Question about using Auto-Comp in a revolver

[9mmepiphany]

I was going through Chrono at a match recently and got to talking to a staff member about shooting revolvers in ICORE or USPSA. The hot ticket is currently the 8-shot 9mm revolvers. The throat of most of the cylinders seem to measure .357", so it isn't unusual to load using .38Spl bullets. A issue which sometimes comes up at cases, held in moonclips, sticking during ejection.

The staff member mentioned that he was loading 147-160gr bullets long to minimize bullet jump and loading them over a charge of Auto-Comp. He said that the slower powder allowed the bullet to seal better and limit cases sticking in the chambers.

Has anyone here tried this or have feedback on using Auto-Comp in a non-compemsated pistol? My only experience using Auto-Comp is in a compensated pistol...to make use of the compensator's ports

 

[Walkalong]

He said that the slower powder allowed the bullet to seal better and limit cases sticking in the chambers.

My guess is it lowered pressures and stop causing sticky cases.

 

[Wreck-n-Crew]

I use autocomp in 9mm HP SD loads. Have used it since it came out. My understanding is the "comp" was short for competition and not compensator. Auto of course is meaning auto loader.

Autocomp is supposed yo have flash suppressant to prevent huge fireballs though some report it being a little flashy. I haven't noticed it in my loads It is also supposed to produce high enough energy in the cartridges it was intended for to meet the minimums for Competition where power minimums exist. It also is meant to burn cleaner than some powders.

Cases stick in revolvers when you dont have enough pressure to blow the case mouth out enough to prevent blowby and bullet base obturation needs enough pressure as well. That soot from weak loads causes extraction issues the more it builds up. Seems to me he was saying that's why autocomp is a good choice.

The drawback to autocomp for me is case fill is lower than i prefer. But it produces the ideal velocities to match factory HP loads as well as burns clean for me and that's why use it exclusively for those loads only.

Hope this helps.

 

[9mmepiphany]

The drawback to autocomp for me is case fill is lower than i prefer.

I detest Titegroup which is very popular with the Action Pistol group...I'm sure it is slower than that.

I usually load 9mm with N320, Sport Pistol or e3...I've even played around a bit with Shooter's World Cleanshot. Do you have any idea how the burn rate of Autocomp compare to these.

I always thought Autocomp referred to it being designed to work with compensators because it was so popular with Open pistol shooters due to the amount of gas it produces

 

[1KPerDay]

I’ve shot autocomp almost exclusively in .45 Colt in an SAA. Accuracy is great, cases are pretty clean, minimal debris. But there is some damage to the bluing on the cylinder just back of the chamber mouths. I initially thought it was leading but it turns out it’s actually gas/debris cutting or wear. Not sure if it’s a factor in other calibers.

 

[Bfh_auto]

I ran autocomp in 357 with 125 xtp. I never got sticky cases. But it's way different than your scenario.
I abandoned this load because the 125s were over expanding.

 

[Jesse Heywood]

I've loaded Autocomp behind lead in 38 spl, 357 mag and 45 Colt. Great accuracy and zero problems. If I didn't already have enough other powders to last a lifetime or 2 I would make it my go to.

 

[fxvr5]

I detest Titegroup which is very popular with the Action Pistol group...I'm sure it is slower than that.

I usually load 9mm with N320, Sport Pistol or e3...I've even played around a bit with Shooter's World Cleanshot. Do you have any idea how the burn rate of Autocomp compare to these.

I always thought Autocomp referred to it being designed to work with compensators because it was so popular with Open pistol shooters due to the amount of gas it produces

It's not clear that Autocomp produces any more gas than other powders that use the same/similar charge weights. For compensators, more gas is better, and with respect to gunpowders, those that use larger charge weights for the same velocity provide more gas. Autocomp tends to use less charge weight than many other powders used in compensated guns, so it does not seem special in that respect.

https://www.hodgdonreloading.com/winchester/winchester-autocomp

"Winchester AUTOCOMP is a ball powder designed for competition race guns. A perfect burn speed to feed the compensators with a higher volume of gas, it is a great choice for 38 Super, 9mm, 45 ACP and 40 S&W. With AUTOCOMP, competitors get off faster shots with minimal muzzle flash."

 

[fxvr5]

Burn rate chart

https://imrpowder.com/wp-content/uploads/2019/12/2020-burn-rate-chart.pdf

 

[JJFitch]

I find it ideal for 9mm, 38 Super and 38 Spl when loading 130-158 grain projectiles. It's right in there with HS6. Mid burn rate and powders a little slower are ideal for the heavier weight bullets like 147 grain 9mm.

I too run 130-135 grain plated RNFP .357 in my 9mm, 38 Sup and 38 Spl.

Smiles,

 

[Mark_Mark]

I use Auto Comp for everything small pistol ! Good STUFF!

 

[Wreck-n-Crew]

I detest Titegroup which is very popular with the Action Pistol group...I'm sure it is slower than that.

I usually load 9mm with N320, Sport Pistol or e3...I've even played around a bit with Shooter's World Cleanshot. Do you have any idea how the burn rate of Autocomp compare to these.

I always thought Autocomp referred to it being designed to work with compensators because it was so popular with Open pistol shooters due to the amount of gas it produces

Me too. I remember reading a post years back that quoted an employee at Hodgdon that stated the comp was meant to be competition. Since i was a member of several forums i cant recall which one it was.

I guess i should also note that i took the poster at their word. It is possible they were blowing smoke but the poster was a regular at not known to be the type of person that would do such a thing.

I dont remember exactly where Autocomp is on the burn chart but it is much slower than Titegroup and not as slow as Power Pistol or Accurate #9.

Back when i did some testing with 9mm powders to compare burn rates and velocity differences from a pistol to a carbine i used Autocomp and it produced a decent increase in the carbine over Red Dot and was faster than Unique if i remember correctly. I posted my findings here on THR. If i find it i will share a link here.

 

[Wreck-n-Crew]

I detest Titegroup which is very popular with the Action Pistol group...I'm sure it is slower than that.

I usually load 9mm with N320, Sport Pistol or e3...I've even played around a bit with Shooter's World Cleanshot. Do you have any idea how the burn rate of Autocomp compare to these.

I always thought Autocomp referred to it being designed to work with compensators because it was so popular with Open pistol shooters due to the amount of gas it produces

Here is the post i mentioned earlier and my findings with slow vs fast powder. Maybe find something useful in here.... https://www.thehighroad.org/index.p...-vs-factory-chrono-test.799017/#post-10190193

 

[Wreck-n-Crew]

Me too. I remember reading a post years back that quoted an employee at Hodgdon that stated the comp was meant to be competition. Since i was a member of several forums i cant recall which one it was.

I guess i should also note that i took the poster at their word. It is possible they were blowing smoke but the poster was a regular at not known to be the type of person that would do such a thing.

I dont remember exactly where Autocomp is on the burn chart but it is much slower than Titegroup and not as slow as Power Pistol or Accurate #9.

Back when i did some testing with 9mm powders to compare burn rates and velocity differences from a pistol to a carbine i used Autocomp and it produced a decent increase in the carbine over Red Dot and was faster than Unique if i remember correctly. I posted my findings here on THR. If i find it i will share a link here.

As it turns out i didnt record the Autocomp loads though i did later test with it and didnt update the results. Sorry about that.

 

[fxvr5]

I dont remember exactly where Autocomp is on the burn chart but it is much slower than Titegroup and not as slow as Power Pistol or Accurate #9.

See the link I posted with the burn rate chart. The chart shows Autocomp (rank #41) as slower than Power Pistol (rank #34).

 

[9mmepiphany]

Burn rate chart

https://imrpowder.com/wp-content/uploads/2019/12/2020-burn-rate-chart.pdf

Thank you very much...I've saved it for future reference

 

[tightgroup tiger]

I've loaded Autocomp behind lead in 38 spl, 357 mag and 45 Colt. Great accuracy and zero problems. If I didn't already have enough other powders to last a lifetime or 2 I would make it my go to.

I use auto comp for lead bullets also in my 327FM for reduced loads and have used it in my 9mms and .357 mags with lead bullets also because it's burns clean and with lead doesn't make as much of a mess on the gun and my hands as other powder does.
And it seems to be just as accurate as the others.

Auto Comp burns really clean, that's what I thought was the big attraction for people shooting compensated pistols. It may make a lot of gas but it's cleaner gas than a lot of powders out there.

 

[blue32]

Though I don't have any compensated pistols, Auto Comp is my go-to powder for 9mm. I run 4.7 gr under a PC Lee 356-120 TC.