Why doesn't the canalure agree with the COL distance?

[mugsie]

I'm doing some of this from memory but I'll try to explain the problem. I'm loading .223, but this happens on other rounds as well. In the case of .223, I'm loading a Remmington 62 grain HPBT which has a cannalure on it. The Speer manual tells me to load this to 2.255 (memory part). I do and when I look at the round, the cannalure is approx .080 above the mouth of the cartridge. (the Speer manual is for an FMJ bullet and I'm using a HPBT but the cannalure is not even close to the mouth). When I set the crimp, I'm using a slight taper crimp, it's well below (Approx .080) the cannalure and not into it. I've noticed this problem on pistol rounds too occasionally - mostly with Remmington bullets with cannalures. I would think the cannalure is there for the crimp, but if I seat the bullet to the cannalure I'm thinking it'll be seated too deep. Any ideas?

 

[Sunray]

"...the cannalure is there for the crimp..." It is, but that doesn't mean you have to seat to it or crimp at all. You can forget the cannelure and crimping altogether.

 

[GunAdmirer]

I've wondered the same thing. I crimp to the cannelure when needed and keep my loads reasonable to account for the usually shorter OAL.

 

[Car Knocker]

The same bullet may have to fit multiple cartridges. For example, the same .308 bullet can be used in .30-30, .308 Win, .300 Mag, .300 Whisper, 7.5x55 Swiss, .30-06, .300 Savage, 7.5x54 MAS, .307 Winchester, .300 RUM, .300WSSM, .300 Weatherby Mag, etc, etc.

Cannelures are just an approximation and use thereof is usually not a must.

 

[Steve C]

You are using Remington bullets not Speers so its no big surprise that the cannelure on the Remingtons do not match the case mouth at the OAL specified in the Speer manual for their bullets. If you where using Speer bullets then there would be some question as to why the cannelure doesn't match the case mouth.

IMO people fuss too much about OAL. Seat the bullet where you want and use the cannelure if you want. The only OAL measurement that's important is if its below the maximum and will the ammo operate in your rifle. Work loads up and if a shorter OAL is going to increase pressure significantly and cause problems you will see the signs before you reach the maximum charge but certainly not at start loads. Generally the most accurate load is somewhat below max charge anyway.

 

[Steve Koski]

Yeah, what Steve C said!

 

[mugsie]

Thanks

Thanks guys. I thought that was the case as stated above. As long as the COL isn't too long or too short it'll be OK. They shoot fine so I guess that's the final proof.
Thanks again....

 

[The Bushmaster]

Crimp at the cannelure and forget OAL...I have yet found a cartridge crimped at the cannelure too short or too long. A bit short? Yes. A bit long? No...But nothing that will do any harm...

 

[45crittergitter]

Crimp at the cannelure and forget OAL...I have yet found a cartridge crimped at the cannelure too short or too long. A bit short? Yes. A bit long? No...But nothing that will do any harm...

Au contraire: I once loaded some .348 Win ammo in SAAMI-length cases and crimped in the cannelure. As everyone knows, .348 bullets are pretty much only used in .348 Win ammo, which in turn is pretty much only used in Winchester/Browning Model 71 lever action rifles, so such a load should have been pretty much perfect. Crimping in the cannelure resulted in rounds a bit too long, and were longer than advised by the bullets' manufacturer's reloading manual. The result? When loaded in the magazine, they tied up the rifle because they would not feed through the action. Big pain in the butt to fish them out through the loading gate.

The cause? Cannelure was mislocated, according to the manufacturer. Apparently something got out of adjustment at the bullet factory. The lesson? Check everything when loading any first-time component, and only load one round in the rifle to begin with.

 

[fmnnc]

"...the cannalure is there for the crimp..."

The first time I tried to load .223 to the maximum cartridge length (trying to duplicate a factory load) the cannalure ended up well above the end of the case. I always thought the cannalure was just for the crimp also until I got to scratching my head and found this:

Cannelure: Circumferential groove(s) around a bullet or cartdridge case. Used for identification, to hold lubricant, or to crimp cases into.

Taken from page 722 of Speer #13

The learning never stops....