Autocomp load discrepancy?

[ipscjoe]

Yes I've used the search function and yes I'm still confused.

A few months ago that article came out comparing autocomp to CFE pistol. From what I'm reading here, the loads aren't jiving.

For super comp brass with 124's guys are saying here they are using around 7.5 gr. or autocomp? And the article is saying 6.9 will be around 170 pf?

Everyone is saying basically you up your charge .2 tenths for CFE vs autocomp. That would mean 6.7 of autocomp would be around 170?

I'm running a 5 inch unported gun with a 9 chamber egw comp.

Super comp brass, 124 MG JHP's

Trying to get a starting point to work up to with autocomp to get to 170 PF

Sorry to ask this again but things aren't right here somehow.

Edited February 15, 2015 by ipscjoe

[kneelingatlas]

I would imagine 7.5gr WAC under a 124 making only 170pf is either a shorty or has lots of holes, make some rounds with 6.5-7.2 and put them over a chrono.

[superdude]

Every barrel is different. Some are fast, some are slow. Different lot numbers of powders can produce different results. You always have to test your ammo/bullet in your barrel to know what your gun will produce.

[BeerBaron]

absolutely. there is such a variety of what people are loading and shooting you cannot just say flat out that (for example) 7.0gn of autocomp with a 124gn bullet makes 170pf in an open gun. Which bullet? plated? jacketed? coated? which gun? which OAL? you see where this is going...

I'd do as kneelingatlas suggested. make up 10 rounds at each of the powder steps he mentioned and run them through your gun over a chrono. If you don't have one there will no doubt be someone local who will let you borrow theirs. just don't shoot it!!

[A63111]

Tested CFE with 3 different guns, 1 loose barrel and 1 fairly new .38 SCs and a 9 mm Trubor none having ports. Power factor was 168 with new newer barrel running 7.0 of CFE with 125 grain Zero JHP-C @ 1.240 in a .38 supercomp, Winchester primers. The slower barrel with the same load yielded a 158 power factor. 70 degrees outside that day last week.

A 9mm Trubor (no porting) with 8.0 of CFE, CCI SRP primers with Zero 115 JHP-C @1.150 gave me a 175 PF . While changing to a 125 Zero and 7.1 of CFE with nothing else changed gave a 172 PF.

We normally load Silhouette(WAP) in these guns the 38 SC uses 7.6 under a 125 for about a 172 PF and the 9 with a 125 @ 7.8 of Silhouette gives about a 172 PF. The next loading for .38 SC will be @ 7.2, 7.4 and 7.6 to see where they'll chrono. I should at least mention that although the powder was bought at the same time and location 1 was from an 8lb keg and the other from a 1 pounder and we have not checked the lots numbers to see if they are the same.

I found the inconsistecies as well, 38 SC will need more work and the 9 mm with 115s could come down some none the less the information was a decent starting point. Even in the article if it's the same I am working from the author used the same gun but 2 different barrels and I don't believe he had a comp on either.

As with the article and everyone else's testing experiences will vary but it is a ballpark to start with.

As always start low and work up.