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Posted: 6/26/2015 5:13:06 AM EDT
[#1]
Watched a dude whack steel at 1000yd with an 18" spr and M855 (in the Yakima wind) like it was his job (oh wait, it is
 ). Ever since that and watching him consistently hit steel at 1500yd with his 7.62 bolt gun with Mk118LR I've completely rethought what "accuracy" is. |
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Posted: 6/26/2015 12:29:11 PM EDT
[#2]
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Science and physics, might want to look into them 
Let me guess, you were really good at home economics and P.E. in high school? Quote HistoryQuoted:
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Looking to build a "long range" AR, is 26" impractical? 5.56? Yes. .308? No. Actually both are not worth going with more than 20in barrels. There is basically no velocity gained going past 20in. When it comes to 5.56 and .308, if you feel you need a longer barrel, you need to re-evaluate your choice in caliber. Barrel length is one of the most misunderstood concepts. It hasn't been till very recently that many people have come to see that most rifle cartridges, (ie. 5.56 and .308) that use a medium burning powder have experienced 96-99% powder burn after travelling 20 inches down a barrel. Even cartridges like .300 WM and .338 Lapua don't need more than 24 inches. Many people are using them to 99% capability with 22 inch barrels. There are very few cartridges out there that require a 26 inch barrel. I have had a couple of varmint ARs with 24in barrels and even had a Krieger 26in, which I had cut to 20in. I sold them all. When it comes to gas-gun 5.56, I just don't see any point going longer than 18 inches. Science and physics, might want to look into them
Let me guess, you were really good at home economics and P.E. in high school? I was just trying to help. Instead of insulting me, please point out where my post was factually incorrect. |
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Posted: 6/26/2015 12:48:05 PM EDT
[#3]
Palma rifles are a good example of extraordinarily long barrels installed to squeeze every last foot per second out of a bullet by holding the bullet in the barrel as long as the gas keeps expanding.
No matter whether the first 90% of speed is obtained in a short barrel, if the gas is still doing work on the bullet in a longer barrel, then the bullet starts its trajectory at higher speed. There's nothing wrong with an AR chambered for .223 Rem with a 24 or 26 inch barrel if a sensible contour is used. The rifle I mentioned before weighs 16.5 pounds with iron sights, and over 18 pounds with the scope. It's a chore to shoot well off hand or during slow fire prone, way too heavy to enjoy. But it shoots like a house afire, so I'll keep it until it stops. |
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Posted: 6/26/2015 12:49:08 PM EDT
[#4]
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In my world, an AR with a barrel over 16" is impractical. Define "long range" and what caliber are you even talking about? These things are somewhat relevant. Same here. My 10.5 is plenty out to 300m. Can't shoot any farther than that, so even a 16" is too long. 26 would be ridiculous. If I feel the need for anything longer than 16" that isn't a clone, then I'll use another caliber. |
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Posted: 6/26/2015 12:51:11 PM EDT
[#5]
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I have a 26" barrel on a 223 AR. Not only are the muzzle velocities several hundred fps higher than in my 16" AR's, and that extra speed is free. The front sight is also mounted near the muzzle not on the gas block and it is way out there, helping me to focus on the front sight. More than anything else, the extra distance helps with accuracy. Contour is key. The 0.92" diameter barrels sold by RRA are just too darned heavy. Even in a 16" length it's ridiculously muzzle heavy but their 26" barrel are a bad joke, IMO. Quote HistoryQuoted:
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I have a 24 inch barreled gun, but part of the motivation for that length was use of iron sights for Highpower shooting. Speeds are slightly higher than from a 20 inch barrel with the bullets I shoot. My recommendation is that you get a sensible contour, not one that is 0.90 or greater for it's full length. The gun will be too heavy, and too muzzle heavy without ballast in the butt stock. Something similar to a Wilson #4 or #5 contour would make a nice 12 to 13 pound gun. I have a 26" barrel on a 223 AR. Not only are the muzzle velocities several hundred fps higher than in my 16" AR's, and that extra speed is free. The front sight is also mounted near the muzzle not on the gas block and it is way out there, helping me to focus on the front sight. More than anything else, the extra distance helps with accuracy. Contour is key. The 0.92" diameter barrels sold by RRA are just too darned heavy. Even in a 16" length it's ridiculously muzzle heavy but their 26" barrel are a bad joke, IMO. I think my gun ended up at 0.93 inches or just a few thousandths larger, I ordered the gas block from JP Enterprises and the front sight base from Accuracy Speaks so the bores could be measured before turning the barrel to final contour. |
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Posted: 6/28/2015 10:50:46 PM EDT
[#6]
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I have a 26" barrel on a 223 AR. Not only are the muzzle velocities several hundred fps higher than in my 16" AR's, and that extra speed is free.. Quote HistoryQuoted:
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I have a 24 inch barreled gun, but part of the motivation for that length was use of iron sights for Highpower shooting. Speeds are slightly higher than from a 20 inch barrel with the bullets I shoot. My recommendation is that you get a sensible contour, not one that is 0.90 or greater for it's full length. The gun will be too heavy, and too muzzle heavy without ballast in the butt stock. Something similar to a Wilson #4 or #5 contour would make a nice 12 to 13 pound gun. I have a 26" barrel on a 223 AR. Not only are the muzzle velocities several hundred fps higher than in my 16" AR's, and that extra speed is free.. It's not free though. Your paying for it with extra weight and reduced maneuverability. ETA: Nothings a free lunch, theres always compromise. |
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Posted: 6/28/2015 10:58:21 PM EDT
[#7]
My friend has a colt 24" stainless that he uses on yotes. Looks silly. Good shooter though.
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Posted: 6/28/2015 11:06:36 PM EDT
[#8]
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My friend has a colt 24" stainless that he uses on yotes. Looks silly. Good shooter though. Some here except it is an H-Bar barrel with a flash hider. Works well and reduced noise a bit. with a good flash hider there is zero flash at night. I do plan to ad a supressor at some point. The only purpose for this rifle is hunting coyotes from a fixed position. |
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Posted: 6/28/2015 11:13:16 PM EDT
[#9]
I'm not operator enough to run stuff.
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Posted: 6/28/2015 11:16:09 PM EDT
[#10]
Quote HistoryQuoted:
Science and physics, might want to look into them
Let me guess, you were really good at home economics and P.E. in high school? Quote HistoryQuoted:
Quoted:
Quoted:
Quoted:
Looking to build a "long range" AR, is 26" impractical? 5.56? Yes. .308? No. Actually both are not worth going with more than 20in barrels. There is basically no velocity gained going past 20in. When it comes to 5.56 and .308, if you feel you need a longer barrel, you need to re-evaluate your choice in caliber. Barrel length is one of the most misunderstood concepts. It hasn't been till very recently that many people have come to see that most rifle cartridges, (ie. 5.56 and .308) that use a medium burning powder have experienced 96-99% powder burn after travelling 20 inches down a barrel. Even cartridges like .300 WM and .338 Lapua don't need more than 24 inches. Many people are using them to 99% capability with 22 inch barrels. There are very few cartridges out there that require a 26 inch barrel. I have had a couple of varmint ARs with 24in barrels and even had a Krieger 26in, which I had cut to 20in. I sold them all. When it comes to gas-gun 5.56, I just don't see any point going longer than 18 inches. Science and physics, might want to look into them
Let me guess, you were really good at home economics and P.E. in high school? So do you have anything to add to the convo or are you just a fly by troll? |
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Posted: 6/28/2015 11:22:44 PM EDT
[#11]
I have a 24" DPMS bull barrel that is the most accurate AR I have shot. It's a heavy fucker too. It wears a 6-24x50 Vortex Viper and I can call my shots on p-dogs on 6x or 8x. I actually use up to 18x to find them in the tall grass if I know there is one in the area. It's one hell of a varmint rifle if you have a rest handy.
As far as "optimum barrel length" it's a crock of shit. Any feasible barrel length will gain you velocity. You start gaining less velocity per inch of barrel length, but it won't stop going up. Even in a gas gun. If anyone knows rifle barrels it's Dan Lilja. And he did a test on this. |
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Posted: 6/29/2015 12:10:32 AM EDT
[#12]
Quote HistoryQuoted:
Interesting factoid: Shorter barrels tend to be stiffer and are generally a little more accurate than longer ones. Quote HistoryQuoted:
Quoted:
snip Barrel length has nothing to do with accuracy. Interesting factoid: Shorter barrels tend to be stiffer and are generally a little more accurate than longer ones. Another interesting factoid in benchrest shooting, some believed 21 3/4" was the perfect barrel length due to a combination of stiffness and barrel harmonics/vibrations. |
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Posted: 6/29/2015 7:22:59 PM EDT
[#13]
Quote HistoryQuoted:
Actually both are not worth going with more than 20in barrels. There is basically no velocity gained going past 20in. When it comes to 5.56 and .308, if you feel you need a longer barrel, you need to re-evaluate your choice in caliber. Barrel length is one of the most misunderstood concepts. It hasn't been till very recently that many people have come to see that most rifle cartridges, (ie. 5.56 and .308) that use a medium burning powder have experienced 96-99% powder burn after travelling 20 inches down a barrel. Even cartridges like .300 WM and .338 Lapua don't need more than 24 inches. Many people are using them to 99% capability with 22 inch barrels. There are very few cartridges out there that require a 26 inch barrel. I have had a couple of varmint ARs with 24in barrels and even had a Krieger 26in, which I had cut to 20in. I sold them all. When it comes to gas-gun 5.56, I just don't see any point going longer than 18 inches. Quote HistoryQuoted:
Quoted:
Quoted:
Looking to build a "long range" AR, is 26" impractical? 5.56? Yes. .308? No. Actually both are not worth going with more than 20in barrels. There is basically no velocity gained going past 20in. When it comes to 5.56 and .308, if you feel you need a longer barrel, you need to re-evaluate your choice in caliber. Barrel length is one of the most misunderstood concepts. It hasn't been till very recently that many people have come to see that most rifle cartridges, (ie. 5.56 and .308) that use a medium burning powder have experienced 96-99% powder burn after travelling 20 inches down a barrel. Even cartridges like .300 WM and .338 Lapua don't need more than 24 inches. Many people are using them to 99% capability with 22 inch barrels. There are very few cartridges out there that require a 26 inch barrel. I have had a couple of varmint ARs with 24in barrels and even had a Krieger 26in, which I had cut to 20in. I sold them all. When it comes to gas-gun 5.56, I just don't see any point going longer than 18 inches. Even if 100% of the power is burned, at say 20 inches, there will still be high pressure behind the bullet to continue to accelerate it for some time. Do you "need" that extra 100-200 fps, and how much benefit you get from it is the question. That extra speed dissipates very quickly. IIRC, in less than 100 yards. To really take advantage of the length, you need to use a slower powder and depending on the gas port location, that could cause issues with over pressure in the gas system. http://www.accuratereloading.com/223sb.html http://rifleshooter.com/2014/04/223-remington5-56-nato-velocity-versus-barrel-length-a-man-his-chop-box-and-his-friends-rifle/ ETA, The longer barrel will have a higher polar moment of inertia than a shorter barrel of the same length. That should make it a little easier for a "average" shooter to aim. The rifle won't be any more accurate, and for a really good shooter it won't matter. |
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Posted: 6/29/2015 7:57:33 PM EDT
[#14]
Make no mistake, the extra speed can make a huge difference in your ability to hit targets. Wind and range forgiveness are both benefited by starting a bullet faster. A shallower angle of attack makes any long target larger, that often can mean the difference between a hit and a miss.
With the proper powder and loads, you should easily be able to get a Berger 70g vld well over 3000 f/s with a 24" barrel. That would be a hot ticket for ringing steel past 1000 yards. Hell, my 18" barrel gets them to 2900 with no trouble at all. Velocity is also a major factor in your ability to kill game and varmints at closer ranges. |
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Posted: 6/29/2015 8:00:14 PM EDT
[#15]
Also, for 24" and longer i would definitely make sure I had an extra long gas system. Rifle length +1 or even +2, so that you can actually use that extra barrel length to build a longer pressure curve.
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Posted: 6/29/2015 8:07:36 PM EDT
[#16]
Quote HistoryQuoted: I'm curious, do any of you notice a significant decrease in muzzle blast with your long barrel ARs (compared to a standard 16" barrel)? If so, at what barrel length do you notice the decrease? HighSpeedSteel With A2 birdcages, 20" seems to have more boom (downrange blast) than bark (sideways blast), though they are similar. I may borrow a 24" .223 bolt gun for this weekend and report back. |
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Posted: 6/29/2015 8:09:43 PM EDT
[#17]
Years ago I built a 24 inch bull barrel varmint/ bench gun.
Its super accurate, but its awkward. Way too much muzzle end weight and just long. A friend fell in love with it and wanted to build something similar, but I was able to talk him into going with a 20 inch barrel. His shoots just as good as mine and isnt awkward as fuck to maneuver. Some day I'll get around to cutting mine down. |
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Posted: 6/29/2015 8:15:02 PM EDT
[#18]
Those barrels are intended for NRA high power match rifle shooters. They help increase the sight radius and increase the weight, both highly desired properties for high power competition.
 Unless you're doing that, there is little point. I'd argue there isn't much point in a barrel longer than 20''. The increase in velocity from 20'' to 24'' is very marginal. |
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Posted: 6/29/2015 8:19:25 PM EDT
[#19]
Quote HistoryQuoted:
Actually both are not worth going with more than 20in barrels. There is basically no velocity gained going past 20in. When it comes to 5.56 and .308, if you feel you need a longer barrel, you need to re-evaluate your choice in caliber. Barrel length is one of the most misunderstood concepts. It hasn't been till very recently that many people have come to see that most rifle cartridges, (ie. 5.56 and .308) that use a medium burning powder have experienced 96-99% powder burn after travelling 20 inches down a barrel. Even cartridges like .300 WM and .338 Lapua don't need more than 24 inches. Many people are using them to 99% capability with 22 inch barrels. There are very few cartridges out there that require a 26 inch barrel. I have had a couple of varmint ARs with 24in barrels and even had a Krieger 26in, which I had cut to 20in. I sold them all. When it comes to gas-gun 5.56, I just don't see any point going longer than 18 inches. Quote HistoryQuoted:
Quoted:
Quoted:
Looking to build a "long range" AR, is 26" impractical? 5.56? Yes. .308? No. Actually both are not worth going with more than 20in barrels. There is basically no velocity gained going past 20in. When it comes to 5.56 and .308, if you feel you need a longer barrel, you need to re-evaluate your choice in caliber. Barrel length is one of the most misunderstood concepts. It hasn't been till very recently that many people have come to see that most rifle cartridges, (ie. 5.56 and .308) that use a medium burning powder have experienced 96-99% powder burn after travelling 20 inches down a barrel. Even cartridges like .300 WM and .338 Lapua don't need more than 24 inches. Many people are using them to 99% capability with 22 inch barrels. There are very few cartridges out there that require a 26 inch barrel. I have had a couple of varmint ARs with 24in barrels and even had a Krieger 26in, which I had cut to 20in. I sold them all. When it comes to gas-gun 5.56, I just don't see any point going longer than 18 inches. There are exceptions to every rule as well. One mistake a lot of people make is to look at data that was taken with factory ammo. Factory ammo is built with a specific length in mine and they match burn rates to that. Powder has come a long way and some real cool combos exist with slow burning powder and long barrels in both pistols and rifles. Quoted:
I'm curious, do any of you notice a significant decrease in muzzle blast with your long barrel ARs (compared to a standard 16" barrel)? If so, at what barrel length do you notice the decrease? HighSpeedSteel There is a little difference but since a lot of the noise is coming out of the action it's not like a huge night and day difference unless you are talking 10" vs 16" which is noticeable. |
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Posted: 6/29/2015 9:32:45 PM EDT
[#20]
Quote HistoryQuoted: With A2 birdcages, 20" seems to have more boom (downrange blast) than bark (sideways blast), though they are similar. I may borrow a 24" .223 bolt gun for this weekend and report back. Quote HistoryQuoted: Quoted: I'm curious, do any of you notice a significant decrease in muzzle blast with your long barrel ARs (compared to a standard 16" barrel)? If so, at what barrel length do you notice the decrease? HighSpeedSteel With A2 birdcages, 20" seems to have more boom (downrange blast) than bark (sideways blast), though they are similar. I may borrow a 24" .223 bolt gun for this weekend and report back. I notice it a LOT going from a 16" to a 24". The 24" is way more hearing friendly. I refuse to shoot a 16" without ear pro, but with my 24" (not threaded barrel) I'll throw a few quick shots downrange if there is something needing shooting that won't stick around for long. Shooting my 16" with a JP brake I could actually feel the muzzle blast in my face. Very annoying. |
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Posted: 7/23/2015 8:27:59 AM EDT
[#21]
Quote HistoryQuoted:
Another interesting factoid in benchrest shooting, some believed 21 3/4" was the perfect barrel length due to a combination of stiffness and barrel harmonics/vibrations. Quote HistoryQuoted:
Quoted:
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snip Barrel length has nothing to do with accuracy. Interesting factoid: Shorter barrels tend to be stiffer and are generally a little more accurate than longer ones. Another interesting factoid in benchrest shooting, some believed 21 3/4" was the perfect barrel length due to a combination of stiffness and barrel harmonics/vibrations. Meh... What do those guys know anyway?
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