Your current AR has a 16" with a carbine length gas system, which leads to a system that is significantly overgassed. The M16 you qualified with had a 20" barrel with a rifle length gas system, which is not nearly as overgassed of a system.
Carbine length gas systems (gas port at 7 inches) were...
Their HBAR barrels should perform just as well as the other profiles. All of them are button-rifled and then hand-lapped for consistency.
IIRC HBAR Criterion barrels are pretty popular in high power competition.
With a $300 budget, you can do much better than Faxon.
Here's a Criterion 20" HBAR barrel for $300. This is a match-grade, 410R stainless barrel with a hand-lapped bore.
https://www.fulton-armory.com/barrelfa20nmhbarss1x8plainmuzzle.aspx
If you prefer a different length or if you like chrome...
They are not Radian Raptors. Radian themselves confirmed that they used to make them for Stag but no longer do as of about 4 months ago, and that these are knockoffs.
Anyone try one of these yet? Seem to tick off a lot of boxes as far as features - FFP, exposed turrets, etched reticles, both MOA and MRAD available.
The 4-16x FFP MRAD is being sold for $293 and the 6-24x FFP MRAD is being sold for $335 at Sport Optics with the Black Friday/Cyber Monday...
I don't have the 3x but do have the 1x Spitfire. For people with astigmatism, you can't beat it for the price. Another benefit - the etched reticle is visible even without illumination, so it is usable without batteries.
Do you have any aftermarket parts in the G27? That doesn't look like a typical Glock primer strike, which is usually a rectangular outline with a circular indent in the middle.