rcbs precision mic tool

[josebd]

i used this for a .223 remington 700 bdl. for checking the bullet seating depth the dummy round measured 2.254 been reloading 2.250 hornady 55 v-max.kinda confused on how to read the mic,used dial calipers.do i need to experiment with the seating,and by how much?it groups within 3/4 of an inch right now at 100 yrds.probably would do better with a good shooter.

[ButlerFord45]

Jose, I reread your topic, oops, I've never used one of those :oops:  :oops:  HOWEVER I still stand by my statement about mic's and caliper's in general




Jose, with a good dial caliper and a little practice, you can read a closer measurement than most people can get with one of these cheap micrometers.  It sounds like a good load, or it would be for me, if you wanted to try for better just for the sake of tinkering, give it a try.  If your using standard 7/8 x 14 dies and have a six sided lock ring, then one  flat will equal .012" if that helps any.

[bigdaddytacp]

i used this for a .223 remington 700 bdl. for checking the bullet seating depth the dummy round measured 2.254 been reloading 2.250 hornady 55 v-max.kinda confused on how to read the mic,used dial calipers.do i need to experiment with the seating,and by how much?it groups within 3/4 of an inch right now at 100 yrds.probably would do better with a good shooter.

......Me again.....I have a RCBS precision mic for the 223 and the "dummy seating round" is nearly worthless due to the spring loaded ejector on the 700 and you have to tighten the dummy shell so tight that it forces it into the barrel to let the extractor snap over the rim aganist the force of the ejector....the Stoney Point OAL tool is much better and easier to use.........the Mic itself works well and "O" is supposed to be min headspace for the headspace measurement.......I use the 55 V-max in molly and my 700vssf likes them .015 off the touch distance I got with my stoney point tool.........I would load some shells at the 2.250 distance and then some at the 2.240 and 2.230.........I shoot 3 shot groups when hunting for a "sweet spot" untill I start getting some grouping that look even and smaller.......then I go to 5 shot groups and change the seating adjustment to .005 difference......MAKE sure the inside of the mic is cleaned and the base of the cartridge is clean and not burred from extraction.......use the mic a few times to get the feel of the contact on the round and I give mine a small shake side to side as I get close to the touch point to make sure the case is flat/flush inside the mic and will  double check a loaded round every few cases just to make sure I'm consistant in the feel of the mic...similar to a non ratchet micrometer......You just read the calibrated scale on the side of the mic to get a reading that is only a reference to that tool.........for quick use you just read from the scale as to being shorter or longer than the touch measurement you  got from the dummy seating tool.......the Precision mic is slower to use because of the threads having to be screwed but it lets those without a good dial caliper do precision measurement relative to the scale on the mic......I use the Sinclair or Stoney Point for use with a dial caliper and just got a Davidson setup for testing that clamps on the caliper.......the marks are supposed to be .001......make written records of the readings so you can track the throat errosion and see when you have to "chase" the lands by seating the bullet longer to keep the jump the same as the barrel wears...... again good luck and good shooting-loading!!