[zetti1]

I am using Win231 and 9mm 115gr Rainier plated RN bullets. I want to be able to use the same ammo in my S&W MP and CZ75B. I’ve narrowed my test loads to what I believe to be the best combination. My favorite load is 4.2gr with an OAL of 1.102 but my CZ has a slight feeding problem with this length. If I use, however, 4.3gr and an OAL of 1.139, I do not have any feeding problems, but the recoil seems to be more noticeable. My question is this…If I use 4.2gr and increase my OAL from 1.102 to 1.139, what problems might I incur (if any)? Thanks for your input!

[rfwobbly]

Normally you couldn't do this with a CZ because the freebore is so short. If this was a FP bullet (like a Hornady XTP) you'd be sunk, but since it's a RN you're OK. Either of these guns should be fine with any OAL out to the SAAMI max length of 1.169". My 2 CZs like rounds from 1.120" to 1.150".

I'd suggest loading up 1 "test cartridge" (no primer; no powder) at 1.120", 1 at 1.130", 1 at 1.140" and 1.150" and that way to can play with them in the mag and in the chamber.

Once you confirm the best feeding in both guns and decide on a single OAL, it's a simple task to load and shoot 10 rounds at 4.1gr, 10 at 4.3gr, and 10 at 4.5gr at that OAL. The whole task will take just under an hour and you'll learn a lot about reloading and your guns.

Hope this helps!

[1SOW]

4.3gr and an OAL of 1.139, I do not have any feeding problems, but the recoil seems to be more noticeable. My question is this…If I use 4.2gr and increase my OAL from 1.102 to 1.139, what problems might I incur (if any)?

Your original load is on the low end of the Hogden 231 data. Adding .1 grain and lengthening the oal to 1.139 shouldn't have given you much (if any) additional speed and recoil. Inside the published load range, adding .1 grain 231 may not have any effect when checked with a chrono. I would double check your load weights if you noticed any significant recoil change between the two loads.

You could test 4.2 grs 231 at 1.139" , but only load '1' rd in the mag., shoot and make sure the target has a hole in it before loading and firing '1' rd again.

If you have access to a chrono (maybe a shooter/loader friend) , that might answer your questions better.

I shoot JHPs in my CZ 75B at 1.1" with no feeding problems, but FMJ/RN, I usually load to 1.125 +/-. YMMV

rfwobbly types faster than I do. ;)