R.W.Dale
Member
First let me preface this by saying that I have no real idea what the chamber pressures involved below are. Unlike other posters I'm not gonna claim these loads are completely safe just because the rifle hasn't blown up and brass comes out in one piece. Use this at your OWN risk.
30 Herrett Tactical Rimless
Rifle- 20" white oak AR15 upper chambered for 30HRT topped with a vintage 6x redfield
Cases- once fired Hornady 6.8spc reformed in RCBS 30Herrett dies, trimmed to 1.590"
Bullet- 125grn Speer TNT HP
Primers- Magtech SR and then CCI400
Powder- AA1680
COL- 2.275"
all groups were 5 shots at 100yds
First off the run using Magtech primers
25.0grs/ avg velocity 2350fps/ group, no data
26.0grs/ avg velocity 2450 fps/ group 1.5"
26.5grs/ avg velocity 2510 fps/ group 1.0"
27.0grs/ avg velocity 2563 fps/ group 2.4"
27.5grs avg velocity 2588 fps/ group 3.1"
the velocity spread with the magtech primers was HORRIBLE as was accuracy , particularly as pressure increased prompting me to go back out today and try a different primer
CCI primers
26.5grs avg velocity 2470fps/ group 1.3"
27.0grs avg velocity 2526fps/ group 1.6"
27.5grs avg velocity 2580fps/ group 1.4"
the velocity spread with the cci's was very tight, in the case of the 27.0grn load only 18fps for the 5 rds fired
NOTES and thoughts
all charges below 27.5 for the most part produced no measurable case expansion just above the head, 27.5 produced about .0002" + or - more (my tools aren't that accurate) Given that this load more or less hits my target velocity of 2600fps and is just where case expansion starts I'm inclined to treat it as the MAX loading.
Some brass failures on the first firing after forming occurred, in the form of cracking radially round the neck shoulder junction. According to Herrett guys if you don't use new cases to form this is a common problem, I annealed the 2nd batch and thus far they've all survived.
the source for this load is the infamous 28grn 7.62x39 load found in the old Speer No12?
CONCLUSION
No doubt about it this cartridge is fast, beating my 20" x39 by 200fps when it's fed charges that don't stretch the brass badly, I'll have to buy a sack O brass and try some 100 and 110grn bullets.
30 Herrett Tactical Rimless
Rifle- 20" white oak AR15 upper chambered for 30HRT topped with a vintage 6x redfield
Cases- once fired Hornady 6.8spc reformed in RCBS 30Herrett dies, trimmed to 1.590"
Bullet- 125grn Speer TNT HP
Primers- Magtech SR and then CCI400
Powder- AA1680
COL- 2.275"
all groups were 5 shots at 100yds
First off the run using Magtech primers
25.0grs/ avg velocity 2350fps/ group, no data
26.0grs/ avg velocity 2450 fps/ group 1.5"
26.5grs/ avg velocity 2510 fps/ group 1.0"
27.0grs/ avg velocity 2563 fps/ group 2.4"
27.5grs avg velocity 2588 fps/ group 3.1"
the velocity spread with the magtech primers was HORRIBLE as was accuracy , particularly as pressure increased prompting me to go back out today and try a different primer
CCI primers
26.5grs avg velocity 2470fps/ group 1.3"
27.0grs avg velocity 2526fps/ group 1.6"
27.5grs avg velocity 2580fps/ group 1.4"
the velocity spread with the cci's was very tight, in the case of the 27.0grn load only 18fps for the 5 rds fired
NOTES and thoughts
all charges below 27.5 for the most part produced no measurable case expansion just above the head, 27.5 produced about .0002" + or - more (my tools aren't that accurate) Given that this load more or less hits my target velocity of 2600fps and is just where case expansion starts I'm inclined to treat it as the MAX loading.
Some brass failures on the first firing after forming occurred, in the form of cracking radially round the neck shoulder junction. According to Herrett guys if you don't use new cases to form this is a common problem, I annealed the 2nd batch and thus far they've all survived.
the source for this load is the infamous 28grn 7.62x39 load found in the old Speer No12?
CONCLUSION
No doubt about it this cartridge is fast, beating my 20" x39 by 200fps when it's fed charges that don't stretch the brass badly, I'll have to buy a sack O brass and try some 100 and 110grn bullets.
