Originally Posted by
kyratshooter
Like I said, and like Anthony said, and anyone else for that matter, the speed you get is going to be determined by the weight of the pellet and the amount of bearing surface the pellet puts against the rifling, since the spring is putting out the same consistent puff of air with each shot.
That is why most serious target guns are either springers or gas piston. the target rifles hold their velocities down around 500-550 to get consistency and stability out of the pellet. All they have to do is punch a hole in a piece of paper.
The current crop of target air rifles of Olympic quality are some of the most accurate guns ever built by man. They are capable of constant one hole accuracy at 10 meters. Yep, 10 meters, 33 feet, is the air rifle standard. Officially 9 feet for B-B guns.
.22 pellets come in a variety of weights and shapes and just like with .22 bullets you have to find what your rifle likes. Lightweight .22 pellets start at 11 grains, mediums like the Crossman and Beeman brands at Walmart often weigh 15 grains and some heavy specialty pellets will top 20 grains. My rifle pushes the 15 grains pellets at around 800fps.
About 5 years back I invested $100 in a chronograph and it has been some of the best money I ever spent. It is especially nice to set up in the back yard and test BB gun, pellet gun and .22 rimfire velocities, I have even tested the velocity of different arrow weights. The way I taught myself to run the machine was shooting a couple of hundred pellets across the light traps in the back yard. I had pellet weights/velocities out the wazoo.
I have set it up at the range to test reloads I am working up. I have a difficult time when I do that though. Everyone at the range wants to see what their latest whizzbang round is doing and I wind up being the physics professor for the rest of the day.
That $100 investment has answered a lot of nagging questions I had for years.
Anyway, I know what my specific rifles will do but that is just my rifles, with the springs they have, the piston weight they have and the lubrication I use.
Did you know a Red Ryder BB gun puts out 275fps? The old long stroke pump guns, I think they were the model 25 Daisey, were reported to get 350 but I never got to measure one.
You can also get a .177 pellet up to nearly 500fps out of the little $25 pump up Crossman 760. BBs go a little faster and average 550fps.
What is a practical test without a chronograph?
I ascribe to the test established by Turner Kirkland, who was owner of Dixie Gun Works back in the day. Turner always claimed that if a piece of small shot, like a B-B or pellet, would penetrate both sides of a soup can it would kill a bird. We are talking about a 1955 era soup can not a 2018 soup can or aluminum pop can. Get a can that held tomato sauce or some acidic food, they are about 1955 tough. A paint can would work too.
If a small shot would penetrate both sides of a 5 gallon metal bucket, the ones like driveway sealer or asphalt come in, it was stout enough for small game like squirrels and rabbits. Over the years I realized that one side penetration was good enough.
Back when I was a kid I also used a "Coke bottle test". Coke bottles (not off band bottles) were heavy green glass about 3/16" thick and tempered for strength. Most BB guns just sent their fodder bouncing off into the wild (you're gonna put your eye out!). If your BB gun would shatter a coke bottle it was a strong shooter. Not many would.
Now over in Great Britain they are not allowed to sell anything that produces over 12 foot pounds of energy, and they measure each and ever air rifle offered for sale in the UK! If they use those light weight pellets to measure velocity/energy at the false level claimed by the factories here in America they would have very little to sell!
The makers therefore limit their rifles to the lower velocities required to meet the standards by selling only average to heavy pellets and reducing the power of the springs in the rifles.
That UK standard of 12 foot pounds is a 15 grain .22 pellet at 600fps. Or a 9 grain .177 pellet at 750fps.
Just about every springer or PCP gun in America will exceed that level, so we start out at what they consider too dangerous for the common man to own.
By limiting the energy and not the velocity they put every caliber on the same playing field but the flat trajectory and penetration of the .177 in that situation give it the edge when hunting. Over here we can push the . 22 up to the 900-1000fps level and always gain energy over the .177 at the same velocity.
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