Brass prep procedure?

[zipollini]

Peterson 6XC brass - DTAC 115 RBT Hbn coated

New brass procedure

Lube brass with Hornady One Shot spray lube
FL size using Tubb 6XC sizing die with .268 neck bushing and without neck expander
Expand neck with .2435" neck expander mandrel for desired neck tension
Trim and chamfer neck with Giraud trimmer
Brush neck ID with nylon brush to knock off any burrs or chips
I do not ream primer pockets or chamfer and normalize primer flash holes after David Tubb said he doesn't do that (good enough for me)

Throw brass into vibratory tumbler with Lyman Tuff Nut crushed walnut media for 1 hour to remove case lube

Check that there is no media in flash holes and remove if necessary
Prime using 21st Century precision priming tool
Load powder using ChargeMaster and analytical balance and Omega trickler
Seat DTAC 115 RBT Hbn coated bullets using Wilson inline seater and 21st Century Hydro press

Fired brass procedure

Tumble fired brass in vibratory tumbler with Lyman Tuff Nut crushed walnut media for 1 hour
I do not anneal as I am jamming bullet .20" into lands and annealing is not necessary if jamming
Lube brass with Hornady One Shot spray lube
Decap and FL size using Tubb 6XC sizing die with .268 neck bushing and without neck expander
Expand neck with .2440" neck expander mandrel for desired neck tension
Trim and chamfer neck with Giraud trimmer
Brush neck ID with nylon brush to knock off any burrs or chips
I do not turn necks as David Tubb mentioned that he no longer sees this as necessary with this quality brass
I also do not clean out primer pockets
Throw brass into vibratory tumbler with Lyman Tuff Nut crushed walnut for 1 hour to remove case lube
Check flash holes for stuck media and remove if necessary
Prime using 21st Century precision priming tool
Load powder using ChargeMaster and analytical balance and Omega trickler
Seat DTAC 115 RBT Hbn coated using Wilson inline seater and 21st Century Hydro press

 

[Kracken McGraw]

On the deburring the flash hole part since running the Teslong down in Lapua cases without the mirror, all you can say is Wow this is pristine. Why would you run a hand tool down there to mess with that! I won’t mention other brands that I have looked at to be nice, but I would check them.

 

[Fire Dog]

Looks good to me, but I'm no expert. I would suggest adding an annealing step after your initial cleaning in dry media. Anneal after each firing.

Get an AMP annealer... No flames and electronically precise each and every time...

 

[Fire Dog]

Yes. A short story...
A good friend was having group performance troubles. He wasn’t a believer in chronographs and such, so I asked him to shoot against my Shotmarker while I also took LabRadar data. He had a “good batch” and a “bad batch” of what was supposedly the same loading. There was a direct correlation between groups and good and bad velocity stats even with the average being the same, so we start the story with him being stubborn about velocity. (He now regularly checks his ammo batches by running against my chrono, and he has learned that SD and ES really are coupled to vertical at 1000 yards.)
I went to visit to look at his loading process. It looked like a glitter factory. I asked him if he always had that much metallic glitter when he loaded and he didn’t notice or know. Scrapped up bullet jacket material isn’t good for the loads or the gun. It also fouls the bbl much more than normal.
His chamfer was scraping and scratching the heck out of his bullets as he seated, so the visual of an ugly chamfer and scratched jackets was a bad warning that he ignored.
Shortening the debugging story, I found his chamfer tool was to blame and once we changed it, his glitter issue went away, his seating forces got under control, and his velocity stats and group size went back to “good”.

I don’t try to turn everybody into a machinist or statistician, but a little attention to cutting tool sharpness doesn’t hurt anybody, except maybe in the kitchen... LOL

Never a poblem with my KM tapered case mouth reamer... Cuts a 17* shallow taper and takes away any peening form SS wet tumbling and allowing for easy, smooth seating of bullet.

 

[PopCharlie]

Get an AMP annealer... No flames and electronically precise each and every time...

Got one, and I love it.

 

[PopCharlie]

Speaking of chamfer, is there a recommend depth for cutting a chamfer?

PopCharlie

 

[RegionRat]

@PopCharlie there are no hard and fast "rules" about chamfer dimensions. With that said, a rough rule of thumb for the chamfer workmanship on the case mouth, would depend on the thickness of the brass for dimensions, but a roughly one third ratio is a starting point. One third for the OD, one third uncut, one third for the ID chamfer.

If for example, the surface of the case mouth is a 0.012" wall thickness, a starting point is to decide if you are going to run equal chamfers on the OD corner and the ID corner. Then you would give roughly 0.004" to the ID and OD chamfer leaving about the same for case mouth, and you can adjust to taste up or down from there.

I remind folks that wet tumbling with pins, or large drums can smear that little 0.004" case mouth facet and smash it over the facet edges. When rotating drum style wet tumbling is taken too far, it can damage the edges of the case mouth facets to the point of causing problems.

You can play with the amount of the case thickness you assign to the chamfers, but remember that your brass cleaning method may not be too kind to the case mouth especially if you bring the two top chamfer edges too close together to the point where the case mouth is a knife edge.

On rifle brass, my OD chamfer is just a 45* edge break (~0.0005") just enough to dull it, and that leaves me more room for the VLD chamfer on the ID. It ends up between 0.004" and 0.005" worth of the wall thickness.

Using a three-way cutter requires attention to the neck diameter. If the case mouth isn't held to the correct diameter, then you end up with over or under cutting one of the facets. Those cutters are initially set up to run about 1/3 proportions in the share of ID, top, and OD.

It sucks getting to where you can't see up close. Without magnifiers I can't see those details with naked eyes any more. YMMV

 

[PopCharlie]

@PopCharlie there are no hard and fast "rules" about chamfer dimensions. With that said, a rough rule of thumb for the chamfer workmanship on the case mouth, would depend on the thickness of the brass for dimensions, but a roughly one third ratio is a starting point. One third for the OD, one third uncut, one third for the ID chamfer.

If for example, the surface of the case mouth is a 0.012" wall thickness, a starting point is to decide if you are going to run equal chamfers on the OD corner and the ID corner. Then you would give roughly 0.004" to the ID and OD chamfer leaving about the same for case mouth, and you can adjust to taste up or down from there.

I remind folks that wet tumbling with pins, or large drums can smear that little 0.004" case mouth facet and smash it over the facet edges. When rotating drum style wet tumbling is taken too far, it can damage the edges of the case mouth facets to the point of causing problems.

You can play with the amount of the case thickness you assign to the chamfers, but remember that your brass cleaning method may not be too kind to the case mouth especially if you bring the two top chamfer edges too close together to the point where the case mouth is a knife edge.

On rifle brass, my OD chamfer is just a 45* edge break (~0.0005") just enough to dull it, and that leaves me more room for the VLD chamfer on the ID. It ends up between 0.004" and 0.005" worth of the wall thickness.

Using a three-way cutter requires attention to the neck diameter. If the case mouth isn't held to the correct diameter, then you end up with over or under cutting one of the facets. Those cutters are initially set up to run about 1/3 proportions in the share of ID, top, and OD.

It sucks getting to where you can't see up close. Without magnifiers I can't see those details with naked eyes any more. YMMV

Thanks @RegionRat! I use a method similiar to yours. 45° on the OD, just enough to give it a smooth break on the edge. But I believe I'm cutting too much on the ID. I'm going to take a close look at this.
PopCharlie