.451 Cor-Bon

I have an ad dated 1991 by Atwood Arms Inc. of Seattle, WA which offers conversions for M1911A1 type pistols in .451 Detonics and .451 Cor-Bon. Does anyone know anything about this last cartridge?

Fede - I have never heard of the .451 CorBon cartridge. This may be a case like the .330 CorBon auto cartridge. I have a CorBon ad from the October 2000 Issue of “GUNS” magazine, page 25, that shows the .330 cartridge, but to my knowledge, it is the only public source that mention of it ever appeared in. It was not until circa 2005 that I found this ad, and at the SHOT Show, I queried people in the CorBon booth about it, and none seemed to know anything about it, even the owner. I wrote them a followup letter in February of that year, but received no reply.

I “rediscovered” my file on this caliber in 2012, and pursued other avenues of approach to CorBon, thru a close mutual friend. This answer was finally received on July 9, 2012, from Peter Pi, President and CEO of CorBon:

 "Ok, we got to the bottom of this.  We really had to search the archives.  This cartridge was never produced.  It was going to be a rimless 32 Auto cartridge for Kel-Tec.  The decided to not pursue the project."

Sometimes cartridges are designed and slated for production, but simply, for one reason or another, never actually happen. This may (or, of course, my not) be the instance with the .451 CorBon.

One other possibility exists. CorBon loaded the .451 Detonics cartridge, but used shortened W-W Super .45 Win Mag cases for the purpose. It could be that no Detonics brass was available. Unfortunately, I acquired mine as a single round, and do not have the box label. For that reason, I did not date the entry in my catalog of when it was made, since I did not have that information. I should have dated it with the date I acquired it, just for the record, but stupidly, I did not.
The .451 Detonics was introduced in 1982, according to my records, and the CorBon entry follows the original in my catalog. It, in turn, is followed by an entry for Qualcart manufacture of the Detonics cartridge, my specimen acquired in 2002. So, all I can say, is the manufacture of the .451 by CorBon must fall between those two years. That fits with the date of your ad in 1991. What doesn’t fit is that the first CorBon catalog entry I have for the .451 Detonics is from 1996, referred from then on in the few years they seemed to have made it as “.451 Detonics” and NOT .451 CorBon. I have no answer for that.

For the record, the CorBon is loaded with a GM-jacketed, HP bullet. The case is a standard Winchester with a nickel primer cup and red primer seal, shortened to the length of the Detonics case. It is possible that in some literature or perhaps on the box label, CorBon referred to the cartridge as “.451 CorBon,” thus the add from Atwood Arms, but I have zero documentation to that effect, and as mentioned above, I do have documentation of their production of the .451 Detonics cartridge under the Detonics name.

Edited solely to repair a very badly worded and poorly punctuated sentence.

Fede, I MAY have a little info on the CorBon cartridge, I will have to do some digging.

John, although it is wandering off Fede’s topic, see this site for a little more info on the Detonics and their cases.http://www.z3bigdaddy.com/site8/page44.html.

USCARTCO - Excellent! Lots of good information. Even mentions the CorBon loading’s bullet weight, which for my own records I had guessed correctly from total cartridge weight, but that confirms it was 200 grains. Also mentions being loaded in 1995, which squares well with it first appearing in 1996 CorBon literature.

Great addition for my Detonics file. I highly recommend that anyone interested in that caliber hit the link provided by USCARTCO.

If you find any documentation about a “.451 Detonics round,” please post it here on the Forum.

John, thank you very much, I really enjoy when you write these long posts. I also thought about those .330 and .308 Cor-Bon cartridges advertised in 1999-2000, but never heard about this .451 until now. Regarding Atwood Arms, I don’t have anything else about this company except for another ad of the same era offering .451 Detonics, .45 ACP and .41 Avenger conversions. They also marketed .451 cases.

The only other .451 Detonics cartridge that I readily found in my files is a custom load by Van Ripper Ammunition Co. made in 1984-85, but I seem to recall about other small companies that at some point loaded this cartridge.

Scott, thank you for sharing this link, very interesting.



Fede - could you either post on this thread, or send to me personally (first option preferred to help complete this thread), a scan of the Atwood Arms ad that mentions .451 “CorBon”? Since it is the only piece of documentation that is, so far, known for this cartridge designation, it is very important.

Regarding Van Ripper, there were at least three loads:

D45-1: Pointed, hard lead bullet
D45-2 Truncated flat point lead bullet with large meplat
D45-3J: Gilding Metal FMJ HP bullet of conventional form, with 6 jacket splits at the nose.

All of these loads are in Detonics-headstamped cases and have nickel primer cups.

Another company that made this round, c. 2002, was Qual-Cart. I have a load with conventional GM FMJ HP bullet much like that in the Van Ripper cartridge. It is loaded in a brass “Qual-Cart” case, nickel primer cup, headstamp: QUAL-CART 451 DETONICS

There were undoubtedly other small companies, what we generally refer to here as commercial reloaders (although many make “new” ammunition, that is, loads in new brass, as well). I don’t know of any off hand, as I don’t pursue loads from these companies unless they load a unique bullet have their own headstamp (of course!) or I come across them in identifiable form, basically from a labeled box so that I know who made them. Even then, I consider them of very, very marginal interest and not of much importance to the overall story.

John, here it is:

PS: I read your mail first so you also have a copy there.


I have a scan ( rather low res. but still readable) of the load manual that came packaged with the .451 Detonics conversion kit.

If interested I will email you directly, just let me know.

Below is a look at the Van Ripper Arcane-style lead bullet loaded on .451 Detonics Magnum (at left), next to a Van Ripper .45acp. The bullets would have been cast from either a Hensley & Gibbs model 938 mold, or a Ballist-cast model 1538 mold.


Rhino Replacement Parts, and Hi-Vel were two other companies that made these pointed lead “penetrators” (they didn’t penetrate much), but only Van Ripper made the .451 Detonics as far as I know. I had never heard of the .451 Corbon, and I wonder if it was just a misprint, or misunderstanding.

Coul “451 Cor Bon” be the denomination of the pistol/convertion?

I just heard from a buddy who owns/owned several Detonics.

I sent him Fede’s ad and he immediately saw the “VT” address on the frame. If the blurred part reads “Island Pond” then the frame was made by Essex Arms. He owned an early one with an Essex frame and several later when the company switched to Caspian frames.
The pistol looks like either a Scoremaster or a Compmaster either of those pistols were available in .451 Detonics. Both models featured six inch barrel with Millet sights. Which is what the pistol in the ad looks like.

There where some knock off pistols made by an ex employee c. 1990. This company may have have been him.

He is stumped by the Cor Bon reference as a dedicated cartridge. He told me what we already know that Cor Bon loaded .451 Detonics ammo.

Matt, thanks for posting these pictures. I just realized that we all wrote “Van Ripper” but the correct name is “Van Riper”, which is the last name of the company’s owner, David Van Riper. This company used Star reloading equipment, H&G molds and Sierra JHP bullets.

Scott, thanks for your help. The frame seems to read “Brunswick, VT U.S.A.”, but not sure if this has any useful meaning.

Thanks for the reminder on “Van Riper” with one P. In my book I have it correct, but even when transcribing, my brain wants to put two P’s in a word like “Ripper”.

DK - You and I are the same. I was just following Fede’s lead, as I figured he never makes a mistake! :-) My own notes show it as “Van Riper” so in truth, it was just me making a dumb error in spelling being a copy cat with Fede’s typo.


Don’t know about Brunswick VT , but Caspian used to be in Hardwick VT .
That would jive with the approx. era of the long slide pistol in the ad. Detonics switched to Caspian circa 1988.

Scott, yes, you are right, that makes sense.

Here is a picture of a side panel of the Cor-Bon box:


There is a local gun shop about 2 miles from my home that has one of the conversions (just the slide or upper if you will) for a 1911 I will check but I do not think is is a Atwell but it is for the 451 Detonics round.