wgj3

In my local matches, I see very few 20-ish round stages. And, if you're a competent reloader (of magazines into gun) there's going to be a place where you take a couple steps and can stuff in a fresh mag to finish the stage when you happen to run into a stage where 2-4 extra rounds in mag could save a reload...

Not a damn thing wrong with it if you have a .45 that you like. You can definitely get 17-18rds in the double stack mags. You give up some options on locations to reload, but often it doesn't really matter. Might also be a factor on steel-heavy stages if you miss a bunch, but otherwise it will work perfectly fine and its easier to score your targets too!

Fairly certain it is

I wanna bring back cutoffs!

Looks like that upper has a proprietary handguard... Are there options?

Light BCG isn't ideal for what is likely a fairly over-gassed rifle... As previously mentioned, barrel is most likely place to save a bit, turn it down some, shorten it, lighter gas block, lighter comp. What handguard? Aero?

Steiner is decidedly better optic!

Gun that fits you best will have least "felt" recoil.

Would running 9mm be staying with the spirit of the rule? Seems projectile diameter would allow it. 9mm "technically" has a rim...

Replacing rear sight on what firearm to be used for what purpose?

HazedCustom

New plug needed so that it has a way to stay in place without the bushing retaining it... May be able to use same actual guide rod.

That is correct, Grump.

HCRI

Same stuff for any other 9mm with minor ammo. There's about a 100 ways to make it work and that projectile should be fine. The RN profile tends to feed well.