They will go into either. I know the threads are not the same, but that is an SIA barrel, and it will go into no1 or a no4 without a drama. With that breeching collar it’s meant for no4.
If you get in touch with SIA, Richard might be nice enough to send you modified bolt head and ejector to suit too, for a very reasonable cost.Information
![]()
Warning: This is a relatively older thread
This discussion is older than 360 days. Some information contained in it may no longer be current.