Thread: Hodgdon 69 gr 223 manual error?

Greetings again @NathanSBR.
I had a closer look at the data and the pressure for each of the loads is close to 50,000 CUP (copper units of pressure) which is below max for the .223. The CUP measures have been out of date for 30 odd years now so it is old data. Some of the .223 data is held a bit below max presumably to give consistent port pressure in semi auto rifles. The 60 grain V-MAX gives a little more pressure than the SMK likely due to the longer bearing surface and deeper seating. From my loading and chronographing it appears that the lower charges in some data is due to the heavy compression needed to get the powder in. In an earlier post I wrote about data variations with the 60 grain V-MAX and BM8208 and there are some test loads in the blocks ready for chronographing so will report in due course.
A couple of years back I did some comparative testing with BM8208, AR2206 and AR2206H with the 125 grain projectile in the .308. In that application BM8208 and AR2206 were close to the same speed with AR2206H a bit slower. This makes me think that BM8208 might be a better powder for the .223 than AR2206H.
Regards Grandpamac.

Originally Posted by grandpamac

Greetings again @NathanSBR.
I had a closer look at the data and the pressure for each of the loads is close to 50,000 CUP (copper units of pressure) which is below max for the .223. The CUP measures have been out of date for 30 odd years now so it is old data. Some of the .223 data is held a bit below max presumably to give consistent port pressure in semi auto rifles. The 60 grain V-MAX gives a little more pressure than the SMK likely due to the longer bearing surface and deeper seating. From my loading and chronographing it appears that the lower charges in some data is due to the heavy compression needed to get the powder in. In an earlier post I wrote about data variations with the 60 grain V-MAX and BM8208 and there are some test loads in the blocks ready for chronographing so will report in due course.
A couple of years back I did some comparative testing with BM8208, AR2206 and AR2206H with the 125 grain projectile in the .308. In that application BM8208 and AR2206 were close to the same speed with AR2206H a bit slower. This makes me think that BM8208 might be a better powder for the .223 than AR2206H.
Regards Grandpamac.

Thanks for the input