Noob needs some help understanding something.

[presspuller]

Am I understanding this right?
Per the Speer book for 9mm 115 gr RN with AA#5 the minimum is 6.1 gr and max is 6.8 with a 1.135 OAL.

Per the AA book the same powder/bullet shows 5.6-6.2 max with a 1.100 OAL.

Is the OAL what is making the difference in max load?

Thanks guys.

 

[greyling22]

I would think you set the bullet further out to give you more case volume, though I could very well be wrong. (I try to use a powder that takes less powder in a case anyway. more like 4 grn in a 9mm )

 

[K5mitch]

Increasing your seating depth reduces the case volume, which can increase initial pressure. Hence, the lower powder charge.

 

[Dave P]

Every bodies book is gonna be a little different.

Start on the low end.

 

[TX1911fan]

The Lee Manual gives a load for AA#5 at 5.7 to 6.3 grains with a minimum OAL of 1.100.

 

[gtmerkley]

That was the way i understaudit to.

 

[Bullet]

I believe if everything else is the same and the only difference is OAL, that reducing OAL’s in handguns the pressure always increases.