I am sitting in a hospital waiting room waiting for my wife to have a routine test, so I thought I would add an update to this thread from 4 years ago. I doubt that there are many people in the world interested in converting a Beretta 626 from single trigger to double trigger, but I will post my experience in case anyone runs across it in a search. There is not whole lot of information like this available, or at least I couldn't find it if it is.
After Jim Bode posted the excellent info above, I set about trying to get all of the parts together to do the job. I had to use all 4 of the companies that Jim linked above, but I thought I could buy everything he listed. I decided I should start with the parts that were only available in Italy, so I placed an order and paid with a CC. The next day I got an email from them saying that nearly all of the parts I had ordered were out of stock, even though their website said they had them. I cancelled the order and gave up on the idea.
Jim also sent me a copy of a 1997 article from Gun Digest where the writer said that he completely disassembled a 626 with nothing but a few screwdrivers and a punch. He explained that the 62x series was made for all the parts to be interchangeable from model to model. By the way, does anyone know if Jim is still around? I haven't seen a post from him in quite a while. Anyway, the article praised the 626 for it's high quality as a mass produced SXS, and lamented the fact that Beretta stopped producing them.
A couple of years ago, a DT 625 came up on GunBroker and I put in what I thought was a very low bid and wound up owning it. It's in decent shape, and the cost was not a lot more than the parts would have been for the DT assembly. It has a different style rib and different dimensions from the 626, plus it's choked a very tight F/M and I found i couldn't shoot it as well as my 626. I put it in the safe and seldom used it.
I got to go on a number of good dove hunts this past fall and used the 626 on all of them. I had several occasions when the inertial trigger failed to reset for the second shot. I never could determine what was causing the problem. It wasn't the problem that started this thread, and it was intermittent and unpredictable. It was aggravating enough that I came up with the idea of switching the triggers in the 2 guns.
I am purely an amateur as a gunsmith and I wasn't sure that this would be within my skill level, but the Gun Digest article gave me a little confidence that maybe I could do it. I started with the 625, and I only had to remove 3 or 4 screws to take out the trigger assembly and the safety. Since the barrel selector of the 626 is on the safety, I had to switch the safety's too.
The 626 was slightly more complicated, but it still was just a matter of removing screws and driving out the safety pin. It turned out, there was really nothing to the job and it could be done in 30 minutes by someone familiar with the process. The parts all interchanged perfectly, the safety's slide normally, and the trigger pulls are exactly the same.
The coin finished triggers don't look quite right in the 626 Onyx, but I never thought that the gold trigger looked right either. I have seen 625 models with the single gold trigger on auction sites, but I might have the only Onyx with coin triggers. I could have them gold plated if it bothered me, but it doesn't. I got to use it with the DT on our latest hunt, and enjoyed being able to select the barrel the way one should on a SXS.
I have told my family to make sure these 2 guns stay together after I am gone. I don't expect that to be a problem. Thanks for all the help here, and I hope someone will find this info useful.
