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Posted: 8/2/2016 7:30:34 PM EDT
Hello ladies and gentlemen of the internet, I appear to be having an alignment issue with my 15" Midwest industries hand guard. I have to crank my rear sight all the way to the left to get my groups anywhere near where they need to be at 50 yards. The pics bellow describe my issue. Thanks for any help!
Note: I'm having trouble posting these pics, I'm guessing it's because I'm new. |
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Quoted:
Get the receiver lapping tool/kit from brownels. To me, it appears the face of your receiver is not square and the flange on the barrel extension when tightened up the out of square receiver face is pulling the barrel to one side. Thanks for the help! Do you think It would be worth sending back? Is there a good way to determine the squareness of the upper? |
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Quoted:
Thanks for the help! Do you think It would be worth sending back? Is there a good way to determine the squareness of the upper? Quoted:
Quoted:
Get the receiver lapping tool/kit from brownels. To me, it appears the face of your receiver is not square and the flange on the barrel extension when tightened up the out of square receiver face is pulling the barrel to one side. Thanks for the help! Do you think It would be worth sending back? Is there a good way to determine the squareness of the upper? No. If you plan on building anymore uppers (which you will, trust me, these things multiply) then just buy the brownels tool. It's easy to use. I've been using if for about the last 10 or so uppers, and I've consistently noticed two things: 1) barrels nuts that need indexing time much easier 2) rear sights require barely any windage adjustment from mechanical zero And this is out of building countless uppers since the ban ended. You are only out of alignment by .06". Excess anodizing on one side of the receiver face can easily account for that. Again, if the forearm rail and upper rail are lined up (I use a carry handle to bridge the gap as I tighten on the forearm) then it's a barrel-receiver interface issue. Just to be conservative, you can pull it apart again and make sure there is no debris (like excess grease) between the barrel extension flange and barrel nut and that the forearm is fully pressed towards the receiver. Did you use the green locktite that MI ships on your barrel nut? If so, use a propane torch to heat up the forearm where it slides over the nut. Just get it hot to the touch. That will loosen the locktite and make it easier to slide the forearm off. |
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Wait... I just assumed you built this upper, but after reading your post again, maybe I'm wrong. If you didn't build it, let MI deal with it and send them the pics. Your barrel is obviously not centered. I'm friends with the OP, we were just drinking beers and discussing this rifle last night, I suggested he ask for the wisdom of arfcom. It is a home built rifle, Spikes upper, PSA barrel, MI rail. Thanks for the info on the honing tool, I'll have to pick one up for myself. I had no idea that even existed. 
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Wait... I just assumed you built this upper, but after reading your post again, maybe I'm wrong. If you didn't build it, let MI deal with it and send them the pics. Your barrel is obviously not centered. That tool sounds like it might be the ticket, I E-mailed spike's customer service (just for fun) and they sent me this reply: "Often people over-think or think the worst. Lapping an Upper is done to remove any slight imperfections and smooth the front of the Upper so the collar around the Barrel sits perfectly against it. The way Uppers are machined it’s impossible for the front to be “crooked” without the entire bore of the Upper also being crooked. And then it would fail the QC process. There are two things that are far more likely be the real problem. One is that the rail itself is slightly warped. Rails are extruded and in that process they will often be slightly warped. It’s more noticeable on longer rails than short rails. It’s also more prevalent on inexpensive rails. The other possibility is that the rail just went on the Barrel Nut crooked. If you loosen the screws and then straighten it and tighten the screws while it’s being held straight it may be fine. The down side to long free float rails is the potential to be knocked crooked. Even our rails are not immune to it. " I'm guessing that is their way of saying it's my problem now. |
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No. If you plan on building anymore uppers (which you will, trust me, these things multiply) then just buy the brownels tool. It's easy to use. I've been using if for about the last 10 or so uppers, and I've consistently noticed two things: 1) barrels nuts that need indexing time much easier 2) rear sights require barely any windage adjustment from mechanical zero And this is out of building countless uppers since the ban ended. You are only out of alignment by .06". Excess anodizing on one side of the receiver face can easily account for that. Again, if the forearm rail and upper rail are lined up (I use a carry handle to bridge the gap as I tighten on the forearm) then it's a barrel-receiver interface issue. Just to be conservative, you can pull it apart again and make sure there is no debris (like excess grease) between the barrel extension flange and barrel nut and that the forearm is fully pressed towards the receiver. Did you use the green locktite that MI ships on your barrel nut? If so, use a propane torch to heat up the forearm where it slides over the nut. Just get it hot to the touch. That will loosen the locktite and make it easier to slide the forearm off. Quoted:
Quoted:
Quoted:
Get the receiver lapping tool/kit from brownels. To me, it appears the face of your receiver is not square and the flange on the barrel extension when tightened up the out of square receiver face is pulling the barrel to one side. Thanks for the help! Do you think It would be worth sending back? Is there a good way to determine the squareness of the upper? No. If you plan on building anymore uppers (which you will, trust me, these things multiply) then just buy the brownels tool. It's easy to use. I've been using if for about the last 10 or so uppers, and I've consistently noticed two things: 1) barrels nuts that need indexing time much easier 2) rear sights require barely any windage adjustment from mechanical zero And this is out of building countless uppers since the ban ended. You are only out of alignment by .06". Excess anodizing on one side of the receiver face can easily account for that. Again, if the forearm rail and upper rail are lined up (I use a carry handle to bridge the gap as I tighten on the forearm) then it's a barrel-receiver interface issue. Just to be conservative, you can pull it apart again and make sure there is no debris (like excess grease) between the barrel extension flange and barrel nut and that the forearm is fully pressed towards the receiver. Did you use the green locktite that MI ships on your barrel nut? If so, use a propane torch to heat up the forearm where it slides over the nut. Just get it hot to the touch. That will loosen the locktite and make it easier to slide the forearm off. If you don't want to put a torch to it, you can simply remove the screws and insert a thin strip of metal into the gap, then run the screws back through the other side. Acts like a mini press that will break the bond. |
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