7.62x39 penetration sks vs mini30

[leonard the punk]

I had my sks and mini 30 at camp on weekend for the first time together.
I was shooting at targets on 1/4" plywood nailed to 10" thick maple ,distance
40 yards.
The sks was sending the bullets rite through the tree where as the mini 30 only the odd one went through.
Same box of surplus amo.
Any thoughts on whats going on there.

 

[deagle2008]

shooting at trees?

 

[Ganderite]

bullet yaw. Try it again at 100 yards and you will probably find they are identical.

 

[mamma]

Most likely barrel length and its rifling (twist, grooves etc.) differences.

 

[leonard the punk]

Bullet yaw ?
Is that when bullet tumbles

 

[mamma]

Twist rate dictates at what distance bullet becomes stable ("goes to sleep") so I am guessing here that stable bullet = better penetration

 

[Bcviking]

The difference is caused because one bore is tighter affecting velocity and twist rate might be a factor .. and also the SKS barrel is 2 inches longer than the mini barrel , this might give you 50 - 100 fps

 

[leonard the punk]

Thank for imput'
Im going to try and determin what twist rates are.

 

[diemaco]

Jeeze, you guys are coming up with all these crazy theories when an obvious explanation is sitting in front of your eyes. The mini 30 was so innacurate he wasn't even hitting the tree most of the time.

 

[Satain]

Jeeze, you guys are coming up with all these crazy theories when an obvious explanation is sitting in front of your eyes. The mini 30 was so innacurate he wasn't even hitting the tree most of the time.

 

[factionrr]

Jeeze, you guys are coming up with all these crazy theories when an obvious explanation is sitting in front of your eyes. The mini 30 was so innacurate he wasn't even hitting the tree most of the time.

Lol I love it