Light primer strikes Ruger Blackhawk

[Choatecav]

Recently bought a vintage Ruger Blackhawk made in 1967. This was before the new model came about so it has the three screws, etc. But, the previous owner did install a transfer bar.
Anyway, it is chambered in .357 and works wonderfully with said cartridge. However, when firing .38 specials, I ran some Winchester whitebox and magtec rounds through it in 38 and only about half fired. Each had a dimple in the primer, but did not go off. Then I loaded it with six Federal hydroshock .38's and all of them fired.
From what I have stated can any of you tell if this is likely an ammo issue or can the striking of the hammer an adjustable thing on the Blackhawk?

thanks,

[BillSWPA]

Isn't Winchester known for having primers which are relatively easy to ignite?

My first thought would be to try replacing the hammer spring.

[awp_101]

AFAIK the only hammer "adjustment" is the spring but it's not unknown for the transfer bar to shift just enough to cause intermittent issues.

[willie]

Historically Ruger revolvers have been over sprung. Many who bought them would clip coils from the mainspring or replace it with one less strong. Wolfe Springs has what you need. If a replacement works, then the spring was most likely your issue.

[BN]

Are your chambers clean? Sometimes a ring of crud forms near the front of the chambers that will prevent the rounds from seating far enough and the strike of the hammer pushes the round further into the chamber but doesn't hit the primer hard enough to set it off. Did the light strikes go off if you tried them again?

I also wonder if something is wrong in the transfer bar. Those were installed by Ruger after manufacture as a safety recall. You might try spraying some gun cleaner down in the mechanism. If cleaning or a spring change doesn't work, I would contact Ruger.

Congratulations on your 3 screw Blackhawk.

Edit: We need pictures.