450Bushmaster.net

Wow. That’s quite a jump.

Texas Sheepdawg wrote:Wow. That’s quite a jump.

Weather permitting, tomorrow I plan to go dump another 5 down the pipe before advancing to a finer grit. The process is explained on the NECO web site. Fire lapping is not new.

Hoot

I’ll be waiting for the next report. Sounds interesting.

Texas Sheepdawg wrote:I’ll be waiting for the next report. Sounds interesting.

Like any reduction process, the rule of the day is go slow and recheck frequently. Being out in the cold for a short time isn't too taxing. Another month and it'll start getting in my blood however! Right now, I'm timing the brake using the good ole pipe tape method but eventually, I'll want to get another shim kit or just get another brake from Kelly and time it in with my lathe.

Hoot

Got it up to .150 freebore and am stopping there until I can get some actual rounds downrange when it warms up to comfortable shooting weather in a month or so. That will have the net effect of polishing things up even more.

A 250 FTX bullet hits the lands at 2.36 COL. The 230 FMJ RN & FP are just at the end of the case by the time they hits the lands. Dawg, do you recall what the COL was when you say you "loaded them long"?

Hoot

Let me see if I have any left and I’ll measure them.

My game plan for the first outing, once the snow melts and temps are comfortable is to load up some 225 FTX to the same dimensions and charge as I originally did with the AR15 450b, in order to compare how a known good performer shoots in the 450BA. After a couple of 5-shot groups, I'll start taking the COL out and charge weight up to when excessive pressure signs occur. Currently, the 225 FTX hits the new barrel's lands at 2.32 COL but only .167 shank left in the case. I prefer at least .226 of shank in the case, so will probably limit the COL to 2.26 . Also will try a slower powder or two for comparison to Lil Gun, given the faster twist and 22 inch barrel.

Hoot

Hoot wrote:Got it up to .150 freebore and am stopping there until I can get some actual rounds downrange when it warms up to comfortable shooting weather in a month or so. That will have the net effect of polishing things up even more.

A 250 FTX bullet hits the lands at 2.36 COL. The 230 FMJ RN & FP are just at the end of the case by the time they hits the lands. Dawg, do you recall what the COL was when you say you "loaded them long"?

Hoot

Good news! I’ve got one box left. Let me find a battery for my calipers.

Hoot wrote:My game plan for the first outing, once the snow melts and temps are comfortable is to load up some 225 FTX to the same dimensions and charge as I originally did with the AR15 450b, in order to compare how a known good performer shoots in the 450BA. After a couple of 5-shot groups, I'll start taking the COL out and charge weight up to when excessive pressure signs occur. Currently, the 225 FTX hits the new barrel's lands at 2.32 COL but only .167 shank left in the case. I prefer at least .226 of shank in the case, so will probably limit the COL to 2.26 . Also will try a slower powder or two for comparison to Lil Gun, given the faster twist and 22 inch barrel.

Hoot

Here ya go.

That in theory (see sig), should leave .2 shank in the case. Not a problem with that stab crimp however. Do you recall the charge? was it 45gr Lil Gun?

Thanks,

How about your famous 230 FMJ RN?

Hoot