SIG 552-300 tested and working....

[amafrank]

I built a SIG 556 into a 552 and made the barrel up for 30-221. Barrel is a bit heavier than the original contour. The gun got test fired last week and works ok with supersonic ammo. I did a bit of fiddling with the gas system and managed to get reliable function with supersonics but marginal with subs. With the suppressor installed it will eject the subs but won't reload. It will however cycle the supersonics with or without the can....I'm thinking the 1.5" of barrel that is past the gasport is just not enough with the low pressure/volume 30 cal round. I will try some different powders, maybe some other powder will have a pressure peak at the right time. We've run H110, VV N110, and 2400 through the guns so far. Very neat gun and even more appealing to me in the .30 cal. I never really liked the .22 cal black rifles.....

Frank