AR Sponsor
Posted: 2/27/2011 5:22:22 AM EDT
|
Hello everyone
I hear alot about barrel extensions. I have yet to see a barrel and an extension come in two seperate pieces. Do they? Built more than a few and they were always one piece. Am I missing something? Thanks Bob R |
|
ok, got it
So, if I understand this correctly, A standard build should set right up with a standard bolt (minus tolerance stacking of course) etc If I want to run a different bullet that requires a different headspace I can change out the extension?? If I want to run those heavy bullet weights, do I change the extension or just throat it? I guess what I am asking is, why would I change out an extension? I have one in my parts bin, how do I measure it to find out what I have?. Ive never built any type, except for your "standard" .223 55gr,62gr etc. |
|
Quoted:
ok, got it So, if I understand this correctly, A standard build should set right up with a standard bolt (minus tolerance stacking of course) etc If I want to run a different bullet that requires a different headspace I can change out the extension?? If I want to run those heavy bullet weights, do I change the extension or just throat it? I guess what I am asking is, why would I change out an extension? I have one in my parts bin, how do I measure it to find out what I have?. Ive never built any type, except for your "standard" .223 55gr,62gr etc. Bullets have nothing to do with headspace. In an AR, longer bullets require a faster twist rate (numerically lower) barrel. |
| The chamber is designed for the 5.56x45 cartridge. You can't use a different cartridge with this barrel (for this purpose I am calling the .223 Remington the same as the 5.56). The barrel will accommodate any bullet exposed length that will work in the magazine. The cartridge is set up so all bullet weights have a maximum overall length that will fit the magazine. Unless I am overlooking something, this should answer your question. |
|
Quoted:
I'm pretty sure those barrel extensions become one with the barrel. I don't think you'll be changing them out in any kind of hurry. I would have to agree about not having to deal with barrel extension removals etc. I brought it up because there seemed to be some discussion about it with another builder. In my experience I never really had to deal with it. As far as running "larger" bullets (75gr) some folks have to throat it just to get it in the chamber. I have mostly built or customized .308 (762x51). IE: built a match grade bolt action rifle, headspaced out to 1.632, would chamber a 147gr to 168gr no problem. 180gr.....NG (the bolt would close but with some difficulty) had to open it up some In this case, it seemed, that to properly chamber some of the heavier bullets a little opening up of the headspace was needed. Anyway, just trying to figure out why folks mess with the extension in the first place. ps not trying to "flame" anyone or anything just trying to learn. Thans Bob R |
AR Sponsor