Gun Review: Cabot Guns Black Diamond – Part 1

By Jon Wayne Taylor

I’ve been looking for a higher end 1911 in .45ACP, and trying to avoid the delay of just having Heirloom build me one. I’ve had some decent 1911s; Wilson CQB, Les Baer, Colt, STI, Ruger, Springfield, etc., and some of those have had quite a bit of quality smithing. Right now, the Colt Combat Elite and the STI Duty One LT 4” are my better shooters, and my daily carry guns. Both of these have had significant work by quality gunsmiths to ensure their accuracy and reliability. I am very comfortable with them, and have yet to have a single failure after many thousands of rounds. So when I got the chance to try out the Cabot Black Diamond, I was interested in how they would shoot against quality factory guns that have had good work done on them . . .

My testing parameters would be pretty simple: seated, shooting from bags at 25 yards for accuracy and precision. Then standing, drawing and walking from 25 yards and 10 yards for just plain ol’ speed and shootability, where a 1911 should really shine. I ran the Cabot against the STI and the Colt with at least one other shooter.

I usually hand load, and both the Colt and the STI have their pet rounds. The STI will feed anything, but its accuracy dramatically changes depending on the round. So I decided to test accuracy between all three guns using a quality store-bought round. I chose the CORBON Performance Match 230gr FMJ. First because it’s a common, quality round, and second because I’ve got about 10,000 of them and I need the once-fired brass.

I also brought along some Remington Golden Saber HP and some hand loads topped with Hornady’s 230gr XTP bullet to make sure the Cabot could feed a couple of different hollow points. I used Wilson Combat ETM magazine in all guns. On day one, I fired alongside a very accomplished handgun hunter and shooter. The next day I got another friend who is an avid 3-gunner to try the Cabot out on its own.

First, the out-of-the-box impression is that photos do not do this gun justice. Whatever they said about their finish process, it’s better looking than you think. Just gorgeous. It’s hard to describe a shiny piece of flat metal as pretty, but there is something about how “flat” it is. As my friend Mark LaRue says, “There’s no measure for parallel. There is parallel, and there is not parallel.”

Against this kind of flat on the slide, no other slide is flat. So, set the gun down and look at it and it pretty much stares back and you and says…“perfect.” Right then I decided that if this gun shot as good as — not better than, but as least as well as — my Colt, I was buying it. That’s how pretty the Black Diamond is.

Picking it up and running through dry fire drills was nice. I love a flattened and milled top slide, because it just makes the sights pop so well. The gun actually feels fairly thin in the hand, and the controls are smooth and well laid out. I don’t know what weight the trigger broke at. I don’t own a trigger scale, but I do own a trigger finger, and it broke very cleanly, without enough resistance to noticeably pull the sights out of alignment for me. The pull was deliberate, but crisp. Very, very good.
 I was stoked, handling what I was sure would be my new, very flat, very shiny pistol.

After a quick inspection and lube, I walked out to the range to squeeze a few off. First was a simple function test. I try to get the hard one out of the way, right away. Ten-yard fast fire on steel, then 25-yard fast fire on paper. All with factory loaded hollow points. All standing. This is where 1911s fail if they are going to fail. The Cabot functioned for both my friend and me flawlessly. Even better, the gun was sighted for point of aim at 25 yards. Right where it should be. Damnit.

The gun tracked well, the sights returning to the target quickly and smoothly. Recoil was mild while the gun itself felt solid, but in no way heavy. It fired both the Remington Golden Saber and my hand-loaded XTPs just fine. No malfunctions at all.

Accuracy was OK. It’s pretty hard to quantify how accurate a gun is in fast fire, as there are so many variables in the shooter, especially without a defined shot pace, but the gun didn’t wow me or the other shooter. It shot well, but it did not shoot incredibly well. We put probably 50 rounds through the gun this way.

Two 5-round groups, factory ammo, standing, as fast as I could get the sights on target (less than three seconds to expend five rounds), 25 yard distance. This is a good representation of the groups the Cabot gave at this stage.

In comparison, this is my STI immediately after the Cabot. Same drill, well under three seconds. This is a horrible group for me, and the STI doesn’t shoot this round particularly well at all. Really, I hate showing anyone this group. But it’s a fair comparison on that day. The STI is a 4” aluminum framed gun, much lighter, with fatter Heine night sights. Jesus, that’s a horrible group.

To the bench!

I’ve used a Ransom Rest before, and they are great, but there is absolute witchcraft in setting them up, and ain’t nobody got time for that. So this is my simple, standard set-up. It gives me a very stable firing platform. And no, that is not one day’s worth of brass. It’s two days worth of brass.

I loaded up the CORBON RN FMJs into a Wilson Combat ETM mag and slid the first magazine into the Cabot. I hit the slide release, and this happened:

The very first word out of my mouth was, “bullshit.”. I assumed I had not fully seated the magazine. I dropped the magazine and tried it again. Same thing. First round failure to feed. I assumed then, (what stage of grief is denial?) that it was a magazine issue. So I tried several magazines, including Cabot’s.

It wasn’t a magazine issue.

Upon further inspection, the round itself — not the case — was being marred on each side, just past the nose of the bullet. This was a consistent, ongoing issue. There was no second round failure to feed, only the first round. The CEO of Cabot Guns and one of their engineers called me. We walked through what some of the issues might be, but all agreed it wasn’t an issue with the round or the magazine, and at least for this one time in my life, it wasn’t operator error.

They asked me to send the gun back to them with some of the troublesome ammo. I was happy to oblige. They were both extremely polite and professional. 
No malfunctions of any kind occurred with the STI or the Colt.

With lots of tries, eventually we could get the slide to go forward on the first round. Sometimes I would load a HP for the first round, then the RN FMJs after that. If that was the case, I didn’t shoot the first round into the target, but did subsequent rounds.

So we took turns shooting groups. All in all, we shot about 200 RN FMJ rounds out of the Cabot, and about 100 rounds out of the STI and the Colt put together.

The average 25 yard, 3-round group size, and a pretty consistent group size, for all three shooters over two days, was 2” on the Cabot. Oddly enough, the Cabot and the STI shot about the same as far as groupings. The best group on the Cabot was 1 ¾ inch. The STI really does not like this round, as far as accuracy goes.

The Colt’s average group was closer to 1”, which is pretty indicative of how this guns shoots.
 I wanted to go out to 50 yards and do a few other point-and-click drills with the Cabot. But at this point, the failure to feed issue was pretty annoying, and my mind was made up.

So, this isn’t my next 1911. And really, that disappoints me. It’s a gorgeous pistol. But at this price level ($5,950), it has to be pretty, run perfectly, and be very accurate. This particular gun’s consistent first round failure-to-feed issues just put it out of consideration for me. Even barring that, the accuracy on this gun just isn’t where it needs to be.

The folks at Cabot have asked me send the gun back to them, and give it another try when I get it back. I’ll be happy to do just that. When I get it back, assuming it chambers, I’ll put a few hundred more rounds through it, and maybe do some load development for it. And who knows, maybe it will be my next carry gun after all.

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The following email was sent by Cabot President Rob Bianchin after receiving the Black Diamond that Jon tested:

Our Black Diamond was shipped back to you earlier today so that you may complete your review. This is our first direct experience with Corbon 230 FMJ Performance Match Ammo. The Black Diamond was previously tested using ASYM Precision, Federal, Armscor, Magtech, TUL, Hornady and Wolf and fed without issue.

Using the Corbon that was returned with the pistol our team was able to replicate the feed issues you experience by manually cycling it, feeding a round into the chamber and back out. The Corbon was inspected by our engineers who noted the ball was seated towards the low end of tolerance of SAMI specifications which creates a more predominate edge at the transition of the casing and bullet. It also had virtually no roll in or crimp at the leading edge which accentuates this predominant edge.

Inspection of the gun did not note anything out of the ordinary except that the extractor seemed to be engaging the casing slightly heavy.

Work done:   The gun was disassembled and inspected. The pertinent surfaces were inspected with respect to the specifications and cleaned and re-polished. The extractor tension was re-tuned. This work resolved the feed issues of the Corbon ammo.

General assessment: The predominant edge on the bullet casing, which creates additional drag as the bullet is fed, and the slightly heavy extractor tension, which adds drag on the bullet casing, combined to create this feed issue. Either one of these items was not significant enough to cause a mis-feed as evidenced by the use of other ammo that fed fine. Further, once the extractor was tuned the feed issue ceased even with the Corbon ammo.

In general, we will not recommend the use of Corbon to be used with a Cabot 1911 in the future based on these observations.

The flush bottom 8 round magazine has a high spring pressure when loaded with 8 rounds. I recommend loading the flush bottom 8 round mags with the slide open or using 7 rounds.

Sincerely,