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Posted: 10/1/2004 2:36:46 PM EDT
I am learning a great deal here. You guys are great.

If I could only make the search function work....

Are there any noticable accuracy differences between these three barrel lengths at 50 , 100, 200, 300 yards etc. ?

I am talking about standard chrome lined barrels.

I understand from my non mil-type weapons and ammo experiences, barrel lengths and particularly different length sight radius's can really make a difference.  
Link Posted: 10/1/2004 2:38:48 PM EDT
[#1]
Velocity, not accuracy. No difference.
Link Posted: 10/1/2004 2:40:11 PM EDT
[#2]
If everything was equal, barrel quality, contour, and you used a scope, the longer barrels would be less accurate. Under real world condintions, sight radius has the most influence, followed by contour, with M4 not exactly being designed as a target rifle.
Link Posted: 10/1/2004 2:41:06 PM EDT
[#3]
http://counterstrikefox.freeservers.com/mv.htm
Link Posted: 10/1/2004 2:43:02 PM EDT
[#4]
Sorry, forgot to mention that I'll let you do that math...
Link Posted: 10/1/2004 2:56:03 PM EDT
[#5]
Link Posted: 10/1/2004 3:05:17 PM EDT
[#6]

Quoted:
If everything was equal, barrel quality, contour, and you used a scope, the longer barrels would be less accurate. Under real world condintions, sight radius has the most influence, followed by contour, with M4 not exactly being designed as a target rifle.



Then why is everyone freaking out about the 12.5" XM8 barrel?
Link Posted: 10/1/2004 3:06:59 PM EDT
[#7]
Link Posted: 10/1/2004 3:07:29 PM EDT
[#8]

Quoted:

Quoted:
If everything was equal, barrel quality, contour, and you used a scope, the longer barrels would be less accurate. Under real world condintions, sight radius has the most influence, followed by contour, with M4 not exactly being designed as a target rifle.



Then why is everyone freaking out about the 12.5" XM8 barrel?



Because it doesn't propel the bullet fast enough to fragment and be effective past 35m with M855. Hitting is good, but if it doesn't cause any damage you might as well have stayed home.
Link Posted: 10/2/2004 3:33:41 PM EDT
[#9]

Quoted:

Quoted:
http://counterstrikefox.freeservers.com/mv.htm



If that's your website, you need to give Bushmaster credit for the velocity figures.



I don't know whose page it is, it just came up when I Googled for, I don't know, "ar15 ballistics barrel length", or something.

I guess those are Bushy's numbers?
Link Posted: 10/2/2004 6:45:07 PM EDT
[#10]
Link Posted: 10/2/2004 7:08:39 PM EDT
[#11]
I know there is no difference in accuracy in terms of barrel length but I just seem to do better with the 20". I really, really wish I could do better with the 16" barrel but I just cannot. The difference in accuracy (for me) is negligible, but I certainly shoot better with the 20" barrel. I'm sure my body type does better with the longer rifle and I seem to be pre-disposed to the 20" sight radius. These are my limitations shooting a carbine though, the barrel length matters zilch.
Link Posted: 10/2/2004 7:12:29 PM EDT
[#12]

Quoted:

Quoted:

Quoted:
Then why is everyone freaking out about the 12.5" XM8 barrel?



Because it doesn't propel the bullet fast enough to fragment and be effective past 35m 5m with M855. Hitting is good, but if it doesn't cause any damage you might as well have stayed home.



Corrected.

-Troy



Seriously? 5 meters? How can that be? I bet a train running over a cartridge could kill you. How could the velocity loss be so great that the weapon is only effective to 5 meters? Why then did the Italian mob use .22 pistols for hits? I am seriously confused here. I'm not doubting you because I admit, I pleade ignorance on this one, but that sounds really disturbing. Say it ain't so.
Link Posted: 10/2/2004 7:21:06 PM EDT
[#13]
The mob used .22s, cause they would get close and make sure they got a couple of good hits in. It wasn't great, but it kinda worked.

In combat you won't always have an opportunity to shoot the guy twice in the eye.
Link Posted: 10/2/2004 7:28:36 PM EDT
[#14]
The 5.56 will still kill an opponent at just about any range, it's stopping power which is the issue. A fragmenting bullet will cause significantly more blood loss over a short period of time and affect the CNS more drastically, which basically means that your opponent goes down before he gets a shot off at you.

Fragmentation threshold for standard military 62 gr. ball is accepted as 2700 fps. A round from a 12.5" barreled HK rifle or an 11.5" barreled AR will retain such a velocity for only about 10m. If you ever need to know why else I don't want the US military to adopt the XM8, let me know.


I am learning a great deal here. You guys are great.



Me too! I don't even own an AR yet and I'm going on 1000 posts. This site r0x0rz!
Link Posted: 10/2/2004 7:31:53 PM EDT
[#15]
1MissouriMule,

If you're in the mood to learn then I highly recommend you pour some coffee and go visit this website:

AR15.com Ammo Oracle

It's the best compilation of ammunition information out there regarding the AR15 rifle and addresses not only your specific question, but a dozen others that will stem from it.

Good luck soldier!
Link Posted: 10/2/2004 7:36:38 PM EDT
[#16]
I understand how the 5.56 round works. I guess I didn't really take fragmentation and yaw into account. 5 meters just sounded weird. Thanks y'all.
Link Posted: 10/2/2004 7:40:22 PM EDT
[#17]

Quoted:
I understand how the 5.56 round works. I guess I didn't really take fragmentation and yaw into account. 5 meters just sounded weird. Thanks y'all.



I gotta say, honestly I used to really despise AR's for years until I educated myself on the wepon. Once you learn the rifle, I believe it is clearly, clearly evident that the AR15/M16 rifle is hands down the finest and tightest battle weapon on mother earth. Please, do not give me the AK argument, I will run it down. I have spent a lot of time learning about a rifle I had no confidence in until about 5 years ago. This XM8 idea is worthless and holds zero compelling reasons for exsistance. I have become 100% confident with the AR. I would bet my ass on it any day. So long as it was a 20" barrel to suit my carbine handicap
Link Posted: 10/2/2004 7:44:47 PM EDT
[#18]

Quoted:

Quoted:
I understand how the 5.56 round works. I guess I didn't really take fragmentation and yaw into account. 5 meters just sounded weird. Thanks y'all.



I gotta say, honestly I used to really despise AR's for years until I educated myself on the wepon. Once you learn the rifle, I believe it is clearly, clearly evident that the AR15/M16 rifle is hands down the finest and tightest battle weapon on mother earth. Please, do not give me the AK argument, I will run it down. I have spent a lot of time learning about a rifle I had no confidence in until about 5 years ago. This XM8 idea is worthless and holds zero compelling reasons for exsistance. I have become 100% confident with the AR. I would bet my ass on it any day. So long as it was a 20" barrel to suit my carbine handicap



+1.  I ate and believed the old Vietnam tales of the jamming black rifle. It was then that I learned two things from this site:

- Double/triple check what information you hear or see before formulating an opinion.
- The M-16 was revised, and now is the best assault rifle in the world.

I believe but do not understand the theory behind shorter barrels being more accurate. Someone care to explain it to me?
Link Posted: 10/2/2004 7:50:01 PM EDT
[#19]
Shorter barrels, all else being equal, are stiffer and their vibrations are more predictable. That means they are more accurate. The Army has tested scoped AR15s to 500m with 14" barrels. Actually, they were testing the accuracy of the system, and shortened the  barrel to improve that.
Link Posted: 10/2/2004 7:50:38 PM EDT
[#20]
Talking about the AK Vs. the AR I can say I own both and I would never go into battle with an AK unless I did not have any better choice. I will be a strong supporter of the AR for life. On the XM8, I have zero experience so I will not say.
Link Posted: 10/2/2004 7:56:08 PM EDT
[#21]

Quoted:
I believe but do not understand the theory behind shorter barrels being more accurate. Someone care to explain it to me?



Sure
Link Posted: 10/2/2004 9:31:05 PM EDT
[#22]
Link Posted: 10/2/2004 9:51:49 PM EDT
[#23]
Link Posted: 10/2/2004 10:25:28 PM EDT
[#24]

Quoted:

Quoted:

Quoted:
If everything was equal, barrel quality, contour, and you used a scope, the longer barrels would be less accurate. Under real world condintions, sight radius has the most influence, followed by contour, with M4 not exactly being designed as a target rifle.



Then why is everyone freaking out about the 12.5" XM8 barrel?



Because it doesn't propel the bullet fast enough to fragment and be effective past 35m with M855. Hitting is good, but if it doesn't cause any damage you might as well have stayed home.



Define effective.

You can definitly kill with a .22 lr, and the XM-8 will achieve that performance past 35 m and well beyond.

Of course, if you want the guy to shut down quickly and you didn't achieve a CNS hit, you might be wishing you had hit him with an M-16A2 or even an M-4.
Link Posted: 10/2/2004 10:52:11 PM EDT
[#25]

Quoted:
I bet a train running over a cartridge could kill you.



If you mean a loose cartrige getting set off, then no.  I've had a .40 round go off on a table right in front of me at the range and the bullet bounced off my wrist.  It gave me a nice bruise but that's it.  But, sorry if that's not what you meant!

Link Posted: 10/3/2004 6:50:45 AM EDT
[#26]

Quoted:

Quoted:
I bet a train running over a cartridge could kill you.



If you mean a loose cartrige getting set off, then no.  I've had a .40 round go off on a table right in front of me at the range and the bullet bounced off my wrist.  It gave me a nice bruise but that's it.  But, sorry if that's not what you meant!




Probably was the case, not the bullet that hit you.  The bullet is heaver than the case, thus it stays put and the case flies off.  Saw an idiot throw a few .22 rimfires into a fire once, all that came out were cases, no bullets.
Link Posted: 10/3/2004 7:07:47 AM EDT
[#27]

Quoted:

Quoted:
I bet a train running over a cartridge could kill you.



If you mean a loose cartrige getting set off, then no.  I've had a .40 round go off on a table right in front of me at the range and the bullet bounced off my wrist.  It gave me a nice bruise but that's it.  But, sorry if that's not what you meant!




No, that's what I meant. How did the round go off? Creepy.
Link Posted: 10/3/2004 1:43:25 PM EDT
[#28]
The biggest variable is the shooter, if you are not an excellent marksman it does't make any difference how short or long the barrel is.
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