I have that 1992 manual, and the second edition Accurate Arms manual. What I have learned about Accurate Arms data is: it could be. It could be on the money, it could stick a bullet in the barrel, and the first round downrange range could blow primers on the recommended starting load. While I have kegs of AA#9, purchased when a 8 lb keg was $64.00 (that was the days!), just like any ball powder, ball powders go from zero to bitch in pico seconds. I never liked ball powders habit of going nasty without any previous warnings. I think it is because the stuff has so much surface area and the initial pressure spike is higher than flake or stick powders.
And then the stuff is hard to ignite in cold weather. One cold weekend I took to the range to shoot two recent acquisitions. The first was a well worn S&W M586 and the other a 95% Colt Trooper Mk III both chambered for the 357 Mag.
I bought a very used M586, the previous owned shot PPC with it, said he fired about 40K of 148 LSWC with 2.7 Bullseye and Federal primers. If you are not aware, Federal primers are the most sensitive primer on the market a combination of thin cups and special sensitive priming compound. These primers are outstanding in pistol mechanisms, especially mechanisms with weak or marginal ignition systems. This is an excellent post on this issue:
IT DON’T GO BANG: FIRES, HANGFIRES, MISFIRES AND SHORT ORDER COOKS IN JERSEY It turns out, there are a lot of fire arms on the market with marginal ignition systems. Federal primers will ignite when other primers misfire. While this is a wonderful benefit for revolvers and pistols, it is not an advantage with semi auto rifles. In these mechanisms, Federal rifle primers, standard and match, are the most slamfiring rifle primer on the market.
The weather was cold there were infact snow flakes in the air, it was overcast and the wind was blowing. The ammunition had been overnight in the bed of the truck. With the M586 I had misfires, no hangfires, but I experienced squibs with a load I tested in 103 F weather. I had rounds that were anywhere between full power and squib. I did not have issues with the Colt Trooper. My load was with a 158 LRN with 12.0 grains AA#9. I used WSP primers. Below is my test data, 12.0 grains AA#9 was close to my “reference” load of 13.5 grs 2400, so that’s what I used.
AA#9 is a very fine grained ball powder. It shot just fine in warm weather.
One round left a bullet in the throat of the M586, another round left a bullet lodged between the cylinder of the M586 and the throat. The bullet stuck in the M586 throat had a column of ball powder behind it. The texture of the powder was similar to cotton candy. Ball powder was all over the mechanism, I had to get a paper towel and wipe it out from under the extractor star, cylinder recess. Luckily I had a long shafted screwdriver. Inserting the screwdriver through the muzzle and pounding on the handle enabled me to knock the lead bullets out and continue shooting.
I may have had light primer strikes with the 586, but as you can see from the primer on the M586 case, I had deep primer indentations. I have looked at the firing pin protrusion with the M586, and that looks to be good. It protrudes a significant distance out the recoil shield. I loaded this ammunition on a Dillion 550B over a couple of years ago. Out of 100 rounds, these were the only two that stuck in the barrel, but I did have squib rounds.
Shot well, even out to 50 yards. The squib loads barely rocked the gong.
As you can see, the primer looks fairly well smacked.
Tested velocities of my loads in a M27 Smith:
Code:
[SIZE="3"]
[b]Smith & Wesson M27-2 6.5” barrel[/b]
158 LSWC 13.5grs 2400 R-P cases CCI primers
9-Oct-05 T = 64 °F
Ave Vel = 1273
Std Dev = 44.03
ES = 176.7
High = 1372
Low = 1195
N = 30
Very accurate.
158 LRN 12.0 grs AA#9 CCI500 Mixed cases
5-Aug-06 T = 103 °F
Ave Vel = 1278
Std Dev = 34.98
ES = 117.4
High = 1344
Low = 1226
N = 27
Accurate little or no leading
158 LRN 12.5 grs AA#9 CCI500 3-D cases
5-Aug-06 T = 103 °F
Ave Vel = 1348
Std Dev = 34.16
ES = 134.7
High = 1386
Low = 1251
N = 25
Very Accurate no leading[/SIZE]
When I got back home, I replaced the old M586 mainspring with a new, took the pistol out in slightly warmer weather, same ammunition, no problems. But the thing is, ball powders require strong primer ignition, and are not tolerant of weak ignition, or weak primers.
