07-08-2020, 10:04 PM
(This post was last modified: 07-13-2020, 11:14 PM by drewthebrave.)
If you want to ensure a tight fit, you may want to consider using a BCM upper receiver. They intentionally size the receiver on the small side of the tolerances so that you have to heat it up to fit the barrel extension. I bought their blemished receivers at $60 and used them for my 11.5" 5.56 pistol and 18" 6.5 Grendel builds. For the first one, I held the threads over the stove, and on the second I used a heat-gun - both methods worked just fine.
However, you may have trouble truing the face, as the PTG facing tool that I have wouldn't fit in either of the BCM uppers I have. If you want a true face that's a thermal fit without buying extra tools, you might want to look at JP Enterprises or Precision Firearms billet receivers. They're pricey, but they have a good reputation.
However, you may have trouble truing the face, as the PTG facing tool that I have wouldn't fit in either of the BCM uppers I have. If you want a true face that's a thermal fit without buying extra tools, you might want to look at JP Enterprises or Precision Firearms billet receivers. They're pricey, but they have a good reputation.