Looks like most of the people here answered your question.. :) I ride a jumper who needs a strong bit when he's in the jumper ring, a gag works great on him when he's competing. Though some are stronger then others, I would not recommend it if you've never used one, and definitely wouldn't use one if you're looking for a step up from a snaffle. There's quite a big difference between the two! Like someone mentioned above though, I'd do whatever training you can to help soften his mouth and see if you still need something stronger. -that might be a possibility if your horse has been pulled on for a long time. Have you looked into a snaffle with a slow twist? Or perhaps a Dr. Bristol? I think Dr. Bristol's are great for a horse that needs a little more bit then a snaffle. I know some hard mouthed horses go well in a Kimberwicke but it's not for everyone. Just a few ideas...
Well the name suits the action. When the rider picks up contact on the reins the mouthpiece is drawn up into the mouth higher. Horrible things really, I mean if someone's horse "needs" one there is a huge training hole. I feel that way about any bit that was obviously designed to cause harm or to be harsher. You just shouldn't have to use a harsh bit and you certainly shouldn't be using a bit for control or breaks.
I agree Jubillee, I have no idea why a gag is called a gag, but it makes it sound in my opinion more horrible then what it really is. (and just to note, it does NOT function by 'gagging' the horse) . There are several different types of gags differing in severity and function. Generally you'll have 1 main rein that you ride off of, and a 2nd gag rein that you use when you need extra leverage, very much like a pelham. I would disagree with the 'ehow.com' article someone posted that it's 'the most dangerous of all bits'. I think a double bridle in the wrong hands can do more damage (and really, a snaffle in the wrong hands can do damage). But like how a double bridle can give an experienced dressage rider the extra precision and control necessary to do upper level movements, a gag can give a jumper the extra precision and control necessary to the jumps, esp on a horse that's ready to GO and may be too excited to listen to the softness of something like a snaffle. My barely 5'2 petite frame does not have the leverage a 6 ft man will have on a huge fit jumper no matter how well trained that horse may be. I start every horse in a snaffle and ideally, it'd be nice if every horse could go in one, but that's simply not the case. But there's no point in over bitting your horse either as you don't get the best results doing that. That being said, for a rider to properly use a gag, because it can be strong, it is absolutely crucial that you be able to balance/jump without needing your arms, have a very soft hand, and ride mostly off your legs/seat. It's not a bit for everyone and I wouldn't recommend it to most people but certain horses do very well in it, which is why it's somewhat common in the jumper ring.
This is the bit that I use for Athena (it also has copper inlay, and the bar isn't as thin as the one in this pic)
She has learned to turn and bend very well because of how this bit is made (you can turn one side of the bit, and the other side doesn't move at all), so I'm probably going to have to find the company who makes these kinds of bits. Since I bought this one at an auction, and so I'm not such where it came from.
Does anyone know the company, website, or any catalogs with bits like this in them?
Aren't they called Myler?