Colt Diamondback misfires

[Michaelm45]

Colt Diamondback 22cal. misfires only when firing double action. Single action ok. I replaced main spring but still experince same problem.Is it possible to bend main spring in a way to apply more force to hammer?
Thanks in advance
Michael

[Dfariswheel]

Before doing anything else, change brands of ammo, and scrub the chambers out throughly.
Test fire again.

UNLESS there is another problem, like a worn firing pin, you can add more tension to the mainspring by carefully bending the upper leg slightly.

However, if you bought a new mainspring, and it's still misfiring, there's likely another problem.

If it's still misfiring, I'd suggest sending it in for a repair, since a new mainspring SHOULD have corrected any spring related problems.

[Sir William]

I agree with the ammunition change. You could also flush the action with brake cleaner spray. reoil and try again. If you still have misfires or light primer strikes, find a Colt gunsmith.

[4V50 Gary]

Spend $5 on some quality target ammo. If the Diamondback misfires, then it's the gun.

[Michaelm45]

Dfariswheel, Sir William and 4V50 Gary
Thank you all very much for your advice. I will try your suggestions soon and let you know.