Thread: Shorter Barrel 223 data

Originally Posted by Tentman

Hello Folks

I recently changed from an 17.75"/450mm Bergara B14 EH stainless barrel to a Bergara B14 St chrome moly barrel at 16.5"/420mm, both in 223.

The 16.5 is still being worked up but initial velocities are very interesting (to me at least!) when compared with the 18" (nominal) given that I have some direct comparisons, with more to come. Most samples are 10 rounds.

Fiocchi Factory (Red box) 55gn 16.5" 3030fps 18" 2982 (cool day) 3020 (hot day) fps
Sako 55gn. 16.5 2990 fps 18" 2984fps
ADI 62 gn. 16.5 2857fps 18" 2848fps

I'm not looking at this from the perspective of maximum speed, rather that two otherwise pretty much identically made barrels from the same company can be different!

Greetings,
You would expect a difference of around 30 fps between the two barrels with the longer one the faster all else being equal. All else is seldom equal though. The round count, if known, would be interesting as would has either been chopped?
GPM.

Originally Posted by grandpamac

Greetings,
You would expect a difference of around 30 fps between the two barrels with the longer one the faster all else being equal. All else is seldom equal though. The round count, if known, would be interesting as would has either been chopped?
GPM.

The shorter barrel is brand new, round count is currently 50. The round count on the longer barrel is about 400 (although some of the recorded velocities go back to its "break in" period).

Im thinking of now running a test on the new short barrel to see if the accuracy improves over its break in. I was thinking to load 100 rounds of cheaper components. Shoot a 10 shot group. 10 also of factory as a control. Blast off 20 rounds at gongs/hares etc. Shoot the 10 round tests again. Blast off 20. Test 10. Blast off 20, test 10. This would take the barrel to just over 200 rounds, which is when "the internet" says it should be fully broken in and shooting at its best (for a cheaper factory grade barrel). Thoughts on this guys?

Originally Posted by Tentman

The shorter barrel is brand new, round count is currently 50. The round count on the longer barrel is about 400 (although some of the recorded velocities go back to its "break in" period).

Im thinking of now running a test on the new short barrel to see if the accuracy improves over its break in. I was thinking to load 100 rounds of cheaper components. Shoot a 10 shot group. 10 also of factory as a control. Blast off 20 rounds at gongs/hares etc. Shoot the 10 round tests again. Blast off 20. Test 10. Blast off 20, test 10. This would take the barrel to just over 200 rounds, which is when "the internet" says it should be fully broken in and shooting at its best (for a cheaper factory grade barrel). Thoughts on this guys?

Given that bullet-barrel interactions are only one part of the puzzle of dispersion, and bullet quality is another part - possibly larger - this test may not demonstrate anything as far as "testing if accuracy improves"


To see a difference (improvement) in precision of the order that you might reasonably expect (0 - 10 % change in mean radius?) from barrel "break in changes", you'd likely need massive sample sizes to have confidence in the result even if you used good quality bullets and ammunition. What you might demonstrate is that there is no meaningful difference that can be established, so people shouldn't worry about it