Invisible Rifling?

[wally]

I was looking at some surplus 9x18 CZ82 pistols and would have bought one except none had visible rifling in the bores. I looked with a bore light and could see no spiral pattern or diffraction effects at any angle.

In another thread, (http://www.thehighroad.org/showthread.php?t=212430) some are claiming this is "normal".

So what's up with the Emperor's new rifling? If such a thing is for real, what will prevent the owner from being hassled about being in possesion of an illegal "short barreled shotgun" since it sure looks like a smooth bore.

--wally.

 

[Ron James]

All I can say Wally, that if your'e really worried about the ATF busting you for owning a shot barrel shotgun, don't buy one. I just picked up one from J&G and I'm very impressed with it. Yes the barrel appears smooth bore but if you hold it up in the light your can see the polygonal rifling. Several gun makers use this type of rifling and it seems to work. All my soures state it is not consided a short barrel shotgun. Remember polygonal doesn't have the sharp edges as normal rifling does. But rather than seek the knowledge of the uninformed and unwashed of a public forum, heck, google the ATF site and double check.

 

[wally]

My point is that the ones I inspected with a bore light had zero evidence of any rifling. I have no trouble seeing the sprials in Glock (polygonal) or Marlin (microgroove) with even a casual look.

So you are saying I should be able to see spirals if I look for them carefully -- which is what I did on the examples in question and found nada!

--wally.

 

[Jim Watson]

Do the Feds often come by and look at your guns?

Wouldn't the importer have to have demonstrated that he was bringing in legal guns?

I think that if I wanted one, I would buy it with a return guarantee if the bullets keyholed.

I once saw a Lancaster Oval Bore safari rifle that had no obvious twist but it worked.

 

[Ron James]

The bullets don't key-hole, in fact it is a very accurate little gun. Plus for a gun to be classified as a "shotgun pistol" there has to a shotgun shell that will fit it. As to this date I don't even know of a " snake shot " cartridge in 9MM Mak.

 

[wally]

OK, now if the bore were oval in cross-section and the oval twisted on its way from chamber to muzzle this could explain how the bullet could spin without visible rifling and perhaps explain what I'm not seeing when I looked for rifling.

This was at a gun show so, no returns or gaurentee of any kind. Ron James' reply suggests I should see a rifling if I look, remember I poked around with a bore light and saw nothing but impressive smoothness.

--wally.

 

[Jim K]

Did you clean the oil out of the bore? Even conventional rifling can disappear when there is a good coating of oil as there always is for shipment.

Jim

 

[wally]

These CZ82 examples were clean and dry. There is another gunshow this weekend, I'll see if I can look at some others. I'll look for evidence of some kind of "oval rifling" and if I find it I'll probably buy one, but if these look as shotgun-like as the ones I looked at last week, I'll pass. YMMV.

--wally.

 

[wally]

Inspected one again at todays gun show (from Military Gun Supply, importer's mark is PW ARMS, REDMD, WA) and brought it home. If you hold the bore light in a fixed location relative to the barrel so the specular reflection is near the bottom of the barrel and then shift your viewing angle so the reflection would move toward the muzzle you can see the bright spot rotate as it follows the changing contour of the "oval rifling". On a shotgun the spot is more of a ring and just moves straight up and down when you do this, although it does highlight any scratches or other imperfections.

There are no "edges" of traditional rifling to be seen. Live and learn, but this unusual rifling system makes it even more desirable for my collection!

Measuring the bore at the muzzle I find a max of ~0.360" and a min of ~0.356" about 90 degrees apart.

Silver Bear FMJ measures ~0.362" diameter. I've a lot more confidence in the deltas than the absolute numbers as my calipers haven't seen gauge blocks in a very long time.

FYI, 13-round CZ83 .380ACP mags fit and lock in and will hold 12 rounds of 9x18. They feed with hand cycling, but the proof is in the shooting which unfortunately won't happen this afternoon as its started to rain

Mine came with a pair of mags, cleaning tool, laynard, and a leather holster that holds the whole kit for $235.

--wally.

 

[wally]

Follow, up. Gun shoots great!

Finally got a chance to shoot my little CZ82. Function was 100% out of the box with Silver Bear FMJ and 94gr JHP. Tried a pair of CZ83 .380ACP mags and they worked perfectly too.

Nice little gun. Seemed to have some trigger slap, but it could just be I was tired at the end of a fairly long and hot range session.

The "oval rifling" once I learned about it, makes it unique in my collection.

Definitely rate this a buy and get them while you can! Since 13-round CZ83 mags work fine and hold 12-rounds of 9x18, no worries about unobtainable replacement mags.

The way I was knocking over the steel plates with it -- nearly always on the big ones, almost never on the smallest makes me think its as accurate as any other small gun with marginal sights. I could hit the smallest plates fine with my reading glassing on.

--wally.

 

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"for a gun to be classified as a "shotgun pistol" there has to a shotgun shell that will fit it. As to this date I don't even know of a " snake shot " cartridge in 9MM Mak"

Yeah, the definition of shotgun is not "any gun with a smoothbore barrel" It has to be able to fire a cartridge that has the charicteristics of a shotshell. As for being a short barreled shotgun i highly doubt any handgun modification unless specifically for firing shotshells would qualify.