[redtail55]

Has anyone had the opportunity to compare these?
I am curious how different the groups would be using the same ammo & optics, out to say 200m.
Would the 6" difference in the barrel length result in a substantial accuracy contrast ?

 

[Cool Beans]

A longer barrel does not translate to a more accurate rifle. Each cartridge has its optimum barrel length achieve maximum velocity. I can't find any data for 7.63x39.

 

[willjr75]

As Cool Beans said, a longer barrel doesn't affect accuracy.

Here is a chart comparing velocities at different barrel lengths. Going from 11 inches to 16 inches only gains a little more than 100 fps. Going from 16 to 20 would gain the same. You are better off with a legal 16 inch barrel as the AK was designed for. I see no good reason to have an extra 4 inches of barrel for only about 100 fps gaining added weight and making the rifle more unwieldy.

 

[redtail55]

Interesting chart, ty for sharing.
I thought that more spin on the projectile from a longer barrel would result in better accuracy, I did not realize it increased the fps.

 

[doubleeddy]

Would FPS effect accuracy at long rang?

 

[Cool Beans]

Would FPS effect accuracy at long rang?

Yes the longer the projectile is supersonic the more range you will get.
But the original poster asked about 200 meters.

 

[redtail55]

Yes the longer the projectile is supersonic the more range you will get.
But the original poster asked about 200 meters.

That is long range for old guys...lol

 

[Vapor]

I don't have personal experience ,but some AK builders say they longer barrels are poorer due to barrel whip. The Ak action is rather violent.

My 16" saiga out classed my SKS by quite a lot. We're talking the saiga 16" is sub 2MOA and the SKS 20" was 4 moa. I don't think it is the barrels though. It was the triggers, stock configuration, etc. My sks was a commerical BTW, so yes the bore was fresh

 

[atTheWheels]

Is the sight radius the same for both barrels? A longer sight radius is a good thing.

 

[RandallOfLegend]

The 7.62x39 was designed for the RPD machine gun, which has a 20" barrel. So I would say the cartridge would be optimal in 20 inch barrel on paper, but a majority of the firearms since then have been 16 inch. So it's possible modern ammo is optimized for the shorter length.