For those of you who own thease how do you like them?  Do they seem to be a reliable and overall good way to carry a few extra rounds?  Thanks, Major  
btw my application would be on a mossberg 500.  

I was sceptical about these, until I got one for my M590.  Where these things really shine is when you are doing a "tactical" reload, with the muzzle pointing at your target.  You can just yank them down, and feed them in, while keeping your eyes and your muzzle on the target.  With practice, this can be done VERY quickly.

Another great advantage is that it keeps your reloads with the gun.  If you have to grab the gun in a hurry, especially at night when you probably won't be wearing clothing with pockets (if any clothing at all), you have at least 6 reloads on tap.

Get one, they are easy to install and the only real way to hold spare shells on a pump.

An alternate to the plastic side saddle is a fabric version made by 3-Gun Gear. These can hold up to eight shells and use Velcro rather then your trigger pin to hold them on.

how do you keep the shells in the side saddle?
mine keep falling out.  granted they tend to stay in most of the time but if i am walking or huning i will look down and one or two will be missing.

  billL223:  have you tried one of the faberic ones?  I have heard the glue on the velcro doesnt cooperate with heat.  or does it simply not get hot enough for this to be an issue.  Ill have to take a look at one and possibly e-mail them for some more answers.  

The sidesaddle seems like something i will get but its a matter of whether the 3 gun gear one or the saddle looks quality and usability wise.  

308wood:  Ive noticed that some brands of shells are slightly smaller or larger than others and tend to feed better or worse in my shotgun. Maybe you could do some testing and find out which shells shoot good and fit snug in your sidesaddle.  i imagine the simple fact of the holder piece being plastic would make it not be incredibly consistant coming out of the mold.  possibly wear too.  

Either way it looks like it would be nice to have so ill invest in one or ther other. thanks for the replies. Major      

If you're having problems keeping the shells in the sidesaddle then put the shells in brass up. That usually works for me.

The 3gun gear sidesaddle ONLY WORKS ON AUTOS.

But it is the best carrier that I have ever seen.

I actually have a 3 gun gear one on my 870. I shortened the forend myself. there is more then enough fore grip there, and there is no reason it has to come back over the receiver. So I took it off and chopped some of the back end off, rounded the edges and it looks great. the 3gungear side saddle fits great. never had any problems even with rapid fire.

I decided to go this route because I saw a buddies plastic one, that mounts with little screws, come off one day at the skeet range. the extended use caused the small mounting screws to shear off.

 I e-mailed the 3 gun gear company and asked about the semi vs pump issue.  They confirmed what i was thinking and essentially what little223shooter did.  They said the 6 shot version would work fine as long as you used the police/ tactical length pump that didnt pass over the reciever.  From how he described it i think that may be the route i go.  It seems like a good product.  Major    

great product. I put one on my benelli shotgun also. only reason i am keeping the 870 is because of the stock adaptor coming out for it......

Is that the CAR stock adapter your referring to?