155 gr Gold Dots AA#7 results a little slow! [Archive] - Glock Talk

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alpha6164
09-13-2010, 14:53
I loaded some Speer GD 155gr over AA#7 this weekend and was a little disappointed with the velocity. COA 1.255", 80deg, Win LG primer (non-mag)

Lone Wolfe 5.15" Tactical barrel

12.0gr= 1225,1216,1263,1265
12.3gr= 1280,1329,1238,1269
12.7gr= 1239,1298,1272,1276
12.9gr= 1396,1338,1321,1351


These charges were weighed by hand individually so not thru a powder measure. What i cant understand is how the velocity is essentially unchanged from 12.3 to 12.7gr. Accurate lists 12.7gr at 1379ft/sec. I had to go to 12.9gr and my average still is not 1379ft/sec. Also, there were no pressure signs at all with any of the above loads.

I checked chrono with other ammo and factory ammo and it was spot on.

AZBru88
09-13-2010, 15:13
Alpha a lot of guys say when you get up to heavy loads they shine with a heavier spring. It gives the round a micro second to burn more powder before opening the slide. Might give it a try see if you see a difference.

Sorry forgot to add where in your chrono set up. Most feel 15' away gives the best readings, that way no powder blast effect on the reading. Just what I've been reading on the threads...Bru

alpha6164
09-13-2010, 15:43
Alpha a lot of guys say when you get up to heavy loads they shine with a heavier spring. It gives the round a micro second to burn more powder before opening the slide. Might give it a try see if you see a difference.

Sorry forgot to add where in your chrono set up. Most feel 15' away gives the best readings, that way no powder blast effect on the reading. Just what I've been reading on the threads...Bru



Sorry i forgot to mention that it already has a 22lb spring installed. I was probably about 5 yards away from the chrono which is about 15ft.

AZBru88
09-13-2010, 18:07
Alpha you've run me out of idea's. Sorry...Bru
Hopefully someone that uses AA#7 will come along. I use mostly Blue Dot and Unique. Some AA#5 in 9mm. Best of luck...Bru

OhioGlockMan
09-14-2010, 10:14
Try a very heavy crimp it gives better ignition and more complete combustion of the power. I do one full turn on the Lee Factory Crimp die