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Posted: 5/27/2008 7:23:39 PM EDT
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After holding out for 2 yrs i can't take it any longer. I am about to take the plunge with model 1 sales. My question: What kind of accuracy should i expect at 100 yards with a 11.5" sbr in 7.62x39 caliber? |
Accuracy is not how long the barrel is it's now it's made and good ammo. IMHO. I have a Model '1' Sales 20'' barrel in 7.62x39 it's one of the best I have for my AR platform. Breaking in a barrel correctly is need to get the best accuracy. Mike |
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It has been my experience in competition shooting and as a sniper for two Police Agencies that barrel length has a LOT to do with better accuracy! The loss of pressure between an 11.5” vs. 20” or even a 23” barrel makes a great amount of difference at 100 yards and greater distances. Now if you are into a spray and pray then it doesn’t matter. However, it does when you want a tight group at the paper down range. Another thing to consider, in low light or night shooting, you are going to light up your position like a roman candle because of un-burnt powder from an 11.5” barrel! ArticWolf |
| shorter barrels means less velocity which in turn means less long range accuracy. If you take 10.5" barrel and a 20" barrel they will be equally accurate to 25 yards. However, take those same barrels and the 20" will out shoot the 10.5" out to 300+ yards b/c 20" has greater velocity. |
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MikeinGeorgia is the only one in my opinion that got it right. Barrel length has nothing to do with accuracy. It has to do with velocity. I think the rest of you get trajectory and accuracy confused. Example: Many years ago a friend and I were setting on his porch at his country farm house. He had a 38 Special Charter Arms. I had a 4 inch barrel Colt Diamond Back in 22 LR. I started shooting at dried clumps of dirt in a plow field at 400 yards away. After a few sighting shots I was hitting them. Them my friend tried. Same with him, after a few shots he was hitting them. Then he said that if we ever told anyone that they would say we were full of shit. Now you going to tell me that a snubnose isn't as accurate as an eight inch barrel??? The only time velocity has to do with accuracy is if it's not high enough to stabilize the bullet and if it isn't it will tumble. Short barrels are harder to aim more precisely if they are equipped with iron sights. With a scope it makes no difference. If barrel length had to do with accuracy, the longer the more accurate, then bench rest shooters would be using them. They don't. |
| How big were the clods? I have walked in shots before with a 9mm and a 45 handgun up to a couple hundred yards on basketball size gongs but on dirt clods how do you know which ones you hit as opposed to the ones you aimed for? On sights I have enuff trouble with the sight blade/picture on my M1-A1 rattlebanging for fun on Turkey silhouette steel at 400 meters,cannot imagaine the fat blade on a fixed pistol sight |
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JFA, Sorry buddy, (No offence intended) but the stats, research, experts, and studies are against you! Accuracy is determined by set in stone factors. The 1st is the cut within the last 2” of the barrel, length, and type of (Bull, MP, Military Grade, & metals used) barrel used. We haven’t even gotten into the type of bullet style, weight, powder used, and matching these factors all together to have the best performance combination to have that “Tack Driver” we are all after. My last sniper rifle was just such a weapon! It held a worlds record for 24 years for a 10 shot group at 100 yards. As such, I was able to out shoot all the other snipers at our monthly/quarterly meetings. Take in mind that I was using a 23” “shadow drilled bull barrel in .222 cal. Unlike your shooting scenario, we trained under the 1-shot, 1-kill rules. Now if your only threat is dirt clods and you have a truckload of ammo, then it doesn’t matter what you are using to kill your clump of dirt. However, if it is food for the table or our life, it is a totally different story…  ArticWolf |
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h I can imagine how unburnt powder may create turbulance behind a projectile. the query remains: what kind of loss in accuracy considering my religious beliefs in balistics can be expected dropping from say 16" to 11.5" with the 7.62x39 round. We are approximating, guesstimating, put your wet finger in the wind.ho |
An 11" barrel is not going to allow all of the powder to burn before the bullet exits, this may cause 'flinging'. Allowing for the already slow velocity of the round, the most likely low twist rate, and judging from 3-gun and action matches were I have seen such rifles fired my best guess would be that you should be able to hold a 24" square piece of cardboard. A group would be unlikey unless fifty rounds or so were fired. Rifles and shotguns have a common trait in that the longer the barrel the tighter the pattern, not to say that they acheive it the same way but the results are the same. A longer rifle barrel will increase bullet stablization. Increased twist rate can improve stability in a shorter barrel, ie increasing twist and slowing burn can produce (generally) the same accuracy from a shorter barrel. HTH AI AR10-Dan in Ga |
I have a 10.5" and 12.5" in 762x39 and have no problems out to 25 yards 
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i'm going with velocity, bullet mass, powder composition, metal composition, etc. as nothing is ever black and white in the real world. Higher velocity due to barrel length will more greatly overcome environmental conditions as any physics professor would clarify. for instance light is made of matter and it is relatively uneffected by the environment unless considering astronomical range due to its speed/velocity & mass ratio.
who needs a hug?|
I usually don't get myself involved in these internet arguments, but I'm going to side with JFA on this one -- barrel length doesn't greatly affect accuracy. Just a couple of quick examples: www.accuratereloading.com/223sb.html findarticles.com/p/articles/mi_m0BQY/is_1_50/ai_110470564 |
The dirt clods where the size that normally come of a tractors plow...so what would that be about basketball size? We could tell where our shots were going because I said they were dry and when your bullet impacted there a dust cloud. It took me one cylinder (six shots) to get my shots in. I do agree there is a difference in longer shotgun barrels and patterns, but not longer rifle barrels. Let's say you have a 30 inch rifle barrel, like commonly found on a 30-40 Krag, and you have a 10-22 Ruger with it's much shorter barrel. If you move your rear sight 1/16 inch in either direction, which will result in more barrel muzzle movement to align the sights? If you didn't answer the 10-22 Ruger you were wrong. The analogy of this is that any sight alignment with a long barrel isn't as much on the target as a shorter barrel. In other words you can aim more accurately the further away the front and rear sights are. This is all negated with a scope. Anyone that thinks I'd choose either of the two handguns I spoke up in the story to hunt either animals or humans needs not be in this forum. Where did I ever say that? |
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Well, I have never been a sniper and all that fancy stuff, but I do know this for certain... There are two kinds of accuracy, mechanical and practical. Mechanical accuracy is not better with longer barrells. In fact, shorter barrells are more accurate. This is because if they are shorter, they are stiffer, if they are stiffer, they whip less or at least more consistetly. Practical accuracy is better with long barrells because of either a longer sight radius making it easier to see deviation in the alignment of sights, or because of higher velocity giving a greater margin of error in terms of range and drop due to a "flatter" trajectory. Suppressors improve accuracy because when a bullet leaves the barrell, all the gas that used to be trapped behind it, now suddenly envelops it and this turbulence marginally destabilizes the projectile. When you use a usppressor, this gas is trapped and the bullett makes a clean get away. tsh77769 |
That's a big +1 barrel length gives a longer range. My AR with a 75 foot barrel shoots great at 25 yards  Mike |
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