????s on 9mm brass,,

[romex2121]

so i loaded some 9mm win brass and trimmed them to speers manuel .744min,,, after shooting these they have shrunk down to .738 im thinking that they are to short now to be safe,, is this true????
i know alot of you do not trim your 9mm brass but my way of looking at is if everything is the same length then the crimp is the same for all,,,, is the brass always gonna shrink after each shooting????
thanks guys :grin:

 

[z11]

Interesting question and it got me to looking at my books.

Trim to length for the 9mm in my Speer #12 is .744. In Hornady #7 it is .754. My Lyman digital caliper data says .754. Other documents specify .754 as well. Go figure.

Was this virgin brass? Did you size before or after trimming?

I have not answered you question. Wiser heads will.

 

[1Shot]

If you are measuring fired cases that have not been resized they will be shorter. Size them then measure them and they will be longer.

Sierra V edition manual says trim to length .750
Hornady 7th says .749
Lyman 48th says .751
Accurate #2 (Revised) says .744
Hodgdon 26 says .751

The manuals that give a MAX over all length all give .754

 

[romex2121]

you both brought up a good point and i do feel pretty silly now :roll:
i did not run them cases thru the sizeing die before takeing the calipers to them,,
i will tell you this tho i wont trim to the .744 min according to speer anymore :wink: