Thank you for drawing my attention to this book.
This is a reprint of Bullseye #3 , Bullsye was a Kirby character he developed for Mainline comics which he ands Joe Simon owned.
Kirby was on fire at this time.
This was published by Mainline, which lasted only a few months and was bought by Charlton, which did not use their characters for long.
I can't find Mainline on CB+ although I am pretty sure they are here.
https://kirbymuseum.org/blogs/simonandkirby/?s=Bullseye+
Bullseye 7 issues covers
https://comicvine.gamespot.com/bulls-eye/4050-20698/
A terrific book but hard to find.
Link to the book:
Blazing Sixguns 12