7.62×39 mm Russian: Effect of barrel length on muzzle velocity

[BobM]

A good, fairly involved and interesting older (2016) article with examples on how barrel lengths effect 7.62x39 ammunition velocity being used. Ammo is two different common varieties of steel cased Russian brands. Has charts for velocity comparisons, item list of materials used and pic's. Results can be surprising.

7.62×39 mm Russian: Effect of barrel length on muzzle velocity

In this post, Rifleshooter.com will be testing the effects of barrel length on velocity for the 7.62×39 mm Russian Cartridge. Chambered in the SKS and AK-47, the 7.62×39 mm Russian cartri…

rifleshooter.com

 

[Recusant]

Is it surprising that a longer barrel produces more velocity? I would have been more interested to see accuracy results as the barrel got shorter. Of course the quality of the ammo used may have been a huge factor as well.

 

[BobM]

Is it surprising that a longer barrel produces more velocity? I would have been more interested to see accuracy results as the barrel got shorter. Of course the quality of the ammo used may have been a huge factor as well.

On velocity, usually does to a point. Within certain lengths, velocity is usually increased by barrel length to a degree, then the barrel length becomes more resistant partially because of propellants gases losing ground and longer barrel length from my understanding.

On accuracy, was hoping they'd do both in the barrel test too. Was quite possible at the time. Unfortunately, they weren't going for groups to measure accuracy. Is partially why stated it was a good article instead of a great one. The ammo they used, they felt was "middle of the road" or mid grade steel cased quality that most people would most likely use in that application, plus they had it on hand. Quality of ammo used and barrel used together can make a difference in velocity and accuracy.

- With Russian ammo likely becoming more scarce in future to be replaced by other suppliers, results and thoughts may change from articles test on ammo being used and results found. Many things can change between 2016 and 2021? Like for example, the 24" barrel blank is no longer available from supplier listed in article. Longest carried now is 20".