527 in 7.62x39

[one eye joe]

Do these rifles have a .308 bore or is it .311?

[woodchukhntr]

It is supposed to be .308 from what I have been told.  I haven't measured mine, but it shoots .308 bullets very well, and I have measured Wolf 122 gr. hollowpoints at .309 dia.  It shoots them very well also.

[R.W.Dale]

 The American Rifleman article published a couple years back stating that the bore is .308 diameter is blatantly wrong!


 My CZ Slugs out to .3105 in the grooves and .300 in between the lands. In a somewhat informal test I preformed shooting .308 and .311 diameter bullets off against each other I found NO measurable accuracy diffrence.

Previously posted by ME

It's been pretty hotly contested as to how much diffrence there is between loading 7.62x39 using .308 bullets vs .310-.311 so here it is. I tested this today and here are the results.

The rifle is a CZ527 carbine topped with a 3x9x40 redfield accutrac scope. The bore measures .300 land to land and .3105 in the grooves

The ammo was loaded with 150 gr Sierre soft points 10 rds of .308 and 10 rds of the same bullet sized .311. Cases were Remington CCI 400 , The powder was 23.5grs of Re-7 with a COL of 2.310

It was about 65 degrees today with a light varible breeze of 15 mph

Shot string 1
.308 bullets

1851
1826
1852
1827
1846
***************
Shot string 2
.311 bullets

1935
1904
1937
1912
1925
****************

Shot string 3
.311 bullets

1953
1888 !?
1915
1932
1925
***************

shot string 4
.308 bullets

1852
1855
1869
1844
1873
_____________

[olsingleshot]

I just got an email back from CZ. It said the bore diameter is .311.

[jeclif]

mine is a hair over .310  and likes 155  bthp   .308  but shoots anything I have run trough it at moa

[Blunderbus]

I had one briefly. It gave me excellent field accuracy with WW white box 7.62x39 ammo. My ejected empties all had blackened necks and shoulders. It was my only complaint, but in a fit of anal-retentiveness I traded it off.

It later dawned on me that the WW was probably .308 diameter and the CZ, being of Czech manufacture, was probably .311. That little bit of slop probably explained the blackened cases.

Very nice little rifle, though. Wish they made it in 6.8 Rem.

[R.W.Dale]

It later dawned on me that the WW was probably .308 diameter and the CZ, being of Czech manufacture, was probably .311. That little bit of slop probably explained the blackened cases.

 No winchester uses .310 diameter bullets in their ammo. The black soot is a result of American 7.62x39 ammo being drastically underloaded. Just like EVERY domestic ammo manufacturer does with a European cartridge.

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