Do some guns have rifling, but no twist?

[Zaydok Allen]

I’ve always wanted a COP Derringer for no other reason than as a curiosity. I know the triggers were crap and the capacity was only 4 as apposed to a similarly sized 5 shot j frame. It doesn’t matter to me though. I just think they are interesting. However that interest is unlikely to warrant the price they go for now.

Here’s a pic from a Gunbroker listing.



Now take a look at this next picture. Is it a trick of the lighting or does it look to anyone else as if there is no actual twist in that rifling?



I’m trying to understand if a lack of rifling twist is in fact the case, what the purpose would be. It seems even in a short barrel, some rifling would help stabilize the projectiles. I realize these were last ditch “belly guns” meant to be shot at very close range.

Anyone have any ideas? Can anyone think of another model with rifling like this? It seems a smooth bore would be cheaper to produce. So I’m puzzled.

 

[DocRock]

There doesn’t appear to be any twist. But whether that is optical illusion or fact, I can’t say. A pistol without rifling would run afoul rod the NFA. Why one would cut rifling but not apply a twist is beyond comprehension, unless it is a defect.

 

[ThomasT]

I always thought a long barreled revolver with straight rifling would be great for shooting shot capsules. And it should meet the ATF requirement for rifling in the barrel. I don't remember ever reading the rifling had to have a twist to it.

But it sure looks like that gun has no twist. Really weird.

I found this. The report says many of the bullets tumbled and missed the target completely. Sounds like bad rifling choice to me.

https://www.thetruthaboutguns.com/gun-review-cop-357-derringer-pistol/

 

[Zaydok Allen]

There doesn’t appear to be any twist. But whether that is optical illusion or fact, I can’t say. A pistol without rifling would run afoul rod the NFA. Why one would cut rifling but not apply a twist is beyond comprehension, unless it is a defect.

The NFA short barrel shotgun, smooth bore thing just dawned on me a minute ago. You’re right. It’s the same reason the Taurus Judge and S&W Gov, Bond 410 Derringers all have to have rifling, even though shooting shot shells is their main marketing gimmick. In fact I remember Taurus trying to put 28 gauge shot shells in their largest revolver size. I think it was crappy results with rifling, but the NFA disallowed smooth bores, so they dropped it.

But yes, that still begs the question of why no twist.

 

[Snowdog]

Considering this review https://www.thetruthaboutguns.com/gun-review-cop-357-derringer-pistol/ mentions horrendous accuracy, it may not be an optical illusion. This was supposedly the "best" group of the day... at 7 yards.

Notice all the keyholes? They very well may be an unusual slight or zero twist rifling. It probably rocks as a garden pistol with shot shells.


ETA: So it does appear to have a slight twist as evident by the YouTube review below.


And yes, it likes the shotshells (especially CCI's #4 shot variety)

 

[Conelrad]

Up close & personal, a keyhole wound is worse...

Conelrad

 

[JohnKSa]

Anything with a barrel under 18" must have rifling, and, based on the latest BATF ruling on the Franklin Armory Reformation, the rifling must have a twist--it can't be straight rifling. I suppose one could get the appropriate tax stamp and then all would be well. I don't know what tax stamp covers straight rifling in a barrel under 18" though...

 

[748]

Look like it would be brutal with larger buck shot.

 

[jmr40]

Up close & personal, a keyhole wound is worse...

Maybe. It might lead to a larger surface wound, but if you don't get the needed penetration to hit vitals it won't be effective.

Typical twist rates for handguns are around 1:16 and would be hard to see on such a short barrel. Maybe they went to something even slower. Some muzzle loading rifles are 1:32, 1:48, and a few much slower than that.

 

[ThomasT]

Anything with a barrel under 18" must have rifling, and, based on the latest BATF ruling on the Franklin Armory Reformation, the rifling must have a twist--it can't be straight rifling. I suppose one could get the appropriate tax stamp and then all would be well. I don't know what tax stamp covers straight rifling in a barrel under 18" though...

Thanks for the information. I hadn't ever seen that before.

 

[LaneP]

If the twist rate is sufficiently slow (i.e., to stabilize round balls) it can indeed appear to have no twist in a short length barrel. But there should be enough to be detectable vs none at all.

 

[22250Rem]

Interesting topic. I've seen handguns with what appears to be no twist rate to the rifling. IIRC they were all some sort of small, derringer like, handgun meant to be used at very close range, so accuracy was not a priority. I have a small 1880's vintage, "defender" revolver chambered in .32 Short Rimfire. The bore is rough but there is rifling in it and I can see no twist. At point blank range is twist even needed ?

 

[Texas10mm]

The NFA short barrel shotgun, smooth bore thing just dawned on me a minute ago. You’re right. It’s the same reason the Taurus Judge and S&W Gov, Bond 410 Derringers all have to have rifling, even though shooting shot shells is their main marketing gimmick. In fact I remember Taurus trying to put 28 gauge shot shells in their largest revolver size. I think it was crappy results with rifling, but the NFA disallowed smooth bores, so they dropped it.

But yes, that still begs the question of why no twist.

The 28 Gauge Judge would be a destructive device.

 

[Koroner]

7 yards? SEVEN YARDS???????

C'mon its A BELLY GUN! You shove it in the cheater's belly and smoke his guts.

You wanna shoot that thing 7 yards maybe you should put a scope on it!

 

[Zaydok Allen]

The 28 Gauge Judge would be a destructive device.

I suppose, over 50 caliber.....

 

[94045]

The 28 Gauge Judge would be a destructive device.

But then we have the Shockwave that dodges it all because it's over 26" and not shoulder fired.

I'm sure someone will correct me if I have a faulty memory but how is a Shockwave different from the Witness Protection Shotguns that required the $5 Tax Stamp?
I think I answered my question in that the production versions had 12.5" barrels and I'm assuming where under 26".

 

[hk940]

What is the current status of the Reformation, is it being produced? Did ATF shut it down? I thought it was not considered a rifle because the "rifling" was straight.

Anything with a barrel under 18" must have rifling, and, based on the latest BATF ruling on the Franklin Armory Reformation, the rifling must have a twist--it can't be straight rifling. I suppose one could get the appropriate tax stamp and then all would be well. I don't know what tax stamp covers straight rifling in a barrel under 18" though...

 

[Bill460]

I have a Hastings 30" Trap Barrel for my Remington 870 Wingmaster, that I purchased back in the 90's. It has straight rifling it's entire length. The concept behind it was for the straight rifling to engage the wad, and prevent it from rotating in the barrel. This supposedly would provide more consistent, denser patterns. The barrel patterned very well, and it shot well. However I can't say either way if the straight rifling was the reason why.

I purchased it because the standard barrel the gun was shipped with, was only a 28" with a solid bored Modified choke. A 30" Full choke is more desirable for Trap shooting. Especially at handicap yardages. I saw this Hastings Barrel advertised in Shotgun Sports Magazine at the time, so I thought I would give it a try.

My Remington 1100 Trap gun shipped from the factory with a 30" Full choke barrel. Exactly the same as the Hastings, except for the straight rifling. The Hastings barrel does pattern slightly tighter. But again, that could be because of the choke boring, and not the straight rifling.

 

[Carl N. Brown]

"Is it a trick of the lighting or does it look to anyone else as if there is no actual twist in that rifling?"
Let's say the rate of twist in 9mm, .38 Spl or .357 Mag barrels runs one full turn in 14" to 18.75" of travel (typical for Colt and S&W .38 barrels). With maybe 2" of rifled bore in front of the firing chamber of a derringer, those rifling twists would be 1/7th or 1/9th of a complete turn in 2" of bore. I suspect the camera angle to the bore could make the rifling appear to be straight in a photograph.

ADDED:
The Internet Movie Firearms Database has a listing on appearances of the COP 357 Derringer. From the listings with Blade Runner, Battlestar Gallactica, Stargate it has a sci-fi appeal.
http://www.imfdb.org/wiki/COP_357_Derringer
IMFDb is an interesting source; some of the contributors are movie prop masters who have worked on these films; most are fans of movies and guns.
In movies, the COP is often represented by the Marushin Airsoft Replica COP 357. Shoots 8mm airsoft-type pellets using CO2. I have seen the replica listed at 69.95.

 

[Bill460]

If you look at the photo in his first post, that shows the gun tilted at an approx. 45 degree angle, the very top land and groove look as straight as straight can be.

 

[kozak6]

What is the current status of the Reformation, is it being produced? Did ATF shut it down? I thought it was not considered a rifle because the "rifling" was straight.

The ATF did indeed shut it down.

They classified it as a non-NFA GCA-SBS, which is unprecedented and baffling.

The GCA defines shotguns as smoothbore and firing shotgun shells, so I really have no idea what's going on and why Franklin Armory is giving up on what should be a slam-dunk.

 

[hk940]

ATF does it again!

"They classified it as a non-NFA GCA-SBS, which is unprecedented and baffling".

What the hell does that mean? If is is classified as a GCA-SBS how could it not NFA?

 

[PapaG]

The NFA short barrel shotgun, smooth bore thing just dawned on me a minute ago. You’re right. It’s the same reason the Taurus Judge and S&W Gov, Bond 410 Derringers all have to have rifling, even though shooting shot shells is their main marketing gimmick. In fact I remember Taurus trying to put 28 gauge shot shells in their largest revolver size. I think it was crappy results with rifling, but the NFA disallowed smooth bores, so they dropped it.

But yes, that still begs the question of why no twist.

I don't think it was a smooth bore, it was over the .5" limit and thus was a destructive device.

 

[jmorris]

“Rifling” is just a helical set of lands and groves, no numerical number of them, their depth or rate of twist required. 1:7 is pretty easy to seen, even in an inch a 1:66 or greater might not be but they are still what they are.

It doesn’t need to be consistent throughout, my gain twist barrels start out fairly straight and the twist increases towards the muzzle.

Some of the old Contenders that could fire 45 LC and .410 shot guns (their “hot shot” 357 and 44 mag barrels too), had rifled barrels with screw in chokes that hand lands and groves that were straight cut, in an effort to stop the spin imparted by the rifling so shot wasn’t scattered as bad upon leaving the barrel.

 

[Texas10mm]

ATF does it again!

"They classified it as a non-NFA GCA-SBS, which is unprecedented and baffling".

What the hell does that mean? If is is classified as a GCA-SBS how could it not NFA?

It's a non SBS SBS. A definition only a lawyer could appreciate.