Do you pick up any more accuracy out of a longer barrel than a shorter one in regards to rifles?

Question

I'm looking at two rifles. One in .243 with a 22 inch barrel and the other 7.62 x 39 in a 20 inch. I'm wondering if the second would be significantly better with a 22 inch one also. I'm thinking it might not be worth the extra money.

Answer 1

Figuratively speaking, yes. Longer tends to mean more accuracy.

Literally and physically speaking, though, no. Length doesn't equate to accuracy.

A bullet, when first fired, is like a quarterback standing on the football field with a ball in his hands and a 300lb linebacker charging him at full speed. When the linebacker hits him, he flies off in the opposite direction with parts of him flailing all about. If you took a picture of him at the second the linebacker hit him, though, you couldn't tell where or how far he'll fly because the forces aren't anywhere close to equalizing on the guy.

When fired, the bullet sits at the front of a mass of fast moving gas that all the sudden shoves the bullet down the barrel....but it's firing at an erratic pace so the bullet (the pressure behind it) is doing a jerky stop-start movement until the forces equalize behind it and it begins to move at a steady rate.

Once the forces equalize and there's a steady pressure behind the bullet, just like the quarterback being carried along by the linebacker, you have the peak of the potential accuracy and all the sudden everything becomes predictable. The linebacker is carrying the quarterback along at ten miles per hour in *this dirction*....the bullet is moving at 2300 feet per second and will hit this part of the target etc.

Physically speaking, as in the science of physics, not the solid part of the bullet, once a bullet reaches its state of equalized pressure inside the barrel, any excess barrel is totally useless. A .22LR for example, reaches its max pressure inside 16" of barrel....so a 16" barrel on a .22 will be just as accuracte as a 24".

A rifle uses slow burning powder so the bullet can get up to speed as smoothly as possible. Rifle ammo today is designed with a minimum 16" barrel the same as the law allows. If you used that same slow burning powder in a 6" pistol, though, it would never reach its pressure equilibrium before the bullet left the barrel and the pistol wouldn't be able to hit the side of a barn. One shot might be at 1300fps and the next at 1100fps and so on.

So, real world? You just need to try diff ammo brands in the diff weapons. You can easily find one ammo that will be super accurate in one weapon and not worth beans in another. You can't really compare the two because all the variables aren't defined.

Answer 2

In this case, the difference in barrel length is really not all that significant. In my opinion, the major difference is in the calibers. The .243 is an inherently more accurate round than the 7.62 X 39. I'd choose the .243 over the 7.62 every time.

In general, longer barrel length does translate to more accuracy. First, the barrel has to be long enough for the gun powder to be completely burned before the bullet exits the muzzle. If you have unburned powder leaving the barrel, the pressure and consequently the velocity will vary pretty greatly. However, in the case of these two rifles, that will not be a problem. If you were going to be using open sights, the longer barrel would give you a longer sighting radius which results in more accuracy. I highly suspect that you are planning to mount a scope on your rifle so sighting radius will not be a factor.

In making your selection, in this case, it will not be barrel length that will determine which is the better rifle, it will be the caliber. Go with the .243.

Answer 3

As everybody has said already, a little extra barrel isn't going to make a difference. I have a 20" rifle that'll shoot out dimes at 200 yards if I do my part. The .243 will generally have better accuracy than Russian surplus ammo, and good 7.62x39 is pretty difficult to get. Really, it depends on the rifle on these two how accurate they'll be able to get. Another important thing to consider is ammunition costs. If you can't afford to practice with the .243, it's not going to be worth the little extra accuracy you have. If you want to shoot often, the 7.62x39 is a lot easier to find and usually a lot cheaper. Russian manufacture 7.62 can be had as cheap as $.15 per round, while the cost of any type of .243 will often exceed $1.00 per round. That adds up fast if you're planning on shooting often. Also, people oftentimes complain that the .243 is too hot of a load in too small of a caliber, and has a tendancy to wear barrels out fast.

If you do your part, and your rifle is a good rifle, there shouldn't be a noticeable difference between the two inside 100 yards. The 7.62 will have more of a drop beyond that, though.

Answer 4

Longer barrels equate better accuracy ONLY if you are using iron sights. With optical sights, two rifles in the same caliber, with different barrel lengths will produce very similar accuracy.

Comparing a .243 Win with a 7.62x39mm Soviet rifle is comparing apples and pineapples. Most 7.62 Soviet chambered rifles are MilSpec weapons, and most .243 Win rifles are made to a higher standard of quality, and will shoot more accurately.

Doc

Answer 5

No, there's no difference in accuracy with barrel length. Heavier barrels tend to have less whip and more accuracy, but length doesn't make any difference. There is a little increase in velocity with a longer barrel, but with the chamberings you're looking at, the velocity difference won't be significant, either. As a matter of fact, since the 7.62x39 isn't useful for hunting purposes, the shorter barrel's handiness will probably turn out to be a plus for you, where you might have to think about the kind of hunting you do if it were a hunting round.

Answer 6

Significantly better?? I don't think the extra two inches is really going to do you that much good.

Personally I think the .243 is a better round the 7.62 x 39, at any range.

Answer 7

There will be no difference in accuracy between 2 inches.... but the .243 will be considerably more accurate than the 7.62X39 especially at ranges over 200 meters.... you should definitely get the .243

Answer 8

The longer barrel stabilizes the bullet for better accuracy. Other factors enter into the equation also, twist rate of the rifling, type of load, weight of bullet, the list goes on. Both the calibers you mention can be same hole shooters with the proper tuning and setup, or can be shot scatterers without. A great deal depends on the loose nut behind the wheel.

Answer 9

the longer the barrel the better accuracy due to rifling

Answer 10

NO* That is positively not true.* You lose very little feet per second by using the 20" versus the 22"...** It will not affect your accuracy.*