Axis 270 to Ruger 375 Conversion
I recently picked-up a very accurate old JC Higgins Model 50 (Mauser action/High Standard barrel) in 270 Win so I'm thinking about converting my almost 2-year old Axis II XP to become my first medium bore rifle (35 Whelen or 375 Ruger). I've already invested in a Boyds stock and improved scope for the Axis and the rifle is accurate so I'm okay with throwing a little more money into an inexpensive rifle for an ER Shaw barrel. I'm leaning toward the 375 Ruger, which would require me to also buy a new 110 Magnum bolt head and mill the bolt head shank shorter, as described here (thanks for the vid, DrThunder88):
http://www.savageshooters.com/conten...cation-(Video)
After reading this, I just attempted to disassemble my bolt:
http://www.savageshooters.com/conten...y-Instructions
I didn't get very far, because my bolt assembly screw (BAS) doesn't have a slotted head or the expected newer hex head on it. In fact, there doesn't appear to be a screw at the back end of the bolt at all; there just appears to be a bare pin sticking out.
So before I grab it with a pair of vice-grips :o (LOL), I figure I'd better ask here for bolt disassembly advice and also opinions and advice on the conversion in general.:help:
Thanks a bunch!
Update to Axis 270 to Ruger 375 Conversion
Well, life on this old homestead got in the way of this project. I acquired two sets of bolt head parts (including all the extra bolt head internals) but I never found the time to hot blue and fit my Shaw 358 Norma Magnum barrel and make the necessary bolt mods until now. I drew a pretty good Idaho moose tag this year so I've re-prioritized this project off the back-burner!
Since I started this thread, Desnolen68 made this discovery:
https://www.savageshooters.com/showthread.php?64828-Axis-Magnum-Conversion-Firing-Pin-Too-Short-Fix
It looks like I'm going to have the same problem with the cocking pin bottoming in its slot/ramp. Desnolen68's solution to extend the cocking pin slot slightly and it seems like a reasonable one (plus, he reported that it worked :p). Given the small amount of additional cocking pin slot length required, it seems to me that the angle, straightness, and smoothness of the "ramp" of the slot can be maintained, thus it should not impact cocking effort. Desnolen68 reported that the cocking effort was not substantially increased.
The other solutions I've contemplated are a lot more work and sometimes very expensive, compared to the price of an Axis. They include custom PTG bolt head, custom machined or re-turned firing pin after TIG welding up the stop surface flange to move the stop surface rearward, etc. (I don't TIG weld and there's probably not enough meat on the firing pin's stop flange to comfortably set it back on the lathe without adding some TIG-metal, which is always a tricky proposition). The firing pin is also likely to be very hard. The firing pins I've made in the past I made from annealed 440C and I heat treated afterwards. I don't know what Savage does. Annealing and re-heat treating might be required so I estimated the additional cocking slot length required with careful measurements, as follows.
The locking lug aft surface to bolt face dimensions of my bolt heads are 0.382" and 0.333" for the longer magnum and shorter original bolt heads, respectively (micrometer and depth micrometer measurements). My current cocking pin to slot clearance is 0.032". My firing pin protrusion is 0.055". If I wish to preserve them both current cocking pin clearance an firing pin protrusion, I would need to lengthen my cocking slot by 0.382-0.333=0.049".
Of course I could get by with less firing pin protrusion and cocking pin clearance but how much less? If I reduce the firing pin protrusion distance to 0.035" (a number I hear commonly tossed about as adequate) and reduce my cocking pin clearance in half to 0.016", then I would only need to lengthen the cocking pin slot by 0.013".
Given that I can always take more metal off of the parts, but I can't easily add it back, I think I start with those reduced numbers and shorten the shank to produce the 0.035" firing pin protrusion, see where I'm at with cocking pin clearance and shoot for at least the 0.016 to start. I test performance the same way I test my muzzleloaders by cold soaking the barreled action in the freezer. If the frozen ignition source reliably goes bang, I'll call it good.
That's my plan right now, anyway.
Desnolen68 reported that it took him two hours to mill the slot so, even very careful grinding might be a better option than milling. I can always start by milling a see how it goes I guess.
I don't know why DrThunder88 didn't encounter this cocking slot/pin interference. Maybe his bolt had a long lug non-magnum bolt head too (which we didn't get a good look-at) so his long lug magnum bolt head only needed to have its shank shortened. I'm nearly certain that DrThunder88, Desnolen68 and I are using the same magnum bolt head (same part numbers) and I verified the dimensions of my magnum bolt head against DrThunder88's magnum bolt head using screen captures from his video (by measuring pixels). Maybe he will drop by this thread again and give us his thoughts. I'd sure appreciate hearing from him.
