Can anyone explain this ?

[Explosive]

 
I have a 7.62X 39 CZ 527, I get about 3" 4 shot  groups at 100 meters.






I have two 7.62X 39 WK 181's that shoot 1/2 " 4 shot groups at 100m meters with the same ammo.







Can anyone here explain this anomally ?

[M1A4ME]

Your bolt action rifle doesn't "like" that ammo.  Don't laugh.  Guns are funny.  Not haha funny.  Two guns, same brand, model, caliber can shoot the same ammo differently.

My brother's AK shoots awesome groups with Tula.  My SIG 556R "hates" that ammo.  The SIG does very well with Wolf.  My brother wn't even buy Wolf ammo for his AK.

I've got a lot of examples of similar stuff from the years.

[Gunnerdad80]

I like turtles

[crosstimbers]

The 527 doesn't work for you. Sell it.

[MeatAxe]

 
I have a 7.62X 39 CZ 527, I get about 3" 4 shot  groups at 100 meters.






I have two 7.62X 39 WK 181's that shoot 1/2 " 4 shot groups at 100m meters with the same ammo.







Can anyone here explain this anomally ?

Interesting… That’s really good accuracy for semi auto in 7.62x39.

Is the WK 181 a piston or direct impingement gun?

Since it’s made in Canada, I don’t suppose we can get these in the US without some 922r compliance parts, which probably could be done.

[HollowDawg]

Have a friend who has the same rifle and caliber. He was having the exact same problem. He could pass a dollar bill between the stock and barrel but figured it had to be some sort of stock impingement on the barrel. He shaved a little wood out of the barrel channel and lo and behold, started shooting moa or less. Worth a try.

[Explosive]

Interesting… That’s really good accuracy for semi auto in 7.62x39.

Is the WK 181 a piston or direct impingement gun?

Since it’s made in Canada, I don’t suppose we can get these in the US without some 922r compliance parts, which probably could be done.

It has a piston, but they redesigned the system in the Gen 2 version.  It stays really clean, as does the receiver.

[Explosive]

Have a friend who has the same rifle and caliber. He was having the exact same problem. He could pass a dollar bill between the stock and barrel but figured it had to be some sort of stock impingement on the barrel. He shaved a little wood out of the barrel channel and lo and behold, started shooting moa or less. Worth a try.

If the barrel was properly free floated I can't see how giving the barrel more clearance would help.  I suspect he tightened the action down improperly when he put it back together again.

[RSR]

Have a friend who has the same rifle and caliber. He was having the exact same problem. He could pass a dollar bill between the stock and barrel but figured it had to be some sort of stock impingement on the barrel. He shaved a little wood out of the barrel channel and lo and behold, started shooting moa or less. Worth a try.

If the barrel was properly free floated I can't see how giving the barrel more clearance would help.  I suspect he tightened the action down improperly when he put it back together again.

Cold barrel is also smaller diameter than hot -- what might have been adequate clearance cold bore could have not been after testing hot and removing add'l material.

[E.Shell]

Shooting ONE 1/2" group is no more proof of precision than shooting ONE 5" group is proof of lack of precision.

Until you shoot several consecutive 1/2" groups, I'd consider that one group a fluke. Based on my experience shooting FMJ bullets 5.56x45, 7.62x51 and 7.62x39 and seeing typical precision of 2-3 MOA even in match grade rifles, I'd say you got lucky with that one group you have posted here.

[RSR]

*Also, 7.62x39 chambers have different dimensions in CIP vs SAAMI, and at its heart, it's a military round.

Provided you're an exceptional marksman or shooting from a sled -- until you ensure your chamber and cartridge are 1:1, and handload, it's hard to say it's the rifle's fault.

[Explosive]

*Also, 7.62x39 chambers have different dimensions in CIP vs SAAMI, and at its heart, it's a military round.

Provided you're an exceptional marksman or shooting from a sled -- until you ensure your chamber and cartridge are 1:1, and handload, it's hard to say it's the rifle's fault.

I have ordered a lead sled, hopefully that will resolve the questions.  I will post pics, or even  better. 

[B2MS]

Honestly, you should shoot better with the bolt action. Bullets shouldn't affect your shot that much unless they are cheapo rounds. Just my 2 cents.

[eth77]

Actually the loading of the round, together with the bullet tip configuration, jump distance, barrel temperature, and several other things make a huge difference.

Shooting 5, 5 shot groups with equal barrel cool-off time (keep the time in the data) will give you a much better idea of how well your weapon shoots.

I like either S&B or Prvi Partizan ammo. Both produced ammo in the bad old days under the communists. Now they're producing excellent ammo for everything.