I found the ballistic tables for the .22mag and the .22lr out of the NAA Mini revolvers. I just bought one in .22lr and was curious to see the velocity difference between the mag and the long rifle loadings.
For those of you who want the abridged addition, skip down the last paragraph. It shows the findings in a nutshell.
Here is the .22mag
Here is the .22lr
There is some difference but not much. I tried to compare apples to apples so I compared the same bbl length 1 5/8" and the same bullet weights.
I averaged the top five 40 grain .22mag averages and got 851 FPS.
I then averaged the top five .22lr 40 grain bullets and got 732 FPS.
There was a .22lr that averaged 765fps and a .22 mag that averaged 805fps so depending on which 40 grain load you chose, your velocity benefit may be very small indeed.
Moving on to lighter and faster bullets tells the same story for the most part. I took the Federal Classic load as a benchmark because that load was available in both calibers.
The .22lr averaged 865fps with a 31 grain bullet.
The .22mag averaged only 980fps with a slightly lighter 30 grain bullet.
I calculate that one grain less weight out of the .22mag gave it an additional 33fps that it wouldn't have otherwise had. That brings the probable 31 grain velocity to about 947fps.
So what I learned from all this is that the .22mag does indeed have a velocity advantage over the .22lr all other factors being equal. The advantage equates to about 10-12% given equal loads in each caliber.
There are some .22lr loads that are faster than some .22 mag loads. All .22lr loads are much cheaper than any .22mag. You can buy the Rem Yellow Jacket which averaged a smoking hot 858fps in the bulk packs of 525 for $20 anywhere. That averages out to less than $0.04 a cartridge. You can find it much cheaper if you catch a sale at Wal-mart. I have bought these bulk packs for as low as $12 recently.
The cheapest I have been able to find .22 mag ammo is $8.99 a box of 50. That is almost $0.18 each. That is 4 1/2 times more expensive for 10-12% ballistic advantage.
The .22 mag kicks much harder and makes a louder bang and bigger flash but doesn't produce much for all that bucking and snorting.
There may be a need for that extra 10% sometime but if you are talking about shooting a human, both the .22lr and .22mag out of a NAA mini is such a poor choice that it is comical to compare which one is "better".
As a side note the only .22 short loading out of the short 1 1/8" bbl NAA Mini was getting 702 fps. That is only 17% less than the .22mag and that is out of the tiny 1 1/8" barrel vs. the .22mag barrel which is 1 5/8"! My guess is if they had a 1 5/8" barrel .22 short, it would bump up the velocity a bit like it does in the other NAA Minis that are available in both barrel lengths. That would give a 1 5/8" NAA Mini in .22 short a velocity very close to the .22lr. The .22 short is only a 29 grain bullet however so it is better to compare it to another loading with a similar bullet weight.
The Aguila Hyper Velocity .22lr weighs 30 grains. It comes out of a .22lr NAA mini with a 1 1/8 bbl at an average speed of 756 fps. That is as close to apples to apples as I can get. That means the .22 short is less than 10% slower than the .22lr coming out of the same bbl after factoring back in the 1 grain heavier bullet weight of the Aguila Hyper Velocity .22lr.
So my findings in a nutshell for those who do not wish to read my entire ramble is that you gain roughly 10% by jumping up to the .22mag from the .22lr and the same increase for the .22lr going up from the .22 short. As the .22lr is both cheaper and more powerful than the .22 short, I am not sure why it exists or why NAA chose to chamber a gun for it. .22 short can be fired safely in any .22lr so it is a mystery to me. My only guess is that it has something to do with cowboy action shooting rules.