The DISPARITY in 5.56 barrels.

[Ginge]

They can still be accurate though. What that lack of spin does is simply limit its range considerably before the bullet starts becoming unstable in flight. Thats why its a 100 yrd weapon at max. Longer, heavier bullets out of the new pdw are more likely to lose stability and increase their potential to keyhole at 100-150, maybe sooner depending on velocity.

 

[TEXASforLIFE]

As always there is going too be variables that are on both sides work/not work!

 

[Ginge]

Yup. It is what it is.

 

[TEXASforLIFE]

This is also true when it comes too bullet manufactures as compared too same weight coupled with velocity! I haven't tried any sub ammo with any various barrel lengths to compare bullet actions.

 

[TEXASforLIFE]

Some of this could be what SMSgtRod is having sighting issues with and not just the optic manual or powered!

 

[Ginge]

This is also true when it comes too bullet manufactures as compared too same weight coupled with velocity! I haven't tried any sub ammo with any various barrel lengths to compare bullet actions.

I got some links up above that have some very interesting information if you haven’t seen them already. I gotta get a new chronograph soon so I can do some testing.

 

[TEXASforLIFE]

I got some links up above that have some very interesting information if you haven’t seen them already. I gotta get a new chronograph soon so I can do some testing.

Okay! I was just getting at it's not about accuracy, but key holing issues that is more related too less than 8" barrels. I have heard others having the same problem.

 

[TEXASforLIFE]

I wonder why they make 4" barrels in the 556?

 

[Ginge]

I don’t believe that super short barrels are a good match for heavier, longer bullets in regards to bullet stability. Mainly those in the 75-80gr weight. Lighter bullets tend to fly better with less spin. A good example is the old M16s, and the 1-14 twist rates, later switching to the 1-12 for better long range stability and accuracy.

 

[Ginge]

I wonder why they make 4" barrels in the 556?

Not sure exactly. I think its more designed to be a cqb weapon more than anything, as that’s about all its good for.

 

[TEXASforLIFE]

Not sure exactly. I think its more designed to be a cqb weapon more than anything, as that’s about all its good for.

Key holing against body armor! I'm just going by manufacture's minimum twist/velocity specs. The best thing maybe too do is get a barrel without rifling for cq if stability is not what you are wanting!