I've tried the ladder test once before, and unfortunately I didn't get much from the results. I thought I'd give it one more shot on a different rifle. This time I tested out a new 6.5x55AI I had IT&D build.

It's a Remington 700 SS action that I picked up here on the Fire, and I had Dave screw it all together for me as well as provide the barrel. The barrel is a Douglas SS Air-Guaged, 1:8" twist, No. 2 contour, finished at 23" with a 1.5" shank. Right now it's sitting in a cheapo plastic ADL stock while I wait on my new KS Edge stock from McMillan. Up top I have a set of Talley LWs and a Leupold VX-II 3-9x40 with the LRD.

After I got it bolted together, I loaded up a couple of rounds for it. Paul had been kind enough to send me some brass (including some Lapua that was already fireformed), so I loaded up the Lapua with 120gr Barnes TTSXs and loads of Ramshot Hunter ranging from 49.4grs to 52grs in increments of .2grs. I shoot a similar load in my 260AI, only with the 120gr Amax instead of the TTSX, and since they have a pretty similar H2O capacity, I knew I would be pretty close.

Unfortunately I didn't take the chrono, so no velocities yet, but I did start to get some slight ejector marks around the 51.6gr mark, though no other pressure signs, and they weren't real consistent. 51.6 had a mark, but 52 didn't for example.

I also loaded up some fireform rounds with 48grs of Ramshot Hunter under a 120gr Amax. The first 5 shots out of the barrel hovered right around an 1" to 1 1/4" at 100. After I figured I had the barrel fouled a little, I turned to the 300yrd line.

Here's the results (squares are 2"x2")...

[Linked Image]

There are 5 shots in there that aren't labeled. Those were the 51.2-52gr loads. Unfortunately it was getting dark and my target was getting fairly swiss-cheesed, so I had trouble plotting where those landed, plus I was running out of time.