Youth Gun???

I'd rethink the PCP and get him a pumper. But if you go with a PCP, I love the lightness of my discovery. It would work for a youngster if you cut down the stock and put a super light scope or a peep sight on it. Also, the TKO moderator, maybe the short one. He's going to be psyched whatever you get him! The disco is also, easy to fill with a pump.
 
I'd go with the .177 disco or .177 new Maximus coming out. Both have 2000psi fills that he should be able to pump up. IMO I think it's important for the youngster to be able to power their own rifle whether it's a pump or a PCP. With the .177 they'll get more shots per fill and then in a couple of years he can move up to a .22 if they want to.

Another idea, assuming you didn't care if your son wasn't "working" to fuel up the rifle, would be a CO2 rifle. Hammerli 850 or the Crossman 1077 are fairly accurate rifles. The 1077 is very light. Of course, the CO2 doesn't shoot well below 60 degrees so if you live up north, you'd run into that problem. Good luck with finding something, and most importantly, have great fun shooting with thim.
 
Marauder pistol with carbine stock attachment would be my first pick. Light, inexpensive, and quiet. The rifle is an under 20 FPE. If he hates it (which I doubt), you would still enjoy shooting it. I also like the BB gun suggestion. My son carried his BB gun while on hunting trips and when it got slow he was out shooting "what ever" to keep things interesting.
 
Benjamin marauder w/plastic stock but unless he has LONG arms you'll need to cut a section out and shorten it.
Better ( to me for youth ) would be the crosman 1720T (again w/ above mentioned stock) single shot - builds good habits- LW barrel 24+ shots if cranked up to 12fpe and a trigger that is alright.
One of the AA200/CZ200 type rifles would be excellent! A bit closer to the quality of Dad's airgun.
If you need as small light and low cost as a discovery, QB79 w/Ninja tank, regulated, all wood & metal , easy to chop the LOP if needed, regulated and a vastly better trigger than the discovery.
How about trying to find a used Titan MPT? That would be outstanding for a youth.

John
 
I would go with the Discovery in 177. Tether it to a paint ball CO2 bottle. Let him shoot away to his hearts content. It is single shot which slows the pace of shooting enough to recover from temperature change and he would not need to limit his shooting to a shot count with the tank. Pellets are cheaper as well. Once he gets the hang of things and you have taught him all the precautions then move up to an Air charge using a hand pump (2000 PSI fill with the hand pump). The pump will help give him more discipline and build strength that he will need to shoulder the gun and perhaps carry it in the field with you. The tethered CO2 Bottle costs about 25 dollars, should already be regulated to 850 PSI (verify the bottle is regulated to 850 PSI at purchase), add a coiled hose (Foster Fitting included) between the rifle and bottle with a shut off (sometimes the shutoff is also a regulator to 850PSI) for about 40 dollars. These both can be purchased at any paint ball store and talking with the store owner or clerk you can become familiar with what it costs to refill the tank (very reasonable) and you show that you will be a repeat customer at some point. Really high shot count from a tethered bottle and consistent PSI which translates into long flat shot string when compared to hand pumping and shooting with an air charge. I purchased a couple of 20 OZ. bottles which included the valve for 24.99 each, had them filled for 3.50 each. Oh I failed to mention they fit my Paint Ball Gun as well.
Just my ideas, price it out. If costs are a problem then I would bag the PCP idea and go with one of the break barrels or single pump rifles.
One other thing. When starting out with a youth you should not push him into a scoped rifle at the beginning. He needs to learn targeting with iron sights first. This is very important because it teaches the basic components of elevation and sight picture.
To keep my grand kids interested I included a lot of varied targets from 10 to 30 yards. We made animal cracker on popsicle sticks, old Halloween candy and chalk on popsicle stick targets that stuck into a bale of straw. Made it fun when they exploded and splattered.


















Great set up to start with in a PCP for a youth that he can grow into. A 22 Caliber is the other option with this set up which would be more useful in knock down energy but the pellet cost would end up being a bit higher. 177 - 750 count Tin versus 22 - 500 count Tin of pellets.
Just my suggestion if you really want to get him started with the PCP and not use up a lot of Air. 
 
I'm with NMShooter - my son is 8 and my daughter is 12 - I bought a Marauder pistol, installed the adapter and a adjustable length AR style stock.

It fits both kids and me perfectly, I have a red dot scope on it and a few mags.

I hear everyone about the single shot, but it's a pain in the rear loading single pellets...I can load up the mags while the kids are plinking away.

We've had a lot of fun and looking forward to more shooting all of the time.

I would not hesitate to go with the Maruader pistol.

eric
 
"NMshooter"Marauder pistol with carbine stock attachment would be my first pick. Light, inexpensive, and quiet. The rifle is an under 20 FPE. If he hates it (which I doubt), you would still enjoy shooting it. I also like the BB gun suggestion. My son carried his BB gun while on hunting trips and when it got slow he was out shooting "what ever" to keep things interesting.
Is this what you're talking about?
http://www.pyramydair.com/s/m/Benjamin_Marauder_Air_Pistol_AR15_Stock/3511
 
PY-2367_Benjamin-Marauder_BJ-BP2220_pistol_lg.jpg
 
I'd vote marauder pistol with stock extension also, because he won't outgrow it. A lot of adults like them. Having said that, you may have to help him cock it at first if it's like the marauder, because the marauder requires a firm pull. That also makes it a father-son deal at first instead of go play. Good time for instruction. I have 1 1/2 year old and 1 1/2 month old grand babies. I just purchased a micro Midas Browning BL-.22, a Ruger 10/22 and a lifetime hunting license for them. 😜
That prod may be next!