Corbon 9mm JHP +P: shorter than other 9mm brands?

ccw9mm · August 5th, 2006, 08:50 PM

Today at the range, I just noticed something: every single CorBon 9mm JHP 115gr +P round I have is shorter than each of five different brand/model of bullets I've been trying. Didn't use calipers to measure, but it's ~ 1/8th of an inch shorter than every other bullet I have. The question is: Why?? And, does this explain the results I saw on the range, today (see below)?

The reason I ask is because I had a couple dozen failures to go into battery and failures to fire, today. Most were that the slide of my Browning BDM 9mm failed to fully go into battery, hanging up during the last 1/8th of an inch prior to lock-up. Had a handful of failures to fire, as well, with light/puny firing pin "touches" on the primer case. Swapped out to a couple different models of bullets and sent several magazines' each through the gun with zero failures.

This short length is the only thing I can see that's fundamentally different from all the other brands of bullet I have. FMJ, JHP, +P's and standard-pressure, CorBon, HSM/generic, Remington range, Remington/UMC range, Federal Hydra-Shok 124gr. Nearly all are of identical length, or near enough to not be sure they're different. However, the CorBons are very definitely shorter than all of them.

Comments/suggestions? If you're a reloader or a match shooter and know what could reliably cause the results I saw today, I'd love to know more about this.

Attachment, below, shows the relative lengths of the bullets I used today.

- Michael

Stephen A. Camp · August 5th, 2006, 09:12 PM

Hello. It is loaded to a shorter LOA due to the very blunt ogive. The straight sides of the bullet extend a greater distance from the base to the "shoulder" where the bullet profile begins to taper inward. If loaded to the same LOA as ball or JHP's with a more rounded shape, the bullet sides would engage the rifling.

When the Walter P88 first came out I tried one. It was tightly chambered and would work fine with any ball or JHP having a similar bullet profile, but when a Corbon 115-gr. JHP +P (or Sierra bullet handload) was chambered, the bullet would engage the rifling and prevent the slide from going fully forward and into firing position. Later runs of the P88 corrected this, but that's why the Corbon 115-gr. JHP +P can be a problematic feeder in some guns. It has to be loaded to a shorter LOA and that coupled with its very blunt nose can cause problems.

The light primer strikes possibly occurred due to the slide not being fully forward even when not obvious. I suspect that the sides of the bullet engaged the rifling and prevented the cartridge from fully seating in the chamber. Most quality semiauto pistols simply will not fire when the slide is not fully forward to prevent damage to the gun and/or shooter.

It is difficult to diagnose without actually seeing the problem, but I'll bet that this is close.

If you prefer the high-velocity approach with 115-gr. JHP's at +P velocities and the Corbon will not work, try Federal's 115-gr. JHP +P. It is a law enforcement load but can be had w/o too much difficulty. Performance mirrors that of the Corbon and the bullet is much more rounded. Frankly, I'd go with Corbon 115-gr. DPX +P in a +P load or Federal 115-gr. JHP (std pressure) for non-+P.

Best and good luck.

Best.

ccw9mm · August 5th, 2006, 09:19 PM

Quote:

Originally Posted by Stephen A. Camp

It is loaded to a shorter LOA due to the very blunt ogive. If loaded to the same LOA as ball or JHP's with a more rounded shape, the bullet sides would engage the rifling.

Ah. Done by design.

Q: Would barrel throating/polishing help with this, in terms of allowing a finicky feeding gun to start liking a given round better?

Q: What about the steepness of the feed ramp and its impact on ability to reliably go into battery/feed? Ie, the Browning BDM 9mm has a fairly long, light-angle ramp; whereas, the KelTec P3AT 380ACP has a very steep one.

Note that I'm not necessarily set on CorBon. I'm set on what works 100% reliably well. I generally prefer the 10K-rounds-on-the-range approach to reliability, along with carry/action work on a carry piece. But this is the first time ever where I've experienced dozens of lockups with the CorBon JHP's.

Stephen A. Camp · August 5th, 2006, 10:45 PM

You might try polishing the ramp and see, but if the bullet is engaging the rifling deepening the leade would probably be of more help. It might be easier to simply change ammunition.

Best.

ccw9mm · August 5th, 2006, 11:55 PM

Quote:

Originally Posted by Stephen A. Camp

It might be easier to simply change ammunition.

Oh, sure. Again, the issue isn't that I necessarily want to stick with CorBon. My goal, here, is to understand what is going on and why. Ultimately, if I can easily get past the issue, this ammo might stay in test mode; otherwise, it's tossed and some other rounds will be considered.

Thanks for the info.

Stephen A. Camp · August 5th, 2006, 11:58 PM

Hello, sir. You are most welcome.

Best and good luck.

ccw9mm · October 27th, 2006, 09:02 AM

Found exactly the same thing with the CorBon Pow'r Ball, as I described on a recent range report for a CZ P-01 compact 9mm. Very short. 100% jams. Unusable.

nn · October 27th, 2006, 11:54 AM

Quote:

Originally Posted by ccw9mm

Found exactly the same thing with the CorBon Pow'r Ball, as I described on a recent range report for a CZ P-01 compact 9mm. Very short. 100% jams. Unusable.

I suppose it depends on the pistol, I'vs not had a problem with them.

Crexrun · October 27th, 2006, 12:24 PM

The Black Hills 115+P 9mm with Speer Gold Dots were basically the same length then, I noticed they were about 1/8" of an inch shorter than the Speer 124 +ps I had. They used the same bullet obviously, but the 115 itself is a little shorter, but it still looked odd to me. Seem to load and shoot fairly well in my Ruger, but I think I'd rather have the longer cartridge, I'd think they'd be more reliable. Who knows. Crexrun

jowgafist · October 27th, 2006, 02:12 PM

All I use is Cor-Bon JHP ammo never had a feed problem...I've ran a few boxes of 115gr in my XDSC9mm and 92FS, no problems.

The other difference is that CorBon runs hotter than any of the ammo that you're firing. Maybe check your grip. Just my 2 cents.

Can't say anything about there Pwr Ball, I've never used those.

August 5th, 2006, 08:50 PM	#1
ccw9mm VIP Member Join Date: Jul 2006 Location: Oregon USA Posts: 6,025	Corbon 9mm JHP +P: shorter than other 9mm brands? Today at the range, I just noticed something: every single CorBon 9mm JHP 115gr +P round I have is shorter than each of five different brand/model of bullets I've been trying. Didn't use calipers to measure, but it's ~ 1/8th of an inch shorter than every other bullet I have. The question is: Why?? And, does this explain the results I saw on the range, today (see below)? The reason I ask is because I had a couple dozen failures to go into battery and failures to fire, today. Most were that the slide of my Browning BDM 9mm failed to fully go into battery, hanging up during the last 1/8th of an inch prior to lock-up. Had a handful of failures to fire, as well, with light/puny firing pin "touches" on the primer case. Swapped out to a couple different models of bullets and sent several magazines' each through the gun with zero failures. This short length is the only thing I can see that's fundamentally different from all the other brands of bullet I have. FMJ, JHP, +P's and standard-pressure, CorBon, HSM/generic, Remington range, Remington/UMC range, Federal Hydra-Shok 124gr. Nearly all are of identical length, or near enough to not be sure they're different. However, the CorBons are very definitely shorter than all of them. Comments/suggestions? If you're a reloader or a match shooter and know what could reliably cause the results I saw today, I'd love to know more about this. Attachment, below, shows the relative lengths of the bullets I used today. - Michael __________________ Your best weapon is your brain. Don't leave home without it. Reports: CZ P01 pt1, pt2. Thoughts: Justifiable self defense. Explain: How does disarming victims reduce the number of victims? Tip: Use the <search> feature.

August 5th, 2006, 09:12 PM	#2
Stephen A. Camp Member Join Date: Aug 2005 Location: Texas Posts: 416	Hello. It is loaded to a shorter LOA due to the very blunt ogive. The straight sides of the bullet extend a greater distance from the base to the "shoulder" where the bullet profile begins to taper inward. If loaded to the same LOA as ball or JHP's with a more rounded shape, the bullet sides would engage the rifling. When the Walter P88 first came out I tried one. It was tightly chambered and would work fine with any ball or JHP having a similar bullet profile, but when a Corbon 115-gr. JHP +P (or Sierra bullet handload) was chambered, the bullet would engage the rifling and prevent the slide from going fully forward and into firing position. Later runs of the P88 corrected this, but that's why the Corbon 115-gr. JHP +P can be a problematic feeder in some guns. It has to be loaded to a shorter LOA and that coupled with its very blunt nose can cause problems. The light primer strikes possibly occurred due to the slide not being fully forward even when not obvious. I suspect that the sides of the bullet engaged the rifling and prevented the cartridge from fully seating in the chamber. Most quality semiauto pistols simply will not fire when the slide is not fully forward to prevent damage to the gun and/or shooter. It is difficult to diagnose without actually seeing the problem, but I'll bet that this is close. If you prefer the high-velocity approach with 115-gr. JHP's at +P velocities and the Corbon will not work, try Federal's 115-gr. JHP +P. It is a law enforcement load but can be had w/o too much difficulty. Performance mirrors that of the Corbon and the bullet is much more rounded. Frankly, I'd go with Corbon 115-gr. DPX +P in a +P load or Federal 115-gr. JHP (std pressure) for non-+P. Best and good luck. Best. __________________ Drop by www.hipowersandhandguns.com and http://hipowers-handguns.blogspot.com/ Last edited by Stephen A. Camp; August 5th, 2006 at 09:19 PM.

August 5th, 2006, 10:45 PM	#4
Stephen A. Camp Member Join Date: Aug 2005 Location: Texas Posts: 416	You might try polishing the ramp and see, but if the bullet is engaging the rifling deepening the leade would probably be of more help. It might be easier to simply change ammunition. Best. __________________ Drop by www.hipowersandhandguns.com and http://hipowers-handguns.blogspot.com/

August 5th, 2006, 11:58 PM	#6
Stephen A. Camp Member Join Date: Aug 2005 Location: Texas Posts: 416	Hello, sir. You are most welcome. Best and good luck. __________________ Drop by www.hipowersandhandguns.com and http://hipowers-handguns.blogspot.com/

October 27th, 2006, 09:02 AM	#7
ccw9mm VIP Member Join Date: Jul 2006 Location: Oregon USA Posts: 6,025	Found exactly the same thing with the CorBon Pow'r Ball, as I described on a recent range report for a CZ P-01 compact 9mm. Very short. 100% jams. Unusable. __________________ Your best weapon is your brain. Don't leave home without it. Reports: CZ P01 pt1, pt2. Thoughts: Justifiable self defense. Explain: How does disarming victims reduce the number of victims? Tip: Use the <search> feature.

October 27th, 2006, 12:24 PM	#9
Crexrun Member Join Date: Oct 2006 Location: Aberdeen, SD Posts: 63	The Black Hills 115+P 9mm with Speer Gold Dots were basically the same length then, I noticed they were about 1/8" of an inch shorter than the Speer 124 +ps I had. They used the same bullet obviously, but the 115 itself is a little shorter, but it still looked odd to me. Seem to load and shoot fairly well in my Ruger, but I think I'd rather have the longer cartridge, I'd think they'd be more reliable. Who knows. Crexrun __________________ Walther P22, Velocitors, on my side. Ruger P95, Speer Gold Dot 124 +Ps, bedside. Mossberg 500, full of steel shot behind the door. And a Princeton Tec Genesis 3 watt led and a Gerber Ridge knife! Don't steal MY Coors Light!

October 27th, 2006, 02:12 PM	#10
jowgafist Member Join Date: Aug 2006 Location: Virginia Beach, VA Posts: 316	All I use is Cor-Bon JHP ammo never had a feed problem...I've ran a few boxes of 115gr in my XDSC9mm and 92FS, no problems. The other difference is that CorBon runs hotter than any of the ammo that you're firing. Maybe check your grip. Just my 2 cents. Can't say anything about there Pwr Ball, I've never used those. __________________ Virginia Citizens Defense League Stay informed on issues regarding the 2nd Amendment, Join VA-Alert. NRA Life Member Get your martial arts supplies here. "Gun on, Pride off." ~John Murphy

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