What is a good Colt 1903 Reference book?

[RevolverRob]

However you plan to use your 1903 when you get one, be aware that none of the originals are drop-safe. The more recent version made by US Armament Corp supposedly is.

Yes and no.

The late Type III and all Type IV models have a half-cock notch and inertia firing pin. All US Armament Corp has done is deepen the half-cock notch a bit and add a heavier firing pin spring. The latter is a simple call to Wolff. The former, I would bet you could fit the US Armament Co. hammer if you could get one. Otherwise, fitting a later Type IV hammer, firing pin, and firing pin spring is (supposedly) possible for all models.

[Robinson]

The late Type III and all Type IV models have a half-cock notch and inertia firing pin.

Thanks for clarifying that.

[Malamute]

Yes and no.

The late Type III and all Type IV models have a half-cock notch and inertia firing pin. All US Armament Corp has done is deepen the half-cock notch a bit and add a heavier firing pin spring. The latter is a simple call to Wolff. The former, I would bet you could fit the US Armament Co. hammer if you could get one. Otherwise, fitting a later Type IV hammer, firing pin, and firing pin spring is (supposedly) possible for all models.

Do you know if the later parts drop into earlier guns if one had the later parts in hand?

[RevolverRob]

Do you know if the later parts drop into earlier guns if one had the later parts in hand?

My understand is they may/may not drop-in but that not much fitting is required for the hammer at least. I haven't looked closely enough at the firing pins to know for sure, that looks drop in based on the schematics.

Numrich only lists later type hammers with the half-cock notch. And from what I've read it's a fairly minor job to retrofit.

[Joe in PNG]

I'll note that the reassembly of a 1903 frame can be an... interesting process.

[Half Moon]

I'll note that the reassembly of a 1903 frame can be an... interesting process.

Any particular gotchas to note? My wife bought a third one at a gun show recently. The trigger stirrup is slightly bent and creating issues with mag insertion. I could just bend it but was figuring on buying a replacement from Numrich and outright replacing it. Never needed to tear one down that far though.

[Joe in PNG]

Any particular gotchas to note? My wife bought a third one at a gun show recently. The trigger stirrup is slightly bent and creating issues with mag insertion. I could just bend it but was figuring on buying a replacement from Numrich and outright replacing it. Never needed to tear one down that far though.

Trying to get all the bits that connect to the hammer lined up proper may take a bit or a lot longer than one may think is logically possible. I've only done it once, and am in no hurry to do it again.