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JeffreyVB
03-12-12, 22:07
Looking to build a 20in AR in the near future. What kind of range can I expect to shoot at accurately with a 20in AR? 300yds? 400yds? 600yds? I am looking to build with a 20in chromed lined BCM barrel/upper.
ZoneOne
03-12-12, 22:46
Define your level of accuracy. I've shot man sized targets stationary and moving with an accurized M16 with AMU. Were they super tight groups, no. But hits none-the-less.

A lot comes into play, not just barrel length. Ammo, optics and operator head space and timing all influence accuracy.
MistWolf
03-12-12, 22:59
Service rifle matches are regularly held out to 600 yards using 20" ARs with iron sights
JeffreyVB
03-12-12, 23:45
Was just curious how far I could stretch out the 20in. I have heard that 16in ARs can reach out to 300yds. Was just curious how far out a 20in would reach.

Looking to hit mansize targets at a distance, not looking to shoot the wings off a gnat at 1000yds.
Iraqgunz
03-13-12, 00:13
We shot Ivan targets out to 500 meters when I was on the battalion rifle team. That was with M855 and iron sights. With better ammo and optics you can probably hit out to 900, although it won't be very effective.
Failure2Stop
03-13-12, 00:16
10.5" ARs will reach out to 600 meters or more in the right hands.
20" ARs are used in competitions out to 1,000 yards.
Sgt_Gold
03-13-12, 00:59
The limiting factor for you is going to be ammunition, not barrel length. An M4 with M855 is a 500 meter rifle against point targets. The same rifle with Mk262 can hit head shots at 700 meters. As Failure2Stop said, there are people shooting 20" rifles in 1k yard matches.
Surf
03-13-12, 01:25
I've shot an 18" version past 900 with pretty boring regularity on 18"x30" steel. Hits were easy enough and while I wouldn't want to get hit with it, terminal ballistics may be a consideration depending on what your needs are.
Casull
03-13-12, 04:28
My understanding is that it should have an effective range out to "...well beyond a thousand meters." Which is a statement we probably all heard from Travis Haley on the BCM mfg website video centered around their rifle lineup. If I were on a better device I could pull a cool video up about his experience doing so. Unfortunately I can't but if I have the ability this week I will.
SMETNA
03-13-12, 04:49
Depending on the specific make and batch of M855s accuracy threshold, and taking the shooter out of the equation, at 500 meters your groups could be as small as around 7.5" and as large as 27.5". (1.5 moa - 5.5 moa). So it depends on how that particular weapon likes that particular load.

Also, as was said, kinetic energy at that range may leave you wanting.
justin_247
03-13-12, 06:12
My understanding is that it should have an effective range out to "...well beyond a thousand meters." Which is a statement we probably all heard from Travis Haley on the BCM mfg website video centered around their rifle lineup. If I were on a better device I could pull a cool video up about his experience doing so. Unfortunately I can't but if I have the ability this week I will.

There's a video of him shooting at various targets with a 20" Bushmaster when he was doing PMC work in Iraq. I think he was inserted in to defend a CPA HQ in Najaf that was being sieged by forces allied to al-Sadr.
Preliator
03-13-12, 08:39
A SSgt from a line company that I fought with in 04' dropped a Jihadi at right around 600 m with a single shot from a 20" with ACOG firing standard M855. I was standing on the roof top right next to him when he did it. So with a bit of luck there is enough 'oomph' left in the round at 600 to take out a man sized target. Never did find out where exactly he hit the guy at, but the jihadi dropped like a ton of bricks and never even twitched.
Smuckatelli
03-13-12, 09:24
20" iron sights 500 yards, M-855...no problems. That is part of the Marines KD course of qualification.

My daughter shot one match using a 6920, iron sights 600 yards with BH 77gr Match, no major issues but once she got the 20" it was a lot easier for her. She was 15 at the time.
C-grunt
03-13-12, 12:24
I shot my Army issue M16 DMR out to 600 meters on point targets and out past 800 meters plinking at cars in Iraq. With good ammo and a good optic I'd say it's about a thousand yard gun if you know what you're doing.
Univibe
03-13-12, 21:04
There's a video of him shooting at various targets with a 20" Bushmaster when he was doing PMC work in Iraq. I think he was inserted in to defend a CPA HQ in Najaf that was being sieged by forces allied to al-Sadr.

Bushmaster? I thought those were inferior hobby toys?
Failure2Stop
03-13-12, 23:22
Bushmaster? I thought those were inferior hobby toys?

If you seriously don't understand the problem with BMs, you need to read more of the stickies and do some searches.
TehLlama
03-13-12, 23:33
That barrel won't be a limitation - but for the same weight, I really think it's worth considering going with the SS 18" unit from BCM, and focusing on the glass if you're looking to run it for longest range - alternatively a slightly cheaper WOA unit might be worth it if it means stepping up to better glass (NF comes to mind as being more than adequate at a good price, Leupold will do too).
C-grunt
03-14-12, 00:21
Bushmaster? I thought those were inferior hobby toys?

Many PMCs don't get to choose what they are issued and do with what they are given. Just because a well respected and talented shooter was able to successfully run a Bushmaster doesn't mean it's an acceptable weapon.