01-24-2016, 01:59 AM
Disclaimer, I am not a gun smith and did not stay in a Holiday in express last night, just a guy who has built a few and is interested in them being accurate.
1 - Using the tool determines how much is needed, if any at all. Run it for 5 seconds and examine the upper. If there is an even ring of anodizing worn off it is done. If there is a "high" spot, run it in short intervals checking often till you are satisfied it is even.
2. Presumably the barrel and barrel extension were cut on a lathe and through the nature of that process are square... However you have to take that on faith unless you have access to machinery and an experienced machinist to check. This falls into the check/ fix what you can catagory.
3. No way I could imagine this having a negative impact.
I have only used a similar tool sold by Brownells on 4 uppers. Three were confirmed square in a few seconds. One needed 3 or 4 five second cycles to square. Does it make a difference? No way to know unless the upper is tested, then squared and tested again. Will I do it again, yes. It is easy to do the first time and not wonder about what would have happened if I had... I'd be interested in a before and after comparison; the people who make the tool would have to do this as everyone I know puts it together with the intention of it staying together.
I'd recommend being careful to ensure the compound is only on the face of the tool that contacts the receiver. Also, check / clean the tool and inside of the upper when the tool is removed - you wouldn't want any of the grit transferred via finger prints inside where a tight barrel / upper fit is desired. (use a q-tip to apply the compound to the tool. Second tip, a little compound is all that's needed. third tip, if multiple grit compounds are available, start with the finest)
Whatever you did in the past works, as evidenced by your great shooting. I always enjoy your videos. If you have reservations, skip it. But, I do feel it is worthwhile, although I think bedding the barrel and getting the barrel nut tight are more important.
Keep up the good work and best of luck with the build.
Bill
1 - Using the tool determines how much is needed, if any at all. Run it for 5 seconds and examine the upper. If there is an even ring of anodizing worn off it is done. If there is a "high" spot, run it in short intervals checking often till you are satisfied it is even.
2. Presumably the barrel and barrel extension were cut on a lathe and through the nature of that process are square... However you have to take that on faith unless you have access to machinery and an experienced machinist to check. This falls into the check/ fix what you can catagory.
3. No way I could imagine this having a negative impact.
I have only used a similar tool sold by Brownells on 4 uppers. Three were confirmed square in a few seconds. One needed 3 or 4 five second cycles to square. Does it make a difference? No way to know unless the upper is tested, then squared and tested again. Will I do it again, yes. It is easy to do the first time and not wonder about what would have happened if I had... I'd be interested in a before and after comparison; the people who make the tool would have to do this as everyone I know puts it together with the intention of it staying together.
I'd recommend being careful to ensure the compound is only on the face of the tool that contacts the receiver. Also, check / clean the tool and inside of the upper when the tool is removed - you wouldn't want any of the grit transferred via finger prints inside where a tight barrel / upper fit is desired. (use a q-tip to apply the compound to the tool. Second tip, a little compound is all that's needed. third tip, if multiple grit compounds are available, start with the finest)
Whatever you did in the past works, as evidenced by your great shooting. I always enjoy your videos. If you have reservations, skip it. But, I do feel it is worthwhile, although I think bedding the barrel and getting the barrel nut tight are more important.
Keep up the good work and best of luck with the build.
Bill