05-05-2017, 06:58 PM
Interesting... subsonics create more backpressure through the gas port, which is why you want an adjustable block so you can tune that down. I'm not sure how a lighter spring helps with that - I assume so that you can turn it wayyy down. But with a lighter spring you have less force coming back forward to strip the next round off the top of the mag, run it up the feedramps, chamber it, and lock the bolt. As with nearly everything involving firearms operation, it is a give and take and you have to find a happy medium. I tend to stick to standard parts because they are proven, but I'll admit that adjustable gas blocks are fun to play with and the SCS has me tempted. I've also used an extra heavy buffer with success, but this is not really needed if you have an adjustable gas block.