. i was taught over 23 ftlbs , and true magnums are .22 and .25 . i had to adjust my own personal criteria down to 21 ftlbs, so that it may include .177 . youre looking at 950 fps in .177 with crosman premier heavies (10.5 gr) and 820 fps in .22 with crosman premiers (14.3 gr) and 680 fps in .25 with ftt pellets (20 gr) . i also consider the weight of the rifle (8.5 lbs and over) and sometimes recoil and cocking effort. i've had several diana 48's. untuned, broken in d48's generally produce 18-19 ftlbs in .177 , 23 ftlbs in .22 , and 20-21 ftlbs in .25 - yet we all know this is a magnum. the r1 and np2 rifles are just on the cusp of being modern magnums. the first airgun i know of to called a 'magnum' was the fwb 124 , which as mentioned above is barely over 13 ftlbs. now that we have .30 cal , i'm sure it will evolve again. hope that helps. - raneman.
 
If it can bust a scope that costs more than the rifle, in less than 2 tins of pellets......it's a "Magnum".

LOL That's so true and unfortunately a hard way to figure it out. I personally don't like magnums in either springers or powder burners but I know there are lots who seem to feel you can never have too much. I don't get the big bore air guns either. If you need more then 20 couple foot lbs why not use a 22 lr of larger. BUT I know this is just my opinion and others see it differently. I've got a couple hammers in my tool bag so I have the ability to pick and choose. 
 
22LR or any firearms may not be allowed in many areas and some can not posses firearms but may be allowed to own airguns. Also the noise, range and possibility of collateral damage well beyond the range of most magnum airguns is a real concern especially when fired at a squirrel upwards in a tree. Many also enjoy the challenge of hunting with air or shooting at longer ranges which magnums can provide. AS far as busting scopes in 2 tins my 36fpe Theoben Dual Magnum has never broken a single scope, good engineering and proper scope selection are required.
 
22LR or any firearms may not be allowed in many areas and some can not posses firearms but may be allowed to own airguns. Also the noise, range and possibility of collateral damage well beyond the range of most magnum airguns is a real concern especially when fired at a squirrel upwards in a tree. Many also enjoy the challenge of hunting with air or shooting at longer ranges which magnums can provide. AS far as busting scopes in 2 tins my 36fpe Theoben Dual Magnum has never broken a single scope, good engineering and proper scope selection are required.

I think all of what is said is true. However I wouldn't minimize the range and potential for trouble with some of the real high power air guns either. ( I"m sure we all are on the same page) Guys are putting suppressors on 22 lr guns and the difference is some what academic. Comparing a 30 air gun pellet and a 22 LR round (?) really what is the difference. I'm poising that as a question. I shoot pigeons off the top of silo's with my 22 air rifle and I am concerned about just how far those pellets could reach out. I'd think a 30 cal air rifle would be a real bad choice for that use and possibly as bad as or even worse then a 22 LR. What do the rest of you think. Squirrels maybe the same. As to the fun factor and challenge of using the air guns for long range not doubt about that. I've shot my 22 air gun at some of the 100 rim fire targets and the boys are impressed with the accuracy and range of that Red Wolf gun. I always like doing it with the lowest power needed to do the job. It's amazing to me just how far you can reach out with a 223 and I've never been able to figure why guys deer hunt in Pa with Winchester 300 mags. And there could be reasons I just don't know about. Scopes ? well the magnums DO have a reputation. I personally am "flinchy" so like my HW 30 and my PCP's 
 
Not sure anyone would be wise to minimize range of high power airguns but the amount of .30 cal users is so far the unusual and not the norm and the amount of .30 cal that make over 120fpe that a .22LR cn make is smaller still. Also unless using slugs and not pellets which again most do even in .30 decelerate vastly more rapidly than a 22LR bullet does. As to magnums and scope reputations look and see how much more prevalent it is now with rifles truly built for just high power and not truly well made. I own 10 R1's and all the .22's and one .25 make over 20fpe and NEVER broken a single scope nor has my RWS 54 22fpe, RWS 56 24+fpe, Theoben Eliminator 27+fpe, Kodiak 29fpe or 2 Dual Magnums 36fpe. Well engineered and proper scope selection.