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Posted: 4/17/2005 8:40:21 AM EDT
Let's say you're using a common barrel wrench such as the DPMS, it's about a foot long. Would you tighten it as much as you could by hand? |
First I suggest that you get yourself a TM (technical manual) and learn the proper proceedures to put a AR together. It will save you some hassles and money down the road, especially if your not doing it correctly. Next, with your problem I would start by properly torquing the barrel nut to the proper 30Ft. Lbs. then line up the next notch in the barrel nut to the gas tube hole. (do not back off on the nut to line up the hole). Then check your YHM FSB to make sure it is properly inline with your rear sight and properly tightend. Take it to the range and try again! |
Well, first of all, I think you should go to Sears and get yourself a torque wrench... DPMS barrel wrench has a 1/2" socket so spend the $29.99 and get this one. If you don't feel like spending the $30, then make sure you put some bodyweight into it... You have to at least get it up to 30lbs and that requires a bit more effort than just hand tightening. But if you like AR's and aren't really strapped for cash, spend the $30. There are more expensive wrenches, but for what you're doing, I don't think they are necessary. Hope this helps... |
Ignore all these fools who tell you to retorque your barrel nut. Don't worry, you did just fine mounting your barrel. The problem is you need to find ammo that your barrel likes. Get something heavier - 62 gr. or 69 gr. - so there will be much less of a jump through the freebore. |
That could also be the problem...but we really don't know. All he told us is that he "hand tightened" the nut. That could mean it is tight enough or about to fall off for all we know. I think it is still a safe bet to double check the barrel nut. You don't need to actually torque it. I usually tighten mine as far as I can and then back it off to the next slot for my gas tube. |
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Sorry for the confusion gents. When I put everything together the first time I hand tightened the barrel nut. I then used a barrel wrench to tighten it to the very next hole that I could put the gas tube in, which wasn't very far from where I left off with my hands. I've already taken the gun down and I'm getting ready to put it all back together. This time I'll be sure to use a little more weight behind the wrench. Like I said earlier I was a little intimidated about realy torquing down on the barrel nut for fear breaking the reciever. I'm almost poitive that this is my problem. If this doesnt work then I'll try the heavier ammo. By the way, loose sights were the first thing I checked for while at the range. This has been my first build and I doubt its my last. So far, this has been the only problem that I've had. Considering that I dont know anyone that has built their own upper, everything that I've learned has come from a book or this web site and all of the good people out there that are willing to pass on their knowlege to others, I really cant complain about the whole experience. Thanks to all for the help and advice. When I get it all back together I'll try and post a picture if anyone is interested. Trial and error = Time and money. |
Asshat, if you have no idea what you are talking about you should just keep quite. |
If you have no idea what you are talking about you should just keep quiet. |
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A 1:9 should shoot 55 grainers OK, but just OK. A 1:12 is better for those light bullets. Years ago I tested 55's vs. 69's in a 1:8 and the 69's would hold the 10 ring at 300 yards, but the 55's went out into the 8 ring. You still need to check the other things mentioned in this thread, but try 75's or 77's and you should see an improvement. Regards, Ray  |
I've done more barrels than you, so I do know what I'm talking about. 2476 in 11 months? Maybe you should spend less time talking out your ass and more time trying to figure out how to use your computer. HTH. HAND. |
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In my experience hand tight, wrench to next hole is always in the 30-60FtLbs area. I usually lift up slightly on the barrel while hand tightening as they have a tendency to sag. Hand tight is as goddamn tight as you can get it with your hands, go at like you are serious. Then wrench to next hole. I haven't found one where I could wrench to the 2nd hole after hand tight without being waayyy over 80ftlbs......... The cheap ammo and irons are not a good combo for accuracy. Just this weekend I ran some AE55g through my 20 inch 1/9 scoped AR and it was brutal at 100m, 6 inch groups. Compared to 1.5inch groups for the rest of the day with AE62g and IVI SS109's, I definately think that ammo blows. Get some decent ammo, 62g minimum and have at it again. |
I am afraid Homo_Erectus has been barrelling AR's in greater qty and longer than most of us combined, and he knows what he is talking about. I would guess the barrel *really* doesnt like that ammo or there is a problem with the barrel itself.... such as a damaged crown or some other defect. A 1/9 twist should shoot 55gr stuff no problem... and should not print like a "shotgun" at 50yds...... so I am leaning towards barrel issue. It would have to be so damn sloppy... to the point that you could rock the barrel back and forth against the indexing pin to upper receiver slot for it to cause an accuracy issue, and even then it would only show horizontal stringing. |
A 1:9 barrel likely will not stabilize 75's, and almost positively not 77's. I would say the "optimum" weight (if there is such a thing) for that barrel twist is the Hornady 68gr or the Sierra 69gr. In any case - my 1:8 wilson barrel shoots 45gr bullets into 1/2" holes at 100yds.... so dont buy into the twist = a specific bullet weight theory. Heavier bullets are almost always better for longer distances, simply because of less wind drift and better BC. But as he said, he is shooting at 50yds.... and *any* weight made for the AR15 from 40gr to 100gr should shoot fine at this distance... and at LEAST print 2" groups (4MOA) provided your barrel can stabilize the round. |
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Sorry I haven't replied in a while, but thanks to all that have taken the time to answer with their knowledge and experience. I completely rebuilt my upper by torquing and re-torquing the barrel nut. This time, I went past the first hole that I was able to index and used almost 60 pnds of torque to get to the next. It is definitely much tighter then the first time. Everything is back together, plus a few scratches, and waiting to be taken to the range. Between the weather and my work schedule this has not worked to my advantage in the last two weeks. I will definitely get to shoot it this coming weekend, April 30. Iam also in agreement with those of you that mentioned that iron sights are not the best way to sight in a rifle. So, I have also picked up a set of scope rings that will acompany me and a fixed 4x scope to the range. And of course I will not rule out the weight of the ammo that Iam using. Thanks again Chris [/i]Trial and error=time and money |
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This brings a question to my mind. When using a torque value by means of a barrel wrench. Is the torque reading on the wrench the face value, or do you calculate the distance from the center line of the barrel/barrel nut to the square drive on the torque wrench? Thus the torque value is the value on the barrel nut, with the torque wrench showing a different value because of the extension calculation of the added length from the square drive to the center of the barrel? I never hear this discussed. Anyone... anyone... Bueller! |
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I got out this weekend and shot again. Everything seems to be in good order now. I was shooting 55grn Wolf at first and had the BUIS and a 4x scope sighted in at 50 yds. Between my friends and I we put a few hundred rounds through the barrel without a problem. First I sighted in the scope to rule out any problems with the barrel and then the BUIS. Some of my earlier problems were definitely related to the ARMS #40, because I was unfamillar with this type of sight, as I had never used one before. It took a little getting used to, but I got the hang of it and was eventually hitting the various metal targets we had down range. I know that 50 yds isn't much, but I was on private property shooting with a bunch of friends and its what I had to work with. The following day I switched to the left over 55grn Federal ammo that I had and the accuracy degraded, even after cleaning the barrel. The Federal ammo was definitely louder, then the Wolf. It also recoiled a little more and shot a good sized fireball out of the barrel. It's obvious that the barrel doesn't like the 55 grn Federal very much. I gave the rest of the Federal ammo away. The next time I get a chance to shoot I'll be sure to give some heavier ammo (62grn) a try and shoot at a further distance. Thanks again to all that offered their advice Chris |
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