The chamber is actually tapered, very similar to an M1 Carbine round's profile. In fact, I use a carbide M1 Carbine die to resize my .32-20 brass for use in my Nagants. The taper permits the lower third of .32 S&WL cases to swell to fill the chamber, often splitting the cases. In any case, they are unsuitable for reloading afterwards. The heavier .32 H&R Magnum cases also bulge to a point I wouldn't expect them to be serviceable in reloading afterwards, although they don't split.
I have shot several boxes of Magtech 98gr LRN .32 S&WL, which I chrono-ed at ~616 fps ave, SD = +/-20 fps from my two Nagants. By comparison, the Russian target ammo made 591 +/-7 fps ave from my two Nagants, while the Fiocchi made 674 +/-6 fps.
My best ammo was the re-sized .32-20 cases loaded with 2.4gr Titegroup and a Meister 100gr LDEWC crimped in the top groove, loaded with the Lee Nagant steel die set, with the Nagant re-sizer replaced by the aforementioned carbide (I don't like to lube cases!) M1 Carbine sizer die. I get 660 +/-7 fps with them. Of course, I do have to modify the Starline .32-20 cases first by removing a few thousandths from both the headstamp by sanding and the rim diameter by turning on a micro lathe. The cases fall out, generally by gravity alone, after shooting. Proper Nagant cases, and bulged .32 S&WL/H&RM cases require the Nagant's SA ejector rod for removal.
Fun piece of Victorian engineering - held together by one screw - which becomes indispensible in it's easy lockwork dissection. If you ever get one, go to the aforementioned gunboards forum for more info.
Stainz
