ball turret

the gage fits fine in the bolt head. the bolt won’t close on it in the barrel extension. to me, this is one of three things and i'll go out on a limb and say that the barrel manufacturer (match barrel) fitted the extension properly. 1. the chamber isn't deep enough. (not likely) 2. the bolt head is too thick. (possible from coating irregularities) 3. the cartridge pocket is too shallow. (possible from coating irregularities) the gage set i have is from a well known manufacturer. since there are three guns being built here i verified chamber dimensions and inspected the gage set. it is correct to the high end of standard gage practice tolerances. the first rifle was built with a premium, but unplated bolt. it was a flawless fit. the second and third builds are using the same barrel but a different BCG. this completely disassembled bolt is tight on the go gage. i can chamber a round with little effort, and I’m sure that during normal function the rifle wouldn’t notice it. However a hollow brass tube is more forgiving to pressure than a solid steel gage. The bolt will just try to start on the gage, but it’s too tight to go all the way and I won’t force it and risk damage to the chamber. So TTT. I need the bolt specs (sizes with tolerance) so that I can make the correct repair without taking the bolt out of tolerance. In the process I would be making the bolt have better geometry. That could help accuracy (these are to be 600 yd rifles) that would be a good thing. On the other hand, like tripleduce said, it will wear in soon enough. I’d still, analy speaking, like to fix it.

i've thought about that too. in the not so grand scheme of things, you're probaly right. it's sooooo close. i'm also sooooo anal, that this is a material on condition and it's fixable.

sent him a pm lets see <thumbsup>

The go. it will go on a cartridge, but not quite on the gage. it's probably only off by .0005 or so. just thinking the rear of the bolt head and the cartridge surface have some plating build up. the bolt functions fine in the carrier and most likely was good before the plating process. i see this all the time in the trade i'm in. i do precision maching and grinding in the gage industry. many customers want chrome or nickel plating for corosion protection and it's alwas a crap shoot judging how much undersize to make a part so that it will be within tolerance after plating. i can correct that, no problem. i can take off .0001 at a time, i would just like the bolt to be in spec when i'm done, can't find the spec though.

i'm having a minor headspace issue. it's nickel-boron and i'm thinking the high spots from the plating process are the cause. i have a lot of experience with chrome doing that and have made countless repairs on non firearm details. anyway, if anybody has a print for the bolt or at least the bolt heat thickness and tolerance, i'd appreciate it.

"when did you get that honey" "oh, i've had it for a while" always worked for the boat and i could buy 15 rifles for what i have locked up in the boat(Break Out Another Thousand).

thanks, i really like the jp rail. fully aware of the add on rail prices, but also like the fact that i'm not going to have rail that i never use. i need to have the tops line up for future iron site use. right now i want to just have a free float for grip and to add a bipod later. it's not a big deal for the gas block to line up, but it would be nice to be able to have options down the road. sustained fire isn't in the program. if anyone can confirm the jp block will line up i'd appreciate it. i can always switch it for a conventional block if it wont. since jp hasn't shipped yet i'm looking for this info now. i'd rather do the trade before than after.

A NEWBIE HERE, AS FAR AS AR’S GO ANYWAY. DOING MY FIRST BUILD TO BOOT. THIS HIGH LOW THING HAS ME BUFFALOED. I HAVE THESE 3 COMPONENTS THAT I’M TRYING TO VERIFY WILL LINE UP CORRECTLY SI DEFENSE GEN 4 308 SET (IN MY POSSESSION) JPHG-1D VTAC FREE-FLOATING MODULAR HAND GUARD. DPMS LR-308 OR SIMILAR. RIFLE. (ORDERED) JPGS-3 JP ADJUSTABLE GAS BLOCK, .936 BORE, WITH RAIL. (ORDERED) SI IS ADAMENT THAT THE UPPER IS LOW PROFILE. I’VE MEASURED IT IN 3 PLACES THAT I FEEL ARE IMPORTANT. THE OVERALL HEIGHT IS 2.06, THE BORE TO RAIL IS 1.31 AND THE TANG ABOVE THE CHARGING HANDLE SLOT IS .210 ACORDING TO AN EARLY POST IN THIS THREAD THE LR308 OLD VERSIONS ARE 2.063. I THINK I READ THAT THE OLD VERISIONS WERE HIGH PROFILE AND THE TANG MEASURED 3/16. THE NEW, LOW PROFILE WAS SUPPOSED TO HAVE A TANG THAT MEASURED 1/8, THAT WOULD CORRELATE WITH THE 2.003 OVERALL HEIGHT DIMENSION IN THE PREVIOUSLY MENTIONED EARLY POST. SO, I’M FEELING THAT THIS IS A HIGH PROFILE RECEIVER, BUT I DON’T HAVE A CLUE WHERE THE .210 TANG DIMENSION COMES INTO PLAY???? EVERY TIME I THINK I HAVE A HANDLE ON THIS BEAST I GET DELT ANOTHER CARD. THE DESCRIPTION ON THE TROY SITE HAS POOR VIEWS AND DOESN’T COVER THE .210 SIZE. I WOULD LOVE IT IF MY RAILS WOULD LINE UP LIKE SURVIVALSHOP’S DID (REPLY #34), NOT LIKE THE EXAMPLE BELOW. CAN ANYBODY HELP? OR AM I DOOMED TO BE :(