Left to right:
Pre-1905 bolt
1905-1910 bolt
Post 1910 bolt
Service bolt for pre 1910 guns.

Attachment 38705

I knew if I asked I would learn something. In this case a bunch. Thanks to all.

However, new questions have arisen. If a gun was sent back to the factory for repair it has been said they automatically installed the hardened wear plate. Did they also replace the bolt? If so, does the later bolt require machining or is it a drop in? From Brian's photos there seems to be a significant difference suggesting a major redo. Brian, have you seen a pre-1905 gun with the wear plate installed and Parker repair codes to indicate a return to the factory? What did they do?

Further, if a pre-1905 gun were found to be worn how would a good gunsmith repair it?

Yes. The bolt on the far right came out of a pre 1910 gun that was retrofitted by the factory. I have even come accross hammer guns with the 1910 setup in them.

The fitting of this bolt requires the bite be machined for the wear plate. two cuts in opposing directions and a hole drilled.

Thanks Brian. I should have picked up on your nomenclature "Service Bolt" and realized what it was, but I did not. So, thanks for the clarification.

Thanks Brian very interesting. How did you arrive at the conclusion that the far right bolt is a "service" bolt? Is there a distinguishing feature?

It has the pre 1910 linkage but a stepped cut.

Thanks Brian - very informative.

I have an 1893 0-frame 16 gauge GH(e) 79355 with the post-1910 replaceable locking plate and corresponding bolt.

Thanks Brian

If you total up the styles of bolts that could be found in factory built Parker guns, the number would be 6. Lifter straight, lifter angled, top action angled, hammerless angled, hammerless 1905-1910 straight and post 1910 cam operated with stepped cut.
Then add to the mix service bolts, the number can potentially increase to 9.
Top action hammer gun bolts are actually slightly shorter than hammerless bolts, so a different service bolt would be needed when converting a hammer gun to the 1910 style bolting. And, I am sure that Parker very well may have put 1910 wear plates in lifters as well, so that would make another style of bolt.

It is this type of stuff that I want to make sure that my book addresses. So that people understand the variation in parts used in Parkers.