now they are all the same for that boolit. No difference in accuracy or proformance.

Shiloh

[rmatchell]

Yeah i kinda held off on seating deeper until i looked into it only because much deeper and it looks like it will be on the powder.

[w0fms]

I just got that mold too and I'm starting to discover 9mm reloading isn't for wimps. Those CZ's are reported to have an issue with the odd ogive on the Lee 2R's. Not a problem for me at 1.125" OAL (Which is what I'll try) but I've read all about it, especially with CZ's. At such a small OAL, when I tried it before I had the occasional hot load (I did 1.070" with the few old Speer LRN's I inherited-- leading as well with 4.0g W231.. much less didn't cycle.. I'm amazed how little range you have with 9mm). So I'm being very careful this time around.

[BBQJOE]

I seat this bullet with just the first lube groove showing. Can't remember the depth, and my caliper needs a battery.
Sit on top of 3.5-3.7 700x. All my leading probs went away.