Plus, I've also learned with my .270 Win that neck tension is significantly more in a once fired case than in new brass. It takes a lot of force to remove the bullet. With adaquate neck tension, a crimp on the .270 Win adds nothing.

slimjim wrote:

Plus, I've also learned with my .270 Win that neck tension is significantly more in a once fired case than in new brass. It takes a lot of force to remove the bullet. With adaquate neck tension, a crimp on the .270 Win adds nothing.

Only thing I could think that it would add Slim would be probably the most important thing...consistency in neck tension, especially when fired.

Here are force readings to remove bullets extracted from .270 Win cases sized with a .302 neck bushing and no crimp.

Fired Brass
49 pounds - 150gr VLD
65 pounds - 140gr TSX

This is force applied at the handle with a mechanical advantage so the real force is maybe 3 or more times that? I don't think a crimp would even be noticable at those forces. Plus, for crimps to be consistent with my dies, all your cases have to be trimmed to the exact length ever time you load them, another variable I don't care to control to maintain consistent neck tension.

SJ, maybe you're looking at it differently than me. When you don't crimp you will have a much greater variation, going from very low (soft, fresh annealed necks) to rather high (hard necks). When you add a crimp there still will be varation, but in % it will be much less.

Example: say without crimp you get forces from 0,5 pounds to 2 pounds and with crimp you vary from 10,5 till 12 pounds. The difference between low and high is the same absolute, but in % there's a lot af difference between the first and the second set.

Ok, time to do a force test with and without a crimp.

Again, for a crimp to even provide consistency, your brass has to be trimmed to the exact same length.

I think we've discussed this before on here some time back and I was convinced at that time to start crimping my loads for auto-loaders. The concern was reducing bullet movement inside the case neck. Bullets could either be pushed back into the case by bumping in to stuff during the loading action or be pulled out of the case when the cartridge stops in the chamber, like an inertia bullet puller. I load .223 for an AR-15 and Mini-14 so I got a Lee Factory Crimp die. Did it make a lot of difference? I really don't know but I feel better doing it that way!

slimjim wrote:

Ok, time to do a force test with and without a crimp. Again, for a crimp to even provide consistency, your brass has to be trimmed to the exact same length.

I agree when you do a rollcrimp, but maybe you should read what Lee says about their factory crimp and I must say that I cannot tell you that they are wrong.
But maybe it's something for between the ears as Pumpkin says and when you have the opposit feeling who am I to make you spend some extra money (and extra time for this extra step in the reloading proces)

That lee factory crimper is a "collet" type of crimper that squeezes from the outside so to say.I have had mixed emotions about using some lee products in the past -but their factory crimper really works,and does'tnt cause shoulder or neck disfigurations on the case.Sure anybody can cause it to create "hourglass" crimps like aloys talked about-just use common sense and adjust it accordingly.The thingy works!

Also, don't crimp.

slimjim wrote:

Also, don't crimp.

Love ya like a brother Slim.

I didn't post that!

Do you blame me?

When you start your computer, do you often get the number 666 on your screen?

Aloysius wrote:

Do you blame me?

Not at all.

Back on topic, I may have to look at the Lee Crimp die. A collet type crimp sounds more effective and forgiving as well.

OK Boys Ive got some feedback. I pulled bullets from all 700 rounds, some of us learn the hard way. I ran 10 of the brass through a RCBS Small BAse resizer. I loaded to two differnt loads. 5 of 43 grns IMR 8208 XBR and 5 with 41 grns IMR 4895. IMR 8208 cycled perfectly. 4895 improved tremendously but had two ejection failures. I think it just didnt have enough power behind. I was still one hell of an improvement. GOing to load 5 more with 42 grns and 5 more with 43 grns. YAll have been great. I'll let you know how the 4895 rounds shoot tomorrow after I get back from the levee.

woohoo sounds like you are on the right track. so now do you think it was the dies ?or the powder charge??