Well, I guess what I meant to say was on DR's with only one set trigger it is always on the front. I'm sure there are some exceptions to this as well, so maybe the word "always" is not proper. But I would be comfortable saying that the vast majority of doubles with only one set trigger have it on the front trigger to the point that anything else would be a very rare bird indeed.

I still stand by my comment that if you are doubling your rifle by firing the front trigger first, there is a problem with your rifle. There is also the possibility that your technique is improper, causing the finger to slip off the front and strum the rear. I also stand by the comment that when contemplating the purchase of a double rifle, one should pay particular attention to the right barrel condition as most shoot the front trigger first.

I suppose there are left handed gun exceptions to this.