What am I missing?

[PhulesAu]

Velocity being a key factor to Accuracy, why look to sub-sonic ammunition? I get that some people need noise reduction. But when 36 to 40gn rounds are the average, shooting in uncontrolled conditions what do you gain??

 

[katokoch]

Subsonic ammunition is the standard for the vast majority of precision rimfire competition (benchrest, prone, etc). Check out equipment lists and often you'll see nothing but Eley, Lapua, and RWS subsonic 40 gr. match ammunition. One reason is subsonic .22lr rounds actually experience less wind drift than a high velocity (supersonic) round.

Check this out: http://www.thewindisnotyourfriend.com/read/long-rifle-wind.html

"The high speed round, then, suffers about 37% more wind deflection than the standard velocity. This remarkable result is due to the very rapid rate at which air resistance increases with increase in bullet speed in the region near the speed of sound. The .22 rimfires are the only important rifle cartridges that occupy this speed range, and they are the only ones that show more wind deflection as velocity is increased."

Because wind conditions can have a very strong effect on the slow, high B.C. rimfire bullets, subsonic rounds win over the supersonic rounds. Aside from being subsonic, a key factor with velocity and .22lr ammunition is consistency- having very consistent velocities from round to round.

 

[PhulesAu]

Thank you for that link. A nice simple explanation. Faster ain't always better.

 

[1Merlin]

Subsonic ammunition is the standard for the vast majority of precision rimfire competition (benchrest, prone, etc). Check out equipment lists and often you'll see nothing but Eley, Lapua, and RWS subsonic 40 gr. match ammunition. One reason is subsonic .22lr rounds actually experience less wind drift than a high velocity (supersonic) round.

Check this out: http://www.thewindisnotyourfriend.com/read/long-rifle-wind.html

"The high speed round, then, suffers about 37% more wind deflection than the standard velocity. This remarkable result is due to the very rapid rate at which air resistance increases with increase in bullet speed in the region near the speed of sound. The .22 rimfires are the only important rifle cartridges that occupy this speed range, and they are the only ones that show more wind deflection as velocity is increased."

Because wind conditions can have a very strong effect on the slow, high B.C. rimfire bullets, subsonic rounds win over the supersonic rounds. Aside from being subsonic, a key factor with velocity and .22lr ammunition is consistency- having very consistent velocities from round to round.

Man... I am fired up to try some of what I just read on that website..... Great Link...

 

[jonbearman]

Now that was an interesting read for sure.Thanks!!!

 

[moorepower]

HV ammo also becomes less stable when going from super sonic to sub sonic

 

[PhulesAu]

I understand the transition. My problem was the only things I've dealt with, where it was a concern use JP4 as propellant. ;D