I'm still getting the bugs worked out of this 1952 Mod 70 .257 Roberts AI. I got it back from the smith who cleaned it well, touched up the bedding, adjusted the trigger, reshaped the grip cap and added a new pad ( old one was rotted away). It had been turned back a thread before Improving by previous owner(s) but is still pretty long. I suspected as much before I took it to get checked out as I couldn't "feel" any crush fit chambering a factory 257 Roberts round. So...
It has a very long throat ( fine with me) but I can't even get the Sierra 117 flat base to "jam" into the lands for fireforming. I "can" get a great "jam fit" with that bullet "if" I seat it "backwards and then crimp it. I've never done it that way, especially with a factory round ( I just pulled the bullets on these, kept factory load/primer in place so far) Not sure if I will try it, but if I do I will reduce the powder charge a bit beforehand. I can also put a false shoulder on the case by running it over a 6.5 tapered expander button, then necking it down with the 257 button back in place until I get a good "crush" fit, and fire the Sierra 117 out "point first" as long as I "can" seat it out and try those. I can also seat out the Sierras and then smear a light coating of Imperieal sizing wax on the neck/shoulder and fire (with no other changes)...that area will pop out, hopefully enough not to thin the web above my case head. I have spoken with people who have all done these methods, and done many of them myself before, including the COW/pistol powder no bullet method. I'm not messing with that one yet, maybe later. If I did I would "definitely" use the false shoulder method. I went to install my scope bases and "the previous owner/bubba" had stripped the screw holes in the rear, have to take it "back" to the smith now for fixing ( 8x40 drill/tap) (I "must resist" pulling my hair out!) :twisted: If it doesn't shoot like I want, after all that and if the bore is still in good shape, I can have it rechambered to 25-06 AI which will clean up the existing chamber. It can be done w/o setting the barrel back again and still be set up for a crush fit w/factory ammo. If the bore isn't worth a rechamber, then a SS Shilen will go on this puppy...but I'm really hoping I can get it wrung out with its existing chambering. For deer, etc, for now, I don't want anything else, just the 257 Roberts AI. I got other rifles for elk, and God only knows when I can hunt them again ha. Oh well.
So....has "anyone" ever fireformed cases with a bullet "base first" jammed out into the lands? If so, how do it work? Thanks.
It has a very long throat ( fine with me) but I can't even get the Sierra 117 flat base to "jam" into the lands for fireforming. I "can" get a great "jam fit" with that bullet "if" I seat it "backwards and then crimp it. I've never done it that way, especially with a factory round ( I just pulled the bullets on these, kept factory load/primer in place so far) Not sure if I will try it, but if I do I will reduce the powder charge a bit beforehand. I can also put a false shoulder on the case by running it over a 6.5 tapered expander button, then necking it down with the 257 button back in place until I get a good "crush" fit, and fire the Sierra 117 out "point first" as long as I "can" seat it out and try those. I can also seat out the Sierras and then smear a light coating of Imperieal sizing wax on the neck/shoulder and fire (with no other changes)...that area will pop out, hopefully enough not to thin the web above my case head. I have spoken with people who have all done these methods, and done many of them myself before, including the COW/pistol powder no bullet method. I'm not messing with that one yet, maybe later. If I did I would "definitely" use the false shoulder method. I went to install my scope bases and "the previous owner/bubba" had stripped the screw holes in the rear, have to take it "back" to the smith now for fixing ( 8x40 drill/tap) (I "must resist" pulling my hair out!) :twisted: If it doesn't shoot like I want, after all that and if the bore is still in good shape, I can have it rechambered to 25-06 AI which will clean up the existing chamber. It can be done w/o setting the barrel back again and still be set up for a crush fit w/factory ammo. If the bore isn't worth a rechamber, then a SS Shilen will go on this puppy...but I'm really hoping I can get it wrung out with its existing chambering. For deer, etc, for now, I don't want anything else, just the 257 Roberts AI. I got other rifles for elk, and God only knows when I can hunt them again ha. Oh well.
So....has "anyone" ever fireformed cases with a bullet "base first" jammed out into the lands? If so, how do it work? Thanks.