Hi All!
I spent last weekend playing with the AM30 a bit. Initially, I was having a little difficulty getting it dialed in where I wanted it in terms of accuracy and velocity. Everything I had played with was definitely minute-of-deer easily inside of 200 yards and some beyond, but I always seem to find myself on the quest for the perfect load... so I took to the powder room to see what powders I had on hand that might hold potential for my holy grail of a load. (Note - I have since found several decent, less than 1/2MOA loads, but this experiment was just prior to these finds)
With the AM30 being a wildcat, I looked to powders that were frequently used with the parent case and also 7.62x39, which was identified as having similar case capacities. I selected from some of these. My initial run of tests (detailed here) only deal with velocities and appearance of max pressure. None of these were shot for groups and I only fired 2 rounds of each load to get a very preliminary feel for velocity.
All loads were with converted Federal brass, Remington 7-1/2 Primer and the 125 gr Sierra ProHunter bullet seated to 2.300". Velocities were measured at the muzzle with a Magnetospeed Chronograph, which I have checked against my other chronographs and found to be seemingly accurate. Here are my limited, but potentially informative results:
Alliant RL7This one is fairly established with the other members of this forum, This powder will easily hit pressure limits before running out of case capacity and is probably a good powder for most of the 125's
28.7gr - 2513fps
29.0gr - 2534
29.3gr - 2547
29.6gr - 2571
I had more loaded at increasing charge weights but saw early pressure signs on the 29.6 load so I stopped here and pulled the higher loads.
CFE223I picked this one because I am getting good velocities and accuracy out of my 6.5x6.8 SPC with similarly weighted projectiles
31.8gr - 2076fps
32.1gr - 2101
32.4gr - 2122
32.7gr - 2135
These were my initial 4 charge weights and obviously very slow, I saw no indication of pressure with any load but this is nearing maximum case capacity with this bullet, I might be able to cram a little more powder in, but I still don't think I'd see velocities in the range I'm looking for. Any kind of boat-tail bullet would likely be a compressed load. I have abandoned further development with this powder.
IMR 8208XBRI selected this for the same reason as CFE223
28.2gr - 2002fps
28.5gr - 2052
28.8gr - 2069
29.1gr - 2101
Like above, these are obviously very slow. I saw no pressure signs with any of these but also like above, case capacity is pretty used-up, I don't think I can fit enough of this powder in the case to get the velocities this caliber is capable of. This powder is also abandoned for further use with these bullet weights.
Ramshot X-TerminatorI selected this powder because it is listed for comparable-weight 7.62x39 loads. I have used this and Accurate 2230 with identical results in other cartridges although I don’t believe they are the same powder, with that said, I can’t differentiate between the two in performance in my limited tests, YMMV.
30.8gr – 2369fps
31.1gr – 2378
31.4gr – 2382
31.7gr – 2416
32.0gr – 2437
32.3gr – 2444
32.6gr – 2460
32.9gr – 2474
The last few loads on this appear to be nearly or slightly compressed with this flat-based bullet. I might be able to fit just a tiny bit more powder in the case but not enough to make any huge velocity differences I don’t believe. I saw no indication of pressure on any of the loads.
IMR 4198This is another powder that was identified as potentially suitable for this cartridge due to it’s density and general burn rate. I have used this powder in dissimilar-sized cases and dissimilar bullet weights but was flying blind with this one, other than listed starting loads for 7.62x39.
25.0gr – 2252fps
25.3gr - 2254
25.6gr - 2288
25.9gr - 2374
26.2gr - 2387
26.5gr - 2389
26.8gr - 2405
27.1gr – 2418
This powder still allows for a little more room in the case with this bullet. I did not see pressure signs with any load, however I didn’t continue with heavier charge weights either due to the velocities I was getting, This one may be able to hit 2500 but the somewhat erratic jumps in velocities between some of the charge weights make this nothing more than a guess. Someday I may revisit this powder and see where the top is, but that day isn’t today.
Hodgdon H4895This powder had listings for the 7.62x39 with comparable-weight projectiles and I had it on hand so I put a few together with this as well.
30.9gr – 2222fps
31.2gr – 2249
31.5gr – 2274
31.8gr – 2277
32.1gr – 2311
The last few loads on this one were compressed although I saw no pressure signs. Based off the results, I think it is unlikely to realize the velocity potential of this cartridge with this powder, I discontinued any further testing with this powder/bullet combination.
Hodgdon H322I selected this powder for the same reason as several others, I had it on hand and it had loads listed for 7.62x39. I have had excellent accuracy results with this powder in other calibers and, if you care, it is in Hodgdon’s “Extreme” lineup; supposedly less temperature sensitive than others.
30.9gr – 2450fps
31.2gr – 2453
31.5gr – 2453 (yes, the same average as 31.2, not a type-o but probably a fluke)
31.8gr – 2474
32.1gr – 2521
The last two showed light marks that could be the beginning of pressure signs and both of these loads were nearly or slightly compressed with the flat-base bullet, as loaded. These velocities are getting closer to some of the RL7 numbers so this could be a potential candidate for the people not able to find or not having luck with that powder. Anyhow, if I decided to do a workup with this one I would be careful at the top end and look for pressure indicators.
Hodgdon H335I selected this powder because it was one of the powders listed in the original test results for this caliber. As I understand from some of the reading, this may not be a suitable powder for high-heat environments, but my purposes are mostly fall-hunting temps so this shouldn’t be an issue for me. If I were to ever use a workup with H335 for any other purpose, I would probably do that in temps relative to the intended environment. The day of my tests with H335 it was 91°F.
32.5gr – 2469fps
32.8gr – 2482
33.1gr – 2485
33.4gr – 2519
33.7gr – 2527
34.0gr – 2535
34.3gr – 2548
The last few loads are probably approaching compressed loads with my component combination. The last load showed very light marks on the brass which could be the beginning of pressure sign. This powder also turned in one of my most accurate groups with a different 125gr bullet in later tests. This is a viable powder, for my application, in this caliber.
This concludes this round of tests for me. I would like to give Accurate 2200 and Accurate 1680 a try before I close this chapter of loading but I don’t have a dealer within a few zip codes that carries it and I’m not too inclined to pay the hazmat fee to have it shipped unless I can find it and something else I need at the same time. Maybe someone else can give a trial run of those and compare them to one of the powders here so the results can be somewhat quantified at least. Hopefully this experiment helps someone along the way, nothing here is intended to be loading advice, some of the loads listed may be outright dangerous, I don’t know; if something in here is beyond safe levels, I didn’t intentionally list it, research your own data before replicating any of these tests, YMMV!
Cheers!
Tim