This is my first post here since I cannot seem to find an answer elsewhere. I apologize if this topic has been beaten to death somewhere but I couldn't find it in the search. It seems like the kind of question no one asks because everyone seems to want the most powerful .22/5.56 ammo they can get and this is backwards from that thinking.
So I live on 5 acres and can shoot most weapons with no issues. But my AR15 is just too powerful. I am building a berm and backstop but my concern is ricochets. Even shooting in a downward direction at a tree base I had a round leave my property and hit a neighbors shed.  The other issue is this "range" is for training and my max distance to shoot is around 125 yards. So I don't need 3000fps ammo. I need to take away the possibility or lead leaving my property as much as possible.
I am wondering, besides the subsonic 5.56, which isn't in stock anywhere, is there a lower velocity .223/5.56? Something between 1500 and 2000 fps maybe? Since I'm shooting under 100 yards and training people on the AR platform, I am sure a 1500 fps .223/5.56 will do the job and either remain on my property or be non-lethal when it finds it's way off my property.
I can train people with a .22 but it seems silly to do tactical training with a non platform pop gun and leaves out getting them used to the functioning of the AR platform. I have seen the Man Marker/RVR training rounds but those seem really expensive. Besides 300fps doesn't seem like it would be effective for training at 50 yards. The goal is to get them handling and reloading an actual AR with all the bells and whistles while keeping errant lead within my property.
Also, since I have never reloaded I don't even know if a .223/5.56  can be loaded in such a way to keep velocities under 2000fps. If anyone has experience with this I can certainly consider reloading.
Thanks for any ideas.

Have you looked into frangible ammo?

PPU is underpowered. So is FGGM, both 223, and both lower velocity than 5.56mm

9mm blowback upper with EndoMags? Manual of arms the same, recoil comparable. Trajectory is like a rainbow and velocity comparably low.

To avoid ricochets?  Hadn't even thought of that. Smart.

For my personal shooting that's a great idea. I do need to have something for students and I think that would make things more expensive but I will definitely look around.

Thank you

Looks like subsonic velocities. I wasn't aware of that. That's why I asked. It takes forever to look up each brand and then their specs.

I will see if I can find any. LOL

Thanks

I'd love to but then I'd have to provide a weapon for each student. My goal is to have ammo on hand (I know that's cute nowadays) to sell to students if they don't have anything we can use.

A 300BLK upper would be great also but the ammo now comes with credit applications.

Stop shooting trees and then blaming your “small” property for it. Now I feel better for avoiding the trees all these years. In my mind I would see the bullets ricochet off one tree then another and going straight to my neighbors house, and thanks to you I now know I did not waste my time.

PPU .223/55 gr averages ~2900fps in near every test/review that I see.


OP, frangible is what you seek. Under powered ammo leads to cycling issues. Improvement of your range/backstops is advised.


Another option....22lr conversions for training.

Although this seems contrary to common sense actually the higher velocity bullets should fragment and break up better than lower velocity ones.

A 55 grain FMJ is less likely to ricochet than a 115 grain 9 mm FMJ or even a 40 grain 22 long rifle.

The 9 mm and 22 long rifle lack the velocity to overcome the bullets structural integrity.

The .223 does not have this problem and the bullet typically fragments at first contact with the target.

OP:
I've got to be honest.............  I don't think your plans are well thought out......

-100yds is good enough for training but you HAVE to have a proper back stop.
Like an honest-to-god big berm that is well constructed.  

-If you are running a business, things like insurance are mandatory.
LONG gone are the days of just having people shoot off your back porch and call it training.

-Getting 223 loads that are down loaded is expensive (if something like that EVEN EXISTS)  and not really the answer.  
The military uses things like the the M862/SRTA for short range training but it is hard to find and expensive.  

So really, I'd approach this differently:

- find a nearby properly constructed "real" range and use that.

-If you are so determined to use your land for it....... use a 22lr system and STILL MAKE A PROPER BACK STOP.
The 22 AR's function and operate the same, they are cheaper and for you have less chances of leaving your range..........
 
"Bighunt" has a point about bullets/velocities and fragmenting but since you are pushing the range idea being on just 5 acres and you've already struck a neighbor
once...........you've GOT TO keep all bullets on your property.  Which means lower velocity and range.

But to be honest, If I were you, I wouldn't do this at all, you are going to get sued (if not arrested) once another bullet strikes something off property.  
Find a nearby range to use.    

 

Bingo. A proper (read SAFE) range is a prerequisite to practice with any firearm, much less training new shooters. Go to a range or buy another property to construct a safe one.

I down load 223 for 3 gun for reduced recoil and faster recovery. I use 55 gr hornady sp for reduced chance of ricochet.  My loads are going 2,300 ft, you can go down slower but have to test for function

223/556 is by design a high velocity round. Reducing that severely reduces it's effectiveness. I don't think you would even be able to find anything like that. Also the round is designed to fragment and to fragment it needs to be going above a specific velocity, so using a lower velocity round, if you could find one, is potentially going to make your problem worse not better.