Considering the forecast for Winchester powders in the Australian is looking bleak, I went back to revisit adi's AR2205 under the budget Speer 125gr TNT bullet. Sadly we cannot bank on Hogdons lilgun supplies in the foreseeable future
In the interim I've been learning more about differences between extruded "stick" powder vs double-base ball type powder. Lilgun is a type of ball powder. What does this mean? Well compared with extruded powders, ball powders are generally harder to ignite, and often give poorer standard deviations. Therefore lilgun really demands a magnum primer. And the harder magnum primers do not gel with with the (at least early model) RARRs (like mine). So in many ways, in my RARR 300aac it's actually
more suited to an extruded powder like AR2205 (with a regular SR primer such as the cci400).
AR2205 was definitely a little finickier to get to group (at least compared with the lilgun loads), but thankfully I found a node with this powder+projectile+rifle combo last night:
- 18gr AR2205 under Speer 125gr "TNT", light crimp. 4x scope.
- speer.jpg (1013.76 KiB) Viewed 6849 times
For the record I went up to a compressed 19gn AR2205 load without any pressure signs (
AR disclaimer in a bolt gun I might add!!). The 18gr load is yet to be chronoed, but from my previous findings, std-dev should be more than adequate with AR2205. I take comfort in knowing it's not the very hottest of loads as I was seeing primer pockets opening up with hot lilgun loads.
This journey has also brought into light the potential need for a crimp; not from an accuracy perspective, but rather the RARR seems to be fairly rough on the projectile as it feeds from the rotary magazine. I feel sometimes the gun would set-back the pill, leading to flyers and pressure spikes. I'll be crimping from now on just to relieve my anxiety about any set-back, which really makes a bullet with a cannelure (like the Hornady SST) a little more desirable... still a light crimp on the cannelureless Speer bullet certainly does not seem to do any measurable harm to group sizes.