Can someone explain to me what weight buffer should be used when?   Carbine gas system versus pistol .... And rifle buffer tube versus pistol tube .....
I'm talking about 10.5 inch barrels on down.

Way too many variables, most notably being the gas port size.

I have no pistol length barrels, but MOSTof my short barrels are overgassed, to compensate.

If I was building another 10.3/10.5 I would order it from ADCO with a custom port size of my choosing.  That being said, if I had recommend a buffer for an off the shelf 10.5, it would be an H2 and an Extra Power spring like a Sprinco Blue.

Not sure why you would want a rifle extension over a carbine extension with a 10.5, but you are limited on buffers for those rifle tubes.  As for pistol extensions, just use carbine components.

I have several short barrels, and they are all getting adjustable gas blocks to address these tuning issues, especially since the addition of a can.

My 10.3 DD barrel is so overgassed that I can "reliably" run a H3 buffer, and Red Sprinco.  I have recently added an ADM reliability buffer, that works good.  This one is the first one to get the adjustable gas block.

Give us more info and specifics.  This is a very broad subject

What about a phase 5 pistol buffer tube.  Is that considered a carbine tube.    Are kak shockwave tubes carbine or rifle tubes

It's all in the fitment of the parts as a whole. I have a bone stock LMT 10.5 chrome bore 1:7 upper, carbine length gas system with the standard FSB and regular carbine buffer and tube. The gas port is .071". It has a GTS/Denny's Guns BCG, ( the old Thunder Bolt) a McFarland one piece gas ring, and BMC gunfighter mod 4 CH. The log shows currently 11,260 rounds through it without a single hiccup of any kind with .223 to 5.56, Wolf to Mk262. Although  most of the rounds have been on the 68-77gr 5.56 side.

The next build I'd like to do would be a spikes tactical billet upper    Daniel defense 10.3  barrel with there gas block.    aero precision or dd bcg.    Shockwave using there carbine stock.   What buffer do you think?

I don't think your getting the concept. There are too many factors involved to choose a buffer simply on who manufactures the parts. Tolerance of parts, ammo used, hell even the altitude and temperature of where your shooting is a factor, just to name a few. In theory all should run just fine on a standard carbine buffer because that is what it was designed for. But that is not real life. The exact same parts used in two different builds may need different buffers. Your best bet is to get a carbine buffer and a H3 buffer so you can mix and match the internal weights for the performance you are looking for.





 

Ok thanks

I'm less of an expert when it comes to different buffers and springs to say the least. But I agree with the above comment. To add to that, perhaps a mil spec m4 buffer tube, buffer, and spring. The cost of changing springs and buffers isn't all that bad in comparison to other parts. If your mil spec carbine buffer and/ or spring seems to suck then you know how it sucks and therefore what's needed to not suck so much. Your specific use, preferences, parts specs, environment, etc. are all different and unique to you, so it's hard to say exactly what to get. Pistol builds are so different from rifle builds, particularly when it comes to the gas.

Bottom line, I say it's easier to start with something simple, basic, and less costly before getting complicated and buying a more expensive buffer and spring that may not work the way you want it to anyway. Spend a lot for uncertainty, or a little for uncertainty. One of those short pistol buffer tubes seems like not quite enough to me.
But I'm not a pistol AR guy, just a rifle AR builder, for a reason. That being said, take my pistol AR advise with a grain of salt. My knowledge on the subject is research only. Hours and hours of it, but still only research.....and applied knowledge of course.

If I'm wrong, someone will say so, in that case disregard. I try to make sense.