Malamute wrote:
Can you run numbers for 30-30 AI in your Quickload program? I'm curious what pressures it actually makes for some loads that people are using. Some claim any increase is simply adding pressure. Not sure if that's correct.
I gave this a go, Malamute. And it was interesting: the first thing I notice is that QL gives 42K psi as max for the standard 30/30, but gives the AI a max of 46,412 psi. I have no idea where that AI max would have come from, but may be quite reasonable if there is indeed a benefit from a straighter case wall for the handling of pressure.
If you don't already have your powder on hand, QL thinks AA 2495, BLC-2, and W748 would be top choices with RL-15, 10x, and 7 not terribly far down the list.
Then with 31.0 grains AA2495, 30/30/170grain :20"bbl provided 2189 fps; 24" bbl provided 2271 at 41.5K psi (500 under max).
I should mention here that QL actually shows IMR 3031 being the top choice in every situation but my personal experience is that QL rather overrates 3031 and I don't trust anything it says about 3031 so have dropped it from my loads in this case.
The AI with 33.3 grains AA2495, 170 Sierra : 20"bbl provided 2235 fps at 41.5K psi, but 34.4 grains provided 2303 fps when allowed 45.9K (500 under max).
With the 125 grain Sierra, standard 30/30 37.8 grains W748 gave 2533 at 41.5K psi from the 20" bbl;
with the 30/30AI 40.6 grains W748 gave 2594 at 41.5K psi, 20" bbl
But the AI when allowed 45.9K psi gave 2680 fps from 41.9 grains of the W748.
Looking at some other AI loads for 20" bbls which have recently been mentioned on the AI thread --
With the 170 grain Sierra you reach 2350 fps with 37.0 grains RL15 at 49,850 psi
Using Varget, 37.1 grains gives the 2350 fps but needs 52,950 psi.
With the 150 grain Sierra 38.0 grains RL15 gives 2400 fps at 43,500 psi (below max)
and with Varget, 38.0 grains gives 2400 fps at 46,500 psi. (just above max)
Note that
ALL of these loads are either near or above or even well above max loads and QuickLoad labels them as
"Dangerous Load -- Do not Use!!"
In summary, there is a small gain with the AI when held to the same pressure as the standard, but a definitely noticeable gain when loaded to a 4400 psi greater pressure.
A limitation of my investigation is that QuickLoad still does not include Hodgden's LVR powder among the choices, and we know that you can achieve close to these AI velocity levels in the standard 30/30 with the use of the LVR powder (at least as far as the 170 grain bullet is concerned. I have not shot the 125 using LVR and have not seen data for it either)
