Howa Mini Load Development Journal

[Paringa]

[LRRPF52]

[Paringa]

[Paringa]

Round 2 of powder/chrony testing, this time with 123 SSTs

Virgin Norma brass

123gr SSTs over ADI Benchmark 8208 (Australian Powder). CCI 215s.

Seated around 24thou off the lands just for powder/chrony testing.

Again, very stable ESs, low of 11 and high of 23, although in this case the ES node was at the lower end of the charge strings, with velocity avg 2395.

ADI published 26.6gr start and 28.4gr as max, just starting to compress. Again, I measured case head expansion at each fired 0.2 increment and it stayed a consistent 1.5thou from min to max charge. Re-primed max load and still firm press fit, so pressure, again, seems very tolerable.

2 things stood out with the 123 SSTs over the 100gr NBTs. Speed and Recoil. Working within ADI limits, the 123s ran 300fps slower, topping out bang-on 2500fps compared to the 100gr NBTs 2825 (and where the NBT's ES node was at the top end of the charge string). Felt recoil was significantly greater, and although still a pussy cat, it's probably stepping past the realm of a kid-tolerant round and into a place that makes the round less unique for power vs recoil.

Interestingly energy comparison puts the 100gr NBT at 1772 ftlb and the 123gr SSTs at 1707 ftlb so I'll take the flatter shooting, lighter recoiling, harder hitting 100grainer any day.

All my brass is formed now, so I'll first shoot some groups using the 100gr NBTs with 30.2, 30.4 and 30.6gr.....pick the best one, and see if I can improve with seating increments of 3thou.

Stay tuned

[PaulieV]

Thanks for sharing mate, it's got me interested in the 100gr NBTs for sure. I'm using factory Hornady Black/American gunner at the moment and will have around 500 once fired brass soon. Already picked up the 123gr eld-m and a kg of 8208, so will add some 100gr NBTs in the mix too.

[Paringa]

Will be dropping back to lower velocity nodes as reshooting 30.2 and 30.4 with the 100gr NBTs today went over pressure.