Different bullets same load

[GlockOp]

I will start reloading 9mm this weekend and have a good tried and true load. I have 3 brands of 124g bullets. Will be using a 550B from Dillon. All of the bullets are FMJ or CMJ. Sizes vary slightly by a few thousandths. What will I need to change (if anything) in the seating and crimping dyes when changing bullets brands?

Thanks

Mike

[G-ManBart]

You may have to make a slight adjustment to the seating die to keep the overall length the same, and you may have to make a very slight adjustment to the crimp die to keep the case mouth diameter the same. The important thing is to have an idea of where the base of the bullets are when seated to the same overall length. If one bullet is deeper or shallower in the case, it will either raise, or lower pressure and velocity. If you were near the limit with one, and substituted a bullet that uses more case volume at the same OAL, it could easily push you over the limit. R,

[dansy]

That is the reason I use the Redding Competition seating dies....I zero it for my main bullet then just make a table for the others bullets that I try with time or used for steel load or just because I cannot get my favourite bullet.

[Justsomeguy]

Bart gave good advice about the internal capacity once the bullet is seated. That is the single most important factor in pressure using a similar powder charge.