Brent,
The bullet's were about 1500 Berger 210's. 30 Cal of course. I did shoot a few amax's, some JLK's, you know, some of everything. Powders that I can think of that I know I shot in matches were, H1000, H4831, IMR7828, IMR4831, IMR4350, W760, W748, H380, H414, R22, again, you get the idea. I never shot the same load 2 days all season.
Speeds on the 210's varied from once at 2675 up to just a tick over 3100 out of a 27" barrel. That 3100 day, you certainly knew when the gun went off. My middle finger was bleeding from the trigger guard hitting me.
The case was (notice, was) a 416 Rigby, shortened to 2.060 with a 40 Degree shoulder and relatively short neck. The body taper ended at .555 at around 1.800 or so. Just a real short fat case like a WSM, just fatter. This new barrel is basically the same case with a longer neck (2.160CL) and has a .125 and .150 radius, so, there is basically no straight shoulder on it. I made the thing myself, made all the tooling, dies, form dies, etc. Lets just say the tolerances were held closer than most. The same tools that made the chamber, also made the dies, but, in a CNC lathe. SO, I have control over the amount I work the brass. I would resize brass BARELY so it was nice going in and if any got tight, go pull the program's back up and make a new die .0003 under the last one. The tools stayed in the lathe for nearly the entire season (the nice thing about having a CNC lathe that's not used for production machining.) Much like my current barrel that was chambered months ago, but the boring bar is in the lathe to this day so I can make new dies as the need arises. I made collet dies, press dies, body dies, neck, shoulder, every combination you can immagine, I have one. Now, theyre all scrap because I've changed the case configuration. The new cases are a TON easier to deal with, not having the sharp transitions. I am going to rechamber the old barrel to the new chamber design, but, not until I get the new BAT action that's comming. This nesika I have has seen it's last dollar.
As a side note, I've seen the threads about concentricity here. I haven't used my gauge for a long time so I got it out the other day to check my loaded rounds that are generally about perfectly round and straight. I had loaded 22 rounds for a test. The WORST case did not have .0003 of runout. Most, I could use a new indicator to measure. That's the beauty of a single pointed chamber. The hardest part was holding the case in the fixture well enough to get an accurate reading. There IS NO runout on these cases.
Anyone out there want to buy a Sinclair concentricity guage???
When the chamber and all the dies are cut in a lathe with a boring bar, there simply is no out of round. I had a feeler gauge to check that the jaws that were bored did not make contact with each other when closed on the barrel because they were SO close to full contact. They were bored with a taper so as to put exactly even pressure on the barrel front to rear, etc, etc. About the only downside is that If I decide to rechamber a barrel, I have to rethread the thing in an engine lathe because the Okuma won't do it. (PS, Okuma, for those of you who are not familiar, is an American made lathe... And, they're,... real .. nice.) Our's is a 6" lathe with 30HP on the spindle.
Anyhow, add it up and you get life out of the brass. They got fired pretty hot at times. My second lot of brass was real crap. 3 firings and the heads all started comming off. They sucked. Also Norma, but, with different bases as I noted in an earlier post to ya.
All the neck turning was done in a fixture in the lathe also. I have a K&M 30 Cal Carbide tool that's easily the nicest neck turning tool in the world that has NEVER turned one of my match brass. The way I do the brass now, they cannot be done without a CNC lathe because I radius the inside as well as the entire shoulder gets thinned in one pass. A peice of brass takes about 40 seconds to run. They end up absolutely identical in thickness and with any profile I like. They get run with the same boring bar that made the chamber, and same insert. I just don't use the through tool coolant (obvoiusly) since they get done dry. I also tried creamic inserts but they're a REAL pain in the ... A .156IC insert with a #1-72 screw in the middle of it is a pretty small peice of glass to try not to break. I did make wiper inserts in the past for necks but I'm not sure it's worth doing the extra grinding. My automated case annealer will be finished tonight as soon as I get back to it and I've considered making a little CNC case lathe for at home out of an old taper attachment we have at work. I could fixture the cases and turn them here, but, mostly I'd just like to do it to say I did. A few stepper motors for axis drives like I made to replace the hydraulics on our surface grinder would work just great. I can talk to an old PC so software in "C" would control the movement from commands issued through the parallel port and viola. Simple movement would be no big deal and a 400 Pulse per rev stepper would be way more than enough for repeatablilty. Accuracy is not an issue since you simply reoffset the tools. Repeatability is all that matters and our grinder repeats to about nothing, it wouldn't be but about a weeks work.
Ask Boyd about the crazy crap I build! He's seen first hand. He hasn't seen the annealer, but, when he does, he's gonna want to use it!
