Two uppered Bulldog/mild to wild in 90 seconds

[Lani52]

90 seconds is how long it takes me to change uppers on my Bulldog.

Upper #1 has the Pitbull short mod, on the ported jar valved lower makes 250 plus fpe and shoots in the 1/2 inch range at 33 yards.

Upper#2 has the mega mod and at 2000 psi shoots 120’s into one hole at 115 fpe at 15 yards which is why it was made.

The difference in power and report are phenominal.

90 second switch is due to the fact that I have drilled two holes in the reciever cover to access the barrel retain screws, 2.5 turns each and the entire upper slides off and the alternate upper is slid in and the screws retightened.  Upper #1 wears a 1x4 Bushnell AR scope, ripper # 2 wears a 1x4 Bushnell shotgun scope, the barrel was porteted to .25 and has also as ben drilled to index with the three corners of the shroud to make use of the shroud itself, the vent holes are located 3/8th of an inch from the muzzle and clear the mega mod barrel attachment

Both uppers have the Pitbull moderators glued on with J B Welch to ensure a longer life and avoid striking mounting screws If too long of a bottom mounting screw is used and can result in bullet strikes if incorrectly mounted.

Next improvement will be a 4500 psi tube which will dramatically widen the chasm of power and noise,  and do it SAFELY.