[ribbonstone2]

Been playing with the nagant for a few years...and will state that it really makes a difference to use the right length brass. The cylinder is bored at the mouth to take a bullet AND the brass case wrapped around it...this makes the chamber mouth about .338". A 32-20 case is not quite long enough to fill this mouth so when fired the bullet has two choices: (1) if pressure is high enough, will bump up to .338" and then slam into a .310-313" barrel or (2) pressur eis too low to upset the bullet to cahmber mouth diameter, so gas leask past the .311" bullet in the .338" throat.

The gas seal actually relies on the long case to fit into the recess cut into the forcing cone...without it, the gas DOES bleed a bit between cylinder and forcing cone.

Worked out a way (with a LATHE) to make usealbe full length nagant cases form .223 brass. will out line it for those interrested:
1. Size .223 case in .30carbine sizer...just until the soild part of the .223 is encountered. Will look like mini-belted magnum brass. Can't size the solid web of a .223 case.

2. LAthe off the belt. this will make the case into a rimmed case as you DO NOT lather the RIm (OK...the .223 is rimless...but once we take the body down, we leave a rim).

3. Cut case to nagant length.

With this brass, get the lvel. that the Nagant was noted for AND good accuracy. Consider: the case feeds the bullet directly into the rifling, the case lockes the barrel and cylinder together for great alignment, and the bullet gets full use of the powder charge (no gap..no blow by...do slamming a .338" bullet into a .311" bore).

Was (and am) amazed at how well the old clunker will shoot with the above brass and HBWC's (light charges). FORGET DA shooting...no way with that system to get anything near a reasonable DA trigger pull.

 

[ribbonstone2]

Have used the 32-20 in mine, and can get it to shoot well, but there have been some pressure jumps...I'd guess that jump signifies where the bullet makes it to .338" in the chamber mouth and then runs into the .310" (on mine) barrel. Doesn't have to be the death-kiss to accuracy.

Most of my shooting is with HBWC's and a very light charge...lobbing a 100gr. WC out at 700-750fps is not impressive on paper, but it is a great small game load.

With full length brass, have gotten 1280fps with cast 88gr.(and perhaps can get a bit more) or the 115gr. at 1010. that's probalby well over the dersign limit of the old Nagant.

Now I'm using converted .223 cases, and their volume won't match 32-20 cases...so the powder charges aren't getting listed. The internal volume of the case isn't really going to change by using full length brass...volume won't care if the bullet is seated out of the case to full cylinder length or seated all inside the case for full cylinder length...BUT the .223 cases have a thicker web/base and the volume after seating is noticably less than 32-20 cases.

 

[ribbonstone2]

OK...will give one example:

115gr. cast bullet:

4.0gr. of X powder =820 FPS
4.2gr. of X powder = 845fps
4.4gr. of X powder = 935fps
4.6gr. of X powder = 1003fps
4.8gr. of X powder = 1022fps

So what happened between 4.2 and 4.4gr? Best guess is that at 4.2gr the bullet was still not quite filling the chamber mouth, but adding just a bit more powder was enough to "slug up" the bullet and seal the system, adding the nearly 100fps. vel. with only a slight increase in powder charge. Continuing up in charge returned to what i'd think of as "normal" velocity increases.

So...I ran the same tests with the same charges, but this time used full length brass. Got higher velocity from the start (due to the lesser volume of the converted .223 cases) but never got a non-proportional jump in velocity.

 

[ribbonstone2]

Bullet is .311" (the bore on this one is right at .3105"), the cases are WW 32-20's (and in the second test, converted military .223's). The cylinder mouth measures right at .338"...that''s large, but it is suposze to hold a case with a bullet inside it.

What I think happens is that with loads light enough not to bump-up the base, the gas has a short secion of .338" hole to by-pass the bullet base (in my example, all the charges below 4.2gr). When the pressure becomes enough to bump up the bullet base, it seals the .338" hole...or partly seals it...and the driving gas stays more behind the bullet giving a sudden "jump" in vel. readings. Never got that "jump" with full length cases...but also never got that jump in vel. using jacketed bullets in EITHER case. Best guess on jacketed bullets is that I never raised pressure to the point were they'd deform the base.

As stated, the accuracy wityh the short cases hasn't been bad with selected loads...the revolvers are in need of some single action trigger work (forget double action...no amount of work will overcome that), the round cross-section grips are not the best, and the design does let the cylinder revolve backwards if you apply pressure (Which would NOT be something I'd care for if I was issued one and expected to actually fight a war). Can fix the trigger and even fix the grip...but as far as the design goes, there have been better ones in the last 100years.