Crimp on semi-auto loads

[Stats Shooter]

I am somewhat new to internet forum discussions, and absolutely did not realize crimping in the hand loading world was such a controversial topic.

I appreciate the thoughts and information. But in the end, I guess do whatever works for you since you are the one who has to live with the results.

[JeepHammer]

I use the factory style crimp die from Lee also.
Supports the shoulder while crimping the neck.
MUCH more surface area on the shoulder than the mouth to get a good crimp.

I would like to see a 6 'Finger' collet crimp instead of 4,
But you get what's out there...

I don't recommend crimping a bullet that doesn't have a cannelure, deforms the bullet too much.
Since you can't order cannelure exactly where you want it, you are stuck with a cartridge over all length that works with the cannelure.

Not a huge issue with most range ammunition, but can be a pain in the butt when you are loading close tolerance ammo for a particular rifle.

[jmorris]

Since you can't order cannelure exactly where you want it, you are stuck with a cartridge over all length that works with the cannelure.

I have a cannelure tool from CH4D, with it you can put them anywhere you like.

[Gunplummer]

Never saw that before. I like the idea.

[Reloadron]

Pretty slick little tool.

Ron

[Stats Shooter]

That cannalure tool is slick..

Have you tested how it effects ballistic performance? Does it make much difference?

[mehavey]

I would note that such a tool is best used on rifle & revolver bullets

Semi auto pistols do not use a mouth crimp since that's where they headspace.
Nor (IMHO) will a "factory (aka swage)" crimp do much to solve poor neck
tension since it swages the bullet smaller right along with the case

[jmorris]

I'll be honest, I almost never use the tool, it was given to me.

About the only thing I have used it for is tube magazines or rather bullets used in them.

For the most part I use neck tension to keep the bullet where it should be.

It's pretty easy to test though, just load as normal, then chamber, eject and measure. Now fire a round, eject and measure. Repeat and measure, if they are not moving you are OK. If they are moving you cure the problem.

[hammer58]

I have been loading .308 for my AR and have been using the Lee Factory Crimp die. However, after reading this thread, I want to try some rounds without the crimp.

So my question is, how does one go about testing neck tension?

BTW, I am using Hornady Match 168 gr HPBT

[mehavey]

Two classic methods, both starting with using a Sharpie to draw a fine ring around the bullet right at the mouth after reloading:

- Using your hands only, firmly press the bullet into a hard surface like the side of your reloading bench. (Don't go crazy, just firmly press.)

........Has the Sharpie mark moved into the case?

- Load and cycle that bullet into the AR a few times.

........Has the Sharpie mark moved into the case?

[jmorris]

You don't need a marker, the calipers you set the OAL with will work fine to confirm the bullet has not moved.

[Clark]

Gunplummer
Never saw that before. I like the idea.

Reloadron
Pretty slick little tool.

Mississippi
That cannalure tool is slick..

It reminds me of my mother's can opener in the 1950s.

[Gunplummer]

I think I am still using that can opener.

[mehavey]

the calipers you set the OAL with will work fine...

Not necessarily -- especially when you have a deformable nose in ANY form (this includes SMKs if/when force is used -- ask me how I know.)

If you have a ogive comparator, fine.
But don't rely on OAL or you'll see changes that "aren't there."

[jmorris]

Not necessarily -- especially when you have a deformable nose in ANY form

Would a nose deformation not show up in an OAL measurement?

[Metal god]

Would a nose deformation not show up in an OAL measurement?

Yes it would and that's the point . If you have a bullet that has a length swing difference of .008 and you make all your cartridges the same COAL . You're just making the jump to the lands inconsistent or your cannelure to crimp inconsistent . Which would you rather have . A very consistent COAL or a very consistent jump to the lands ? I know which I prefer .

Although I note what my rifle loads COAL's are , I do not use that measurement in any official way . I set my seating dies ( all micrometers for rifle ) to my intended O-give measurement then check several cartridges to get my avg COAL for my notes .

In this picture you can see I note all three measurements COAL , Comparator measurement (comp ) and my seater die setting


When loading pistol I still use COAL most of the time . I recently had a 45 bullet that was all over the place when measuring COAL so I used a comparator measurement to set up the seating die for that bullet .

[SARuger]

I lightly crimp my Mini 14 reloads. I found the accuracy to be slightly better and very little chance of bullet jump at the end of a 30 round mag

[Average Joe]

I have the FCD so I use it. Never had a bullet slip out of the case during cycling either.

[DownInTheDark]

I crimp my 460 Rowland loads, for feeding reliability, that's about it for semi autos.