mid length gas system vs carbine length

[NC_DAVE]

Sorry to hash this one up again, but I just read all attached treads relating to the middy vs the carbine on a 14.5" or a 16". I feel like I understand the concept, but does the difference in gas effect shooting 55 grain ammo. I could not find anything stating it did but before I order one I would like to make sure.

[Magic_Salad0892]

Parts replacement, preventative maintenance, DD/Centurion FSP rails, or ''Kino'' setups on 14.5'' barrels basically mitigate the ''issues'' with the carbine system on 14.5'' barrels.

For recoil, small gas port, VLTOR A5 buffer system, avoid comps unless suppressing the gun, building a precision rig, or game guns.

To answer the guy above me: shooting 55 gr. ammo should be fine.

The barrel profile will make more of a difference than gas system will.

However... carbine on a 16.1'' barrel is plain shortbus stupid. I would rather go midlength, or KAC BR.

[kwelz]

What about something like this?
http://www.weaponevolution.com/forum...4A1-RIS-II-FSP
Dustin

I think he has the same problem I do. The most comfortable grip on the weapon would put his support hand right where the FSB is on a carbine. No rail can cure this. The only option it to chop the FSB or go middy.

[NC_DAVE]

Does the lesser pressure with middy create a problem if you installed a h buffer or greater to the ar platfrom?

[GTifosi]

My undeducated guess would be 'no'.

An H2 buffer weighs in at 4 1/2 ounces and a rifle buffer with its longer yet gas system weighs in at 5 1/10 ounces and works fine.

Of course distance from block to muzzle would likely have bearing, so I could be well off on that thought process.

[rob_s]

Sorry to hash this one up again, but I just read all attached treads relating to the middy vs the carbine on a 14.5" or a 16". I feel like I understand the concept, but does the difference in gas effect shooting 55 grain ammo. I could not find anything stating it did but before I order one I would like to make sure.

Not sure where you are with this, or what you already have, but if this is your first or only AR I would stick with the 16" mid-length.

The 14.5" CAN be finicky, MAY have issues with some ammo types, COULD present problems if you start monkeying with buffers and springs, and WILL present a greater challenge to changing out parts later on WHEN you decide to do so.

[NC_DAVE]

Not sure where you are with this, or what you already have, but if this is your first or only AR I would stick with the 16" mid-length.

The 14.5" CAN be finicky, MAY have issues with some ammo types, COULD present problems if you start monkeying with buffers and springs, and WILL present a greater challenge to changing out parts later on WHEN you decide to do so.

This is my second AR my first is a CMMG bargin bin and would like to own a nicer one. I really would like an AR that can eat just about anything i feed it and would be very reliable. I also have limited funds, so I think i will get just an upper (16") and new bcg for now so i can buy some more ammo.

[Robb Jensen]

Sorry to hash this one up again, but I just read all attached treads relating to the middy vs the carbine on a 14.5" or a 16". I feel like I understand the concept, but does the difference in gas effect shooting 55 grain ammo. I could not find anything stating it did but before I order one I would like to make sure.

There's a lot going on which effect function, some of these are gas port size, gas tube length, carrier weight, buffer weight and buffer spring rate, amount of barrel between the gas port and muzzle and the pressure and obviously the burn rate/pressure curve of the ammo.
The diameter of the gas port and the gas tube length (Pistol/CAR,Mid/Int/Rifle) is going to control gas volume and pressure energizing the gas system.
The amount of available of barrel between the gas port and the muzzle is controlling how long the system has to pressurize the gas system before the bullet leaves the barrel. This can be controlled in part by how heavy the buffer is and the spring rate of the buffer spring. The buffer and spring hold the carrier forward while it's filling with gas when the round is fired, once it can't fill with anymore gas the bolt carrier will defeat the buffer and spring and the bolt carrier begins to move rearward, the bolt then unlocks and the excess gas in the carrier is vented off through the right side of the bolt carrier. The BCG continues rearward and the spent casing is extracted and ejected from the carbine, once the buffer hits the inner rear wall of the receiver extension then the buffer spring pushes the buffer and BCG forward and if there still ammunition in the magazine the BCG will push a loaded cartridge off of the magazine and into the chamber.

So you can see there are MANY combinations out there that can work or not work. Having a real understanding of how the system works is really required before dicking with something that you don't understand because all the sudden you could end up with a non-functional carbine. The AR is a complete system with separate systems within it. If you make a change to one of it's internal systems you can adversely effect the other systems.

Much like the 1911 is really an aficionados pistol the 14.5" midlength barrel is really an AR aficionados barrel.

[NC_DAVE]

Thanks for the feed back, I know there is alot going on with the the ar system. Alot of which I don't completely understand yet. I am really trying to grasp as much as I can. If you have any suggestions on ways to help me understand the system more completely I would be glad for the advice. I don't want to be that guy who thinks he knows what he talking about when really he has no idea. So be ready for more questions. (hopefully they all will not be bad ones)

[rob_s]

The single best way is to get a basic gun and go shoot it. Mid-length gas and A1-profile barrel are about the only deviations I'd recommend to start out. Well, that and to replace the A2 grip simply because I find them intollerable for the majority of people.

ROBB knows what he does about the AR system from SHOOTING his guns. a lot. and understanding what makes them work the way they do. His theoretical knowledge would be worthless without his actual end-user experience.

Of late this site is too full of people that don't understand the difference but feel qualified to wax poetic about all things. Your willingness to learn things the right way is commendable.