Chamfering by hand causing runout?

[dboyles]

Any of you fellows ever found chamfering by hand to contribute to bullet runout? I usually use a light touch with the chamfering tool, and typically use just the standard RCBS "rocket ship" tool, but for one reason or another I recently loaded a small batch that I used a Sinclair VLD chamfering tool to give a pretty strong chamfer. Runout seems to have increased overall, but especially on the extreme end, where I'm seeing .004-.005" of runout on a few of the rounds (usually .003" is the worst I'll get). Seating was done with a Wilson hand die. Just curious if I should invest in a chamfering bit for the Wilson trimmer.

 

[Immike]

I have found that runout is usually a die and brass problem. I still deburr my brass by hand because I enjoy doing it even though I have what I need for the wilson. I have found that either a die makes straight necks or it won't and rotating the brass doesn't seem to fix it. One thing I have found is the shell holders causing some of the trouble. I tried the shell holder in several locations and was able to make an improvement on a die that was at. 003 out and brought it down to. 001 on turned brass.

 

[thefitter]

This is something I too have wondered about, but never really looked into. I don't chamfer by hand I use a Hornady machine. And I have since gone to using a LCD as the last step before loading.

 

[dboyles]

I typically use the LCD as well, but this time around I grabbed the Redding bushings, and that may have contributed to my slightly larger-than-normal neck runout. With the LCD my necks are rarely off more than .001". But even with that considered, the bullet runout is higher than expected:

I did the colors so I can segment both batches of 10 by best and worst runout (5 shot groups) and see how drastic the effect is on paper.

 

[drumcorpschamp]

OK guys, what's an LCD?

 

[jonbearman]

Lcd,now thats a new one like IIRC.

 

[kelbro]

Lee Collet Die

 

[Shynloco]

Any of you fellows ever found chamfering by hand to contribute to bullet runout? I usually use a light touch with the chamfering tool, and typically use just the standard RCBS "rocket ship" tool, but for one reason or another I recently loaded a small batch that I used a Sinclair VLD chamfering tool to give a pretty strong chamfer. Runout seems to have increased overall, but especially on the extreme end, where I'm seeing .004-.005" of runout on a few of the rounds (usually .003" is the worst I'll get). Seating was done with a Wilson hand die. Just curious if I should invest in a chamfering bit for the Wilson trimmer.

Check ur PM.

 

[fdshuster]

I've been using the K&M inside taper neck reamer with the center pin that fits through the primer flash hole, making it impossible to get an uneven cut around the circumference of the case mouth.

 

[ridgeway]

I've been using the K&M inside taper neck reamer with the center pin that fits through the primer flash hole, making it impossible to get an uneven cut around the circumference of the case mouth.

I use the same tool and it works great. Best chamfer tool made!

 

[bozo699]

I've been using the K&M inside taper neck reamer with the center pin that fits through the primer flash hole, making it impossible to get an uneven cut around the circumference of the case mouth.

Spot on Frank,...+ 1 for me as well!! I am a huge Wilson fan but didn't like chamfering on the Wilson trimmer, bought many different chamfer tools, then I bought large and small K&M and have not looked back since the purchase!
Wayne

 

[Luke_NL]

Also not a fan of chamfering on the wilson trimmer. Seems uneven at times, though you'd think that is probably due to uneven necks. Bought a RCBS VLD for the inside of the case mouth, and use the standard on the outside. Am considering to chuck them up in a lathe and drill small holes in them, tap said holes and screw in 'guides' that will sit in the flashholes. Seems like a bit of work but the guides are easily turned and to replace them per caliber would be a breeze. Match them to your trimmed length, and perfect chamfering in theory at least

 

[bozo699]

Also not a fan of chamfering on the wilson trimmer. Seems uneven at times, though you'd think that is probably due to uneven necks. Bought a RCBS VLD for the inside of the case mouth, and use the standard on the outside. Am considering to chuck them up in a lathe and drill small holes in them, tap said holes and screw in 'guides' that will sit in the flashholes. Seems like a bit of work but the guides are easily turned and to replace them per caliber would be a breeze. Match them to your trimmed length, and perfect chamfering in theory at least

Well let us know how that turns out for you, I always like to see someone do something neat like that, hope it works for you my friend
Wayne.

 

[kelbro]

Please help me to understand how the case mouth chamfer, either inside or outside, could contribute to the linearity or accuracy of a loaded cartridge.

My current technique is a couple of twists on each inside and outside to knock the burr down. With .001-.002 of neck tension, I have not been able to detect any benefit from using a VLD chamfer tool. I did see a difference when my neck tension was .004.

 

[Immike]

Please help me to understand how the case mouth chamfer, either inside or outside, could contribute to the linearity or accuracy of a loaded cartridge.

My current technique is a couple of twists on each inside and outside to knock the burr down. With .001-.002 of neck tension, I have not been able to detect any benefit from using a VLD chamfer tool. I did see a difference when my neck tension was .004.

I think where the concern is that if the the bevel is uneven the bullet will tip as it is seated. The wilson flaw is the case isn't straight after sizing and it's operation depends on concentric case. It will work better on a fired case that has not been sized. Something self centering would be the solution.