Cast in CZ52

[singleshotbuff]

Gentlemen,

Finally got around to shooting a couple of groups today with cast boolits in my CZ-52 7.62X25mm. The load tried is;

S&B case
WSP primer
5.0grs unique
120gr LFN boolit, sized .309", lubed with Javelina alox
Chronographed velocity is 1251 f.p.s.

Groups were fired over a sandbag rest at a range of 25 yards, all groups were 5 shots. There was a fairly brisk, variable wind, although I tried to shoot between gusts.

Group #1 measured 3.0", with 4 rounds in 1.5".

Group #2 measured 4.5", with 4 rounds in 2.1"

I had to quit after 2 groups as the wind really picked up.

There was a little leading in the barrel after shooting, but nothing terrible. Maybe because I'm using a plain base boolit @1250? Lube maybe?

I'm very happy with the groups, considering the range, the cost of the gun and the HEAVY trigger. Not sure about the flyers though, could be me, or???

I'm gonna start working down with the powder charge. I don't need this much velocity, and I'd like to tame the VERY POSITIVE ejection of the pistol. I fired a total of 17 rounds today (10 for group and 7 at a steel gong) and I lost 5 pieces of brass.

My goals are to maintain this level of accuracy (or better) and slow down the ejection cycle, while retaining 100% reliablity.

Anyone else loading 7.62X25? Care to share thoughts? Loads?

All input appreciated.

SSB

[singleshotbuff]

After I posted this thread, I looked through my notes on the CZ-52 and noticed that I never slugged the barrel when I aquired the gun.

So, out came the pure lead slugs, a brass rod and a hammer. I wrapped the barrel in leather, clamped it in a vise and slugged away.

Bore slugs .311".

This may explain the leading with .309" boolits?

In light of this, I'm even more pleased with the groups I was getting, considering the .002" undersized boolit.

I also slugged the throat and measured some case necks for thickness. If my cipherin is right, this chamber will not take a loaded round with a .312" boolit. .311" may even be pushing it.

Not sure where to go with this. I may just keep shooting the .309" boolits and live with a bit of leading.

SSB

[9.3X62AL]

SSB--

I have a long and checkered history with the 30 Mauser/7.62 x 25 Tokarev. This includes a Broomhandle (C-96) Mauser, ChiCom Type 54 Tokarev, and a CZ-52.

Regarding your tight neck problem--I had this same issue with the Tokarev, .311" grooves and tight chamber neck with the reformed 9mm Win Mag cases I was using before Starline started producing cases in this caliber. I resized the cases without using the expander ball assembly, then used a 30 caliber neck reamer to hone out about .003" of inside neck diameter. Instant clearance.

Starline case necks when expanded to .309" support .311" boolits just fine and have sufficient clearance in the Tok chamber to enable safe release.

[singleshotbuff]

9.3

I'd be interested in any data you'd care to share on the 7.62X25. What's out there seems limited. I'm currently working with Unique, but I'd like to maybe try Bullseye too.

What about SLOW powders like Blue Dot and Win296, do they have any usefulness in this cartridge?

Thanks for your reply about the brass, I'll look into getting a neck reamer.

SSB

[9.3X62AL]

Probably the single best powder I've found for the 30 Mauser/7.62 Tokarev is AA-7, jacketed or cast. I've used Bullseye, Unique, and WW-231 with castings--all will work OK. Lemme dig out some info, and I'll post a little later with it. I don't want to work from memory on this one.

The most recent Hornady reloading manual has some pretty hot loads for the CZ-52 published. Reading those about curled my hair.

I also bought some of the Winchester white box (WWB) loads recently to try the brass out. These have an 85 grain FMJ/RN bullet, and run like water through all my pistols. The brass reloads well, at least it did the first time through.

Back in a bit.

[9.3X62AL]

SSB--

Here goes, sir.

With the Lyman #313249--the Hornady limited production 86 grain .308" RN's, the current 90 grain .308" XTP, or the Hornady .312"/85 grain XTP.......7.5 grains of AA-7 gets about 1350-1400 FPS in the Tok or the CZ. The Tok gets the .312" j-words, while the CZ uses the .308" redcoats in its .309" grooves. Castings are sized .309" for the CZ, .311" for the Tok.

The Lee 100 grain RN will just clean up in a .311" size die, and gets 7.0 x AA-7 in both pistols, sized to fit their respective bores.

Other data, as sourced--

Winchester shows 4.2 grains of WW-231 as a top load for the 30 Luger and a 93 grain FMJ. I tried this load in the larger Tokarev case with the same 85-90 grain bullets/boolits listed above, and it made a nice light load for the CZ-52. The Tokarev wants a little more oomph to cycle correctly, and 4.5 grains made that balky bee-otch act right. The Lee 100 grainer runs well in both pistols with 4.0 grains of WW-231.

"Cartridges of the World", Barnes et al--

Shows data for 86 grain FMJ bullet only, 4.5 grains of Bullseye giving 1160 FPS and 6.0 grains of Unique for 1230 FPS. I use the Bullseye load for my Broomhandle as a top end charge in deference to its aged condition. Jacketed or cast, it will operate all 3 pistols with 85-90 grain bullets, red or silver. Another good, light load. The Unique load runs both the CZ and the Tok, but isn't real accurate in my pistols. AA-7 beats it all hollow. I have used these same powder weights with the Lee 100 grainer in the CZ and the Tok, and they shoot pretty well--and have a pretty good safety margin. Let's remember that the Tokarev runs the 86 grain bullet at 1390 FPS, and some of the Czech ammo ran to 1600 FPS+ in the CZ-52. That the CZ-52 will function with loads running 86 grainers at or under 1100 FPS says volumes about its engineering.

Accurate Arms shows data for its powders in this caliber. Dunno how true this "urban legend" is, but I've heard and read that AA-7 was specifically developed for the Czech version of the 7.62 Tokarev, and after trying it out I'm inclined to believe that. Jeff Bartlett has some powder he calls "#7", and advises it uses AA-7 data. I bought 8# of it, and after trying to run it through a couple different powder measures I threw in the towel and bought the Lee Loader Spoon Set to pour these fat little discs. The stuff absolutely refuses to meter in my RCBS or a buddy's Lyman measure. I may still have 7.9# of it here, but it did run the pistols all right with j-words.