7.62x39 and 150 grain Plain Base

[richhodg66]

Can't remember the mold number offhand, but it's an old Lyman design that has a nose shape very similar to the 311291 and weighs about 150 grains. I want to shoot this in my CZ Mini and figured on it being a plinking/squirrel load.

I'm guessing about 8 grains of Unique as a starting point? Is that too high for a plain based bullet that is going to have to be seated with the base below the neck of the case?

[Maven]

8gr. Unique may be a tad stiff for so small a case as the 7.62 x 39mm. (I use 8.7gr. Unique in my .30-06 with PB cast bullets.) Start with 6.0gr. and work up to 7.5gr. even if neither will generate enough pressure to operate the action if it's a semi-automatic.

[Ben]

richhodg66

I don't shoot mine in a CZ Mini, but I do believe you're referring to the 308241 :

I'm glad that I found one , it is a super accurate bullet as long as you " keep it in its speed range - - 900 fps - 1,400 fps ". :

http://img.photobucket.com/albums/v494/haysb/SAECO%20%20315%20Plain%20Base/029.jpg

http://img.photobucket.com/albums/v494/haysb/308241/0032.jpg

http://img.photobucket.com/albums/v494/haysb/308241/0091024x768.jpg

http://img.photobucket.com/albums/v494/haysb/308241/0011024x768.jpg

[Nobade]

Are you sure it'll need to be seated below the neck? Those rifles have quite a throat in them.

I shoot a 150gr. boolit in my CZ, 1800 fps, using 17.5gr. WC680 plus enough plastic shot buffer to make a compressed load. Very accurate,no leading, and no gas check needed.

[richhodg66]

Yep, 308241 is the bulletI lucked into a single cavity variant of it somewhere and it casts well, but this will be its maiden voyage for me.

Looks like 6 grains of unique for starters. I'll be using old R-P cases with SR primers, but I don't have many left, so will have to do LR primers soon enough. Don't know if it'll make any difference.

[HARRYMPOPE]

i shoot PB 150-180g in a #1A and 77 Ruger 7.62 x 39.Use 5-6g of Unique to start for nice gentle loads.With a good rifle you get 1.5" at 100 some of the time.Like Ben said below 1400. i like 100-1200 myself.I use the 308241 and like it also.

George

[richhodg66]

i shoot PB 150-180g in a #1A and 77 Ruger 7.62 x 39.Use 5-6g of Unique to start for nice gentle loads.With a good rifle you get 1.5" at 100 some of the time.Like Ben said below 1400. i like 100-1200 myself.I use the 308241 and like it also.

George

I'd be tickled to death to get that kind of accuracy out of this combination. I haven't worked with this little rifle much yet. Seems like the perfect "everything from squirrels to deer rifle". I shot it with some Wolf factory ammo when I got it and it shot decently at 100 yards. Has a cheap 3x9 Simmons on it now, if I put a good scope on it and experiment with some good handloads, I'm sure it'll be a good shooter. The trigger ppull is probably the worst thing about it, so I may have to see about doing some work on it. I did try some 100 grain .32 bullets ion it, that are sized to .311 and got poor accuracy at 25 yards with them. I'm hoping these do better.

[excess650]

CZ 527? Mine hasn't seen a jacket since it was test fired at the factory. Admittedly, I've not shot any plainbase.

This was only a 3 shot group, but at 100 yards and at 5x. Mine has a decent trigger, and I do not use the set.

[Adk Mike]

I bought a 308241 on e bay last winter. I sized some .311 with 8.5 unique in a Sears (mod 70copy) 30.06. 1 inch groups at 50 yards. This bullet is a lot of fun. Mike

[richhodg66]

I should get the rifle out tomorrow afternoon (Easter Sunday afternoon was a good shooting day last year). I hope this works out, I'd really like a good load without gas checks. Wish I could find a multi cavity version of this one.

[HARRYMPOPE]

I should get the rifle out tomorrow afternoon (Easter Sunday afternoon was a good shooting day last year). I hope this works out, I'd really like a good load without gas checks. Wish I could find a multi cavity version of this one.

one of my 308241's is an 8 cavity Armory mold

[richhodg66]

one of my 308241's is an 8 cavity Armory mold

Wow! I sure would like to get ahold of one of those!

[richhodg66]

Are you sure it'll need to be seated below the neck? Those rifles have quite a throat in them.

I shoot a 150gr. boolit in my CZ, 1800 fps, using 17.5gr. WC680 plus enough plastic shot buffer to make a compressed load. Very accurate,no leading, and no gas check needed.

Turns out you were correct, I seated them even with the base of the neck and they chambered fine. Good to know I can do that, but it does leave an exposed lube groove. Loaded these with 5.7 grains of Unique (because that's what a #11 rotor on my Little Dandy throws) so we'll see how she shoots. This one is a Charles Daly rather than a CZ, but I believe them to be basically the same rifle, both made in the former Yugoslavia I think. I sized these bullets to .311 and lubed them with standard NRA formula. Hope they shoot well, I may try bigger size on them next time.

[excess650]

My best groups from my CZ 527 have been with boolits cast from an old Lee single cavity mold. I've since purchased (2) double cavities of the same design from different distributors, but the dimensions are different enough that I've reserved the SC to my CZ.

I THOUGHT the Charles Daly was the same as the Interarms Mini Mark X. The CZ 527 is a completely different action with detachable, single stack magazine and single set trigger.

[richhodg66]

My best groups from my CZ 527 have been with boolits cast from an old Lee single cavity mold. I've since purchased (2) double cavities of the same design from different distributors, but the dimensions are different enough that I've reserved the SC to my CZ.

I THOUGHT the Charles Daly was the same as the Interarms Mini Mark X. The CZ 527 is a completely different action with detachable, single stack magazine and single set trigger.

You may be right, I've never compared closely. This one does have an internal magazine and hinged floor plate, otherwise I thought they were the same.

[Nobade]

Other than being small Mausers they're nothing alike. Different extractor setup, different barrel threads, totally different trigger, etc.

If your barrel is throated like my CZ, which is like a military rifle, it will have a large tapered cone throat. This allows very heavy boolits to be fired but not to fit in the magazine. The Yugo version has a snap over extractor so single feeding shouldn't be a problem. The CZ has a Mauser claw, and needs to either feed from the mag or replace the mag with a single shot loading tray like Calhoon makes.

I have found that the use of granular filler in my rifle allows far better accuracy than without, presumably because it stops gas blow-by in the rather generous throat. Once I started using filler it was no big trick to shoot sub MOA groups off the bench.

BTW, my new favorite load for that rifle is the NOE 247gr. Whisper boolit over 8.5gr. AA#9 or WC820. A loaded round is half again as long as the magazine but it shoots nearly one hole groups at 100M off the bench, plain base and no filler. Great fun!

[richhodg66]

Interesting, guess I should pay closer attention to these things.

Accuracy with my load today wasn't great, but a lot better than before with the hard cast .32 bullets. I shot four five shot groups once I got it zeroed, one inch groups at 24 yards, however, in almost all of them three or four were touching with one or two horizontal flyers.

I think I am going to try experimenting with seating depth now that I know I have a lot f throat to work with and also trying some of these unsized. Maybe I'll try some with a tuft of dacron on top of the powder.

Any thoughts on the small rifle vs. large rifle primers for accuracy?