Double cannelure

cptmclark · October 16, 2007, 09:24 PM

I have some Hornady 300 grain 44 bullets with two cannelures. I can't find any info in Hornady's manual or elsewhere on bullet seating of those. I plan to shoot these in a rifle, and thinking longer is better if the leade allows. Are they intended to be loaded long for some applications?
Oh yea, my plan is for the 445 supermag, and to use the 44 mag loads as well. Any favorite rifle loads for that number?

swmike · October 16, 2007, 09:40 PM

The only bullet I have seen with a double cannelure is a .308 that was designed to be loaded as either .30-06 or 7.62 Nato. The rounds have different OAL's and since the bullets were military, designed to be shot in Auto-Loaders thus the cannelure for both lengths. Just use the one that comes close to your desired OAL.

tarheelshooter · October 17, 2007, 08:05 PM

http://www.midwayusa.com/eproductpag...212&t=11082005Try this link and read the reviews and technical specifications. I have some on the reloading bench but have not loaded any yet.I plan to use them for a 444 Marlin.If you come up with some good loads for the 444 or a 44 magnum,please send them my way.

cptmclark · October 19, 2007, 08:24 PM

I will. Also I would really like to be able to load the long loaded 445 supermag in the marlin 444 rifle. Some say it's too short to cycle and too long for the 1894. So it's a single shot operation now.

imdarren · October 20, 2007, 01:15 AM

Clark,
I cant speak for using them in a rifle, but some of us crimp in the lower / second cannelure when loading really hot loads in modern revolvers with longer cylinders IE: Ruger Redhawk, Freedom Arms, you can fit in more powder this way.
Don't try this in older guns however.
In a rifle, you would want to make sure you that if you do crimp in the second cannelure that the C.O.L. is not too much and have a problem with the bullet jamming into the lands / rifling when you chamber a cartridge.
Load a dummy round WITHOUT a primer or powder in the second cannelure and see if it cycles ok, or gets stuck when you try to eject the round. Some folks mark the bullet with a black felt tip to see if the rifling scratches through the black on the bullet. Then you know it's too long.

D

MotoIdaho · January 10, 2008, 01:15 AM

I have a box of Hornady .38 cal. 180gr. XTP that I'm reloading in .357 for hunting. My gun is a 6" GP100. This bullet has a double cannelure. I have not had a chance to test which is correct for COL.

If the cylinder is long enough is there an advantage to using the second cannelure even if I don't need it for powder capacity? Perhaps shorter jump to the barrel? I'm going to start with Lil'Gun so the case will fuller than empty.

cptmclark · January 10, 2008, 10:17 AM

The second cannulure, according to HornadyCS (not written anywhere I can find) is for stretched "supermag" cartridges, in my case the 445 SuperMag. The longer loading is allowed by the longer cylinder of the supersized caliber. I'm guessing that the second one on your 357 is for the 357 Maximum.
The benefits are to increase your case capacity and also to reduce the jump to barrel. I'm not sure how much it helps accuracy in a revolver, where there is a big jump anyway, like the good results we get shooting 38 in the 357s for example.
In my case, I'm shooting these in a rifle with a very long throat, and so want to reduce the jump to near zero if possible. I've also now tried seating bullets way long and not crimping them (single shot). So far there has been no accuracy benefit to this, probably because there's not enough bullet in the case for a hard pull on ignition.
Of course you'll get more velocity with the larger case capacity, but that requries loading with data for the extended caliber. In your case, someone suggested loading a dummy and seeing if you have room in the cylinder. Probably not, I'm guessing. Remember youre changing the internal geometry by lowering?? pressures. ??"? is because some manufactures like for Win 296, say that you can get high pressures by too little powder. I'd recommend sticking to the recommended overall cartridge length, unless you keep in mind that you're wildcatting if you change things without data.

MotoIdaho · January 10, 2008, 01:31 PM

If there is no space problem with the 13-15 gr. of LilGun I'm inclined to use the forward cannelure and standard COL.

Thanks for the info...

October 16, 2007, 09:24 PM	#1
cptmclark Senior Member Join Date: November 22, 2004 Location: Indiana Posts: 432	Double cannelure I have some Hornady 300 grain 44 bullets with two cannelures. I can't find any info in Hornady's manual or elsewhere on bullet seating of those. I plan to shoot these in a rifle, and thinking longer is better if the leade allows. Are they intended to be loaded long for some applications? Oh yea, my plan is for the 445 supermag, and to use the 44 mag loads as well. Any favorite rifle loads for that number?

October 17, 2007, 08:05 PM	#3
tarheelshooter Member Join Date: December 20, 2006 Location: NC Posts: 28	Try this http://www.midwayusa.com/eproductpag...212&t=11082005Try this link and read the reviews and technical specifications. I have some on the reloading bench but have not loaded any yet.I plan to use them for a 444 Marlin.If you come up with some good loads for the 444 or a 44 magnum,please send them my way. Last edited by tarheelshooter; October 17, 2007 at 08:07 PM. Reason: Wrong link

October 19, 2007, 08:24 PM	#4
cptmclark Senior Member Join Date: November 22, 2004 Location: Indiana Posts: 432	loads I will. Also I would really like to be able to load the long loaded 445 supermag in the marlin 444 rifle. Some say it's too short to cycle and too long for the 1894. So it's a single shot operation now.

January 10, 2008, 01:15 AM	#6
MotoIdaho Member Join Date: December 2, 2007 Location: Boise, ID Posts: 25	Hornady .38 180gr. XTP for .357 I have a box of Hornady .38 cal. 180gr. XTP that I'm reloading in .357 for hunting. My gun is a 6" GP100. This bullet has a double cannelure. I have not had a chance to test which is correct for COL. If the cylinder is long enough is there an advantage to using the second cannelure even if I don't need it for powder capacity? Perhaps shorter jump to the barrel? I'm going to start with Lil'Gun so the case will fuller than empty.

January 10, 2008, 10:17 AM	#7
cptmclark Senior Member Join Date: November 22, 2004 Location: Indiana Posts: 432	2nd cannulure The second cannulure, according to HornadyCS (not written anywhere I can find) is for stretched "supermag" cartridges, in my case the 445 SuperMag. The longer loading is allowed by the longer cylinder of the supersized caliber. I'm guessing that the second one on your 357 is for the 357 Maximum. The benefits are to increase your case capacity and also to reduce the jump to barrel. I'm not sure how much it helps accuracy in a revolver, where there is a big jump anyway, like the good results we get shooting 38 in the 357s for example. In my case, I'm shooting these in a rifle with a very long throat, and so want to reduce the jump to near zero if possible. I've also now tried seating bullets way long and not crimping them (single shot). So far there has been no accuracy benefit to this, probably because there's not enough bullet in the case for a hard pull on ignition. Of course you'll get more velocity with the larger case capacity, but that requries loading with data for the extended caliber. In your case, someone suggested loading a dummy and seeing if you have room in the cylinder. Probably not, I'm guessing. Remember youre changing the internal geometry by lowering?? pressures. ??"? is because some manufactures like for Win 296, say that you can get high pressures by too little powder. I'd recommend sticking to the recommended overall cartridge length, unless you keep in mind that you're wildcatting if you change things without data.

October 16, 2007, 09:40 PM	#2
swmike Senior Member Join Date: June 25, 2005 Location: Marysville, WA Posts: 670	The only bullet I have seen with a double cannelure is a .308 that was designed to be loaded as either .30-06 or 7.62 Nato. The rounds have different OAL's and since the bullets were military, designed to be shot in Auto-Loaders thus the cannelure for both lengths. Just use the one that comes close to your desired OAL.

October 20, 2007, 01:15 AM	#5
imdarren Senior Member Join Date: April 21, 2005 Location: Washington State Posts: 164	Clark, I cant speak for using them in a rifle, but some of us crimp in the lower / second cannelure when loading really hot loads in modern revolvers with longer cylinders IE: Ruger Redhawk, Freedom Arms, you can fit in more powder this way. Don't try this in older guns however. In a rifle, you would want to make sure you that if you do crimp in the second cannelure that the C.O.L. is not too much and have a problem with the bullet jamming into the lands / rifling when you chamber a cartridge. Load a dummy round WITHOUT a primer or powder in the second cannelure and see if it cycles ok, or gets stuck when you try to eject the round. Some folks mark the bullet with a black felt tip to see if the rifling scratches through the black on the bullet. Then you know it's too long. D

January 10, 2008, 01:31 PM	#8
MotoIdaho Member Join Date: December 2, 2007 Location: Boise, ID Posts: 25	If there is no space problem with the 13-15 gr. of LilGun I'm inclined to use the forward cannelure and standard COL. Thanks for the info...