Thread: Advice please

Originally Posted by grandpamac

So please explain how 2 inches of extra barrel drops the pressure by almost 5,000 PSI? It should be exactly the same.
Grandpamac.

I’m leaving muzzle velocity constant in GRT. The longer barrel will produce the same velocity with less pressure requirement due to longer acceleration time.

Normally the pressure would be the same for the same charge. This is all a rough estimate.

Originally Posted by Magnetite

I’m leaving muzzle velocity constant in GRT. The longer barrel will produce the same velocity with less pressure requirement due to longer acceleration time.

Normally the pressure would be the same for the same charge. This is all a rough estimate.

Thanks Magnetite that makes sense. Out of interest what was the load of AR2209 powder used for the revised barrel length? I assume GRT will show this.
Regards Grandpamac.

I used 53.0gr for both 20”, and 22” barrels.