Dont be a cheap bastard. Just build a different upper.

>>30655175
LMT did this like 15 years ago and they aren't a flyby night me too company.

Solution for a problem that doesn't exist.

No benifit at all. Sights would have to be released zeroed, and depending on the round, the bolt would need to be swapped. Just build a second upper.

>>30655237
/thread
all other answers are inferior

>>30655187
this, literally takes 15 seconds to undo the pins to remove the upper plus then you can have different optics and theyll all keep their zeros

I dunno if it helps, Im about one tier above a nogunz, but I want to be able to switch out quickly for different barrel lengths, so I can have a 7" barrel or whatever without ATF fucking my anus for SBR, as long as I don't attach it, and a 30" barrel for hunting scenarios.

>>30655749
>30" barrel

Ruger SR556 Takedown has quick change barrels

>>30655175
faggotry

>>30655749
If it wasn't an SBR and you had a 7" barrel, you could get pegged for constructive intent.

>>30655749
you'd best buy an AR-15 pistol with a brace and a 30" upper for hunting.

just never put a stock on that thing and always deny that you used the brace as a stock. you used it as a "cheekrest" and despite how it looked it wasn't touching your shoulder.

or just get an SBR, but those are illegal in many states.

30" is way too long for a barrel, what's the point? go for a 20"

>>30655866
Thanks man, that's actually helpful. >>30656415
My idea was to have a long ranged rifle that mimics a sniper rifle as closely as possible without extra weight, I read that every inch of barrel length should account for about 25 fps, enough to massively alter the ballistics of the rifle.

You guis really think I should stop jewing around and just but another upper?

>>30657157
It's actually about 100 fps per inch, up to a certain point. But yes, you should definitely build another upper. Buy a really nice expensive barrel with a matched bolt and buy the other stuff on sale or blemished from psa

>>30657157
Another "buy a second upper" vote here. Almost done with my 16" 5.56 upper build, planning a Grendel build with a longer barrel and scope eventually.

>>30656415
wtf do I have to do to make it an AR-15 pistol?
>>30657327
If I were to build another upper, could I just slap a different upper onto the same lower, like a .308, and pair it with a new mag and barrel? No need to match up a new lower to account for it? I've never done this before