To Crimp or not to crimp cannelure and purpose?

Status
Not open for further replies.
N

ninosdemente

New member
When I first started buying equipment for reloading I had purchased a box of 100 - 30 Cal Hornady 150 gr FMJ-BT. Never reloaded it but had other projectiles without cannelure I reloaded. This has a cannelure. Now that I am doing more reloading, am more confident now I want to load this projectile. I made a dummy round and it is not crimped.

Do all projectiles that have cannelure always have to be crimped? From what I read and seen on videos all mention its for having grip. But is there another purpose to it? Are these type popular as I don't see much of these styles in the shelves at Cabelas. I mostly buy reloading items from here.

Here is my dummy round with no crimp.
http://mentegraphics.com/pictures/90.jpg

By the way it measured at 3.1700" in case you are wondering.

Due to my inexperience with crimps, I avoided projectiles with cannelure. This box was purchased as it was on sale at 25% off at the time of purchase many months back.

I had purchased these as at that time I only had a 30-06 hunting rifle and wanted to use it for target shooting also. But now I have other rifles and are easier on my shoulder. LOL. But now don't want to have these go to waste.

Thanks for the help.
 
From your length, i'm guessing 30-06?

Just because the bullet has a cannalure does not mean you need to crimp.
Best places for crimp are
1) semi-auto
2) lever guns
3) pump guns ( i prefer to )
4) really hard recoiling guns(more than 06)
5) monolith bullets.
 
What std said, plus, you do not have to use the cannelure as a seating guide either. It can be longer or shorter to suite your requirements.
 
Sometimes a caneleure can be about helping to lock the jacket and bullet core together.
You are asking about a 150 gr FMJ 30 cal,which is typically used in 308 or 30-06 military rifle applications.Its not typically used as a hunting bullet.

There is a concern that in the feeding process of a semi-auto military type rifle or even a machine gun the bullet might snag up on something and be forced deeper into the case.Thats not good.

Crimping is an answer to that problem if you need it.If you don't have the problem,its unnecessary .

A crimp needs a compressible zone on a bullet to crimp into.The knurling provides that.
Do as you please.Myself,I avoid crimping unless I have a reason to crimp.

Generally,that comes down to handgun ammo,usually for revolvers.
 
Thanks guys for the help.

This bullet in particular bullet I am not using for hunting. I had purchased this when at the time I only had the 30-06 rifle and was going to use it for hunting and target. Hunting was the main reason why I got it. But as time passed by before I started loading I had already obtain two other rifles that I prefer to shoot instead of the 30-06. But since I have these, well now I have to use them.

This is going to be used on a bolt action.
 
Your call

The 150 FMJ's will really only serve to punch paper, deer and elk are not signatories to the Geneva convention.
From what I read the USA is not a signatory anyway.....so carry on.

Now we know why you got them on sale....
 
I cannot speak to cannelure. I don't do it myself. Range brass that has been cannelured typically goes in my scrap, trade, or swage piles.

As to crimping, I load a significant amount of cast and swaged rounds. So I tend to flare my cases in my turrent before seating the bullet - then I crimp after seating the projectile.

Especially on the cast lead rounds, this case flare prevents the case from scraping off lead from the cast projectile. It's rare for all the dies and press pieces to be dead on precise which is why there is a tiny bit of give in the dies to allow stuff to self center. This means, with lead rounds you usually end up with lead scrapings if you don't flare your brass a bit. Even though I size my castings AND ever so slightly bevel the butts of the flat castings, I still get lead shavings if I don't give the case a good flare.

The crimp does 2 things for me in that it removes my case flare and ensures a tighter seal around the bullet always giving me a firm hold on the projectile and what will end up being a tighter more moisture / weather resistant seating.

This process will shorten the life of my pistol brass - so be it - the crimp gives me better outcomes.
 
First 3 replies are 100% correct. Since they are Hornady bullets, seat the bullets to Hornady's suggested OAL and disregard the cannalure. In the future if you feel the need you can tweek the seating depth to fit your gun "better"...

A cannalure on a case is a whole different animal... :rolleyes:
 
The original reason for the case cannelure was to aid in preventing bullet set back in a semi-auto that head spaces on the mouth of the case. These cannot be crimped, thus the case cannelure.

While I am at it, those FMJs that you have are good for turkey shooting. They don't destroy much of the bird. They are legal for that here, I am not certain about other states.
 
Taper crimp all my 45ACP. Even the casings that have the cannalure.
If your shooting semi auto pistol, you'd better be crimping! Slight setback of the bullet on the small case volume significantly raises pressures!
 
Different crimps for different purposes.

Revolver ROLL crimp,helps keep bullets from pulling out of the case under recoil and aids in ignition.

Remember,some ammo gets loaded in lever action or other repeater tubular magazines. Case cannelures help against recoil in the magazine tube.

Taper crimp is used for cartridges that headspace on the case mouth and need to resist setback during cycle.

Any crimp can be used to just smooth down the bell.

If you meaure a taper crimp at .010 smaller than case mouth diameter,you have crimped into the bullet approx .005 per side,or you have thinned the brass .005 per side. That .010 went somewhere.
 
Last edited:
A case cannalure is originally meant to prevent bullet set back, but I have a bunch of 38 Specials, 357 Magnums that have case cannalures and if I recall correctly so does some of my 45 Colt brass (not a semi-auto cartridges). I have my brass out in my shop so I can't say for sure if any other revolver cased have cannalures.

ninosdemente, as mentioned earlier, bullet cannalures can be crimp locations and bullet construction (locking jacket to core).
 
I have some .38 Spl brass that has a double cannelure. two rings, a short distance apart, approximately in the middle of the case. On those cases, I believe that they are for identification, not for a mechanically functional reason.

But that's just a guess.
 
I have some .38 Spl brass that has a double cannelure.
Click to expand...

Did you mean bullet ? If bullet , I heard they are there for the two different cartridges they can be loaded for . 38spl uses the bottom groove and 357 uses the top groove . Same with 44spl and 44 mag .

I have some 180gr 38/357 bullets that show on the box there are two grooves but the bullets inside only have one .
 
I have some .38 Spl brass that has a double cannelure. two rings, a short distance apart, approximately in the middle of the case. On those cases, I believe that they are for identification, not for a mechanically functional reason.
Click to expand...

I have some of those too. They are factory, and have wadcutters in them.

They were made for auto loaders and target shooting. The S&W M52 comes to mind.
 
"...Best places for crimp are..." The only place a crimp is necessary, cannelure or not, is in a lever action and a cartridge with heavy recoil. Semi-auto's and pumps don't absolutely need a crimp.
"...and aids in ignition..." Crimping does nothing for ignition. The powder will ignite or it won't with or without a crimp. Crimping is detrimental to accuracy though.
"...Range brass that has been cannelured..." It's done in the factory. Nothing wrong with it. Other than cosmetically.
3.1700" is too short for .30-06. Load it out to 3.340". That's the SAAMI max.
 
Status
Not open for further replies.
Back
Top