[jm10mm]

Upon having a case blow out with a 38 super I decided to cut a few cases open and see why this could happen. It wasn't a double charge, it was just an old case. Probably 70's vintage. The results of measuring the webs are below.
38 ACP(Winchester) = .025
38 Super(Starline) = .025
38 Super Comp(Starline) =.035
9 Super Comp(Starline) =.036
9x23(Winchester) = .054
WOW, what a difference. No wonder Winchester billed it a the strongest pistol cartridge ever made.

 

[Dane Burns]

Perfect example why 9mm Super Com is not 9x23 Winchester. It also weighs 10 grs more IIRC. And why the round works better for the loads Wincester developed.

Thanks for the info :grin:

 

[EchoFiveMike]

Starline 9 Super Comp case(once fired, deprimed) weighes 64.5gn
Winchester 9x23 case weighes 78.7gn(twice fired, deprimed). Semper Fidelis..Ken M

 

[Clark]

What?
Win 9x23 brass is heavier than Starline?

My experiments showed that the Starline 9x23 brass was no better than 9x19.

If, true, this changes everything, I must order Win 9x23 tonight.

 

[eerw]

yes its true..

the Winchester brass is much thicker than the 9mm supercomp from starline. All the supercomp does is give you a tapered case much like the 9x21.

Winchester brass is very hard to find and if you do very expensive. When it first came out it was $80/500.

 

[Clark]

OK, I sent for some Win 9x23 brass, cross secitoned it, and Voila! It is thicker!

The Starline Super Comp has .150" web and .032" walls.

Win 9x23 has a .183" web and .054" walls.