"Kino" Question

[Robb Jensen]

I have been investigating the "Kino" SBR confiuration and have a couple of questions. I have been using the Bravo Company link as a reference:
http://www.bravocompanyusa.com/BCM-1...m4-12%20kd.htm

Why is this considered an optimal setup? Why have a carbine length gas system with a gas block and an FSP. Why not just have a mid-length gas system and just an FSP with no extra gas block?

I apologize if these are remedial questions. I was just thinking about building a "kino", but BCM is out of them right now. I was talking to another manufacturer about it and they suggested just cutting down a mid-length 16" upper to 12.5". Will this work and be reliable?

Thanks for your input!

Longest rail available for a 12.5" barrel with a FSB. Midlengths don't work well with barrels under 13.7". Midlengths are best used on 14.5-16" barrels.

[RAM Engineer]

Mid-lengths have been so popular on the 16" platform, some people think "mid-length" is a panacea that will improve ANY AR. Like "mid-length" = teh awesum!

"I want a mid-length 10.5" gun! With a piston!"

"I want a mid-length 20" rifle!"

This is not meant as a dig at the thread originator, but just an observation over the last year or so.

[Magic_Salad0892]

"I want a mid-length 10.5" gun! With a piston!"

I laugh at that now, but I hear LWRCi tried to make one of those. 0_o

[RyanB]

Mid-lengths have been so popular on the 16" platform, some people think "mid-length" is a panacea that will improve ANY AR. Like "mid-length" = teh awesum!

"I want a mid-length 10.5" gun! With a piston!"

"I want a mid-length 20" rifle!"

This is not meant as a dig at the thread originator, but just an observation over the last year or so.

I tend to believe that it is best to use the longest gas system possible on each barrel length.

[mbacelonia]

I tend to believe that it is best to use the longest gas system possible on each barrel length.

If I understand the DI system its more of an issue with the dwell time with respect to that barrel, so the longest possible gas system could be problematic. The gas ports in the barrel being the longest possible could mean that you have too much or too little pressure building up in the gas system to effectively make the rifle function.

[rob_s]

I tend to believe that it is best to use the longest gas system possible on each barrel length.

The question is how do you define "possible"? If you mean the longest that will physically fit on the gun, pushing the gas port to within 3" of the crown may prove difficult to get running right. A lot can be overcome by jacking the gas-port size but it may be less than optimal.

For every discussion where people try to explain that putting the gas port that close to the crown is less than ideal, there is always someone that's done it and has done it successfully. That may be enough for some that want to tinker and get it running. Others of us are more interested in examples that have been proven over the long haul. For me personally, that means I'm not going with a mid-length gas system on any barrel under 14".

[RyanB]

I should rephrase. By possible I mean the longest that will work effectively in all atmospheric conditions I expect the rifle to work in, with the ammunition I expect to use in it.

So a 14.5 should be a mid, a 16 should be intermediate, 17 and longer, rifle. I haven't figured out where 12.5 goes, although the carbine plus 1 gas port location would undoubtedly be nice for that.