I had an email exchange today with ar15parts.com and they just sent me an email saying after checking thier 6.8 spc 18 in stainless steel barrels, they have had gas ports drilled at .078 and should have been .085. they are telling me to use a 3/32 drill bit and drill this out myself, (Wouldn't this cause a bur in the barrel?) or use red loctite around the gas block and gas tube to fix it. IS THIS RIGHT? Would this maybe fix it. I am getting the bolt stuck over the magazine like it is not coming back far enough. Seems they should ask me to send it back and they correct the problem. I am getting worried about this purchase as I am beginning to wonder if it is even an spcll barrel cause it is not marked that way but they told me all barrels now are spcll chambers. I like the upper but am not sure about this now. Thanks for any advice you can offer. Just an after thought would an adjustable gas block be better option?
drvrbob
Bob,
tell them you are NOT comfortable doing the port work, ask if they want to help fund a gunsmith to do it, or provide a mailing label.
3/32" is NOT the correct size. (0.09375") That would REQUIRE an adjustable block.
You can get a cheap set of #drill bits at places like HarborFreight. You can MEASURE the port size. If 0.078" (a 5/64" would be tight or not pass) than THEY need to step up.
I think the 6.8 community knows that a .078" port probably does NOT run well on an 18" Mid Length and Factory ammo.
If a regular gas block (full open because it doesn't adjust) won't run, adjusting gas down won't help.
Three things you MUST determine. SPC or SPC2, and gas port size, and who to talk to at ar15parts.com.
tell them you are NOT comfortable doing the port work, ask if they want to help fund a gunsmith to do it, or provide a mailing label.
3/32" is NOT the correct size. (0.09375") That would REQUIRE an adjustable block.
You can get a cheap set of #drill bits at places like HarborFreight. You can MEASURE the port size. If 0.078" (a 5/64" would be tight or not pass) than THEY need to step up.
I think the 6.8 community knows that a .078" port probably does NOT run well on an 18" Mid Length and Factory ammo.
If a regular gas block (full open because it doesn't adjust) won't run, adjusting gas down won't help.
Three things you MUST determine. SPC or SPC2, and gas port size, and who to talk to at ar15parts.com.
A .082" should be used for a mid gas 18", .086 for a mid gas 16". The 3/32 is large IMO. Burrs aren't a problem after the initial hole has been drilled just don't force the bit. Spin it fast, feed it slow. Most are worry about making a bit last so thet spin slow and lean on it...not the correct way for a gas port.
Buy the proper bit, insert a steel cleaning rod or a wooden dowel into the barrel so you don’t push through and damage the lands on the opposite side. Drill slow while using plenty of lube/cutting oil.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
You really need to determine what size it is now.
Bits of interest to measure would be:
5/64 0.0781
#47 0.0785"
#46 0.081"
#45 0.082"
#44 0.086"
You can also get a 2.15mm (more common than you would think) 0.0846".
The HarborFreight #Set has all the number ones.
Ebay has the 2.15mm
Bits of interest to measure would be:
5/64 0.0781
#47 0.0785"
#46 0.081"
#45 0.082"
#44 0.086"
You can also get a 2.15mm (more common than you would think) 0.0846".
The HarborFreight #Set has all the number ones.
Ebay has the 2.15mm
Ok got the barrel fixed gas port was drilled out to 0.082 and they put an adjustable gas block on it. I used some federal fmj 115 gr to adjust gas block. I have it functioning perfectly over 40 rounds thru it no problems. Groups tightened up also. several 3 shot groups are covered by a dime others not so much, but I know it was me.
1 question though as long as it functions as it is supposed to, is it ok to have the block allowing the least amount of gas through to keep it running right? I did take it 1/2 turn more to the open side after it was working, just as extra insurance.
1 question though as long as it functions as it is supposed to, is it ok to have the block allowing the least amount of gas through to keep it running right? I did take it 1/2 turn more to the open side after it was working, just as extra insurance.
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