Question on ballistics...

[Mr.T]

If a certain ammo (.223 55gr) is suppose to fly at 3240fps out of a 24" barrel, what should I expect from a 11.5" barrel. I have a sh*tload of 55gr and my gunclub doesnt allow anything over 3200fps.

 

[peter3334]

If a certain ammo (.223 55gr) is suppose to fly at 3240fps out of a 24" barrel, what should I expect from a 11.5" barrel?

It would be less, maybe I'll "crony" the two barrels in Feburary.

 

[joe-nwt]

Using the 25-50fps per inch of barrel rule, you should be 300 to 600 fps slower. If that "certain ammo's" velocity rating is a factory rating, chrono them out of your 24" barrel. Sometimes the factories are a little "optimistic" with their velocity claims.

 

[sunray]

It's actually about 100 fps drop per inch.
"...gun club doesnt allow anything over 3200fps..." Do they actually chronograph ammo? Just curious. Makes you wonder why they think a .22 calibre bullet at 3,000fps would be less damaging to range equipment than one 240 fps faster. It also eliminates a lot of calibres.

 

[JasonYuke]

From what I have experienced with the 22 cal rifles nothing that short but from 27" to 20 its about 25-50FPS per inch pending the load.
More avg 25 per inch.

 

[Mr.T]

It's actually about 100 fps drop per inch.
"...gun club doesnt allow anything over 3200fps..." Do they actually chronograph ammo? Just curious. Makes you wonder why they think a .22 calibre bullet at 3,000fps would be less damaging to range equipment than one 240 fps faster. It also eliminates a lot of calibres.

Yes they do. They allow up to .458 WinMag.