Sig 553LB

[68ar15]

Sorry for the necro post, however, reading this brought to mind a question. I have a 553 sb that I ordered a suppressor gas plug for. It has a 0.9 mm port. It is very soft shooting and pleasant suppressed. I also have a 553 lb. It came with a 1.1/1.2 mm port. It was overgrazed and unpleasantly snappy. I used the chart above and ordered a 1.05/1.1 mm plug which helped some but is no where as soft as my 553 sb suppressed.

My question is why wouldn’t the lb require at least as small of a port as the 553 sb suppressed? Also does anybody know if you can custom order gas ports not listed on that chart?

To the question of why a 553 lb vs 551 it is a very well balanced natural pointing firearm, for me anyway.

[Bret]

My question is why wouldn’t the lb require at least as small of a port as the 553 sb suppressed?

For the 553LB unsuppressed versus the 553SB suppressed, I think you'd ideally have to just find the smallest gas port hole that works reliably. Unfortunately, they don't provide that option.

Also does anybody know if you can custom order gas ports not listed on that chart?

I'm pretty sure the answer is no, but you'd have to ask Dave to be sure. The ideal solution would be to buy gas valves that are initially drilled with tiny holes that you can drill out until you get to your desired hole size.