Offset primer strikes

Checking primer strikes on a recently purchased   S&W model 28-2 the primer strikes are not centered, any idea what would cause this?

The timing could be off. This could be caused by wear on the hand, bolt, corresponding areas on the frame, and where they contact the cylinder.
It also may just be tolerance stuck-up in how parts were made. There are quite a number of factors.
-Ron

Does it go bang every time?

bruce martindale wrote:Does it go bang every time?

Yes every time, I'm just obsessive of off center

Check your hammer nose swivels freely, more or less. 
A pic of spent primer would help. Off center to what side?

Tripscape wrote:Check your hammer nose swivels freely, more or less. 
A pic of spent primer would help. Off center to what side?

All six off to the right

Next please shine light through the barrel to check cylinder alignment and measure cylinder front from forcing cone to either side. Sounds like you may be having cylinder alignment issue. Unless it's the hammer alignment. What ammo do you shoot and do you see excessive sputtering at the forcing cone and front cylinder?

Tripscape wrote:Next please shine light through the barrel to check cylinder alignment and measure cylinder front from forcing cone to either side. Sounds like you may be having cylinder alignment issue. Unless it's the hammer alignment. What ammo do you shoot and do you see excessive sputtering at the forcing cone and front cylinder?

Very light 158gr. handloads, would a few hammer shims added to the right side help to move the hits to the left??

Tells us nothing without pictures.

jcullen47 wrote:

Tripscape wrote:Next please shine light through the barrel to check cylinder alignment and measure cylinder front from forcing cone to either side. Sounds like you may be having cylinder alignment issue. Unless it's the hammer alignment. What ammo do you shoot and do you see excessive sputtering at the forcing cone and front cylinder?

Very light 158gr. handloads, would a few hammer shims added to the right side help to move the hits to the left??

It's hard to say.  As Ron says above she shift can be a number of factors.  If you shim you may create friction against frame, or not, depends on tolerances of the pistol.  

What I am driving at is that shift in primer strike can indicate bigger issue, I hope that's not the case, but something you need to review.  Cylinder timing / position in the frame and relative to the forcing cone due to warping of crane, frame, improper cylinder cut or timing from the factory, or maybe due to part wear Ron describes above. Or none of the above and just a shift in hammer position from the factory. Or hammer itself is slightly warped - this I actually observed first hand and had to sand down flat, but donor hammer was so warped it was catching the frame I was installing it in, though nose was right on primer dead center. 

Good thing is that you can go through list one by one to make sure all is well.  Look at the parts and check for wear. Check for excessive fouling at the forcing cone and measure that the cylinder is centered. Check for play in the hammer, lay it flat check for flatness.  Look to see that the hammer nose is installed in the center of the hammer and is flat as well.  Look at the primer through the frame hole with no hammer in place to see if it's positioned centered. 

I went through a number of revolver internals and sometimes do see some fairly visible and measurable abnormalities in parts.  They usually don't pose any functional issues, but that's because the assembler accounted for that particular abnormality.  So if you transfer this part into a different revolver it may not function until proper mating is done.  So you may have a part abnormality and it functions fine and it was meant to be this way...no need to fix that.  But you owe it to yourself to check.

I'm with Bruce on this for sure. If it goes bang every time I'd leave well enough alone.
Oh, and don't look at the spent rounds.

Texasref wrote:I'm with Bruce on this for sure. If it goes bang every time I'd leave well enough alone.
Oh, and don't look at the spent rounds.

I would agree IF the accuracy and finger sausages are not impacted.

IIRC, some bullseye pistolsmiths would purposely set up their pistols so that the firing pin strike would be ever so slightly off center. The idea was that there was more primer compound for the firing pin to strike for more complete ignition.

Did you buy a gun with a left- leaning or right-leaning hammer/pin? Some folks might suggest that it depends which state where the gun was purchased!



As an alien, I am not permitted to make such statements! All in jest, of course!

RoyDean wrote:
As an alien, I am not permitted to make such statements!

I've been wondering which planet you're from...

Your next trip back, please beam me up.