Chamfer case mouth

[deputy bruce]

I was just wondering if small chamfer on the
case mouth on 5.56 brass would take away the strength of the case being it is so thin? Just had a thought.

 

[LiveLife]

When you trim resized .223/5.56 cases to length, you are supposed to chamfer the inside/outside of the cut case mouth to deburr the sharp edge and to allow the bullet to slide into neck during seating.

 

[.38 Special]

Chamfer for sure. Otherwise you're likely to end up with scraped bullets (and bullet scrapings in your die) along with uneven bullet pull, round-to-round.

 

[GeoDudeFlorida]

I was just wondering if small chamfer on the
case mouth on 5.56 brass would take away the strength of the case being it is so thin? Just had a thought.

Just make sure you understand the difference between a chamfer and an inside-diameter bore. Some folks get a leeeeetle carried away with their chamfering tools.

 

[whughett]

Amazon carried a case debuting tool. Many guys just use a pocket knife. As noted your only removing burrs. Haven’t loaded rifle in many years but I seem to recall the deburring was only needed primarily after trimming to length.

 

[AJC1]

This is one of the hand loading routines I believe is overdone a lot. One twist by hand is plenty. I prefer a vld style but even a countersink tool works just dandy. More is not better.

 

[.38 Special]

Amazon carried a case debuting tool. Many guys just use a pocket knife. As noted your only removing burrs. Haven’t loaded rifle in many years but I seem to recall the deburring was only needed primarily after trimming to length.

I often find it necessary with new brass as well. But yes, it easily can be overdone, and it certainly does not need to be done after each firing.

 

[kalielkslayer]

I do it with a Franklin Arsenal case trimmer, only when I trim cases.

1 second on the outside and one second on the inside.

I do run my thumb over the outside. If it has any burrs, I do both again.

 

[Walkalong]

All you need to do is knock the 90 degree edge off, especially after trimming, but even if you over do the chamfer/deburr operations, it won't be hazardous.

 

[Reloadron]

I was just wondering if small chamfer on the
case mouth on 5.56 brass would take away the strength of the case being it is so thin? Just had a thought.

As mentioned don't confuse neck turning where we remove case neck material from case neck down to the start of a shoulder on a bottle neck case with case mouth chamfering or deburring.





All we are doing is cleaning up the case mouth. This makes loading, especially flat base bullets much easier. As walkalong points out removing the 90 degree flat after case trimming. Neck turning is a different ballgame where we remove material from the OD or ID of the case neck and normally done for tight neck chambers.

Ron

 

[buck460XVR]

I was just wondering if small chamfer on the
case mouth on 5.56 brass would take away the strength of the case being it is so thin? Just had a thought.

The amount of area the chamfer covers on the case neck is pretty insignificant, especially if it is done correctly. Nor will it diminish enough neck tension to make a difference. I've found that a proper chamfer makes so one does not need as much flare/bell on the case mouth to start a bullet, thus it actually adds to neck tension. Some folks claim a chamfer can actually increase the holding power of a proper roll crimp.