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Post by dsastgguy on Jul 11, 2016 11:31:45 GMT -8
I finally got the chance to assemble a new upper using an Aero enhanced M5 upper/handguard combo, Aero black nitrided bolt and a BHW 18#RTS as mentioned in my last thread. I also ordered the Clymer GO/NO GO gauges to check headspace. I have removed the ejector (left the extractor in as it does not seem to interfere).
Turns out this bolt closes on both gauges, which has me somewhat concerned. I do not have a Field gauge to check further. In one of the other threads here, measurements are mentioned for a DPMS bolt from the bottom to top of the lugs being .320 and the bolt depth at .130
I checked all the lugs and they are all about .308 The bolt depth measures pretty consistently at .1265
Just curious if anyone can suggest a possible problem based on these measurements and possible solutions. I'd hate to have to send the barrel and/or the bolt back to be checked but better safe than sorry.
Thanks in advance for any thoughts.
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Post by dsastgguy on Jul 11, 2016 11:37:21 GMT -8
OK, I just re-read that post by GLShooter where he states that it is likely the Clymer gauges do not work properly on the BHW chamber.
Hmmm...
Any suggestions on the proper gauge if that is the case?
Thanks again.
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Post by GLSHOOTER on Jul 11, 2016 13:28:49 GMT -8
OK, I just re-read that post by GLShooter where he states that it is likely the Clymer gauges do not work properly on the BHW chamber. Hmmm... Any suggestions on the proper gauge if that is the case? Thanks again. PT&G. Your bolt is right where it should be.in depth. I haven't had any BHW barrel show a deep chamber yet. I have three BHW 233's The chambers are so close I don't have to move my sizer die from barrel to barrel. When they did yours it was gauged before it was sent out. I wouldn't be overly concerned. To cause problems you would have to have a huge chamber. It just isn't going to happen. Greg
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Post by dsastgguy on Jul 11, 2016 14:18:36 GMT -8
Thanks, Greg. I really appreciate the feedback. I had hoped that using all new parts would take me in the right direction. I'm pretty handy but not a master gunsmith, so I appreciate the thoughts. Found the PTG on Midway's site, so I'll be spending more money on tools! Quite a bit more money than the Clymer but worth it IMO. Can always justify that.
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Post by GLSHOOTER on Jul 11, 2016 14:39:29 GMT -8
Thanks, Greg. I really appreciate the feedback. I had hoped that using all new parts would take me in the right direction. I'm pretty handy but not a master gunsmith, so I appreciate the thoughts. Found the PTG on Midway's site, so I'll be spending more money on tools! Quite a bit more money than the Clymer but worth it IMO. Can always justify that. Actually all new parts was the right way to build. Each BHW barrel you get is going to be plus or minus 0.001 or 0.002. They are that consistent. They are chambered using computerized tooling. Once it's done nothing will change the HS unlike what can be done on bolt guns. Are you afraid it's going to blow up? Greg
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Post by dsastgguy on Jul 12, 2016 1:10:01 GMT -8
haha Yea, I don't want the boom stick to go kaboom! Well, when it closed on the Clymer NO GO, I certainly started to question the headspace a bit. Granted, apparently I used the incorrect gauge so that could be the problem. Everything I have read (not here specifically) has said to check headspace, even with new parts. This is the first upper I have built and certainly wouldn't want any problems first time I squeeze the trigger. What do the majority do when using all new parts? Not trying to put you on the spot, just curious if others are putting these things together and just shooting them?
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Post by GLSHOOTER on Jul 12, 2016 6:29:34 GMT -8
haha Yea, I don't want the boom stick to go kaboom! Well, when it closed on the Clymer NO GO, I certainly started to question the headspace a bit. Granted, apparently I used the incorrect gauge so that could be the problem. Everything I have read (not here specifically) has said to check headspace, even with new parts. This is the first upper I have built and certainly wouldn't want any problems first time I squeeze the trigger. What do the majority do when using all new parts? Not trying to put you on the spot, just curious if others are putting these things together and just shooting them? Hardly putting anyone on the spot. I can tell you that I have 40+ uppers right now. None were ever checked once I got them. They were checked at the barrel makers business. I have checked a few over the years because I happened to be standing in the shop when they were built but that is it. To have an issue you would have to be over 0.020 too long and that is not going to happen. We routinely fire form shoulders out that much using some techniques involving jamming bullets or corn meal but that is on a known wildcat we designed. I have ten, at last count, 223's from various makers. Case shoulder height varies from 0.000 to 0.008 over SAAMI minimum. No issues so far in 40 years or so. A little look back in history here. There was one notable fellow with a 308 that spent THREE weeks arguing over his HS gauges he was using in a 308 on his chamber. He measured this, he measured that and kept saying it wasn't right and he found out that three different gauges were three different lenghts. After almost a month he FINALLY fired a round in the rifle. Measured the brass and it was exactly what the specs called for. How could that be? Perhaps he didn't know what to measure. His big issue was the chamber was too short one time and too long the next time he measured it.that not all aguges were the same. As I mentioned previously based on how these are chambered if you got 50 barrels from BHW they are going to be so close as to be laughable in number. Use your HS gauges and record your data then go shoot one. AR's just don't come apart with factory ammunition period. Handloads yes but I've NEVER seen one do it unless it fired out of battery and all of those I have seen were handloads and some idiot neck sizing his cases or putting pistol powder in a rife case. Greg
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