Cor Bon .357 Sig 125gr JHP in Clear Ballistics Gel

[5pins]

Test Gun: Sig P229.
Barrel length: 3.9 inches.
Ammunition: Cor Bon .357 Sig 125gr JHP
Test media: 10% Clear Ballistics Gel. Distance: 10 feet. Chronograph: Caldwell Ballistic Precision Chronograph G2. Five shot velocity average: 1397fps
Gel Temperature 70 degrees.

It’s been a long time since I used Cor Bon ammo. Back in the late ’80s, it was my load of choice in the 9mm. A lot has changed since then and ammo today is no exception. At the time their 115gr JHP +P was the cats meow so to speak. If my chronograph at the time was to be believed I was getting almost 1300fps out of my Glock 19.

This test was the first time I have shot any Cor Bon in forever but I decided to pick up some in my recent ammo buying spree. It’s also been a while since I tested any .357 Sig, so I got it in that caliber. As we will see, it was unfortunately wrought with problems.

I got a five-shot average velocity of 1397fps with a high of 1493 and a low of 1355fps. That’s a 138fps extreme spread.


Five shot at ten yards offhand.

When picking up the fired cases I noticed that one of the cases had blown a primer. At that point, I decided to check every case as it came out of the gun.



The first round across the chronograph had a velocity of 1335fps, and when I picked up the case it had a noticeable crack around it about midway up the case. It was also visible on the inside of the case as well.





At this point, a smarter man would have stopped, but I’m not a smarter man and decided to move forward. There were no other blown primers or cracked cases for the rest of the four rounds.

The first round into the bare gel had a velocity of 1410fps and penetrated to 16 inches. The recovered weight was 91 grains and it expanded to .48 inches. Round two. Wait, what happened to round two. The round would not chamber and I discovered the previous round had a case head separation and the front portion was still in the chamber. I tried to find the case from the first shot before loading the second but I couldn’t. I finally found the back portion the case after looking some more.





At this point, I became a smarter man and stopped. After getting the front half of the case out of the chamber I fired 20 rounds of some Sig FMJ and a few Sig V-Crown I had left over. There was no blown primes or cracked cases.

 

[Heir Kommt Die Sonne]

This makes me nervous to test my longshot 147 grainers in my .357...
Yea, stick to the Sig V-Crown. Any brand I'd trust it'd be the original designers of the ammunition. Been wanting to get some V-Crowns myself sometime.

 

[RJM52]

...hummmm... I heard that the original owner, Peter Pi, retired and sold the company...always figured his son would take over one day as he was pretty involved with the business...

I'm running Buffalo Bore 125 Gold Dots that I think were in the 1500s from a 6" G40...no issues at all.

Bob

 

[JimKirk]

I have shot Hodgdon data (Max) with out any issues using Long shot & 147 grain XTP.... In my Glock 31 ....

I like the 800X load slightly better.... less pressure ...but much harder to meter... just a little more velocity also ...1300 + fps...

Back when I could get my hands on Gold Dot 125 grain ...they shot excellent with the 800x load ...bumping 1500 fps over my chronograph.

 

[TTv2]

For a premium ammo you would think they'd have better quality control. That box of ammo is downright unsafe.

 

[Koroner]

Hmmmmmm,.... I've spent a bit on Cor-Bon but tried very little.

Guess I need to trot some out. I never got into those bottle necked pistol cartridges after an initial disappointment. Hopefully thats where the problem lies.

I have a bunch of 9mm +p 115gr, some .223 55gr, a couple .40 180gr, and .45 185gr I think.

Anybody have experience with those?

 

[SDGlock23]

that's odd. I've used Starline 357 SIG with good results, using 800X running 125gr XTP @ 1620, 140gr XTP @ 1455 fps and 158gr XTP @ 1390 fps. Longshot did well, but not as good as 800X (btw barrel was a 4.5" KKM in a Glock). Brass looked fine, it was brass, not nickle plated.

 

[5pins]

I have a headspace gauge on the way and I will let everyone know what I find.

 

[Zaydok Allen]

Wow, that quite the extreme spread for a premium brand, and the case failure and blown primer worry me.

 

[whatnickname]

Welcome to the ultra-hot world of the 357 SIG. I have experienced much of what you have, with the exception of case head separation. I have had others on THR suggest that I may not have reloaded my ammo correctly thus causing these problems. I have several pistols that fire the 357 SIG round, Glocks and SIGs. I have seen once fired factory ammo, fired in my pistols, that was so hot that the primer pockets expanded to the point that the brass was unusable. I have had primers that disappeared on firing as you have. These problems went away when I started checking my primer pockets with a "go / no-go" gauge. Cor-Bon is a reputable company. This round is a technical challenge as regards reloading. Give them a call. I'm sure they will replace your ammo.

 

[Paul Toms]

I have a headspace gauge on the way and I will let everyone know what I find.

I think you're gonna find your (their) brass is out of spec. The neck looks long on those rounds.

 

[5pins]

Well, the gauges came in and the pistol checks out fine. So it's not a headspace issue.