UPDATE: The issue was resolved and I look forward to doing more business with BHW and CRA.
I received a 10.5", C5 configured, 300 Blk barrel, installed it with the supplied gas tube and a SLR Rifleworks adjustable gas block. I noticed that the BCG will not go into battery. In the attached pic, the C5 configured barrel is on top. Looks like a problem to me. I'd appreciate any assistance on this.
Yes. The supplied gas block compared to the SLR Rifleworks unit. Also compared it to a couple of other gas blocks and I don't think that the few thousandths difference in the gas tube pin location would even begin to take up the slack necessary on the working end of the tube.
Judging from the gas block dimensions being almost identical and the distance required to take up the needed slack on the BCG end of the gas tube, I don't think it would change enough to matter, so I didn't bother to try the supplied gas block. As discussed previously with J.P. before I bought the barrel, any gas block should work just fine. The difference was with the gas tube length which was supplied with the barrel.
You have a C5 gas port? IT WON'T WORK WITH ANY OTHER GAS BLOCK OR GAS TUBE. The difference is .250 in port placement from a standard and the C5. Use the supplied gas block and your problems should be solved.
So, I installed the supplied gas block (which is adjustable) and still have some questions. Also, I forgot to mention earlier that I couldn't mate the upper to the lower with the SLR gas block installed without using a tool to compress the buffer/buffer spring because the bolt carrier overhang was interfering.
Picture 1 - The SLR gas block with the C5 gas tube compared to another upper. Note the gas tube location referenced to the half-moon cutout. According to all of my research and available data, the end of the tube should be centered in that cutout.
Picture 2 - The supplied gas block and C5 gas tube. There was ~ 0.0275 of difference made by swapping gas blocks and it's still not centered in the cutout .
Picture 3 - Again, according to all of my research and available data, the bolt carrier should be flush with the upper. Previously, the overhang was ~ twice this amount causing the upper not mate with the lower. Got the same result with three other BCG's.
Picture 4 - Notice the gap between the bolt carrier and the upper. This is as far as any of the three other BCG's would go into battery. Whenever I've seen something like this at the range or on the bench - it sets off my spider senses.
In summary, my CAD drawings indicate that the cut-out that I've used for a visual reference is 0.635 +/- 0.005 in diameter. Halfway is 0.3175. I'm thinking that if the gas tube was say, 0.3175 inches shorter, we wouldn't be having this conversation.
I was looking at the pictures of that guys gas block. I don't think the block that came from BHW is the right one. It should measure.250 longer than standard. The extra length should be at the rear of the block so the extra length is taken up with it. The C5 on your upper is a clamp on block not a set screw like the one shown in the pictures.
Looks like a call to JP. That is a standard block.
Here is a real C5. Note the hole drilled behind the middle bolt. This goes in the dimple area to line up the port.
Last Edit: Nov 20, 2016 7:46:38 GMT -8 by GLSHOOTER
The best firearm for self defense? Any loaded one will do.
Eureka! Ok then, nice pics Greg. I see exactly what you were describing earlier about the differences in the gas blocks. Now my question is - is that special gas block adjustable and who is the manufacturer? Thanks