SBR upper question

[XD45]

I am going to be doing an SBR here eventually, and I came across a few people saying that the stock pistol uppers will not work correctly with the regular stock buffer tubes on a rifle. If this is true what are recommendations on what to look for in an SBR upper?

Good thing is I have months and months of waiting before I can even order an upper so I have time to figure it out![/sarcasm]

[bug]

Could use a little more info. I assume you're talking AR15 platform. What cal SBR do you have in mind? What make is the lower receiver?

There are a few places that may cause problems such as using both 9MM and 223 uppers with the same lower etc but for the most part it's almost too easy to set up an AR SBR.

[Pa. Patriot]

Assuming your talking about AR's

I have a good bit of exp with both pistol and SBR uppers.
The answer is dependent on several things.
Cal, brand and config.

Typically, NO, rifle buffers work fine with pistol uppers.
Pistol uppers create problems that folks try to solve with different buffers.
The biggest of which is gas impulse delay and gas impulse duration from the shorter barrel both infront of and behind the gas port hole.
Pigtail or "fat" pistol gas tubes solve most of the common problems. Cheap assed uppers come with std (but short) gas tubes and that is where the problem's are.