ATTN Walther owners

[44 AMP]

A friend related this to me when Walther came up in discussion. In 2003 he had an expierence with seveal Walthers and Cor-Bon ammo.

The Cor-Bon ammo would not fully chamber. The guns were a Walther P-4, a P-5, and a P-5 Compact. The slide would stop slightly (about 1/8") out of battery. Cor-Bon 124gr +P, 147gr +P, and 2 different lots of Cor-Bon 115+p all refused to lock up. Yes, the chambers were fully cleaned. Rounds dropped straight into the chambers also refused to enter all the way.

All three guns functioned flawlessly with Rem 115, 115+P, Federal 115BP, 124gr Hydrashok, Win Silvertip, and Speer Gold Dot 124gr. All the ammo (including the Cor-Bon was hollowpoint). The Cor-Bon worked flawlessly in both a Sig 228, and a Sig 229, as well as a Beretta.

The P5s were probably 80s production, and the P4 from the later 70s. All guns were bought used.

My friend (and I) would like to know if anyone has had a similar experience, either with Walthers, or with 9mm Cor-Bon. I know Walthers generally don't wor5k well with the cheap ammo. but Cor-Bon is not cheap ammo.

If you have trouble with one gun, and one type (or even one lot) of ammo, that is usually an individual thing, but this was 3 different guns, and at least three different lots (and bullet weights) of one brand of ammo. This is not something "ordinary". Unfortunately, my friend was not able to provide me with the lot numbers, only that they did check them and were sure the 115gr+P was two different lots.

So, anybody out there ever have anything like this happen to them (or someone they know?

 

[denfoote]

The answer, right off the top of my head is that it has to do with the shape of the Corbon bullet.
The guns in question were designed for full metal jacket bullets, not the wide mouthed Corbons!! My PPK/S has trouble with Corbons, as does my Glock 36.

For these pistols, you probably want to stick with a bullet that has a shape as close to hard ball as possible. I use 115gr Winchester USA USA9JHP, a standard design hollow point ammunition in my P5, and it does just fine!!

 

[44 AMP]

Thank you

I am curious, why the wideness of the hollowpoint would interfere with chambering. Feeding, I can understand, but in the case described to me, even rounds dropped into the chamber by hand would not reach the proper depth. And the rounds worked fine in a couple of Sigs.

My personal theory is that perhaps the crimp (case mouth dia) was on the large side, and the Walthers chambers on the small end of the tolerance. I base this on my reloading, where cases without enough taper crimp tend to stop short in the chamber, and when recrimed with proper adjustment of the die, chamber properly. However, it is only a theory, and I am open to suggestions.

Again, three different Walthers, 4 different lots (3 different bullet weights) of Cor-Bon, identical problems. Other ammo wokds fine, problem ammo works fine in other brands of guns. Could this be a case of max specs on the ammo and min specs in the Walthers chambers?

denfoote, does your P5 have trouble with the Cor-Bons as well?

 

[denfoote]

I'm not a gunsmith or a balliistician by any means, I can only give my opinion based on the published work of others.
That said, I think it has very much to do with the feed ramp and the chamber.
Also, the overall length of various rounds differs from company to company!! That's why, with any gun, certain cartridges will work and others might not.

The tolerances of the chamber are the culprit here. These tolerances can vary from maker to maker by as much as several thousandths!!! This is referred to as being either "tight" or "loose".
It is possible to design a gun that accepts only one brand of ammunition!! The older LWS Seacamps are a prime example. They were designed to chamber ONLY the .32acp Winchester Silvertip!! On the other side of the coin, Glocks have an extremely loose chamber and will chamber almost everything out there. This is a good thing because the gun was designed as a multinational military pistol. It does, however lead to some problems as the several reported KBs in the .40S&W chambering indicate!!

I have not tried Corbons in my P5. The ammo I use works and I see no need to attempt to use anything else!!

The combination of feed ramp geometry and chamber tolerances mean that certain brands of ammo may not work!!
That is why it is a good thing to test your pistol with several brands of ammo and pick the one that works the best!!

 

[44 AMP]

What we are looking for here is

If anyone else has had a similar problem, either with Walthers or with cor-bon ammo. It is NOT a feeding problem.

We do believe it is a min spec chamber/max spec ammo situation, what we want to find out is has anyone else had this happen to them?

All the Walthers run ok with other ammo, the Corbons run fine in other guns.
3 different models of Walther, 4 different lots/3 different bullet weights of Cor-Bon ammo.

Denfoote, we know all this, between us we have over 70 years of shooting, reloading, and gun tinkering experience. Thank you for your info, we are looking for any other instances of it happening to people.

 

[denfoote]

I think part of your problem is that there probably isn't but a handfull of people on this board that own a Walther P5 or the P5C.
Certainly not a P4!!

It was not a popular pistol during it's heyday.
Now, there may be a scant handfull that have picked up one of the surplus P5s that have seen the light of day, but I would not hold your breath!!

I've been here a long time and I bet you can count the P5 threads on the fingers of one hand!!

A better place to post this probably is: http://www.waltherforums.com/vb/

Althouge not specifically for the P5, the people over at http://www.p38forum.com/ may know of what you seek.

I do know at least a couple of us have P5s and P5Cs over at the walther section of: http://www.handgunforum.net/

I hope this helps you out better than my last attempt!!!

 

[P5 Guy]

You too!

P88 and P5c will not chamber Corbons. The slide remains out of battery and is very hard to pull back to remove the round that did not fully chamber. The shape of the ogive is too long and engaged the rifling in my P88. This would have been a diaster if it had gone into battery. Way too much pressure for the pistol to handle.

 

[Don H]

44 AMP,

If you mark the Corbon bullet with a Magic Marker and attempt to chamber it, I believe, upon extraction, you will see where the rifling has prematurely engaged the bullet, preventing the round from fully chambering.

 

[sigp6]

Yes, I have run into the same problem with my P5 and Cor-Bon ammo. My P5 eats everything else without a problem. Definitely a chamber size issue.

 

[rock185]

What Don H said. The CorBon/Sierra bullet retains full diameter further forward of the case mouth than most other designs. Due to the bullet's profile, it is running into the rifling leade which prevents the round from chambering properly. I've had the same issue with certain bullet/firearm compatibility situations ( not Walther ). Probably nothing wrong with your guns or the ammo, just not compatible.

 

[44 AMP]

Very Interesting....

Thank you all for the input. If it is the bullet hitting the rifling, then it could be said that that Walthers have a "short throat" compared to Sig and other brands where the Cor-Bon works reliably, yes?