Crimping a .223 cannalure bullet

[dradave]

Folks, I load .223 with 55gn FJMBT with a cannalure bullet. I have a few questions pertaining to crimping a cannalure rifle bullet.

Previously I loaded a hundred rounds of .223 at an OAL of 2.240 using Winchester 55gn FMJBT bullets with a cannalure using Lee dies and a Lee FCD as the crimping die. The problem at this OAL is that the cannalure, when seated, was above or just at the case mouth. The cases were trimmed to a length of 1.750. I shot these rounds and they were fairly accurate and cycled fine in my AR.

My question pertains to the cannalure and the crimp. The Lee manual suggests an OAL of 2.230 with my load of AA2230 @ 23.5gns. Even at this OAL the cannalure is just at the case mouth and not seated where the crimp would actually engage the cannalure.

The FCD crimp die came with the die set and is a collet type. Is it necessary that the cannalure of the bullet be seated inside the case mouth where the crimp would engage it (like in a roll crimp for a pistol round) or is it ok for the cannalure to be above the case mouth and the crimp engage the flat part of the bullet below the cannalure?

I'm assuming the length of the case plays a part as the cannalure will be in varying contact with the case mouth depending on the length?

Thanks...

 

[DANS40XC]

Ensure by taking a couple measurements of your sized necks & then with a bullet seated to verify that you have .003"-.004" press fit when seating naked bullets & forget about crimping bottle neck cartridges.

 

[cfullgraf]

The crimp is not necessary in the AR. Don't crimp and problem solved.

If you really must crimp, the bullet should be seated so the case mouth lines up with the cannelure.

 

[JimKirk]

As the guys have said ... if your neck tension is what it should be, then leave the crimp off. If it ain't then fix it ! Crimp pistol and revolver rounds leave the rest uncrimped.

Jimmy K

 

[MrOldLude]

With plinking rounds in my AR (basically the same as yours - AA2230, Winchester FMJ), I seat them to the cannelure.

 

[NCsmitty]

No cannelure crimp needed if your neck tension on the bullet is proper.
Case length is important only if you crimp with the bullet seating die.

If your Win FMJBT bullet is an open base with lead exposed, do not expect match accuracy. They do work for plinking though.
Commercial SP or HP will usually give you better accuracy than most FMJBT.



NCsmitty

 

[dradave]

Thanks for the replies. I wasn't sure if the crimp was necessary, I'll try not crimping and see if there are any issues.

Is it absolutely necessary that the cannelure be seated in the case mouth or is it okay to be above the case mouth with proper neck tension?

How do you determine if you have proper neck tension with the seating die?

Thanks...

 

[NCsmitty]

How do you determine if you have proper neck tension with the seating die?

With cartridge in hand, push against a solid surface, if it moves easily, then you need to spin sand the die expander button to .002" smaller than your bullet diameter.
If the bullet is hard to move, it's probably ok.
The cannelure position is irrelevant as long as you do not crimp and you are achieving the COAL that works for you.



NCsmitty

 

[dradave]

Thanks NCsmitty, you answered my questions. I've been loading .45 ACP for quite awhile but am new to rifle reloading.

 

[rcmodel]

All good advice.

I would suggest though, that if you are loading bullets with a cannelure, and do want to crimp, forget the suggested OAL measurement.

They are the correct length for that bullet when seated with the back edge of the cannelure inside the case so you can crimp into it.

If you notice, your Lee manual didn't bother to mention what brand of bullets they were talking about when they seated to 2.230".
And every brand of bullet will be just a little different nose shape, or have a slightly different cannelure location on it.

rc