Another barrel and frame question

[paul45/70]

hello all  new member here   
 
Graybeard this site is awesome been readin it for awhile
 
my question is i have a 1970's circa frame and 2 barrels from that era works flawless. Have 3 newer barrels  dont open properly
a 375JDJ and a 357mag both are contender barrells purchased new. The 45/70 barrel works fine. The 2 barrels in question have stainless split locking lugs (i think thats what there called)   the 45/70 has different taper on them not stainless,  original barrels have a similar taper to them.
The problem occurs with spent ammo as well as no round in chamber however a fired round in chamber makes it worse.
 Mild or plinker loads still same result
It appears when opened like the firing pin hangs up as there is a drag mark on the bottom of the primer indentation caused by the firing pin.
Is this a locking lug problem if so how can i fix.
Thank you

[Dezynco]

Sounds like a broken firing pin to me.  The 2 barrels that you're having trouble with probably have a bit closer barrel-to-frame gap and are dragging the firing pin as they open.  It's not uncommon for the space between the barrel and breech face of the frame to be different from one barrel to the next.
Take a look and see if the firing pin is projecting past the breech face after you let the hammer down.  You'll need to take the barrel off of the frame and use a screwdriver or something similar to trip the "interlock" for the hammer to cock.  That's the little bow-tie looking piece down inside the frame that the locking lugs push against when the barrel is closed.  It keeps the hammer from cocking if the barrel is not locked up securly.
When you let the hammer down, you'll see the firing pin projecting out of the breach face.  When you let off the trigger for the hammer to rebound into it's safety position, the firing pin should return back into the frame - it has a spring that returns it back to the neutral position.  If not, then the firing pin is broken and it will need to be replaced.
Just one suggestion....
 

[paul45/70]

Dezynco
thanks for the advice, tried what described seems to be workin properly.
the firing pin retracts and the hammer is reset the instant the trigger guard is pulled.
even with no round in chamber the opening of the action seems jammed, however doesnt happen every time(jams 3 outta 5 times)
once a round is chambered and fired seem to have problem every time especially with 375jdj barrel.
 

[HHI-7420]

paul, try backing off the grip bolt/screw a turn or two. Sometimes it can be so long that it jams into the trigger guard spring-might work.  Pat