9mm pcc load update

[nickbfishn]

9mm 147 bayou bullets

1.130 oal

mixed brass

cci primers 

n320 2.8/2.9/3.0

16" barrel 

Ati milsport 

 

so today the 3 loads were tested. Prior to changing each powder level the loader was cycled several times than the grains measured 3x for accuracy. 

 

2.8 of n320 ran a pf averaged to 130.6

 

2.9 of n320 ran a pf of 137

 

heres where things get weird...

3.0 of n320 ran a pf of 137.8

 

and with all rounds the brass is wicked dirty afterwards

[jlo86cj]

Sounds about right. I ran my production load through an ATI and got 141. Its 3.2 gr of n320 with an acme 147 at 1.100".

How many rounds are you running through the chrono for your average?

[v1911]

If you're running a Dillon press, it can vary as much as .1gr per throw. Also, mixed brass will have an effect on consistency. 

[nickbfishn]

14 hours ago, jlo86cj said:

Sounds about right. I ran my production load through an ATI and got 141. Its 3.2 gr of n320 with an acme 147 at 1.100".

How many rounds are you running through the chrono for your average?

3 strings of 5 

[nickbfishn]

14 hours ago, v1911 said:

If you're running a Dillon press, it can vary as much as .1gr per throw. Also, mixed brass will have an effect on consistency. 

True on the Dillon, and the brass was mixed, but it was once fired and ultrasonic cleaned and no military

[gatortommy]

14 hours ago, v1911 said:

If you're running a Dillon press, it can vary as much as .1gr per throw. Also, mixed brass will have an effect on consistency. 

 

This. Internal case volumes vary greatly by manufacturer. Different case volumes will vary pressure. If you want precision, I'd start by using same headstamp brass for your testing.