I want to get some new oversized replacement bolts for my Remington 700 big game hunting rifles from Dave Kiff at Pacific Grinding. My Remington actions are all 416 stainless. I can get either chrome moly 4140 bolts (and have them nickeled for corrosion resistance) or 17-4 stainless bolts. Some have told me that even dissimilar stainless materials will gall, while others say the 17-4 is considerably harder than the 416 and will not present a problem. Comments please!

terry.berkhouse@umontana.edu

Terry,
I don't think that you'll have a problem with Dave's bolts but why not give him a jingle and ask..
I shoot several benchrest actions that are stainless with stainless bolts although dissimilar... Keed the lugs, cocking ramp and primary extraction surfaces lubed with a good grease.

Dave says he is not a metallurgist, so doen't know whether I should use a 17-4 bolt with a 416 action or not. He did say that hardly anyone is ordering the 17-4 bolts.

I'm a metallurgist ,maybe I can help. Galling is by definition , cold welding.The worst case would be two pieces of soft stainless such as type 304.To avoid galling go to a harder stainless and it's better to use two different types such as 416/17-4.Early use of stainless in firearms came from using material too soft.A 416 bolt should be fine, 17-4 even better.There are also lubes on the market designed for stainless steel and high pressure applications [ o/u hinge pins]such as RIG +P.

So, by your comments, a 17-4 bolt with a 416 action should be fine?

Also, can a 17-4 handle be silver soldered onto the 17-4 bolt body similar to the way Remington's come standard, or should they be TIG welded together?

17-4 is a precipitation hardening stainless steel.Like any hardenable steel you should first know it's original heat treatment and then see if you can maintain it after brazing or welding.That would take a bit of research for me.

Thanks for the information. I think I will definitely go with the 17-4 bolt.

I am a metallurgist also.

17-4PH is commonly listed as having "good" to "excellent" resistance to galling. It is commonly used as a shaft material. There are much superior alloys for like-on-like galling resistance. But this rating is often in reference to moving equipment and parts subject to vibrations.

I would think it would perform wonderfully in an application of a bolt lug. This is only my opinion though. Also note as an added bonus that is quite corrosion resistant to atmospheric conditons.

17-4PH is redily weldable. This is more of my area. However, it will affect the heat treatment of the immediately adjacent metal. In contrast to Cr-Mo steel, where this areas may be very hard and brittle, the 17-4 PH can soften somewhat as the precipitates go back into solution. It is more usually more brittle in this state too. The areas away from the immediate HAZ may also be somewhat effected, but usually not significantly. Much of it depends on the starting heat treat condition. Being as you are welded the handle onto the rear of the bolt, this is likely of of no major consequence. The annealed condition still has significant strength. See attached links from Armco, who holds the trademark.

armco data sheet

data sheet

Hope that helps