CM40 and Reloading

[ar33c9]

I know Kahr says not to use reloads, but my reloading keeps expenses down. I am finding the PM40 to be particular with ammo. I reload lead bullets, 180g measure .401. I used the col of factory champion which chamber well. The oal is 1.120. When I matched that with the lead bullet it would not chamber. I had to take it down to 1.150 for it to chamber but the gun would not eject a live rnd. To get it to chamber and eject a live rnd I had to go down to 1.000 which is way under all other col's out there I've ever seen. I am concerned about the pressure that might create.

I read where one member filed a bit of metal off so cartridges would chamber better. Anybody got pics of exactly what to file?

Anybody here had success reloading for the pm40 or cm40 with lead?

[scosgt]

Do yourself a favor and don't do that. Making the rounds shorter will cause a KABOOM.

If you can, just get jacket heads that will fit. Still cheaper than loaded ammo.

[ar33c9]

I should have added that I used a dummy rnd to determine the 1.000 col that would chamber and eject. I should add that I wouldn't want to go below the 1.120. I am disappointed that it appears I can't reload lead for this.

[scosgt]

There are many cases of Glocks that went KABOOM because the same round was used to strip off the top of the mag into the chamber numerous times, resulting in setback and overpressure.

For whatever reason it seems to be something to avoid in .40

So be very careful. A little setback adds a lot of pressure.

[SDGlock23]

No manufacturer recommends using reloads in their guns, none of them. It's because your reloading practices are out of their control, so Kahr not recommending it is the norm.

I know your problem, the throat in the CM40 barrels is very short, which limits the OAL you can use with certain bullet types.

What bullet type are you using? I reload for nearly everything, and have shot a number of reloads through my CM40, including lead. There are many different opinions out there, but one positive thing is that the CM40 has excellent chamber support, the best I've ever seen on a production gun.

Don't shave metal off the cartridge, your problem lies elsewhere. If you're having to seat the bullet to a short OAL, it's the profile of the bullet along with the short throat that's causing you to have to seat to 1.100". In other words, the rifling starts very soon and longer OAL bullets, depending on the profile will not chamber because the sides of the bullet touch the rifling. On the opposite end, I have a KKM .40 barrel for both my Glock 23 and Glock 20 that will accept a .40 loaded all the way out to 1.260"+...it has a long throat on it.

For example, I have a 180gr TCFP loaded to 1.130". It won't pass the drop test in my CM40 barrel, but a factory 180gr Winchester PDX bonded at 1.120" will drop in just fine. I've found that usually it's the lead loads that are more effected by this, most plated and FMJ/JHP bullets have a more sleek profile to them that will allow for the use of a longer OAL in your CM40. I've got some handloaded 180gr XTP (JHP) loaded to 1.135" that will drop in perfectly, so you have to be more selective on bullets in the CM40 if you want to load to a longer OAL.

What you can, and need to do, is load the the OAL it will feed the bullet, which you mentioned was 1.100". However, just drop the powder charge an extra .5gr or so to make up for the deeper seating, don't use max data for a longer OAL load in your short OAL loads.

[otium]

Good to know that the Kahr .40 chamber is supported well. I wondered about that. Presently have one .40 and its in a glock 23. I certainly know what the glock smile on the case looks like.

Seeing those deformed cases made me not want to even try reloading that caliber and have to believe that bulge weakens the case wall, so have stuck with 9s and 45s.

Suppose a different barrel might help if it has better support and I do have a kkm conversion from 40 to 9 and that works good.

[ar33c9]

No manufacturer recommends using reloads in their guns, none of them. It's because your reloading practices are out of their control, so Kahr not recommending it is the norm.

I know your problem, the throat in the CM40 barrels is very short, which limits the OAL you can use with certain bullet types.

What bullet type are you using? I reload for nearly everything, and have shot a number of reloads through my CM40, including lead. There are many different opinions out there, but one positive thing is that the CM40 has excellent chamber support, the best I've ever seen on a production gun.

Don't shave metal off the cartridge, your problem lies elsewhere. If you're having to seat the bullet to a short OAL, it's the profile of the bullet along with the short throat that's causing you to have to seat to 1.100". In other words, the rifling starts very soon and longer OAL bullets, depending on the profile will not chamber because the sides of the bullet touch the rifling. On the opposite end, I have a KKM .40 barrel for both my Glock 23 and Glock 20 that will accept a .40 loaded all the way out to 1.260"+...it has a long throat on it.

For example, I have a 180gr TCFP loaded to 1.130". It won't pass the drop test in my CM40 barrel, but a factory 180gr Winchester PDX bonded at 1.120" will drop in just fine. I've found that usually it's the lead loads that are more effected by this, most plated and FMJ/JHP bullets have a more sleek profile to them that will allow for the use of a longer OAL in your CM40. I've got some handloaded 180gr XTP (JHP) loaded to 1.135" that will drop in perfectly, so you have to be more selective on bullets in the CM40 if you want to load to a longer OAL.

What you can, and need to do, is load the the OAL it will feed the bullet, which you mentioned was 1.100". However, just drop the powder charge an extra .5gr or so to make up for the deeper seating, don't use max data for a longer OAL load in your short OAL loads.

SDGlock 23, thank you for your post. I am using a lead 180g, .401 Flat Point. I will have to try with something other then flat point. What lead bullet shapes have you had success with? My lead bulliets supplier has a 175g semi wad cutter, do you think that would be better?

[ar33c9]

Think I found what I'm looking for. Just loaded 175 grain, Semi Wad Cutter at 1.121 OAL with 4.5 of WST. Drops in and out of the barrel and cycles through. Will confirm it at the range.

[muggsy]

There are many cases of Glocks that went KABOOM because the same round was used to strip off the top of the mag into the chamber numerous times, resulting in setback and overpressure.

For whatever reason it seems to be something to avoid in .40

So be very careful. A little setback adds a lot of pressure.

Show me one documented case where bullet set back has been determined to be the cause of the catastrophic failure of any handgun. So far, no one has been able to.

http://dailycaller.com/2013/03/05/battered-bullets-does-bullet-setback-matter/

[scosgt]

Show me one documented case where bullet set back has been determined to be the cause of the catastrophic failure of any handgun. So far, no one has been able to.

It does exist. Happened in a Federal agency (don't remember which off hand). Guns were issued at the start of tour, and they used the same round for the top of the mag load a number of times.

Setback was determined to be the cause.

[muggsy]

It does exist. Happened in a Federal agency (don't remember which off hand). Guns were issued at the start of tour, and they used the same round for the top of the mag load a number of times.

Setback was determined to be the cause.

Like I said, show me one documented case where bullet set back was determined to have caused the catastrophic failure of a hand gun. No one including you has. Everyone has tales to relate, but no one has documented proof. Allow me to offer this. Back in the early days of handloading wildcatters used compressed powder charges in an effort to achieve the highest velocities possible. Some guns were turned into hand grenades, but not because the powder charge was compressed. It was due to an excessive charge of powder. That and bore obstructions are what cause handguns to go kaboom. They do not go Kaboom from bullet setback.

http://dailycaller.com/2013/03/05/battered-bullets-does-bullet-setback-matter/

[scosgt]

There are numerous documented Glock .40 KABOOMS with factory ammo.

In every case the round had been chambered several or numerous times.

Just Google it.

[Bobshouse]

Sorry to bring up a old thread, but I figure it would be better to ask here than start a new one...

Now Im looking at CM40's. When I get one, Im probably gonna have to set up to reload and was wondering if the CM40 barrel fully supports the chamber. I don't want any "glock smiles" or weakening of the brass.

Appreciate the replies!

Bob