Taccom ULW Complete Upper

[Flatland Shooter]

1 hour ago, alvinsmith75 said:

 I achieve the same PF as you with only 3.5gr of N320.

 

N320 3.5gr, 125 BBI

1142/1122hi-lo

1132fps

142pf

 

My 16" barrel is PSA with over 10k rds through it.  My chrono is ProChrono digital.  I'm about 200' above sea level and the temp when ran was around 65 degrees.  Setting up the Dillon powder measure I weigh the powder drops with an RCBS 505 scale.  The N-320 is from a 16# order purchased in late 2015 or early 2016.

 

My guess is the barrel makes the difference.  I have another upper with a fairly new Spinta barrel (also not throat reamed) and will try to chono the loads with it and report the results.

[alvinsmith75]

3 hours ago, Flatland Shooter said:

 

My 16" barrel is PSA with over 10k rds through it.  My chrono is ProChrono digital.  I'm about 200' above sea level and the temp when ran was around 65 degrees.  Setting up the Dillon powder measure I weigh the powder drops with an RCBS 505 scale.  The N-320 is from a 16# order purchased in late 2015 or early 2016.

 

My guess is the barrel makes the difference.  I have another upper with a fairly new Spinta barrel (also not throat reamed) and will try to chono the loads with it and report the results.

Yep definitely some differences there.  Makes sense now.  Thanks.