Ringworm
I'll make a stab at answering your question since no one else seems to want to help.
So when building a custom on a military reciever isnt it standard practice to replace many of the parts you are mentioning as faults anyways?
what i am talking about is custom. replacing the parts which wouldnt suit a fine rifle. The trigger is military so out with that and in with a timney trigger and timney safety. The angled rear receiver screw i dont think is something you can change. but have to work around, yes. So i guess what i would like to know is what parts of a springfield 1903, say a remington built A3, would you replace that you normally wouldnt replace if using a mauser or another action as a build?
the pic below is a A1 with a replaced speedlock/ safety that i have been trying to ID the make of.
I would definitely change the trigger and safety on any Springfield. The Timney trigger works well for my money and I wouldn't look any further. I prefer side swing safeties, either two or three position, but the Timney is also a good option. It is a copy of the old Buehler style and has been well proven in the field on many different actions.
I am unsure if the pictured rifle is what you plan to use but if you do plan on using a Remington 03A3 action I myself might be inclined to use a different bolt simply because some A3 bolt bodies were not finished to well. I would look for a smooth 1903 bolt that still has the handle kicked back a bit. The ones with straight handles are from the earlier 1903s and are a little less desirable. I would also replace the stamped triggerguard with an 03 milled one. The cost of a different bolt and triggerguard may make it attractive to find a 1903 that already has these parts on it.
Speedlocks were made by several different manufactures at one time or another and no doubt did improve the two-piece firing pin setup. The first Springfield custom I ever had made had a custom made one piece firing pin and the lock time was reduced. I really didn't see much difference in the actual function of other rifles I had built after that one so I didn't do any more like it. As far as the two-piece firing pin I have never found it to be a problem. But if it bothers a person you can always have a one piece one made. I might add that on 2 three position safeties I have on two different Springfields, both came with a two piece firing pins from the manufacture.
The rear angled guard screw is a total non-issue if the action is bedded properly. The Springfield has a healthy recoil lug unlike the Ruger which is smaller. I would have the triggerguard profiled and the floorplate converted to a hinged design. I have had a couple different smiths do this and they turned out nice. One thing I like about the Springfield bottom metal is that the rear of it is angled down slightly and it flows into the grip nicely. This is one reason I use them on Mauser 98s.
You can make a very nice rifle using the Springfield. Things many people complain about don't bother me in the least. I happen to like the boltstop and I don't know of another action whose ejector doesn't need a spring to operate it. The third lug doesn't bother me and the high bridge is easily adapted to scope mount bases if the smith knows what he is doing. I have rifles with both custom Kimber and Buehler bases on them. Standard one piece bases are available from different companies and some two piece ones are also.
I hope I have answered some of your questions. If you have more just pm me if you don't want to post them here.
