Adjusting for new bullets?

[saibot]

I've been shooting Precision Bullets 9mm 125g bullets for a while and bought BBI 130g when I wasn't able to get the PBs. I was using 3.9g of AA Solo1000 and now I need to know what you all think about adjustments with the new heavier bullet. Would I need to reduce the powder to maintain PF? If so, how much?

Thanks!

[JimmyZip]

I've been shooting Precision Bullets 9mm 125g bullets for a while and bought BBI 130g when I wasn't able to get the PBs. I was using 3.9g of AA Solo1000 and now I need to know what you all think about adjustments with the new heavier bullet. Would I need to reduce the powder to maintain PF? If so, how much?

Thanks!

You shouldn't need to lower your charge if your last bullet was lead like the BBIs are. I like them for 9mm. Check the search on the 9mm section as I had a thread on these and there were some recipe suggestions. I can't find my load data right now, but IIRC 3.9 sounds allright. I think maybe even 3.8.

JZ

[boz1911]

Yes you will need to reduce the powder charge any time you use a heavier bullet. How much I don't know and until you check the results over a chrono, you won't either. Keep good records irregardless.

[saibot]

Thanks you guys for the responses!

I know ultimately I'll need to chrono them (but I don't have access to one) and was hoping for some cool rule of thumb or mathematical trick I didn't know about to figure it out.

Oh well. I will set to 3.8 and crank out a test batch and beer-bribe someone with a chrono.

Thanks again everyone!