Brass for long range competition

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Brass for long range competition

Postby Doug Coulter » Fri Jul 05, 2013 3:43 pm

Get ready - this is going to make some people's heads hurt, some say it's not worth it (till I beat them), and some will love it (yes, I'm a tool freak too), but there's just a lot to this if you want to win competitions regularly. While you can't buy some of the skills involved, it is definitely easier if you have the right gear and the right preparations, so here goes - this is what I do, and did to win the all-time record at hunter benchrest, and do for my new hobby - egg shoots at a kilometer. Yes, we actually hang up chicken eggs in pantyhose at .5-1km range and scramble them! As the Marines say, marksmanship begins past 400 yards or so. This assumes a bolt type gun. The rules are a good bit different for an auto-loader, since they need a looser fit and may somewhat damage the ammo in feeding. Guess why you don't see them too often at competitions? They are simply at a disadvantage to a simpler action, though they can be made to shoot well - just not as well as reliably. I've proved they can work at this - but it's a lot harder, and I don't need the extra effort, personally.

I buy new brass for this, usually winchester, though I have had one bad batch of that. In general, it lasts longer than most of the others and is more uniform and a bit stiffer than most others right out of the box. I then proceed to get absolutely anal about blueprinting it to perfect uniformity, losing a bunch of QC rejects along the way - those become my "plinking ammo".

Process first, then details of the tools - some special - I use.

I begin with a lot of at least 500 - sometimes 1000, all the same manufacturers lot. I size them FLR for the first go - they come with the odd ding and such that it's useful to get out before doing the rest.
Then I trim them all to the same length, usually .020" below the max listed by SAAMI (reasoning for this later).
I then chamfer them inside, and outside the necks. You don't want to scrach your bullets when you seat them, and you don't want a ridge on the outside that might flake off in the gun's chamber either.
Then, I make sure all the flash holes are debnurred inside, and the primer pockets are all flat and the same depth - I want everything as exactly the same as I can have it, always. Deburring isn't the issue it once was, but it's good to do (and do it uniformly) because now and then, you'll find a piece that was punched out of the hole still attached in there.

OK, now you'd think I'd be done, but I'm not. I turn the necks to all the same thickness all around - and to decide how to set up the neck turner means I first have to measure a bunch of brasses so I know what the minimum shipped thickness is. If that's too thin - those get tossed out of the batch, but in general, I don't have that issue with most brass vendors. I usually wind up with about 12-14 mil thickness on say, .223 brass.

Still not done - now it's time to visually inspect and ditch any that look odd, and weigh every single piece of brass to the highest accuracy I can. I divide them into .1 grain weight lots. To do that, I use a piece of masking tape along the edge of the bench, labled with the weights, and place ieach piece of brass in a column behind that after weighing. What you normally will get is something that looks like a plot of a gaussian curve - their original error in punching out the blank they make into brass. This is done last, because I want to account for any brass I removed in earlier steps. The point isn't really what it weighs, but the precise case capacity, which affects burning rates and pressures, and therefore barrel vibrations that in turn affect point of impact vs point of aim.

I will then divide this mess into lots. Usually, there will be at least one lot that's all the same, and enough pieces for a full competition (88-100 rounds), but not always. I will sometimes wince and add one of the other .1 gr increments, but that does not happen not often. You can usually get several lots out of a big batch of brass, and a single lot will often do for a year's worth of work - at least, since it's usually a little larger than you need, and that takes care of the few you cull during their lifetime, keeping the lot intact otherwise.

I then fireform them for the gun I'm going to use - just that one. I use a more or less straight up same load as for competition to do this, but usually reduce the powder charge a little since full length sized brass has a bit less capacity than fireformed will have.

Now, it's actually ready to clean, reload and shoot. Since I've already uniformed the primer pockets, I only need to scrape the crap out of them from now on, or almost always - a high pressure load can set back a primer pocket sometimes - and usually the best response is to toss that brass and back the heck off the load. For the first 4 or so times through the process, I only neck size the brass - this keeps it from much further stretching, improves life, and keeps it a perfect fit to the chamber it's going to be shot from.
Once a few get to the point of needing a full resize, I do the entire lot, fireform it again, and repeat.

If resizing results in a need to trim them - I trim them all to the same size again, and repeat the chamfering. I find it's OK to do this once. Twice is getting dodgy, since I'd already trimmed them 20 mils short and am doing it again. More than that means the brass is getting thin near the case head, and may fail. I have a scar on my face I'll carry for life from one of those. It's not worth it - I don't trust the paperclip test many may know of to detect this well enough to feel confident and unworried at the firing line, personally.

Most of this prep work you only have to do one time, thank heavens, but you do it because you want the best, and there's no point going out to get better at this if you leave yourself any easy excuses to blame your misses on. Of course, if you have to trim the brass after sizing - you have to chamfer it again, and should weigh it again, since no two will remove the same amount of brass, and what we are looking for here is total uniformity in every aspect - case capacity being a very important parameter as will be explained in another thread later about how barrel vibrations affect point of impact.

The point of all this work is this - making your ammo as perfect a fit and as identical as possible for that one gun is the most basic key to accuracy - everything else is less important, if still somewhat important. A bullet that doesn't enter the rifling straight will be deformed by the pressures, and not fly striaight after that - nor will a scratched one. I will generally load my chosen bullet about a few mills "into the lands" with an appropriate charge of powder to ensure that each round is perfectly located centered in the gun, and there's no random jump to the rifling.

Yes, I have some preferred tools and dies for this - I've bought probably every single one on the market at some point, and well, you learn which ones work the best doing that. While you do tend to get what you pay for, it's not always a good correlation. For example the RCBS bushing neck size die doesn't do anywhere near as good a job as the far cheaper Lee collet neck sizer, as slightly customized by me to get the exact ID I want for the bullet pull friction I want. Not even close.
Yet, the RCBS easily costs 10 times more if you buy only a few bushings.

I will be making some videos and still pix to add to this thread to detail the process the way I do it - others may vary and get good results as well, but this is how I get them. Yes, it's a lot of work. But also, yes, it's a thrill to win! And that's not something one can usually buy with mere money or a little work - to beat the best, you have to be better yet - and this is only one aspect.

For fun, here's a little "gun guy porn" of some of the brass I'm currently in the process with - lake city in this case, you have to keep trying things to stay on top (ask David Tubb about this) - and the nifty (but expensive) Sinclair priming tool and neck turner tool I use. I chuck the neck turner into a battery portable drill on slow speed and hold the brass by hand for this, so as not to leave clamp marks on it...it's a bit of an art, and by-feel, as is the priming tool, but it's the only way to get perfection, so I tolerate the inconvienience.

CompBrassnTools.JPG
Brass, bullet, and some tools sitting on the back of my Volt (sun is nice for pictures).

BulkSupplies.JPG
The stuff in bulk, prior to sorting and loading it up for fireforming.


If you look carefully at these (as usual, click the pic for a full size view) you will see that I didn't quite fully turn the necks, and a small amount was untouched by the tool. This was deliberate, and doesn't seem to matter. For moly bullets (I'm using Sierra 53gr flatbase moly for 100-400 yds in this gun - 1::13 twist) - you want a strong grip so I wanted to leave the brass as thick as possible for that, without compromising too darn much. I load these about 15 mils into the lands, enough so they just push back into the neck very slightly (in this case, about 5 mils) when chambered, breaking any inconsistent static friction they may have developed between loading and shooting. Did I warn you this can get complex?

On the other hand, as an engineer who for years helped people make products cheaper via the use of feedback mechanisms to correct their flaws, there's a certain joy in doing this fully feed-forward. In this case, there's no other way anyway.

I'll be adding some things to this thread as time goes along...pix and vids of the process. It's so much easier to pick up that all-important "feel" for process and "how you hold your mouth" from those than mere words, IMO. There's just only so many hours in a day, however, which is why they aren't here already.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Doug Coulter
 
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Re: Brass for long range competition

Postby Doug Coulter » Fri Jul 05, 2013 4:11 pm

Note on my primer pocket cleaning tool. I'll get a pic the next time I can find it, but it's pretty simple and saves a lot of effort.
Since I've reamed all my primer pockets to uniform depth, and utterly flat (unlike the way thay came) - even if it means they are a little deep (easily compensated by the Sinclair primer tool anyway, and my guns don't care), all I need is what amounts to a perfect little screwdriver. Essentially, I take a small piece of soft steel rod, and grind a screwdrive end onto it, then grind it so it fits the pocket diameter perfectly. Chuck that baby into the ubiquitous Makita or Ryobi hand drill on low speed, and doing a perfect job cleaning primer pockets becomes easy and fast. Not all of this is that complex if you think about what problem you're trying to solve at the time. I just hand-hold the brass for this job - you don't want to push too hard and scrape any amount out, just the crud from the last primer that was in there.

For neck sizing, I use Lee's collet neck sizer. I found I had to turn down the inside shaft a couple of mils to get just the bullet grip I want. You must use one of these in a single stage press, and set it up very carefully. Lee deliberatlly used an aluminum top screw - and if you put too much force on this, you WILL break it (I've had to make replacements here, but then, I have a machine shop). If you set it up just so (do use the lock ring and the same press and shell holder each time) - you can just run the handle of say, an RCBS rock chucker press all the way down and get really uniform results. The unique construction of this die is such that the rod the case necks are being squeezed against by the collet is centered at the top by the assembly screw, and at the bottom by the flash hole - so the necks come out perfetcly straight. And this matters more than anything else, it seems, and matters even more if you can't load to the lands of the rifling (as in say, an AR-15 with a long jump).
LeeToolApart.JPG
disassembled so you can see how it works.

ColletNeckSizer.JPG
Assembled. The shell holder on the press pushes the collet up to squeeze just the case neck against the guide rod.



Yes, I have tools to measure Total Indicated Runout (TIR). The Hornady tool is a good one, I like it better than the other one I have. In theory, you can also use it to bend crooked ones back straight. Don't do this! They'll recover their original bentness in part between the time you do it and the time you shoot them, so it doesn't really help. Those tools are mainly to help identify process issues you then go fix to prevent making bent rounds in the first place...that's how we roll.
HornadyTIRTool.JPG
TIR measuring tool with old .223 mil-surp in it. Yes, they aren't very straight the way the military makes them, and straightening them doesn't really work.


Chamfering - I use one of the commercial tools, chucked into a special, tiny, desktop drill press running about 100 rpm, and just hold the brass up to the bit for a short time. Works great, it's slow enough that it's easy to do uniformly (and doesn't have the oops of a sloppy drill press stop you can just force). They chatter a little...it doesn't seem to matter.
ChamferTool.JPG
Nothing special here, simple and it works fine - you just have to hold the brass up to it straight. The tooll reverses for outside chamfering.


Of course, after all this you put the prepped brass through the cleaning process again, to get rid of any shavings, round off any sharp edges, and so forth. That's not real hard work, since all you have to do is wait for it to get done.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: Brass for long range competition

Postby Doug Coulter » Sat Jul 06, 2013 12:26 pm

So, how do we get those primer pockes just so? Using a special tool, of course. This one I got from Lyman (via midway). It's the one on the left in the picture below (don't forget, click the pic for a bigger view). In the middle is what's called a VLD reamer, one with a shallower taper than the normal chamfering tool at right. I got this in the search for hyper accuracy, but I can't say it makes any big difference over the one on the right, which is cheaper, and drill press mountable with a special socket mount you can get from Sinclair, or make yourself.
SpecialTools.JPG
Special tools


The pocket reamer can be set for a precise length via an adjustable stop. It will also remove any crimp from a military surplus brass that had a crimped primer pocket. I don't find these to be as much of a problem as many say they are. Since I always pay attention to how primer seating feels - no matter what seating tool I'm using, I find it not so hard to tease in a new one even if the crimp is still there. Slows you down a little bit, is all. No biggie. But for hyper accuracy, yeah, no variables, we cut that crimp out of there.

I also set the pocket cutter a couple mils "too deep". This ensures I'll cut every single pocket perfectly flat, edge to edge, and my priming tools and guns don't mind a little bit of a recessed primer. Most guns have plenty extra firing pin extrusion length, unless they have a serious headspace issue (say a very old and used mauser is the only one I've had issues with), and those guns, well, we're not talking about competition with those - you fix the gun first, understand?
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Doug Coulter
 
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