Home Forums Hunting & Shooting Single Shots Ruger No.1 Breech Block Gap

Hi,
I just got a used No.1 Tropical 458 Lott. I noticed the breech block moves when cocked then tightens up after dry firing. Even with an empty case in it does this and I measured 10 thousandths of a gap between the empty case and the breech block. Does this sound like a problem? It seems excessive to me but I know nothing about this type rifle. Been straight out so haven't had time to really look it over but a cursory look everything else seems ok, hoping to look closer and load some rounds tomorrow night, will start out low charges

Sounds like you may have to fireform some brass to take up some headspace.

Sounds excessive. It headspaces on the belt and is a straight walled case so I don't think brass can be fireformed to suit.

For anyone that comes across this in the future:

I called Ruger, very quick and helpful but wouldn't say anything concrete. Hours searching forums etc I found two guys that built custom No1 rifles. One said he tried for 8-10 thou clearance on the breech block, the other tried for 5 but "wouldn't cry over 10". Both were very clear to say they weren't talking about headspace but breechblock clearance; this matched what Ruger said, that you cant measure the headspace with feeler guages down the breechblock. I started searching block clearance but found little so I moved to headspace search. Neither worked, I found what I needed after scrolling through approx. 50 pages of the forum.

THE ACCURATERELOADING.COM GUNSMITHING FORUM had the info, I'm not searching further