WW Autocomp 9mm 125 gr. Lead too light!

[gbw]

I wanted some 9mm /125 RNL, and I had Win. AutoComp on hand, a new powder to me.

Loaded 4.6 gr. and 4.8 gr, which Hodgdon says is max., giving 1100+ fps. This surprised me since AutoComp shows around Unique or HS-6 on the burn rate charts, yet the 4.8 gr. max. charge is far smaller than for Unique or HS-6.

Both loads felt very light in a BHP. Confirmed on my somewhat suspect chrono, they showed less than 775 fps, not 1100. Hardly a 'max' load for 9mm.

Anyone else used AutoComp with 9mm lead? (I re-checked everything & broke down a couple of unfired cartridges - 4.8 gr.)

 

[GLOOB]

I have always thought that Hogdon's published data appears suspiciously conservative in 9mm. I have made plated 9mm loads with AutoComp, and I was underwhelmed with the cycling/recoil.

I hate to repeat speculations that could put people in danger, but I've heard the theory that Hodgon might have lawyerized their 9mm data, expecting it to be a hit with the 9mm major crowd as the next WAP/Silhouette.

Rather than pushing past the max data, I am using most of my AutoComp in 40SW, which is what I bought the powder for in the first place.

Also, just a side note. I shoot 125 gr cast 9mm bullets with Unique, and the max load for my Glocks is somewhere near 5gr. I ran into some issues when going any much higher. IIRC, I dropped back to 4.7, even. So 4.8 gr AutoComp doesn't sound that low for a cast bullet. I know you can't directly compare two different powders, but the published charge weights for Unique and AutoComp are pretty similar for most other calibers, just not so much in 9mm.

 

[tootalltrucker]

My limited experience to date:

I just resumed reloading after a long hiatus. I am using Autocomp for the first time because it was all I could find. I have loaded 124 Rainer plated RN with 4.9 and 4.8 gr both of those with 1.12"oal.i was looking for a lighter load so I also loaded some with 4.5 gr and a 1.14" oal. All functioned well in Glock 34, XDs and M&P compact. As you would expect, the lower charge and longer OAL seemed the softest and seemed to group the best (shooting freehand at 10 yards). You might want to experiment with OAL as the data I saw for LRN gave an OAL of 1.1" for 115grn and 1.12" for 124grn. I do not have a chrono.

 

[Rule3]

I use Win AC on occasion in 9mm. I have not chronograph any loads unfortunately

Hornaday #8 shows almost the same start and max load for their 124 gr LRN with a max velocity of 1050. 4" barrel.

I suspect your chrony readings are a bit off. You can't go by the burn rates.

 

[brutus51]

Just started using Autocomp myself, on my first attempt I loaded 50 rounds of Extreme plated FP's. on top of 4.8gr. It was a very pleasant, exhibited pretty good accuracy and seemed to burn fairly clean. Seemed a bit on the mild side though so I'm currently loading up 200 rounds with 4.9 and 5.0 grains to see if the accuracy improves.

 

[Tree Rat]

I switch between Auto-Comp and WSF for 9mm and 40 performance loads. I can tell you over the last few years I've worked up what I consider safe loads significantly above published data, which appears to be way conservative.

I'm running 1200 plus fps with 9mm 124's, and 1000 plus fps with 40/180's with no issues.

I assume the risk for working past max published loads but in the case of these two Winchester offerings, I think I've demonstrated a margin you normally don't see with other powders.


TR