HK SD9 Tactical
Member
I was loading some 9mm RN bullets on my LnL AP and was having difficulty obtaining a stable COAL. So in an effort to get a stable COAL, I decided to seat my bullets with the seating die stem for flat nose bullets figuring that I would at least obtain some semblance of consistency in COAL.
Out of 594 rounds loaded, here are the results of COAL.
476 had a COAL of between 1.156 and 1.164 (I was shooting for 1.160 with +/- .003 but I decided to accept +/- .0045)
25 had a COAL of 1.155
14 had a COAL of 1.154
12 had a COAL of 1.153
20 had a COAL of 1.152
10 had a COAL of 1.151
8 had a COAL of 1.150
and 29 had a COAL of between 1.140 and 1.149
This means that a full 25% of the cartridges I loaded on the LnL AP were out of generally accepted specs (my specs as well) for COAL.
The LnL AP was set up as follows:
Station 1 Deprime/Size
Station 2 Charge and Bell with PTX expander
Station 3 RCBS Lock Out die
Station 4 Hornady New Dimension Seat Die with flat stem, set for seating only.
Station 5 Lee Taper Crimp Die
All cases were previously cleaned and primed so there was no priming done on the LnL AP. Cases were auto fed with the Case Feeder. I took special care to insure that all stations were occupied at all times so that any flex would be accounted for.
Obviously something is out of whack to get this variance in COAL. It could be a warped/bent shell plate but near as I can tell, the shell plate is flat. I ran a stainless steel ruler edge over both sides of the shell plate and no variance was noted. No variance was noted on the sub plate using the same method. The shell plate did not come loose at any time and was properly tightened down. The press is in alignment and is timed as indicated in the instructional videos. No adjustment had to be made to the timing. No die is touching the shell plate and powder drops measured (about 1 in 10) were within .1 grain on my RCBS Charge Master 1500 scale. The combo seating/crimp die is set up for seat only and the die is backed out to compensate for the small variances in the brass length. All brass measured between .744 in and .754 in with the majority at or near .754in.
COAL variances of this magnitude can mean pressure changes of ~ 2000 psi if not more.
What am I doing wrong?
Out of 594 rounds loaded, here are the results of COAL.
476 had a COAL of between 1.156 and 1.164 (I was shooting for 1.160 with +/- .003 but I decided to accept +/- .0045)
25 had a COAL of 1.155
14 had a COAL of 1.154
12 had a COAL of 1.153
20 had a COAL of 1.152
10 had a COAL of 1.151
8 had a COAL of 1.150
and 29 had a COAL of between 1.140 and 1.149
This means that a full 25% of the cartridges I loaded on the LnL AP were out of generally accepted specs (my specs as well) for COAL.
The LnL AP was set up as follows:
Station 1 Deprime/Size
Station 2 Charge and Bell with PTX expander
Station 3 RCBS Lock Out die
Station 4 Hornady New Dimension Seat Die with flat stem, set for seating only.
Station 5 Lee Taper Crimp Die
All cases were previously cleaned and primed so there was no priming done on the LnL AP. Cases were auto fed with the Case Feeder. I took special care to insure that all stations were occupied at all times so that any flex would be accounted for.
Obviously something is out of whack to get this variance in COAL. It could be a warped/bent shell plate but near as I can tell, the shell plate is flat. I ran a stainless steel ruler edge over both sides of the shell plate and no variance was noted. No variance was noted on the sub plate using the same method. The shell plate did not come loose at any time and was properly tightened down. The press is in alignment and is timed as indicated in the instructional videos. No adjustment had to be made to the timing. No die is touching the shell plate and powder drops measured (about 1 in 10) were within .1 grain on my RCBS Charge Master 1500 scale. The combo seating/crimp die is set up for seat only and the die is backed out to compensate for the small variances in the brass length. All brass measured between .744 in and .754 in with the majority at or near .754in.
COAL variances of this magnitude can mean pressure changes of ~ 2000 psi if not more.
What am I doing wrong?