Cannelure not right for a cartridge

[mgstucson]

Just a little perspective on size. The bullet in the Ultimate Cannelure Tool II Stretch Frame Version is a factory Hornady 50bmg (510 caliber) 750gr A-Max bullet. This bullet is made with ultra long ogive and a precision aluminum ballistic tip and boat tail base. These characteristics are to maximize velocity retention and maximum distance in hypersonic (i.e. stable) flight. They also make the bullet VERY LONG for weight. My calipers have the OAL of this bullet at 2.56", just a fuzz longer than a 458 WM CASE length. These bullets are commonly used in the King of 2 Mile Competitions where targets are shot on timed intervals starting at 1 mile, then 1.5 miles, then 2 miles with the 50bmg rifle.

First picture is the UCT in normal mode with both left and right precision bullet placement screws in place, and the wheel horizontal adjustment roughly in the middle of the tool. The A-Max bullet is just placed on the base of the tool for size perspective.

Second picture is the left bullet placement screw removed (sitting on left edge of tool just for visual information) and the right bullet placement screw is adjusted all the way to the right. (UCT is the only cannelure tool with two, left and right, bullet placement screws. CH has none, and Corbins has one.) The A-Max bullet is on the rollers ready to be cannelured. Notice the wheel horizontal adjustment has been moved all the way to the right to compensate for the long ogive on the bullet and the relatively small bearing surface on the right half of the bullet in the picture.

Last pic is my son sighting in my 50 bmg at Christmas 2024. He loves to shoot it.

 

[Monski]

Great thread! I must get a cannelure tool. Interesting on how to eliminate the neck flare out. I loaded some swift solids in the past in 505 Gibbs and they didn't have a crimp groove. Despite a LCD in that caliber, they were easily set back under recoil. I don't like that!

 

[metricman]

For common cup and core bullets, like common pistol bullets, the CH tool and Corbin tool can work, but when you get into the world of premium rifle bullets, you will have thicker bonded jackets, harder alloys, sometimes steel on solids. Solids may also contain high antimony alloy lead which may also have been hardened by quenching in the bonding process. On these bullets, the CH and even the Corbin tool will need to be modified by lengthening the handles.

Below is a picture of the Ultimate Cannelure Tool next to the Corbin Cannelure Tool. The length of the pressing handle and length of the turning handles are where leverage comes from. Leverage is power and equals depth and ease of proper cannelure. You could take a 1"x2"x12" length of hardwood and drill and screw it onto the Corbin handle and get good leverage, but you might damage the body of the tool because it is only stamped steel sheet metal.

View attachment 662356

The picture above is the first version of the UCT and had a round knob for a handle. After feedback from early users like me and others, they changed the design, making it wider to handle long rifle bullets, and changing the handle effectively almost doubling the leverage. The UTC body was also precision machined from aircraft grade aluminum to withstand the forces generated. The result was the UTC II pictured below.

View attachment 662357

The 2 bullets pictured below are premium solids 50 caliber 400gr. I got quite the deal on these because they had no cannelure, and were practically useless in the heavy recoiling firearms for which they were intended because no crimp would hold, not even with a Lee factory crimp die. I know because I tried. Even the Corbin tool although helpful (with great effort/pressure exerted in the handles and MANY turns of the wheel.) Then I tried the UCT I with the round handle. Better, but still not great. Then with the UCT II finally got a great crimp without having to try to muscle the tool around.

The first picture was a bullet crimped with the UTC I. Note that tool has more that twice the leverage of the Corbin tool, and 3x to 4x the leverage of the CH tool. Enlarge the image and note the depth of the cannelure.

View attachment 662358

This next picture was the same type bullet cannelured with the UCT II tool, with nearly twice the leverage of the UCT I tool. Notice the increased depth and uniformity of the cannelure.

View attachment 662359

This quality is the only cannelure I would trust on a safari, especially for DG. I only trusted this crimp when used with a factory crimp die.

You can produce factory or better quality projectiles and cartridges at home, but only with meticulous attention to detail, and proper tools. If you don't have those, better buy premium factory rounds.

very enlightening. i have the ch tool so guess i'm out of luck with the more heavily jacketed bullets as i doubt the tool will take the increased leverage you describe

 

[mgstucson]

@metricman, The pressure lever pivot pin and the knurling wheel pivot pin are only supported on one end. This means under increased pressure they will tend to deflect, if not permanently bend. So I would say your assessment is probably correct. I certainly would bow to your greater experience with the device. I bought a used Corbin tool off fleabay at a good price as my first cannelure tool. As soon as I saw the UCT being advertised on a bullet swaging forum, I jumped on it because of the obvious precision and mechanical leverage advantages. The UCT was collaboration between a retired aircraft machinist and a retired marketing guy. They sold them for a few years, then I think they moved on to more fun retirement pursuits. There was another retired machinist on that forum site that said he was going to start building similar units. That was about 6 months ago. If the new ones actually go up for sale, I will let everyone here know.