The thought has crossed my mind to cut down my BCM 14.5 midlength to SBR lengths somewhere around 10.5 to 12.5. Is this doable or more trouble than it's worth?
Thanks...
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The thought has crossed my mind to cut down my BCM 14.5 midlength to SBR lengths somewhere around 10.5 to 12.5. Is this doable or more trouble than it's worth?
Thanks...
I could be wrong but I believe that the shortest you can get and keep the middy gas length is 14.5. You can have the 14.5 barrel cut down to those lengths listed but wont be able to keep the middy gas system.
Thanks bro. I figured that if it was doable, someone would have been building them already.
Talk to bigbore at ADCO (I think). I believe he cut down a mid-length to 12.5" without issue,
If Steve did, it was probably with some sort of special gas block he makes...
A 12.5 inch mid can be done. I even know the gas port size!
Opinions differ on how appropriate that idea would be. One of these days I'll start asking how well a can works on increasing dwell.
Seems like a "why bother" to me. This whole midlength thing is getting out of hand.
Midlength getting out of hand? You probably mean the length people will go to to keep or get a midlength when the carbine gas system would do much better for them, as in this case, right?
Why bother? Seems like an odd question. I guess we could ask why bother with almost anything outside of a well-made stock gun.
Anyway, I'll try to answer... First off, as I stated above, I already have the barrel. I'm on a budget and paying $100 (I know it's less, just ball parking with shipping and such) to get a good cut job is a lot cheaper than buying and outfitting a whole new barrel or upper.
Secondly, I do like my middie. I personally feel there is a benefit over the carbine length. I know others may not, but I do.
So to answer your question, I'm looking for cost and performance benefits. After all, isn't that 99% of why we discuss things on these boards? Having got my answer, I will not being going out of my way to make it work. Thanks to all.
Obviously it's "doable", but it would seem to be more trouble than it's worth. IMHO there's little to nothing gained with midlength gas systems on barrels under 16". You'd also likely find yourself in a situation where you needed to start playing games with the gas port size.
Then there's the cost:benefit analysis. Given that a midlength gas system is about 9" and an FSB is probably another 2", I would think that they shortest you'd get the barrel would be 12-12.5", which is only 2" savings on your 14.5".
Remember what Pat says, "the mission drives the gear". While you may not have a "mission" (I don't) you should at least have an intended purpose. I find that when I do, all the questions seem to answer themselves.
You can make one right down around 10 and some inches. But you are going to need to make a gas block for it.
Different barrel lengths are possible. The shortest I've seen is a 7" barrel. I'm working on a 11.5" barrel for my SBR. From what I've found out so far is that you have to have different gas port sizes to match the length of the barrel. Sometimes it's hit and miss which is half the fun and a learning experience.:)
Steve had a few 11.5 and a least one 12.5" barrel with a 1" extended gas system.
Carbines with 1" extended, right? Not mid I don't think...
Rob was questioning your comment that the shortest you've seen is 7", assuming you were stating that you've seen midlength systems with barrels as short as 7".
If not, what were you trying to say? I don't understand.
A standard AR (or military M4) carbine is 7"+/- from the front of the upper receiver to the rear of the front sight base. Hence, the Daniel Defense, Larue Tactical, and other makers "7.0" rail for standard AR carbines.
A midlength gas system pushes the front sight base out another 2"+/-. Hence the "9.0" rails from Daniel Defense, Larue Tactical, etc.
Having a 7" barrel on a 9" gas system would be a little difficult. In fact, having a 7" barrel on a 7" gas system would be kind of tough as well. Most 7" barrels push the gas block back to somewhere in the neighborhood of 4-5" from the front of the upper.
Is shortening a middy to 10.5 to 12.5 doable? Yes (It may or may not function reliably)
Is it more trouble than it is worth? That's for you to answer not us. The gas system on the AR requires the bullet to be in the barrel beyond the gas port for some amount. On a carbine it is often reported that for reliable performance you need a 10"+or- barrel to accomplish this. That would lead me to believe that you would need a 12"+or- barrel with the middy. If you think it is worth the money savings to experiment and end up with a maybe reliable maybe not SBR that's for you to decide. If you want a 10.5" barrel and you want to use your middy, go for it. You can let us all know what gas port diameter you ended up with and if you needed an adjustable gas block. When you get it all worked out you'll know if you saved any money. If you do this let me know then I'll be able to actually save money because somebody else did all the experimentation. :D
For a reliable SBR 13.6-7" is about the shortest you can go on a middy.
I am currently thinking about what barrel length i want for a SBR and was planning on using a ~12.5" barrel with a midlength gas system. How i was looking at it is it would pretty much equate to a 10.5 as far as the location from the end of the barrel.
Some of the benefits would be (if it worked;) ):
-longer sight radius for a fixed front sight (without being set up as a dissapator)
-Im able to recycle my midlength handguard
-12.5 gives more velocity than the 10.5
I see allot of people go with the 12.5" in order to allow certain suppressors to be used but past that i dont see why the carbine length system is manditory. Then again i have never delt with a short barrel so its just speculation. I would think that some gas port tweaks would be an issue though.
gotm4: What is it about the midlength 12.5" long that makes it any different than a 10.5"? Im not saying your wrong or anything i was just curious since i was making plans to have the barrel cut.
SethB: What size gas port is nessisary to make a midlength work?
Overall i like my midlength gas system on my 16" ar and thats another reaon i wanted to use it for a SBR barrel. The thing is i wouldnt want to go any longer or shorter than 12.5". I think much longer than 12.5 will not give the returns of a SBR. 5.5" less than my current barrel would be nice though considering my suppressor is around that length.