Flash hole deburring
- Thread starter Utectok
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long_range_rob
Well-Known Member
I’ve never felt a need to but I wouldn’t knock anyone for doing it.
Probably a complete waste of time, but I uniform and deburr the flash holes and uniform the primer pocket depth.
Unlikely to make any difference what so ever, but I am making custom ammunition for my rifles and therefore I try to remove the possibility of inconsistency of flame front from primers and an inconsistent primer seating depth.
There is a difference between brands of brass, Norma and Lapua, both processes remove very little brass so they are good from the start.
S&B, Hornady, Winchester, significant amounts of brass chips from inside the case and from the primer pocket.
I used to do it when I was re-using Hornady Match brass. Resize. Trim to length, then use a Lyman flash hole uniforming tool....which consists of small centre drill in a holder which has a little boss on it to register on the case mouth to make the flash hole chamfers the same depth, hence the resize and trimming first.
It seemed like a good idea at the time to regularise as many variables as possible.
After a dozen or more reloads some of the primer pockets became slightly looser and I moved on to Lapua cases which appear to be burr free.
Alan
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I fear primer pocket uniforming often leads to premature lose fitting primers.
K
K
trickie
Well-Known Member
If your reloading the likes of Sellior and Bellot, then I would as the inside of the flash holes I reloaded were far from ideal neither consistent, all had burrs on the inside that could be seen with a bright light, the Hornady and Lapua seemed to me not to need deburring, no need to add un needed steps imho
If you reloading milsurp then yes and other steps
trickie
If you reloading milsurp then yes and other steps
trickie
trickie
Well-Known Member
A nice simple method, I have a slightly longer method, Add deprime, anneal, then much as yours. SS tumble, full size, trim chamfer a quick SS tumble again to remove lube, dry, prime powder and bullet.
I do like the case to be cleaned before any size or trim work, it allows inspection before to much time is wasted.
trickie
Utectok
Well-Known Member
Sounds good mine deprime with the neck sizer
trickie
Well-Known Member
I always use a Lee depriming die multi cal for my 223 & 6.5 cm both Tikka’s sits in its own single stage press (lee)
I'm not sure how the mechanics of taking a thou or so out of the bottom of the primer pockets with a uniformer could lead to slack pockets?
On the other hand using a pocket reamer I can see that pockets could become slack as it is taking material from the wall of the primer pocket.
Never had an issue with uniforming the pockets, but every day is a school day, so happy to learn the what, where and how's of why this is a bad idea.
As @Jelen says, it's a horses for courses issue, worthwhile if the rifle is capable benefitting and the distance and type of shooting justifies it. Unneeded in any event with Lapua brass, maybe Norma. RWS, I've no real experience with, but it may join the Scandi pair in this respect. On other makes, the size of some of the brass chippings cut out is impressive on occasions. I've got a pic somewhere of a figure 8 sprue cut out of an early Hornady 6.5CM case in deburring. Calling this a 'burr' would be a massive understatement and it must have largely obstructed the exit side of the hole.
I also gave up on primer pocket uniforming on Lapua cases years back as they're so good out of the factory that any improvement is so marginal you'd not justify it except maybe in short-range Benchrest. Remington, Winchester etc pockets are usually inconsistent and have concave floors with much-radiused floor to side joins. The uniformer tool initially cuts the corners and as they're squared works inwards on the floor levelling it. I can't say I've ever noticed much if any actual improvement in results on the range from this action though. I use my uniformers a lot though mounted in a small rechargeable electric screwdriver as they are great devices for cleaning fired priming compound crud out, and you uniform the pockets a bit while at it. (I've got cases loaded with stout loads that have tight pockets after double-figure numbers of firings and use of the uniformer on this basis on every reload has never produced slack pockets. Over-high pressures for the case-head expands it and as a result the pocket - that's what slackens them, nothing else!)
The third member of the ignition bits prepping trinity is flash-hole (diameter) uniforming. Most people think they're doing this with the type of tool that @Alantoo illustrates above with the pic of the Lyman tool, but most American brass seems to have larger flash-holes than the cutter head so aren't touched. Obsessives buy pin-vices and sets of micro-drills and select a drill size just above that of the largest dia. hole and laboriously hand-drill them out. (Been there, tried that, given it up!)
flash-hole uniforming « Search Results « Daily Bulletin
I prefer the Sinclair International tool as also shown in the above Accurate Shooter daily blog piece. It goes in from the rear indexing off the primer pocket and I only use them (two models - one each for 1.5mm and 2mm flash-holes) on quality brass. I (very) occasionally find an under/oversize example on Lapua cases. Easy job and do once only. This type doesn't do the exit deburr job. As they only increase the nominal hole diameters by around 3 thou', they don't touch the sides of the flash-holes on most makes of American case.
I also gave up on primer pocket uniforming on Lapua cases years back as they're so good out of the factory that any improvement is so marginal you'd not justify it except maybe in short-range Benchrest. Remington, Winchester etc pockets are usually inconsistent and have concave floors with much-radiused floor to side joins. The uniformer tool initially cuts the corners and as they're squared works inwards on the floor levelling it. I can't say I've ever noticed much if any actual improvement in results on the range from this action though. I use my uniformers a lot though mounted in a small rechargeable electric screwdriver as they are great devices for cleaning fired priming compound crud out, and you uniform the pockets a bit while at it. (I've got cases loaded with stout loads that have tight pockets after double-figure numbers of firings and use of the uniformer on this basis on every reload has never produced slack pockets. Over-high pressures for the case-head expands it and as a result the pocket - that's what slackens them, nothing else!)
The third member of the ignition bits prepping trinity is flash-hole (diameter) uniforming. Most people think they're doing this with the type of tool that @Alantoo illustrates above with the pic of the Lyman tool, but most American brass seems to have larger flash-holes than the cutter head so aren't touched. Obsessives buy pin-vices and sets of micro-drills and select a drill size just above that of the largest dia. hole and laboriously hand-drill them out. (Been there, tried that, given it up!)
flash-hole uniforming « Search Results « Daily Bulletin
I prefer the Sinclair International tool as also shown in the above Accurate Shooter daily blog piece. It goes in from the rear indexing off the primer pocket and I only use them (two models - one each for 1.5mm and 2mm flash-holes) on quality brass. I (very) occasionally find an under/oversize example on Lapua cases. Easy job and do once only. This type doesn't do the exit deburr job. As they only increase the nominal hole diameters by around 3 thou', they don't touch the sides of the flash-holes on most makes of American case.
I understood it was the deburring and flash-hole (length) I was uniforming with that Lyman tool, hence the resize and trimming of the cases and the 0.010" cut set-up instruction that came with it.
The centre drill tip actually measures Ø1.93mm so is clearance on a Ø2mm flash hole. I presumed the shoulder profile similar to a lathe centre drill was what kept it axially aligned finally.
Have to say that I only acquired the tool and went through the brass after doing a few reloads with the burrs in, and noticed not the slightest bit of difference afterwards at my shooting skill level!
Alan
Steff
Well-Known Member
The purpose of your tool is to deburr the flash hole and to uniform the flash hole diameter, not the length. The boss is only to keep you from cutting too deeply into the case head with the wider part of the tool which does the actual deburring job. Even if you set up the boss accoring to the instruction the front drill bit will protrude through the flash hole and thereby cover 100% of its lengths.I understood it was the deburring and flash-hole (length) I was uniforming with that Lyman tool, hence the resize and trimming of the cases and the 0.010" cut set-up instruction that came with it.
The centre drill tip actually measures Ø1.93mm so is clearance on a Ø2mm flash hole. I presumed the shoulder profile similar to a lathe centre drill was what kept it axially aligned finally.
Have to say that I only acquired the tool and went through the brass after doing a few reloads with the burrs in, and noticed not the slightest bit of difference afterwards at my shooting skill level!
Alan
As a side note. The difference between e.g. Lapua and Winchester brass is that the flash holes on the Lapua brass is drilled while it is punched on the WW brass. Punching it out leaves a much larger burr inside the case than drilling it.
Bavarianbrit
Well-Known Member
How did you
How did you manage the Ø symbol? It seems crazy to me that it is so hard to do on Word docs.I understood it was the deburring and flash-hole (length) I was uniforming with that Lyman tool, hence the resize and trimming of the cases and the 0.010" cut set-up instruction that came with it.
The centre drill tip actually measures Ø1.93mm so is clearance on a Ø2mm flash hole. I presumed the shoulder profile similar to a lathe centre drill was what kept it axially aligned finally.
Have to say that I only acquired the tool and went through the brass after doing a few reloads with the burrs in, and noticed not the slightest bit of difference afterwards at my shooting skill level!
Alan
Steff
Well-Known Member
Open the Character Map (Zeichentabelle, in case you have a German Windows version). From there you either copy it to your document or you can key in the combination indicated in the map. But this only works if your keyboard has a number block. The number keys above the letters don't work for this.
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