This is a generic AR build question, but two of us are putting Grendel ARs together. My buddy swears by this tool for truing up the barrel to the receiver.
Wheeler Engineering Delta Series Upper Receiver Lapping Tool AR-15
Apparently, the gizmo indexes off of other surfaces inside the upper receivers to square the surface for the barrel to mate with. While I understand the concept of wanting a properly mated receiver and barrel, I fail to understand how this is necessarily accomplished. The concept seems to be predicated on correcting the tolerances of one aspect of the receiver based on the tolerances of another aspect of the receiver.
My first concern is that how do you know if you need this? What is the test to determine if you need it and if you do, how do you determine that the work you did accomplished the task properly?
Second, since the barrel mates to the upper, shoulder the barrel not also be lapped to assure proper squaring. Otherwise, you are just fixing 1/2 of the potential problem, right?
Third, is there anything detrimental that could result from doing this? If this is supposed to alter the mate surface sufficiently, could this also not produce a change that would have a negative impact?
What I got from my buddy was that he felt that at worst, his receiver would be no better off than had he not done the work and that it would very likely improve things. He did not feel that anything could be screwed up by using it. He knew of no way to verify that the work was needed, - No way to verify that everything was properly aligned to do the work, - No way to verify that the resultant work had produced any actual benefit.
My thoughts on the deal are that you build the upper first. If things don't appear to be true, then take it apart and then maybe see about trying this gizmo to seem if things can be brought into alignment...but I have never built from scratch before, just rebuilt uppers.
Thoughts?
Wheeler Engineering Delta Series Upper Receiver Lapping Tool AR-15
Apparently, the gizmo indexes off of other surfaces inside the upper receivers to square the surface for the barrel to mate with. While I understand the concept of wanting a properly mated receiver and barrel, I fail to understand how this is necessarily accomplished. The concept seems to be predicated on correcting the tolerances of one aspect of the receiver based on the tolerances of another aspect of the receiver.
My first concern is that how do you know if you need this? What is the test to determine if you need it and if you do, how do you determine that the work you did accomplished the task properly?
Second, since the barrel mates to the upper, shoulder the barrel not also be lapped to assure proper squaring. Otherwise, you are just fixing 1/2 of the potential problem, right?
Third, is there anything detrimental that could result from doing this? If this is supposed to alter the mate surface sufficiently, could this also not produce a change that would have a negative impact?
What I got from my buddy was that he felt that at worst, his receiver would be no better off than had he not done the work and that it would very likely improve things. He did not feel that anything could be screwed up by using it. He knew of no way to verify that the work was needed, - No way to verify that everything was properly aligned to do the work, - No way to verify that the resultant work had produced any actual benefit.
My thoughts on the deal are that you build the upper first. If things don't appear to be true, then take it apart and then maybe see about trying this gizmo to seem if things can be brought into alignment...but I have never built from scratch before, just rebuilt uppers.
Thoughts?
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