I think this might be a dumb question, (again im new to reloading) but all the load books i read say only crimp bullets with Cannelure, but then on radom forums I see people saying you can put slight crimps on any bullet. Any conentional wisom on this?

I (most) only crimp cartridges used in tubular magazines and in heavy recoiling revolvers.

Mostly I don't crimp anything used in bolt action rifles and occasionally I do but then only into cannelures. I can find no reason to "taper crimp" any bullet.

So is taper crimping used to crimp bullets with no cannelures? And if so how do I tell the difference between dies that taper crimp and other kinds of crimp. What kind of crimp does a standard rcbs die do? I have a lee factory crimp di, I picked up for my .223 that says it neither roll crimps or taper crimps but uses a collet and it says it will form a cannelure in the bullet as it crimps it even it theres not one there.

Sorry for all the crimping questions, just seems all the load books I have don't spend a whole lot of time talking about crimping.

I relly don't plan on crimping most of my loads, but I wanted to for my mini 14 and my ptr-91 for reliablity. Ecpecially for my ptr cause it is very recoil heavy.

There are a number of terms used to describe crimpimg.

there is:
roll crimping (might be referred to as conventional crimping)

Taper crimpimg

Profile crimping.

I the last two are similar.
Taper crimping is used to straighten out the bell mouth yet leave a straight cased auto pistol round with enough case mouth edge to headspace.

Another form of crimping is accomplished with the Lee factory crimp die. I suppose you can crimp any rifle cartridge on any bullet with the Lee die but I would never use it like that.

I don't crimp anything just for the hell of it.
There has to be a very specific functional reason when I crimp.

1. Crimping into the cannelure on tube magazine rifles
2. Crimping in the the cannelure for autoloading rifles
3. Crimping revolver ammo to retain the bullets form recoil movement.
4. Straightening up the bell mouth in autoloading pistol rounds
5. Straightening up the bell mouth on cast bullet rounds for BPCR rifles.

The Lee factory crimp die is an excellent crimping die but I would never crimp a case into a non cannelured bullet. I have never heard of a bench rest shooter that would deliberately damage a bullet like that.

Well thanks for the info, that cleaered allot up for me. Like I said im really not wanting to crimp most stuff just for my semi autos. But it sounds like I should just start with a 55grn with cannelure and go from there. Nail driver accruacy isn't really the most important thing I was looking for for the mini-14 anyways being as its a pretty inaccurate gun in the first place its more just my shtf gun that I wanted to basically load a bunch of stock pile ammo for to get me more used to the equipment before I start loading for the guns I want more accuarcy out of. But I still want to load the most accurate yet reliable round I can for it, if that makes sense.

Thanks for the help though seems like if I went with a different bullet for better accuacy without a cannelure I would just loose the better accuracy from crimping it anyway.

Sounds like I got allot of experimenting to do which I look forward to...

1) Yes taper crimping is used to crimp bullets with no cannelures and auto loaders with cannelures.

2) Dies will be stamped "taper" for taper crimp.

3) Standard RCBS does roll crimp.

4) I don't use those Lee crimp dies. Don't understnd them. Sounds odd to me.

5) Don't appologize. Glad you joined.

6) Roll crimp carefully for cartridges that chamber on the mouth.

Thank you for the question.

I use a Lee Factory Crimp Die in every caliber that I can get them in. In tests I have done with identical loads except for the crimp, the LFCD has increased velocity an average of 10 fps and decreased group size an average of 1/8".

The Lee Factory Crimp Die does not need a cannelure and the trim length is not critical.

For me they work out well and they are cheap enough to try one and see if they work for you. Now I don't worry about my bullet moving either.

Saeed's crimping tests

Having shot service rifle competition for many years with M1 Garand and later with M1A, have loaded thousands of rounds of match ammo for use in these autoloaders w/o crimping. Also load for AR15 and do not crimp. Never had a problem w/bullets slipping in case necks.

The only rifle I have that requires a crimp is a 375 h&h which sometimes shoves an uncrimped bullet back into the case of the last round in the box magazine.

Used to have a couple of Winchester 92's & 94's w/tubular magazines that needed crimp, also.

Crimp if you like, but it is seldom necessary IMHO.

Regards,
hm

quote:

Originally posted by woods:
I use a Lee Factory Crimp Die in every caliber that I can get them in. In tests I have done with identical loads except for the crimp, the LFCD has increased velocity an average of 10 fps and decreased group size an average of 1/8".

The Lee Factory Crimp Die does not need a cannelure and the trim length is not critical.

For me they work out well and they are cheap enough to try one and see if they work for you. Now I don't worry about my bullet moving either.

Saeed's crimping tests

X-2

quote:

Originally posted by woods:
I use a Lee Factory Crimp Die in every caliber that I can get them in. In tests I have done with identical loads except for the crimp, the LFCD has increased velocity an average of 10 fps and decreased group size an average of 1/8".

The Lee Factory Crimp Die does not need a cannelure and the trim length is not critical.

For me they work out well and they are cheap enough to try one and see if they work for you. Now I don't worry about my bullet moving either.

Saeed's crimping tests

x-3

quote:

4) I don't use those Lee crimp dies. Don't understnd them. Sounds odd to me.

It's a collet die just like a collet in a lathe.
As the case pushes up on the collet, The collet collapses around the case and bullet but only at the neck with in say .030" of the case mouth.
Lee promotes it because there is little downward force applied to the case neck. the collet squeezes relatively evenly around the diameter only.
The roll crimp and taper crimp are applied by running the case into the die and forcing it into a smaller diameter( taper) or into a roll form In these there is a lot of downward force on the case mouth. Which is why it is easy to foul up a case by over crimping with a taper or roll crimp.
Personally I like the Lee factory crimp

I do use a Lee crimp die for 22 Hornet loads and accuracy has improved, in conjunction with using Lil-Gun powder and small pistol primers.
I haven't seen any need to crimp other cartridges as accuracy I get without crimping them is very good.
Might just have to do some testing as Woods has done after the snow goes... There's always room for improvement.

Don

Thanks allot for all the info, seems like I found a great community with lots of knowledge on reloading.
Im going to do some test rounds of different grains all with and without the crimp by the LFCD and see what i find. I took apart a ultra max .223 round last night and it was crimped without a cann ring in it so I dunno. My issue with the can ring is that there seem to be hardly any selection in bullets for the .223 that have it, I'll try the 55grn horndy sp with it try some without.

This is what i looked most foward to about stating reloading is the great excuse to get out to the range more often to test my loads.

The Lee Factory Crimps will work best if you do not crimp into a cannelure.

I use a taper crimp on my revolver rounds to minimize brass working. Will a Lee Factory Crimp Die improve the performance of my loads in any significant way while reducing the working of the brass?

I'd say the only way it would improve your rounds is to provide a more consistent crimp and it will work the brass less with less chance of damaging the brass