01-29-2014, 10:49 PM
LRRPF52 Wrote:If you guys use grease, tighten, then back off, tighten again, you will have better results aligning the teeth on an AR15 barrel nut. Minimum torque for a 5.56 NATO is 35 foot pounds. Armorer manual says 35-80ft lbs, but many experienced smiths will say you can exceed 80ft-lbs no problem on a 7075 T6 Type III hard coat aluminum upper.
I have a box of broken uppers given to me by people that were using the Panther Claw insert. I have always used the clamshell, but you can also clamp the barrel with circular vice inserts, apply gripping compound so the barrel won't spin, and torque the nut that way.
Then there is the reaction rod method.
I agree that clamshell types are the best way to go. The panther claw in conjunction with the delrin flat top upper slide on piece looks the best imo.
With this said I've had no issue using a dpms panther claw putting barrels on/off uppers... I had to use around 100Ft lbs to remove the PF installed barrel on my mono and didn't damage it. The guys with the broken uppers must have had some low quality uppers and/or didn't support the upper when they were cranking with the wrench.
I also use the grease tight/untighten/tighten method using white lithium grease.