EcoHeliGuy
Member
- Location
- Vancouver island
Wildcat 22 for my bl-22, and 40g CCI mini mags for my CZ
help a newb buy some bulk 22
- Thread starter GunNewb
- Start date
That depends... on temperature.
Indeed, you don't want a bullet to go transonic (either from supersonic to subsonic or vice versa) in mid-air. If it leaves your barrel subsonic, you want it to stay subsonic. If it leaves supersonic, you want it to stay supersonic until it hits the target and then it abruptly becomes asonic or no-sonic
.I can't remember the math I calculated, but at reasonable outdoor temperatures I found that the Win 333/555 stayed supersonic until around 50 to 75 metres. Since my gun likes Win 333/555, at 50m it still shot very accurately (well, more accurately than I can anyways). But going out to 100m, it would go transonic and then subsonic... leading to opening groups. The CCI SV however (at reasonable outdoor temps) starts out of the barrel subsonic and stays that way (of course) so doesn't suffer from transonic instability.
That being said, temperature is key. As an example, @ -15 °C the speed of sound is around 1055 fps, so CCI SV will leave the barrel super or transonic (1070 fps) and drop from there... essentially being unstable from the get-go. We haven't had temperatures that cold here in the Lower Mainland so I can't perform accuracy tests, but I suspect that the Win 333/555 may be more accurate in colder weather (at least from a speed of sound perspective.)
So there you go... temperature is the key to that question. If you can get the bullet to hit the target before approaching the sound barrier... other factors will be more important to accuracy. Also keep in mind that, even if the bullet still goes transonic before the target, the closer it is to the target when it does, the less time it will be unstable in flight and therefore the less the groups will open up.
RadMan
hometownhero
CGN Ultra frequent flyer
- Location
- Toon Town, Sk
It is. Thats why target ammo is less standard velocity.
That depends... on temperature.
Indeed, you don't want a bullet to go transonic (either from supersonic to subsonic or vice versa) in mid-air. If it leaves your barrel subsonic, you want it to stay subsonic. If it leaves supersonic, you want it to stay supersonic until it hits the target and then it abruptly becomes asonic or no-sonic
I can't remember the math I calculated, but at reasonable outdoor temperatures I found that the Win 333/555 stayed supersonic until around 50 to 75 metres. Since my gun likes Win 333/555, at 50m it still shot very accurately (well, more accurately than I can anyways). But going out to 100m, it would go transonic and then subsonic... leading to opening groups. The CCI SV however (at reasonable outdoor temps) starts out of the barrel subsonic and stays that way (of course) so doesn't suffer from transonic instability.
That being said, temperature is key. As an example, @ -15 °C the speed of sound is around 1055 fps, so CCI SV will leave the barrel super or transonic (1070 fps) and drop from there... essentially being unstable from the get-go. We haven't had temperatures that cold here in the Lower Mainland so I can't perform accuracy tests, but I suspect that the Win 333/555 may be more accurate in colder weather (at least from a speed of sound perspective.)
So there you go... temperature is the key to that question. If you can get the bullet to hit the target before approaching the sound barrier... other factors will be more important to accuracy. Also keep in mind that, even if the bullet still goes transonic before the target, the closer it is to the target when it does, the less time it will be unstable in flight and therefore the less the groups will open up.
RadMan
Thanks for all this, something I hadn't thought about.
One thing though, are you suggesting a projectile would increase velocity? That isn't right.
Or maybe hit a cold air pocket? Seems unlikely.
Before you go out and dump some cash on bulk ammo, I would strongly recommend you buy one box of as many different brands and types as you can get your hands on, and try them in your particular 22. What works great in mine may give you headaches in yours, even though they are the same model rifle. My son has a CZ that just loves Remmy Subsonic. My Norc shoots like crap with it. Winchester Wildcat is the best for mine, unless I go to the Eley Match stuff. Some ammo will cycle in some semi's and not in others. Better to have 1/2 a box of inaccurate or unreliable ammo (for your gun) than 500 or 5000 rounds. If you're just going to be shooting at tin cans and don't mind the odd FTF or misfeed, then go out and get whatever is cheapest.
No, I was just in an "academic" mind frame when I typed that up... I didn't mean to suggest that a projectile could increase in velocity.
