Winchester AutoComp 9mm Experience

[BallisticianX]

Hello all, Been awhile since I posted rather than just read but I want to pick your brains. I am embarking on developing 9mm loads for a compensated 9mm "open gun" built on the M&P platform. My intension of this build is for a Steel gun rather than USPSA competitions, although it may develop into that too. I know the M&P is not the optimum "open" platform but I had one for IDPA ESP use and a spare slide and time on my hands...enough said. So my target point is about a 140-150 pf with a 124 Berry's plated for steel while getting the comp to work enough to fufill its purpose.

Here are the gun specs in case you want them to digest;

M&P9 platform

FS slide length, slide lightening cuts and some weight reduction done.

KKM Precision fully supported Barrel

Carver 3 port comp

Non encapsulated guide rod with 11lb wolff spring

Slide ride mounted Delta point (not the C.O.R.E. its a dovetail mount from Leupold)

Compensated auto's are a new venture for me. My reloading has been for standard auto's and ported revo's. But I have a full understanding of the science around them and the general idea for tuning. That said for load development I chose to try Win AC powder as it seems to be a favorite to produce the desired gas volume and higher muzzle pressure while keeping chamber pressure to safe levels. So I loaded 5.5 grains behind the 124 plated pill with a fed standard GM match small pistol primer and chronoed. 8 shots with a low of 1101 and high of 1139fps (139 pf avg.) No problems with the gun, fed and ejected flawlessly and happy with the functioning. The comp seemed to keep the gun reasonably flat and the recoil was felt pushing straight into my palm. I want to increase the charge and test the feel as I work up etc. I want a bit more improvement on muzzle rise so going a bit hotter for more gas etc is my next step. BUT...always a "but", there was a considerable amount of singed powder kernels in the bore and in the chamber. So with my minimal experience with this propellant my question is.....Is this is normal for this stuff? Or is this one of those niche powders that only becomes clean when pushed hot (like I have found with 231 or unique) or is the flashpoint of AC higher requiring a hotter primer. I know generally speaking the slower the powder the higher the flashpoint due to increased concentration of retardents present but there are always exceptions looming in the chemistry of propellants. So some of you have been through this already I am sure. SO before I go any further any experience with this powders characteristics or ignition requirements will be much appreciated. I dont want to wast my precious and seemingly irreplaceable components seeking the answer if it is already known. Thanks for any input!

Edited September 26, 2014 by BallisticianX

[toothguy]

For minor loads with comp efficiency, you might try a lighter bullet for more powder to run the comp at a given power factor. Bayou Bullets has a 95 gr RN and a 105 gr FP bullet that would be worth experimenting with.

[DWFAN]

A buddy shot autocomp in 9mm minor. It wasnt very clean and I would guess what you are seeing is normal with lower pressure loads and Autocomp.

(it was really bad in .45 acp)

[BallisticianX]

For minor loads with comp efficiency, you might try a lighter bullet for more powder to run the comp at a given power factor. Bayou Bullets has a 95 gr RN and a 105 gr FP bullet that would be worth experimenting with.

I have some 115's I could try. I do understand the physics around the point you make and is certainly worth trying. The reason I went with 124's is I like the KKM barrels in the M&P. IMO they are the single most impactful addition you can make to an M&P to improve accuracy. I have employed 3 of them in different M&P's and they shrunk groups down considerably compared to factory and Storm Lake. I have tried both 115's and 124's out of them all and I always get the best accuracy out of them with 124 pills, though the 115's arent bad. The KKM uses a 1 in 20" twist rate so anything heavier than 124's start to destabilize. No matter anything heavier than that from what I understand reduces comp effectiveness in 9mm with required reduced powder charges etc. With such a slow rate of twist there is minimal resistance to atribute to pressure rise. WIth that consideration I figured I would just use the proven 124 for accuracy and a little more time in the barrel to better utilize the slower powder. I have 25+ years at the bench but is has been with conventional pistol recipe's and precision benchrest rifle. So the compensator adds a new dynamic that though I can wrap my head around the scientifics of it there are alot of little variables that effect it that you would only be aware of from applied experience. That is an area I lack right now. Before I start using a bullet I am not sure of I wanted to rule out the variables of the powder itself to see if I cant make a bullet I know is accurate work. I foresee alot of test firing in my future lol

Edited September 26, 2014 by BallisticianX

[cecil]

I shoot a STI Steel Master for steel... using 5.8gr Auto Comp ignited by SPP .. 124 gr Precision Delta bullet seated to 1.16.. could not find my chrono results.. but I do NOT notice any powder kernels in the chamer or barrel it is not as clean burning as CFE Pistol but I do like Auto Comp .. this load shoots very flat .. I am very pleased with Auto Comp powder and wish I could find moew. as Dec last year... I have not been able to find any...

[Sarge]

I shoot a STI Steel Master for steel... using 5.8gr Auto Comp ignited by SPP .. 124 gr Precision Delta bullet seated to 1.16.. could not find my chrono results.. but I do NOT notice any powder kernels in the chamer or barrel it is not as clean burning as CFE Pistol but I do like Auto Comp .. this load shoots very flat .. I am very pleased with Auto Comp powder and wish I could find moew. as Dec last year... I have not been able to find any...

Did you mean meow?

https://www.youtube.com/watch?v=mXPeLctgvQI

Edited September 27, 2014 by Sarge

[BallisticianX]

That movie is the official training aid for my local PD lol

[BallisticianX]

I tried 115 gr Extreme plated pills and am up to 6.5 grains. Im still getting the singed kernels.....

[Sarge]

I tried 115 gr Extreme plated pills and am up to 6.5 grains. Im still getting the singed kernels.....

All of your loading experience is hindering your adventurous spirit! 6.5 WAC with a 115 is nothing. You need to get up to about 7.4-7.6 to get that extreme up to clean burning MAJOR speed. I load MG 115 JHP with 7.8 @1.165. Gets me about 174 PF which works my Cheely Comp really well.

I have been up to 8 grains but didn't see any improvement so I backed it down a few ticks. Heck, I typically run 7.2-7.4 with a 121.

Turn it up!!

[BallisticianX]

s

I tried 115 gr Extreme plated pills and am up to 6.5 grains. Im still getting the singed kernels.....

All of your loading experience is hindering your adventurous spirit! 6.5 WAC with a 115 is nothing. You need to get up to about 7.4-7.6 to get that extreme up to clean burning MAJOR speed. I load MG 115 JHP with 7.8 @1.165. Gets me about 174 PF which works my Cheely Comp really well.

I have been up to 8 grains but didn't see any improvement so I backed it down a few ticks. Heck, I typically run 7.2-7.4 with a 121.

Turn it up!!

I have been mulling over "turning it up". But remember I am using a dishwasher safe tupperware pistol here. Despite assurances from Bobby Carver that the M&P9 platform will hold up just fine to the rigors of major I still have my reservations. Coupled with the guy at KKM telling me it wont last 6 months feeding it a steady diet of Major loads. Even though the M&P9 has been used for Major for something like 2-3 years now I still feel the practice is in it infancy and has not been done long enough for conclusive proof that the gun will last. So the powerful emotion of preserving my investment fueled by paranioa and contridictions has been overcoming my adventurous spirit! This gun is my first experience with a polymer platform. So my own expereince is lacking and have not used it long enough to become confident in its capabilities. I despised plastic guns for the longest time but gave in. Only because I wanted a cheap alternative to the .45 for IDPA and USPSA and sought a 9mm. My wallet could not afford the STI 1911 Trojan in 9mm I wanted so woolah I went plastic and chose the M&P. I chose it after srutinizing and comparing all options as it pointed and felt the best. Now here I am with a spare slide, a dream, and a supply of WAC..... lol.

Edited September 27, 2014 by BallisticianX

[Sarge]

Forgot about that. For starters the ammo may not work in the mags with 115's since you have to load so long to cram enough powder in there to get them up to speed. This is why the Glock guys stay with 124 grain bullets. They can load shorter and still make major. You probably want to try 124's. As for the M&P holding up, all I can say is Glocks do, with the right barrels and loads of course.

[BallisticianX]

I am going to try some 124's again with a hotter load. The 115's over 6.5 gr WAC are moving along at 1300fps (150ish pf) and no signs of pressure concerns. My current dilemma now is I only have plated pills in my arsenal. Weary about going any higher with them. The 115's I have are extreme bullets and they say max 1500 fps but recommend staying around 1200 and at 1300 I see no considerable fouling. The 124's are Berry's and they warn nothing over 1250fps...... They both offer heavy plated bullets for comp major loads and I am going to have to get some before I go any further. The heavy plated bullets are a cheaper buy than MG or Prec. Delta jacketed so I will start with them.

[Sarge]

EXTREME HP bullets are all rated for 1500. They come heavy plated. With the round nose you have the option of standard or heavy. You can push those Extreme 115 HP's. There are quite a few on here who run them in open guns.

[kneelingatlas]

I shoot all Xtreme RN with the standard plating in my Open guns and haven't had any issues with the plating coming off even pushing the 100gr bullets up to 1,650; I regularly shoot the 115s over 1,500.

[tiberiumgold]

I have been looking for a good major load for an 9mm STI steelmaster if anyone out there has starting point using 124 jhp zeros (have a bunch) really have not been able to find a formula that works.

Thanks in advance

[cecil]

I shoot major using 124gr PD bullets using 6.7gr Auto Comp w/SPP ... bullets seated to 1.16... makes 171 PF -- 1387 FPS .. I do suggest however, to start low and work up..

[hornetx40]

BallisticianX You started off talking about steel loads...You said you have a 3 port comp. But now you are pushing up towards major PF loads. Steel has no PF requirements so why abuse yourself and shoot loads with twice as much powder. Use either 115 gr or 95 gr bullets. Shoot for a load around a 120 PF. That means 1040 fps with the 115 or 1265 with the 95's. To do that you will not be able to use WAC. Autocomp likes higher velocities with those bullets to shoot clean. You need a faster burning powder like Titegroup to shoot clean at the slower velocities. You will have to change the recoil spring in your gun to shoot the lighter loads. I have done this in both a glock open gun with the same comp you are using and in 1911 open guns. The glock is harder to get to run the light loads due to making sure it locks up on return to battery. To light of a spring and it won't lock up. the 1911/2011's are much easier to get to return to battery with light loads. Remember there isn't a PF requirement in steel ..shoot light loads and have fun

[BallisticianX]

I originally started the project for steel and was going to experiment with WAC as I have a good supply. I am also well aware of the SCSA ammo requirements. I have been shooting USPSA, ICORE, and SCSA for years. In the back of my mind I figured I would run this gun in USPSA also. I am just unfamiliar with the characteristics of WAC and with experimentation I have learned what your saying. I wanted to use a powder for light loads that gave something for the comp to work with. I have since scrapped WAC for light steel loads. I will use my go to powder for the 38, .45 and minor 9's.....dependable titegroup. I loaded the 12 remaining MG 115's I had left over with 7.0 gr of WAC for a USPSA major load. Little light yet but put 3 shots touching at 20 yards. I tried BERRY's and EXTREME plated pills with loads at 150ish pf and they flew all over. Regardless of what they say for usable velocity, standard plated bullets lose accuracy over 1100fps at least in all my guns!! I wasn't surprised with the extreme bullets grouping like crap. Every one I ever tried does. The Berry's have always shot great in my standard 9's and my regular go to in my ICORE revo. So.....I am curious to try some of the berry's heavy plate concave base bullets to see if they shoot good for hotter loads and how they compare to the MG's. They make them just for hot rod opens guns. Anyone ever use them?

[grouptherapy]

A buddy shot autocomp in 9mm minor. It wasnt very clean and I would guess what you are seeing is normal with lower pressure loads and Autocomp.

(it was really bad in .45 acp)

Really. I'm looking at a new major load with 45 and autocomp. Not what I wanted to hear. Guess I will see how it goes.

Sent from my iPhone using Tapatalk