The elusive 20inch AR15 BBL
- Thread starter jdman
- Start date
Questions (for the sake of information):
1) What is the maximum barrel length do you reccommend for an AR15?
2) If shooting 5.56 out of 16" AR barrel requires a person to rethink caliber- what caliber would you point said person in the direction? .223 Wylde? .300 Blackout/Whisper? 6.8SPC?
One of the reasons the CF stuck with the 20" barrel on the C7A2.
You get 2,700 FPS with a 10" barrel... Your point is invalid.
Listen to Kevin B. He knows a thing or two............
That... Or $$$
both. the benefits with going with a shorter barrel did not outweigh the cost of replacing every 20" barrel in the CF with a 14-5" or 16"
I'm not trying to hijack the thread but that statement itself is incorrect. Yes you can achieve 2,700 fps at the muzzle from a 10" but it won't be over that 150 yrds away.
Now it may seem like a moot point to have "killing power" as a paper punching civilian using a range queen but to discredit the 20" as being useless is a blanket statement. It may be useless for YOUR applications but not to everyone.
Now there isn't a golden fragmentation threshold, it varies by bullet grain, however. When you start having 10" barrels you don't leave yourself a lot of room to play.
If an AR firing NATO Ball ammunition out of a 14 1/2" barrel leaves the threshold after 65yrds, what do you think the "effective range" of a 10" barrel firing that same ammunition would be? Probably around 40yrds.
Source
Ok found a 20 inch Barrel. Wolverine has them in stock. DPMS with FSB installed for 229$!
Thanks wolverine.
Thanks for the info- checking it out myself to see if it'll fit the bill for my build.
EDIT: Better yet- mind providing a link? Can't seem to find it/
FSB installed? This suggests that it would be an excellent barrel for assembling an issue configured rifle. i.e. with barrel nut, weld spring, delta ring and a pair of handguards & related hardware. Great for an A2 project.
For a DMR, maybe not so much.
For a DMR, maybe not so much.
Sorry I got cut off at work when I was posting.
Crane also had longer than 20" uppers - 22" and 24" barrels where tried as well. For the 5.56mm effective range zone - Crane decided that the 18" barrel was optimal from a precision standpoint to 800m
The original user group had wanted a 16" precision upper - but you see what happens when a comittee assists
Terminally - its not like a bullet just stops being effective below its fragmenting velocity. BoatTail bullets tend to yaw regardless when they run into human tissue.
Bullet placement is more important than anything.
Also keep in mind Military decision are based on several factors.
To the OP who mistakenly beleive I was saying the original Gene Stoner 20" was 'wrong' - no, he built the system based on downsizing from the 20" 7.62mm AR-10
the 20" M16 barrel profile was fine -- however a heavy longer barrel is not fine.
Crane also had longer than 20" uppers - 22" and 24" barrels where tried as well. For the 5.56mm effective range zone - Crane decided that the 18" barrel was optimal from a precision standpoint to 800m
The original user group had wanted a 16" precision upper - but you see what happens when a comittee assists
Terminally - its not like a bullet just stops being effective below its fragmenting velocity. BoatTail bullets tend to yaw regardless when they run into human tissue.
Bullet placement is more important than anything.
Also keep in mind Military decision are based on several factors.
To the OP who mistakenly beleive I was saying the original Gene Stoner 20" was 'wrong' - no, he built the system based on downsizing from the 20" 7.62mm AR-10
the 20" M16 barrel profile was fine -- however a heavy longer barrel is not fine.
Apart from stresses applied to the upper receiver by a long heavy barrel and ballistic issues, these long heavy barrels have a negative affect on the handling of the rifle. This is significant if the rifle is going to be used for anything more than bench/rested/bipoded shooting
Bolivar
CGN Ultra frequent flyer
Kevin
I think by 'OP' you mean me. I wasn't trying to imply you were saying anything negative. (I have enough trouble with words in my own mouth, no point putting then in others) Just asking for clarification regaring 20 inch barrels being bad juju. You have clarifed this for me. Thanks.
I think by 'OP' you mean me. I wasn't trying to imply you were saying anything negative. (I have enough trouble with words in my own mouth, no point putting then in others) Just asking for clarification regaring 20 inch barrels being bad juju. You have clarifed this for me. Thanks.
Bolivar
CGN Ultra frequent flyer
Honestly, for what I do, a pencil barrel would work fine but I will live contently with my somewhat heavier profile.
I have a reliable rifle, a reliable load and a good enough optic. Now I have to work on that jerk behind the trigger
1/9, 5.56 would have liked a Govt profile, but it is HBAR. Meh, i can always have it lathed down to something else at a later date.
Honestly, for what I do, a pencil barrel would work fine but I will live contently with my somewhat heavier profile.
I have a reliable rifle, a reliable load and a good enough optic. Now I have to work on that jerk behind the trigger
That jerk has given me pleanty of sound advice the last while!!!
