.355 or .356?

[1SOW]

I've read here and other places about using .356" diameter 9mm bullets in place of the standard .355", and I have no experience with .356 for 9mm Luger use.

I shoot a CZ75B, and have used .355", 124gr, FMJ over n320 with MG, PD & some Win bullets---128-130PF. The MGs needed more powder to get my PF. harder jacket/tighter fit?

Running short of bullets, I found some ZERO 124FMJrn at P.V. to use temporarily. They took more than .2 grains less powder to meet my normal PF and slid into cases like they were 'undersize' but weren't. My groups weren't as good as normal and they just felt different.

I have .355", Zero 125JHPs on the way.

Are the Zero 125 JHPs going to feel this loose. ANYWAY, will the .356" 124gr run and shoot differently/better in my CZ?

What are the pros and cons of switching to .356" 124/125gr FMJ in a 9mm gun?

Thanks. Sorry I'm so 'wordy'.

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Edited January 29, 2010 by 1SOW

[Jaxshooter]

I have shot both .355 and .356 bullets in my open guns and never noticed any difference. I did not chrono them side by side but both were right at 170 PF with no adjustment in powder or OAL. According to Wil Schueman a .357 is ideal in a .355 barrel. Load some of the .356 bullets and see if you notice a difference in your gun. Let us know.

[lcs]

The Zero JHP should perform well unless there is something wrong with your barrel. The Zero bullets have an excellent history regarding performance.

[1SOW]

Thanks for the replies.

JAX (NAS?) I'm shooting Production and loading to 128-130 PF.

The ones I've got coming are .355. I was just asking about the benefit/or not in trying the .356 Zeros.

Does the .356 tighter fit improve accuracy in the light Production loads?

Edited January 27, 2010 by 1SOW

[lcs]

Thanks for the replies.

JAX (NAS?) I'm shooting Production and loading to 128-130 PF.

The ones I've got coming are .355. I was just asking about the benefit/or not in trying the .356 Zeros.

Does the .356 tighter fit improve accuracy in the light Production loads?

I don't think you'll see any difference in accuracy. Your good to go with the .355

[Glockcomma]

The bore of guns can vary, I was lead to believe that if you measure your bore then add a thousandth that should be the optimum bullet dia for accurcy.

[anoshoot]

I have used both in my Glock and I don't see any problems between the two.

[G-ManBart]

The bore of guns can vary, I was lead to believe that if you measure your bore then add a thousandth that should be the optimum bullet dia for accurcy.

That's more a rule to use with lead/plated/moly than jacketed. R,

[G-ManBart]

The Precision Delta bullets (.355 marked) I've measured actually were almost .356" and the Montana Gold bullets sold as .355" seem to actually be under that (more like .3545...I'll measure some tonight). That difference will cause the MG's to require more powder since they don't seal as well. It hasn't hurt the accuracy any, so I guess it's not a big deal. R,

[1SOW]

The Precision Delta bullets (.355 marked) I've measured actually were almost .356" and the Montana Gold bullets sold as .355" seem to actually be under that (more like .3545...I'll measure some tonight). That difference will cause the MG's to require more powder since they don't seal as well. It hasn't hurt the accuracy any, so I guess it's not a big deal. R,

Thanks Bart, My Digital Vernier isn't precise enough to measure beyond 3 decimal places.

I've read here how some shooters recommend/prefer them and wondered why. One shooter mentioned accuracy as an issue.

I haven't seen the subject discussed as a thread, just comments on other threads.

Edited January 29, 2010 by 1SOW