02-16-2014, 02:12 AM
Trock03 Wrote:SNS - Won't get a chance to shoot until tomorrow but just got done running through your checklist. Here are my results with factory Hornady 123gr SST:
First, I removed the ejector and gravity fed a round into the chamber. Bolt bolt closed with a little effort. I can't drop the round in and spin the bolt freely but a slight push and twist allows me to lock the bolt. The round won't fall out without dropping one of the small Otis brass rods down the barrel but I can't find any marks on the bullet/casing. To be honest I'm not sure if the bolt should close and lock with no effort at all or if there should be a little resistance. Regardless, I'm not concerned about the slight amount of resistance I'm seeing.
Reassembled the bolt and hand chambered a round that I had colored with a Sharpie. Used the weight of the BCG to chamber the round. Slowly extracted the round without allowing it to be pushed against the barrel extension. Observed very slight land marks that start 0.074" from the end of the case. The marks were just enough to lighten the coloring I applied but not remove it. Round measured 2.242" before and after.
Grabbed an AA 123gr Scenar and chambered with the weight of the BCG. Locking and extracting was significantly more difficult. Had to tap the charging handle with a dead blow to unlock. Land marks were a little more pronounced. Land marks start .127" from end of the case. Round measured 2.264" before and after.
Brass dimensions are identical for the most part.
Will post some pics comparing AA and Hornady primers after the range tomorrow.
TC
Trock03,
Thank you for sharing your in-depth report. Like you (but with factory-loaded Hornady 123-grain A-MAX cartridges), I experienced the need to use a cleaning rod to tap out the cartridges: in my case, after firmly inserting each into the chamber by hand (When using the spring-loaded BCG to chamber the cartridges, I noted some resistance upon extracting the unfired cartridges). And, like you, I noted marks on the bullets: in my case, approx. 0.075" - 0.080" forward of the necks of the cases. I'll trust to the analysis of your input, by other Members of our Forum.
Good shooting, tomorrow! Looking forward to your pics of fired primers.