Crimp in the lube groove?

I have a question. There’s a bullet I’m looking at and I’ll just say it’s noe version 379449 and it has many lube grooves. This is a good question because I never thought of a rational answer but do you gentleman sometimes crimp into a lube groove or do you just apply the crimp on a location somewhere on the drive band? My 45-70 I have a mold that I crimp onto the driveband lightly as to just keep the bullet from setting back but I was wondering what do you do?

Crimp in a lube groove. I do it when I use that bullet in 375 Win.

Any of the above, or none, depending.

I try for a groove, or just put one where I want it, or taper crimp.
sometimes you have to take what you can get.

Amen

If you are shooting the heavier loads in a lever gun and want them in the magazine..... You will have the most dependable loads by crimping the '449' in the top lube groove. You want the brass to crimp in just at the top of the groove to shoulder in and prevent the bullet from receding back into the case from heavy recoil while it rides it out in the magazine....... Ask me how I know.

If nose length with the '449' was too long to function this way (which may come up) I would shorten the nose length making a more WFN design before I would put the bullet into a 'mousey' crimp situation and then has Murphy's Law show up right along with a shot of a lifetime.....

Pete

I use the 375449 and crimp up top too.
I also don't fill all the grooves with lube.

Yep, I just lube the bottom two grooves.

Because I use 45-70 bullets sized down to .454 or .452 in the 454 Casull and sometimes lighter 300 grain in 45 Colt heavy loads I often end up mucking around with seating depth and crimp location to get them to fit when working up a load. I usually shoot for a lube groove if I am seating out long, if I am seating in deep I try to crimp in the ogive right where it is about the same diameter as what a crimp groove would be. This works because the load is already compressed with a lot of case tension so the bullet gets held between the crimp and the powder even under very heavy recoil. In some other bullets I have that are 350 grain, the crimp groove for 45-70 works great for 454 Casull once it is properly sized. What I really need to do is get that same mold in .454 so I don't have to step down size so many times from the .460 that it currently drops at. Right now I go 460->459(lube at first size step)->458->457->454->452. Every step after the first is done in a nose first sizer a friend made for me that takes Lee push through dies(picture attached). Still takes a while but I elk and deer handgun hunt with this bullet quite a bit so it is worth it.

In 30 Carbine I have to seat the bullet I use on the front driving band and taper crimp, but there is so little recoil and it is a revolver so I don't worry at all about the bullets creeping. There is a lot of neck tension in that load too, so I doubt if it would creep in that gun even if I didn't crimp. The crimp is really there for better powder burn in that load.

AndyTheCornbread said:

The crimp is really there for better powder burn in that load.

Click to expand...

I posted the following in another thread last month. The purpose of this testing was to show the effects of various crimps from NO crimp at all to a hard crimp.

Rick said:

I've posted these results several times in the past several years, it serves to quite clearly show that the crimp has little to do with consistent ignition. One thing all five of these tests have in common is consistent neck tension. Some are carbide die sized, some are not sized at all. Some have a roll crimp, some have a profile crimp and some are not crimped at all. 44man was right, straight wall handgun ammo accuracy is all about consistent neck tension. That means brass fired the same number of times and not so many times the brass has lost it's elasticity, all sized identically.

Crimp Tests​

FA 357 Mag 9”
RCBS 180 GC Silhouette @ 192 gr. (WW +2% Sn HT @ 18 BHN)
16.0 gr. H-110
Winchester brass
CCI 550 primer
Temp 70 Humidity 38%
January 29, 2008

All chrono tests 10 shots
​

1> My normal profile crimp, second firing of WW brass, Carbide die sized
E.S. 30
A.V. 1518
S.D. 9

2> Roll crimp, second firing of WW brass, Carbide die sized
E.S. 30
A.V. 1520
S.D. 9

3> No crimp, second firing of WW brass, Carbide die sized, very slight bell
E.S. 30
A.V. 1528
S.D. 9

4> Light profile crimp, virgin WW brass, not sized, not expanded, slight bell only
E.S. 26
A.V. 1532
S.D. 8

5> My normal profile crimp, virgin WW brass, not sized, not expanded, slight bell only
E.S. 26
A.V. 1536
S.D. 8

Click to expand...

I guess better burn would have been a more accurate way to put it. I use 4227 in the 30 Carbine and without a hard taper crimp I end up with a lot of unburned powder or filler or whatever it is in 4227 that doesn't get burnt up at lower pressures. I am shooting them from a Blackhawk so those granules tie up the cylinder eventually if I don't heavy crimp and the load uses a slightly heavy for caliber bullet as well(125 grain). Doing that I get complete burn and no little granules laying around. 30 carbine isn't straight wall, it is a double tapered cartridge.

That Green Smasher looks really handy!

it looks like a reversed C&H swage press.

I don't know what a C&H press looks like. I'll have to google it. A friend of mine is a machinist who builds race cars as well as a bunch of other types of custom machining stuff. He shoots a lot of cast and needed a press for nose first sizing for something he was doing. He cast these up from melted down car parts of some sort and asked me if I wanted one when he was done getting them working the way he wanted. If he ever makes more I will buy a couple more off him. They are super handy.