222 ACK IMP

[L Murphy]

Does anyone have any experience with a 222 ack imp?

I’m interested in load data and what is your recommendation on reloading dies?

 

[AWS]

Why

 

[ASbobcat]

Does anyone have any experience with a 222 ack imp?

I’m interested in load data and what is your recommendation on reloading dies?

I just tried a 30deg IMP version. I was not interested in more performance, because a 223 gives you that. I thought the sharper shoulder angle, coupled with slightly wider shoulder (.357) would stabilize brass flow and reduce trimming. I used a shortened 20Tactical F/L bushing die with the through hole widened to .250 with a diamond tool.
It turned out to be a fools errand. A lot of effort for questionable return. I just shipped my reamer back for regrind to straight 222.
I have come to the conclusion that the 23deg shoulder is actually desirable. A sharper shoulder angle makes shoulder bump increasingly critical. A 40deg Ackley shoulder MUST be bumped at least .001 or it becomes difficult to chamber, placing added stress on locking lugs, and makes bolt lift harder after firing. A 23deg shoulder is more forgiving, and allows zero shoulder bump if you resize for ,001-,002 and it doesn't quite get there for some cases with work hardened shoulders.
I believe the venerable 222Rem is the Goldi-Locks sweet spot for .224 bore case capacity. Almost 223 performance with significantly less powder, and equal performance to 221FB at lower pressure with the flexibility to shoot heavier bullets. The longer neck provides more flexibility in bullet choice than either 223 or 221, and it was the king of BR for more than three decades before PPCs.
My reamer neck is .250, which is perfect for shortened LC NATO 5.56 brass without turning (.248 loaded).

Hope this info saves you some time, trouble and money.