I had the same problem on my mx-8
i had purchased a top barrel and needed it to shoot first.
what i did and what i ended up doing...

to shoot the top barrel i had to remove the bottom barrel cocking shoe. (push the pin partially out, removed the shoe and pushed pin back) this worked but it took about five minutes when i had to put it back for doubles.

what i ended up doing was spending less than 300 dollars and sending it to don rackley (Don Rackley's Gun Parts Store | Welcome)
he put a selectable thing in. i still had to drop out the trigger then just push the dove tail to which ever barrel i wanted to fire first.
shipped and back less than a week.
mike

 

Thanks, I already did it on my removable trigger but this is about fixed trigger

 

ok...
good luck and let us know what you did.
mike

 

At last the answer by jim white is :

If i only want to change the firing order then i only need to change the three that is the same as removable trigger

Also i can convert my receiver to barrel selector but i need to change some parts
Like the trigger blade to can permit the inertia block to move from left to right, the three, safety button parts and others.

 

It's the Tree Change Out...Have done Many over the Years from Top to Bottom Fire...will Look around for Parts. Bart

 

It's the Tree Change Out...Have done Many over the Years from Top to Bottom Fire...will Look around for Parts. Bart

Thanks, let me know if you have the part

 

Eduardo,

Sorry I have been traveling the last few days. On your gun, you need to change the tree, part number 157. If you want the top barrel first, it's part number 157L, for bottom barrel first, it's part number 157R. Both need to be properly fitted for good, reliable trigger functionality.

I have the parts and can perform the work.

Don Rackley
www.donrackleygunparts.com

 

Eduardo, Don is the way to go...as He will be Sure that it is Adjusted and Safe...Not just a Swap and Go part. Bart