Concentricity Guages??? Worth it, especially for semi-auto?? If so, what brand?

elfster1234

Gunny Sergeant
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  • Jun 3, 2012
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    Concentricity Guages??? Worth it, especially for semi-auto?? If so, what brand?

    I was thinking the hornady LNL concentricity gauge IF I do purchase one.

    Never used one before. Was thinking about picking one up but not sure if it's needed for semi-auto especially when the ammo is slammed into the chamber.. I could totally see this for a bolt action, but what do you think about using it for a precision semi-auto?? I currently only own AR rigs. I will eventually get a bolt action in the year or so.
     
    It's one of those tools that give you feedback about your loading process. Not necessary but it depends on if you're looking for answers. I bought the Sinclair and usually check one or two rounds to confirm all is well then put it away. IMO your money is better spent on Lapua brass and a redding competition bullet seating die. If it ain't straight with those two things it ain't gonna be straight.
     
    Not for a semi auto, but an absolute must if you care about Precision in a bolt gun, IMO.
    But as stated, good brass, dies, and reloading practices will provide concentric ammo. It is nice to see the fruits of your efforts on a dial indicator though.
    If you do get one, i recommend one that rolls on the body of the brass, not the base.

    PCR/XLR/TAC338 http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111453_255_zps1b498f0d.jpg http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111325_951_zps290ebdd0.jpg
     
    I have a Sinclair. I use it to sort my practice ammo from match grade for AR-10T because I load to magazine length. I don't recall how much the bullet jumps but it's a long ways and it has to be straight to shoot <MOA at a grand.
    I also bushing neck size, because it's the easiest way to keep things straight. Actually just not using the neck expander button in standard sizer dies will keep things straight, then use the competition seater and it will be about as straight as it's going to get.
     
    I think the Sinclair model is easiest to use. The Hornady model is built like a tank and kind of clunky to use, in my opinion; and I also don't like how it grabs the tip of the bullet vs just laying the cartridge onto a surface. The best, hands down, is the Neconos rig as it measures quite a bit more than just simple runout.
     
    For a gas gun probably not worth the investment but as mentioned above nearly a necessity if loading for precision. I found the gauge very helpful in eliminating variables in the reloading process. I started with a Sinclair gauge and it works well but upgraded to an Accuracy One gauge which is extremely accurate and IMHO the best on the market. I have found that the S Type bushing dies w/o the expander consistently produce low runout especially when the reducing the neck size by .005 or less at a time.
     
    I have several. I bought the Hornady first, then a Neco and a 21st Century Shooting. I like the Hornady best simply because it offers a method of correcting concentricity. I bought the straightening jig from Neco, but it is hit and miss. I did upgrade the dial indicator in the Hornady to a Starrett .0001", but now I have to hold tension against the side of the right hand shaft (which is designed to be used to rotate the bullet) or it bounces around in the cast iron stand. Now I have to rotate the bullet itself. I also got a roller designed for use with a dial indicator from Grainger. It is still a black art. I have gotten pretty good at it over the years and can now straighten most out to concentricity of +/- .0005" in 10 seconds on average. Of course, with skimmed necks, and Redding competition sizing and bullet seating dies, they aren't off much to start.

    The jury is still out on the necessity of doing so, I'm just CDO. That's the same as OCD, but the letters are in alphabetical order, as they're supposed to be.
     
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    When you can pull down M2 Ball from 1968, minimal trim to square up mouth, debur, charge with new powder, and obtain this at 200M:
    519 200M.jpg

    .519".........I would say that brings a lot of the obsessive "must do" variables into serious question, let alone using a concentricity gauge. No I did not run them through a sizer die. Most of the brass is pretty dinged up. I know, 3 shots, this was just preliminary testing.

    Yes I owned and used a concentricity gauge, a NECO. I sold it over 15 years ago. I probably bought more bullets and powder with the proceeds, a much more worthwhile investment. If you NEED a concentricity gauge, you probably need better loading equipment, a new gunsmith, or both.
     
    Yeah, I didn't care for the Neco either. Good shooting by the way. I'm still learning, so for now I will stick with what the benchrest guys are doing. I may not be that good a shot so far, but at least I won't be able to blame it on my equipment. My best at 200yd F-TR is not as good as your shots, but I am working on it with a 600-42X. In the meantime, I will also be striving to make the best ammo I can, using any trick that MIGHT work.
     
    I would give a qualified 'yes' answer. Concentricity has relevance in direct relation to the chamber and firearms in which the ammunition will be used. If the chamber spec allow generous clearances for the loaded round (and I am primarily referring to SAAMI Standard Spec chambers here), then concentricity will likely have minimal relevance (i.e. you can get it good, or not, and the chamber will likely shot either equally accurately). Tighter match/competition chambers will likely demand concentricity of a much higher precision.

    Greg