Flash Hole Chamfer- is it awesomer?

[ucsfl05]

Trying to find some info on chamfering the inside of the brass. All the flash holes are uniform on the alpha brass, but does doing this extra step help propagate the flash in a conical fashion that will ignite more pellets?

example below.

 

[moaorbust]

My instructor taught me to chamfer the flash hole during initial case preparation. I don’t know that there is a measurable difference and I have never seen anyone say they could. It is just done to ensure maximum consistency across all brass.

 

[bunny too]

^^ That is why I do it ^^

 

[Steel head]

I really think in some brass with badly punched holes it’s helpful.

 

[Mudmarine]

Its a one time thing for me and i usually just cut deep enough to remove the burr, and go no farther. The pic in the OP looks a little aggressive to me.

 

[hafejd30]

I’ve done it in Winchester brass. You’d be surprised the amount of brass shavings that come out. I only run Lapua or other high quality brass now and see no need to do this step

When I do this I’m just removing the burs from the punched hole. Not actually removing any brass from the case head

 

[Steel head]

I’ve done it in Winchester brass. You’d be surprised the amount of brass shavings that come out. I only run Lapua or other high quality brass now and see no need to do this step

When I do this I’m just removing the burs from the punched hole. Not actually removing any brass from the case head

Yep
In my Winchester brass the punched holes were pretty sloppy.
I don’t bother with my ADG brass.

 

[AllenOne1]

I just remove any burrs on the inside of case around the flash hole I don't cone it in like the OPs picture is showing. Doubt that would make any difference but if you do it to one case you have to do them all.

 

[supercorndogs]

I have never done it with any brand of brass. If there are burs in there, I shoot them out. Same goes for pocket uniforming. Whats your end game? Can you shoot the difference? Is it worth your time? Every little twist of the brass prep tool is a little more arthritis as you get older.

 

[supercorndogs]

Looks like you need to debur the cut the deburing tool left. Do they make a primer pocket debur deburrer?

 

[ucsfl05]

I have never done it with any brand of brass. If there are burs in there, I shoot them out. Same goes for pocket uniforming. Whats your end game? Can you shoot the difference? Is it worth your time? Every little twist of the brass prep tool is a little more arthritis as you get older.

Totally agree. Definitely cannot shoot the difference.

 

[MtnCreek]

I remove the bur on punched boltgun brass and brass that will be run through a swagger. Swagging with a dillon superswag the bur can effect pocket dia and can also get folded over the flash hole.

 

[Mike Casselton]

I have never done it with any brand of brass. If there are burs in there, I shoot them out. Same goes for pocket uniforming. Whats your end game? Can you shoot the difference? Is it worth your time? Every little twist of the brass prep tool is a little more arthritis as you get older.

That's why I finally spent the money on the RCBS brass prep machine.
Saves a lot of overnight numbness and pain.

 

[Brettmparker1]

I haven’t seen a measurable difference either. I have done some brass that looked like shit inside but I don’t honestly know if it did anything as far as velocity is concerned.

 

[lightman]

I do it to all of my rifle brass including Norma and Lapua. But I don't cut as much as the picture shows. I do it because...............

I can't say that it makes my groups tighter or my scores higher. I use a tool from K&M thats non adjustable.

 

[Halfnutz]

K&M is the best design IMO, whether it makes it better or not.

 

[stewarmy01]

I have used a myriad of flash hole deburr tools in the past (Lyman, 21st Century, Redding, and K&M). K&M wins for me. The carbide is worth it.

 

[NukeMMC]

I deburr the flash hole in all my brass except the Lapua and Norma (drilled hole). Even LC Match has punched flash holes. Does it make a "shootable" difference? I doubt it, but it does make a difference in my confidence in the brass/load. THAT is a shootable difference.

 

[supercorndogs]

Lapua is not drilled.

 

[Greg Langelius *]

When I chamfer flash holes, I begin my trimming the brass to a uniform length.

I then set the stop by adjusting it so that it trims away the metal flashing the flash hole punch leaves behind, but not deeper. I attempt to avoid leaving any bevel in the inner end of the flash hole.

IMHO, this directs the flash directly along the case axis, and extends the the flash's reach as deep as possible into the propellant column.

IMHO the best internal burn pattern is along the case's central axis, from the center line toward the case wall. I believe this generates the most consistent pressure curve.

Mine is mounted on my RCBS case prep station, and interchanges with the pocket brush depending on whether dealing with new or fired brass.

Greg

PS Don't get upset about the brass in the picture. My first few batches looked exactly the same until I learned better. Yours will shoot and likely be accurate as well. I just believe the no-bevel approach ends up better.

You will probably find, as I did, that as a beginning handloader, all your skills will improve (be more consistent) concurrently. This means that any issues due to the beveled flash hole will likely end up being perceptible on the target as your consistency with all those other skills reaches a better level. It's not a big deal, and nothing has been ruined.

When you buy Lapua and pay the premium, this part of what that extra buys. It really is better, but if one chooses to prep their own brass, and does it well, it's a tradeoff between luxury and sweat-equity.

Just go forth and sin no more, youngster.

 

[Rob01]

Used to do it and then did some testing and found no difference in performance so stopped. If you need a mental fist bump then do it but my time is more important to me now so my flash hole tool just sits in a box now.

 

[Ledzep]

Used to do it and then did some testing and found no difference in performance so stopped. If you need a mental fist bump then do it but my time is more important to me now so my flash hole tool just sits in a box now.

Ditto. Have tested it several times with and without and never found any correlation to anything. About the only thing related to flash holes that could cause consistency issues is if there was drastic diameter variation or if there's a complete or partial 'plug' from the manufacturing process left dangling.

 

[Greg Langelius *]

Rob01 and Ledzep; you posts confirm my personal suspicions, I think we just never did a group check on the validity. Thank you for simplifying my overall handloading process. IMHO, simpler is usually better.

Thank you;

Greg