View Full Version : Am I boned?
benthughes
07-12-09, 19:12
I'm new to building ARs and am working on ( almost done with) my 6.8spc build. Today I installed the barrel, gas block/tube. The upper reciever is a Larue billet. I used a table vice and wrapped the upper receiver in an old sheet as not to damage it. I got the barrel nut adequately tightened and installed the gas block/tube. I did a mock fit with a DD F/A BCG and the fit of the BCG is incredibly tight to the point it won't move freely within the upper reciever. It's loosening up a bit as I manipulate it with the charging handle and forward assist but it's still very tight.
I was considering taking a pry bar and some padding to the receiver to hopefully move the receiver walls outward.
Before I proceed does anyone have any other suggestions or am I hosed?
Moral of the story..... Don't be a cheap ass. But an action block or have someone else do it. :(
I used a table vice and wrapped the upper receiver in an old sheet as not to damage it. I got the barrel nut adequately tightened and installed the gas block/tube. . .I was considering taking a pry bar and some padding to the receiver to hopefully move the receiver walls outward.
I not a gunsmith or anything of the like, but that sure may raise some questions around here. Hope you get your "fix" on that build of yours! :cool:
You might want to consider, STOPPING, right now and seeking a couple of the pro's on this board for their expertise, before you ruin something beyond repair. I have never heard of a crow bar being used to build an AR.
hmm.. where in the receiver does the BCG hang up? it's possibly you didn't do anything to the receiver, but since you probably didn't test fit the BCG before install, you don't have any way of knowing if anything's changed. i'd test fit another BCG, and try the BCG in question in a different receiver. then i'd take measurements of the receiver walls on the underside, looking for signs of warping.
if it's bent/warped, you don't really have anything to lose. if it was me, I'd probably proceed with the install, since you say the BCG will go in and function, even if tight- check headspace, put on a good stout jacket, maybe a welders mask, thick gloves, and shoot it.
could be you can "wear" the receiver to function after some considerable break-in. could also be you could end up with a single-shot rifle, or one that cracks while detonating, or even blows up. could be it'll shoot like a dream, and never give you problems. make sure you loob up really good with something thick.
but the first step, if at all possible, is to check the receiver with a different BCG.
ETA: or, perhaps a better first step would be to send it back to Larue and have them tell you whats up with it.
benthughes
07-12-09, 19:34
Oh I've stopped. ;) I know its not right and it has to be addressed before moving on. I'm not touching it until I get an idea of how to proceed.
benthughes
07-12-09, 20:22
Threw a CMT F/A BCG in there, same deal. It seems to start sticking right before the ejection port. I lubed the crap out of it before putting the BCG in initially. It seems to be loosening slightly the more I work it. Standing by.
well at least we've narrowed it down to the receiver. unless you're super unlucky.
i assume you were installing a free floating handguard- what kind, and what did you torque it to? how exactly did you fit the receiver into the vice?
Did you check your gas tube? If your gas tube is not strait then it can cause the exact problem you are describing. The quickest way to find out is to remove the gas tube and try the Bolt carrier.
I was considering taking a pry bar and some padding to the receiver to hopefully move the receiver walls outward.
:(
Is this the plumber or auto mechanic approach to gun-smithing?:eek::rolleyes::D
Did you check your gas tube? If your gas tube is not strait then it can cause the exact problem you are describing. The quickest way to find out is to remove the gas tube and try the Bolt carrier.
good call, 5pins
might not be anything wrong with the receiver at all. definately check this, OP.
benthughes
07-13-09, 01:04
As to plumber or mechanic's method of gunsmithing..... neither. Apparently it's the medic approach to it. It started sticking well before the carrier key contacted the gas tube but I'll check the tube.
It's a Larue upper and Larue free float handguard. I've thought that maybe I should have started with cheaper components but it is what it is. I'll likely take it to a gunsmith tomorrow and have him give it a once over.
Past that everything fit together well, hopefully I can get this resolved and start shooting. Live and learn I suppose.
A STRONG WORD OF CAUTION.
Be very careful who you take it to. As a matter of fact I would ask them if they are knowledgeable in the AR and if any of them have attended an armorers course. Just because someone has a "gunsmith" sign hanging out front doesn't mean that they know jack about all weapons.
A few questions and then some comments.
1. Did you possess the proper tools?
2. How tight did you tighten the vise? My feeling is that you may have tweaked the upper.
3. How do you know that everything was tightened properly and to spec?
Now as to what I would do before I would see the local butcher.
1. Get the correct tools from Brownells or other reliable source and completely disassemble the weapon.
2. Insert the BCG into the upper while it is stripped and see if you are getting the same results. If you are, it may well be that you hosed up the upper receiver.
3. Re-install the barrel and gas tube and then check everything again. It is entirely possible that what you are experiencing is a bad case of new parts break in. Have you considered contacting LaRue to find out if it's normal for their uppers to be tight?
As to plumber or mechanic's method of gunsmithing..... neither. Apparently it's the medic approach to it. It started sticking well before the carrier key contacted the gas tube but I'll check the tube.
It's a Larue upper and Larue free float handguard. I've thought that maybe I should have started with cheaper components but it is what it is. I'll likely take it to a gunsmith tomorrow and have him give it a once over.
Past that everything fit together well, hopefully I can get this resolved and start shooting. Live and learn I suppose.
benthughes
07-13-09, 02:55
The fit of the WOA barrel into the upper receiver was incredibly tight. It took quite a bit of pulling to separate the 2. I had a proper armorers wrench but no action block to hold the upper. Again hindsight being 20/20......yeah, I cut corners and now I'm begging for help. My next build will be better because of this I'm sure. The armorer I know has been building ARs for years and I absolutely trust him.
So am I to ass-u-me that the barrel is out of the upper? If so, you should now insert the BCG into the upper and see if it still binds up.
When you go to reassemble the barrel make sure that use the correct torque. What's listed in the TM may or may not be correct depending on what set up you have.
The fit of the WOA barrel into the upper receiver was incredibly tight. It took quite a bit of pulling to separate the 2. I had a proper armorers wrench but no action block to hold the upper. Again hindsight being 20/20......yeah, I cut corners and now I'm begging for help. My next build will be better because of this I'm sure. The armorer I know has been building ARs for years and I absolutely trust him.
benthughes
07-13-09, 03:11
30 lbs of torque then a bit over to line up the barrel nut and the hole for the gas tube. You ass-u-me corectally ;), I removed the barrel and it still bound up at the same point.
Notwithstanding Iraqgunz' sage advice, what the hell were you thinking? :)
First of all, if I had the opportunity, I would take an armorer's course. Second of all, I would purchase the correct tools for the job. A pry bar is not on any AR tool list.:D
Third and lastly, you could have asked your armorer/gunsmith to give you some tips and hints and to give you advice about a good tool kit for working with the AR upper assembly which is deceptively difficult to work on.
I know that I would never attempt to work on an upper just because I had already put together a couple of lowers.
As for my own experience, I asked a friend of mine for help and he walked me through the process of putting together a lower.
We have done other stuff on the lower before (Magpul PRS stock and MIAD grip installation) but I do not consider myself even slightly competent to work with an upper.
If I were you, I would have sent that upper to a competent smith or to WOA and had them work on it. But I know I am not so I will shut up now. No offense or insult meant, I think you just got too impatient and underestimated the pitfalls of the job at hand. ;)
Hey, it's your money and your choice. The sad part is that those build parts you had sound like real quality stuff and you just did not have the right tools or experience. I guess we live and learn.
All the best to you. :)
A STRONG WORD OF CAUTION.
Be very careful who you take it to. As a matter of fact I would ask them if they are knowledgeable in the AR and if any of them have attended an armorers course. Just because someone has a "gunsmith" sign hanging out front doesn't mean that they know jack about all weapons.
A few questions and then some comments.
1. Did you possess the proper tools?
2. How tight did you tighten the vise? My feeling is that you may have tweaked the upper.
3. How do you know that everything was tightened properly and to spec?
Now as to what I would do before I would see the local butcher.
1. Get the correct tools from Brownells or other reliable source and completely disassemble the weapon.
2. Insert the BCG into the upper while it is stripped and see if you are getting the same results. If you are, it may well be that you hosed up the upper receiver.
3. Re-install the barrel and gas tube and then check everything again. It is entirely possible that what you are experiencing is a bad case of new parts break in. Have you considered contacting LaRue to find out if it's normal for their uppers to be tight?
benthughes
07-13-09, 05:01
Notwithstanding Iraqgunz' sage advice, what the hell were you thinking? :)
First of all, if I had the opportunity, I would take an armorer's course. Second of all, I would purchase the correct tools for the job. A pry bar is not on any AR tool list.:D
Third and lastly, you could have asked your armorer/gunsmith to give you some tips and hints and to give you advice about a good tool kit for working with the AR upper assembly which is deceptively difficult to work on.
I know that I would never attempt to work on an upper just because I had already put together a couple of lowers.
As for my own experience, I asked a friend of mine for help and he walked me through the process of putting together a lower.
We have done other stuff on the lower before (Magpul PRS stock and MIAD grip installation) but I do not consider myself even slightly competent to work with an upper.
If I were you, I would have sent that upper to a competent smith or to WOA and had them work on it. But I know I am not so I will shut up now. No offense or insult meant, I think you just got too impatient and underestimated the pitfalls of the job at hand. ;)
Hey, it's your money and your choice. The sad part is that those build parts you had sound like real quality stuff and you just did not have the right tools or experience. I guess we live and learn.
All the best to you. :)
I got it loosened up and now the BCG slides freely in the upper reciever, functions properly when manipulated with the charging handle, will lock open with the bolt catch. I'm hoping I dodged a big bullet.
As far as inexperience and impatience, absolutely :D . I'm willing to dink with my own rifles but would not claim to be very knowledgeable or willing to try my hand on others. Hopefully it'll function properly when all is said and done.
Action block on order from Brownells. I'll use this to finish the job.
Were you able to figure out where the binding was at? Are there any rub marks that indicate what was happening? Is the barrel and gas tube now separated from the upper?
I got it loosened up and now the BCG slides freely in the upper reciever, functions properly when manipulated with the charging handle, will lock open with the bolt catch. I'm hoping I dodged a big bullet.
As far as inexperience and impatience, absolutely :D . I'm willing to dink with my own rifles but would not claim to be very knowledgeable or willing to try my hand on others. Hopefully it'll function properly when all is said and done.
Action block on order from Brownells. I'll use this to finish the job.
CryingWolf
07-13-09, 12:17
As far as inexperience and impatience, absolutely :D . I'm willing to dink with my own rifles but would not claim to be very knowledgeable or willing to try my hand on others. Hopefully it'll function properly when all is said and done.
Action block on order from Brownells. I'll use this to finish the job.
Don't sweat being a kitchen table / garage / man cave gunsmith not all of us can find armorer's course nor the time or $$$. I think it is importaint to make sure you don't bite off more than you can chew, have the right tools, and if you are unsure seek expert advice
I see you solved your issue may we ask how or did it just work itself out?
benthughes
07-13-09, 17:19
No rub marks after examination. Took it to my friends house ( the armorer) who had a couple different action blocks. He put it on a block that fit up into the receiver and pinned it to the block. The idea being that hopefully the manipulation of the barrel nut in tightening and loosening on that block would move the receiver walls outward slightly. Very tight fit on the block.
Removed the barrel ( which was always a very tight fit) and test fit the BCG. Still tight. The upper receiver was the culprit likely due to my stupidity :rolleyes: We took a pair of pliers with each side covered with rubber tubing and used it to push the receiver walls outward slightly. Tried it at the bind up spot and the BCG slid through the receiver better. We worked the length of the upper using the same method then reassembled after working it thoroughly. The BCG now moves freely through the upper.
He was free in calling me an idiot and that the fix with the pliers was only because otherwise the upper was probably done and we're lucky it worked. Good thing Larue makes a beefy product or the upper may have been perma-hosed.
wow...
well check your headspace and wear armor when you test fire
good luck
benthughes
07-13-09, 18:00
I hate to hear that but it's good idea. How do I check my headspacing ?
benthughes
07-13-09, 18:33
Y'know....... I'll let someone else check head space. I've gotta learn my lesson.
bth,
Step 1. Purchase a 5.56 Field headspace gage from Bill Ricca or Bushamster.
Step. 2. If using the gage from Bill Ricca simply slip it into your chamber, insert the bolt carrier group and using light finger pressure attempt to close. Bolt should not lock up.
Step 2. If using the Bushamster gage remove the extractor assembly perform same as above. Bolt should not lock.
Step. 3. If you pass, remove gage and reassemble weapon.
I hate to hear that but it's good idea. How do I check my headspacing ?
benthughes
08-03-09, 23:41
Received my CMT bolt from Ranier Arms today ( great outfit BTW) and took my build to the range. Head spacing checked out by local gunsmith. Carrier group travels in the upper as it should no evidence of wear in the upper.
At the range I used Horandy V-max with brand new PRI magazines. The brass was ejected cleanly in a fairly consistent pile. The only issue was a double feed that was cleared without issue. I used a Nightforce 2.5-10 with FC-2 reticle and it grouped neatly, I didn't zero it but determined that it wouldn't blow up on me. All in all it turned out as well as I could have hoped. Of course pics to follow soon.
congrats. as with all weapons, run it hard, hot and often, before you go trusting your life with it.
eager to see some pics, and some groups
benthughes
08-03-09, 23:58
congrats. as with all weapons, run it hard, hot and often, before you go trusting your life with it.
eager to see some pics, and some groups
I appreciate your input on it. This thursday I'll be running about 300 rounds of Barrett and Federal 110 and 115 grain ammo through it. The gas block was pinned and position checked by a local machinist. I'll run the hell out of it in the next couple weeks and likely take it Caribou hunting this October. I'll have to dig a bit and see what bullet would work the best for this. Thanks also Iraqgunz
Glad you got it worked out. Chalk this up to a lesson learned.
benthughes
08-04-09, 01:00
nah.... ;)
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