308 Winchester load development help

[ZR2Chevy22]

Hey guys and gals,

I've been over here scratching my head. I have some AA-2230-c powder and they say load it as you would AA 2460. My question is this, I want to do a ladder test but I've seen varied max loads between the hornady manual, Sierra manual, and Accurate manual. I'll be loading 168 grain Sierra match King BTHP's. What would you recommend as a good ladder test to start with?

This 2230-c powder is a sealed 8 pound keg that's probably 8 or 9 years old. Has been stored in an attached garage. Accurate advises to load based on 2460 load data.

 

[jmtyndall]

I find the Hornady manual to be quite conservative, so I usually run with the Lyman manual recommendations. When that isn't available, I go with powder manufacturers. How much do the loads between the manuals vary? If you use the highest one and reduce by 10%, I'm sure you'd be in a safe range for all three manuals. Slowly work up looking for pressure signs and you'll be fine

 

[ZR2Chevy22]

Sierra - 38.1 to 41.9
Accurate - 38.3 to 42.5
Lyman - 38.0 to 42.0

Powder I'm using is Accurate 2230-C. On the powder keg it says, "A military surplus ball propellant that is slower than Accurate 2230. Use 2230 load data." On their website it says use 2460 load data. Spread above is for 2460 data from the manuals.

 

[ZR2Chevy22]

Good find.... Upon further inspection of the keg of powder under another label on the side of the powder it says for 308 range is 37.8 to 42.


Here's the ladder tests I've concluded on based on the ranges. 38.5, 39, 39.5, 40, 40.5, 41, 41.5, 42 and 42.5. I'll be checking for pressure signs when I hit the last 4 loads and really looking at 42 and 42.5 although the powder company says 38.3 to 42.5

 

[jmtyndall]

41.9 to 42.5 is a 1.5% difference in max loads. I wouldn't be concerned loading to any of those numbers. Sometimes you'll find 1 manual is ~5% lower than others. That can really get in your head.

Doesn't hurt to check every piece of brass for pressure signs as you shoot them. You've only got a handful of shots!

 

[ZR2Chevy22]

So I loaded 2 rounds each at 38, 38.5, 39, 39.5, 40, 40.5, 41, 41.5, 42 and 42.5. I figure I'll shoot the ladder test both forwards and backwards on 2 different white boards. Here are the load specs I ended up going with. OAL length is ~2.800" but I measured to the OGive to have a better length consistency.

Brass - Hornady Match brass
Trim - 2.005"
Primer - Winchester Large Rifle
OGive - 2.205"
Bullet - Sierra 168gr BTHP Match King
Powder - Accurate 2230-C

 

[BearNaked]

I always pick the lowest change when looking at multiple sources and work up to the highest charge. I am cautious when i am starting a load.