CZ 527 with .314 bore

[wjham77]

Slugged my 527 7.62x39, and found out it had .3135 to .314 groove dia. I don't have a lot of molds that will cast that large. Anyone with similar problems and molds that you used to work up good load?

[edp2k]

Powder coat will gain you a thou or 2.

[northmn]

Beagle the molds a bit. I have used the foil tape and done so. I ran into a Russian carbine 7.62 that slugged 317 and could not get it to shoot cast all that well. Looking back I could have tried a 32 special mold but I did not think it would chamber. The 7.62X39 used faster powders and with a combination of beagling the mold and exterior lubes like mentioned might work. Softer alloys can slug to barrel, but the loads need to be more mild.

DEP

[Texas by God]

I'd call CZ and arrange a return; that's too large. How does it shoot jacketed?

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[PB234]

From the CZ website, "Built to CIP specifications, our 7.62×39 chambers are ideal for shooting steel-cased surplus ammo. Designed to shoot .311 bullets"

Another fellow I Private Messaged with years ago was very sucessful shooting cast he believed were cast about .312 and used a .313 sizing die to attach gas checks. I still have his PMs and can share his loading technique by PM if you want it. His targets at 100 yards were one expanded hole. My recollection is he was using a Lee mold so obtainig a new mold like his would be inexpensive.

His groups were remarkable. His load was stout. My foggy memory is he was getting about a third or half an inch group at 100 yards. He spent considerable effort with case and boolit preparation, lube type and lubing technique, etc.

CZ 527s are typically excellent. If I could only have one rifle it would be a 527 Carbine or an American. My guess is with the right boolit/load your Carbine will shoot excellent.

[PB234]

I just cut and pasted one of the PMs mentioned above. I took out the load data as it is stout.

With the Lapua brass I didn't have any problems. My normal load is (deleted) under that Lee C309-150F sized in the .313" die. I tried .312" and it didn't do as well. I don't crimp, and the boolit is set out to lightly engage the front band. 23-25gr all shot good groups, but I chose 24gr to give me some leeway with temperature change. WLR primers seemed to give me better accuracy than F210s.

My mix would be close to 50/50 wheelweights and soft lead with a few % tin added and water dropped. this makes for a malleable metal that will mushroom, but is not brittle. I'm using homebrew lube ahead of the GC ONLY. Your mileage may vary......my CZ527 has seen no jacketed rounds other than what it was factory test fired with.



The CZ will chamber and shoot longer and heavier boolits. My load is pretty snappy, so I chose to not use heavier boolits. I want to experiment with the NOE 311008 in GC form (125gr).

This is a really neat little rifle. Its size and the size of its cartridge really disguises its capability."

I realize the Lee mold is advertised as a .309 mold and have not tried to duplicate his loads.

[northmn]

Lee makes a bullet specifically for the cartridge weighing in at 160 grains.

DEP

[wjham77]

It shoots decent with steel cased wolf, 1"-1.5" (best 3 of 5 shots would be 1") My handloads with Hornady 123 fmj and Fioochi 1x brass were Not Good.

[wjham77]

Pb234, thanks for info, feel free to pm anything else you scrounge up. I got 311465 that casts .313-314. my Lee 155 mold drops 312 with wheel weights, might try 50ww/50pb and see what I get. Considering a neck die from Lee. Beagling may be an option I'll try to get an extra thou or 2

[gpidaho]

My CZ 7.62X39 shoots great with .313 cast bullets. I have several moulds (30cal.) that drop close to that and I do powder coat.Gp

[PB234]

Recently I measured some respected manufacturers jacketed bullets surprised some were not sized perfectly. Some brands were perfect. One was too small. Amazing manufacturing quality to get them all perfect. I recall Sierra and Berger were spot on. The too small ones might be useful in an old Hornet.

[Prodigal Son]

Never slugged my bore but it shoots Brown Bear factory bug holes maybe you got one a little big! 123 gr j words killed many of things with it in my day!

[Texas by God]

I just slugged my new 7.62x39 AR barrel and happily it is .310"
If it shoots $3.50/20 steel case well, i'll only reload for hunting!

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