Archive | September 2014

Ammunition for Long Range: Part 4

Continuing with our handloading tips we’ll cover some case preparation steps.

Tumbling: There are a lot of competing ideas around this. Do you use liquid and stainless steel media or crushed corn-cob or walnut? Do you vibratory tumble or ultrasonic clean. I don’t honestly know that it matters. I use corn-cob media and vibratory tumbling. I do a 2 stage tumble. First is with clean fresh media to do the hard cleaning then I use a different set of media that I toss a lump of chrome & brass polish into. My cases emerge clean and shiny. Tumble your brass before you deprime. This will help keep grit out of your depriming die. Keep your media fresh. Don’t overfill your tumbler.

Trimming: RCBS makes a slick case trimmer (Trim Pro-2) that locks on the extraction groove. More recent examples of trimmers I’ve seen from some other brands seem to use this strange collet based design that clamps onto the rim itself. I hate the collet system. It’s not a repeatable system. What you don’t do for sure is use anything that tries to trim brass fast. Fast = inconsistent. You should only need to trim your brass every few firings if you’re not running pressures super high and you’re only neck sizing. If you full length resize, then trimming will probably be necessary each time you reload the brass. Just make sure you get them all the same size and you trim only as far as the TTL value given in your manual.

De-Burr/Chamfer: Trimming causes a large burr to build up on the case mouth. When you deburr don’t try to knife edge your brass. That weakens it and causes case neck splits and uneven neck tension. You only need to use the chamfer/deburr tool just enough to remove those burrs.

Primer Pocket: Military brass commonly has the primer crimped in. It makes depriming a little harder but it makes re-priming almost impossible. There are a lot of ways to remove the crimp. The accepted method is primer pocket swagers/uniformers. Those are nice but high effort and I’ve had more case rims damaged with them than I care to deal with. What’s worked for me is to use the deburring tool to shave off the crimp ring around the primer. A few good turns is all it takes. The upside is that it chamfers the primer pocket so primer seating is a little easier. Be smooth however you do it. What you should NEVER do is use a drill bit. You’ll likely end up over-sizing the primer pocket and have some high pressure gas released in your face for your trouble.

Case Sorting: I would recommend you sort by case head stamp and by number of times the brass has been used. As you fire them the brass flows a bit and the cases change capacity. If you keep the cases the same the whole time you’ll have more accurate and easier to produce ammo.

Discarding brass: You should accept that brass is a consumable. It’s consumed slowly so you get to use it a few times normally but still, it wears out. You need to learn when to toss a case. If the neck splits, pitch it. If the case was hard to extract or the primer blew out or the side split or you see the shiny ring of incipient case head separation. The only thing keeping your eyes away from 50,000 psi gasses of fire is that case. If you don’t trust your vision to it, toss it out. 30 cents or even a dollar isn’t worth going blind or being otherwise maimed.

Here’s a good order of operations: Fire, tumble, inspect, size, inspect, trim, prime, inspect, charge (+ visual inspect), bullet seating, final inspection, boxing. Fire and repeat.

Ammunition for Long Range: Part 3

Handloading is a serious investment, mostly of time. You can’t just dive into handloading/reloading though. You really need to understand what you’re doing, how you’re supposed to do it, how to set everything up and all kinds of specific terminology that’s common in the machining world but is very uncommon in the rest of the universe. We’ll go about this with the notion that you’re already handloading and you’re just not doing it for extreme range work.

Loading match grade rifle ammo is actually pretty easy, it just takes a huge amount of time. Here are some tips that will make you more successful:
1. Buy your components in as large a quantity as you can. Try to get your powder 8lbs at a time. You’ll want it to be all from the same lot so getting a 8lbs jug instead of 8x 1lbs cans will help. Your loads will be more consistent this way. Primers and bullets and brass are the same way but to a lesser extent. Still, get your bullets several hundred at a time. It’s cheaper to ship 400 bullets at once than to ship 100 bullets 4 times. Primers actually keep really well so long as they’re properly stored, so does powder. Bullets and brass store forever. I like to buy 500 rounds worth at at a time.
2. Sorting brass/primers/bullets by weight is only necessary if you’re getting components of sub-par quality. I use and encourage the following: Federal primers, Berger||Hornady||Sierra bullets, Lapua||Remington||Winchester brass, IMR powders.
3. Process your brass in large batches. Make sure you trim exactly the same way, size the same way, lube the same way, etc… The steps being identical makes the results easier to make identical. Identical results will mean more accurate ammo.
4. Don’t try to completely load any ammo from components in 1 day. Processing brass for loading can be a long process. You don’t ever want to be in a hurry when you finally get to priming/charging/seating step. Make sure you process brass completely and then set it aside for future loading. This means when you finally get to dropping powder and stuffing bullets in cases you’ll be relaxed as far as having all your prep steps done already.
5. Don’t mix containers of components. Don’t pour powder from one container into the other. You may have been sloppy with the almost empty can and stored it badly. That can degrade it. Don’t mix old stuff and new stuff basically.
6. Buy the best bullet you can get. Even if it’s more expensive than you wanted. With better bullets you’ll hit more often and your shooting sessions will be shorter so it all breaks out even in the end and you’ll be better off with better bullets.
7. See #6. See #6. Seriously, read #6.
8. Learn the OCW (optimum charge weight) method of load development. Learn the ladder test method too.
9. You’re wasting ammo if you don’t shoot it over a chronograph. Chronograph your loads. Before you load your first cartridge purchase a chronograph and learn to use it.
10. Don’t full length size if you don’t have to. Brass life is substantially increased by not working it. If you shoot a bolt action or single shot rifle then you can get away with neck-sizing which will increase your brass life substantially.
11. DO NOT MIX BRASS. 1 kind of brass, 1 load spec. You’ll hate yourself for breaking this rule.
12. Buy the best brass you can get. I recommend Lapua brass, then Remington, then Winchester. For military calibres surplus is a great way to go but avoid SAW brass like the plague and remember that machine gun fired brass will usually be way oversize and will require substantial effort to resize (even multiple sizing runs). Military brass should be considered on-par with Lapua as far as quality. Drop 1 grain or so from your max before loading in Lapua or Military brass. They’re thicker than Remington/Winchester/Hornady/Nosler/etc… and so you lose case capacity and need to drop the charge weight a bit so you don’t go over-pressure.
13. Wolf primers are not crap but they’re not the best. CCI and Federal are what I consider premium. Winchester primers are not something I like.
14. If you use Sierra Match King bullets, jamming the bullet into the lands a tiny bit is usually considered a good thing. I use Berger and Hornady before Sierra. Bergers seemed to like a short jump to the lands. Hornady SST’s liked a much larger jump.
15. Don’t get into velocity chasing. Get into accuracy chasing. Velocity is what it is. You have a performance window you’ll be in regardless of what cartridge you’re using so don’t fight it trying to get 20fps more. If your load groups under 1-inch at 100yrds then you’re doing ok for long range. For extreme range I’d suggest getting down to .5″@100yrds or smaller with your 3-shot groups and 1″@100yrds or less for 10-shot groups.
16. More chronograph data is better. Track every shot you are able to. Magnetospeed is a good way to do that.
17. Track how many firings each case has gone through. Start a set of buckets/bins/jars/etc… with labels. 1-fire, 2-fire, 3-fire, etc… You’ll get to see how many of your cases last how long and you might be able to make a decision that will increase your case life. It’ll help you see exactly how much service you get from your brass which will allow you to have more accurate price:round data.

Stay tuned for more!

Ammunition for Long Range: Part 2

Let’s cover some bits about ammo that you buy already loaded. Most long range aficionados will tell you that you need to get into handloading to get the full potential out of your rifle. Well, that’s pretty true but not totally true. Yeah, I know you thought of truth as being on or off like a light switch or being pregnant but it’s not as far as this goes.

Not handloading means you’re accepting whatever comes out of the box and your only options for tuning your rifle/load combination end up being done in rifle hardware because your only other option is to pick a different load entirely. So what do you do if you go to Big 5 and buy a box of Federal Gold Medal Match and it shoots like crap from your rifle? Well, there’s not much you can do there. Maybe add or remove a brake, tinker with action bedding, barrel floating, etc… but that’s likely to get you only so far. Most people would switch from FGMM to some other load, maybe one from HSM or Black HIlls or whathaveyou.

If you’re sticking with factory ammo you can try changing to a different projectile (if SMK’s don’t treat you well, try a load with Berger VLD’s, etc…) or a different brand or try to find a lot that works well and buy all of it you can find. You see why experienced long range shooters that handload are so bigoted about handloading being the way to go.

However you end up going about it, if retail ammo is your approach then you’ll find this to be an expensive hobby. On the upside, retail ammo is pretty consistent stuff most of the time and match quality ammo is even better. If you happen to find that any ol’ box of FGMM will do the trick for you then count your lucky stars and buy a lottery ticket. If not, consider really seriously that there’s a reason we handloaders are so snippy about not handloading being nothing more than finding a very expensive and short sighted form of laziness.

Once you find the ammo you like you still need to go through all the data collection steps that you would with handloaded ammo. On the upside, retail ammo of high quality is available over the counter in most areas. I will caution you that buying already loaded ammunition of sufficient quality and consistency that comes with the right bullets for long range precision work will be a shocking experience for your wallet. You might pay 3 bucks a round or more for rifle ammo of that grade. To load it yourself you can manage with the same bullets and quality to get substantially under a dollar a round. The savings is really substantial. You won’t actually save any money by handloading. The way it ends up working out is that you spend the same amount of money you would have but you end up with vastly more ammunition to burn and you might end up with a few rounds left over after a day of ringing steel.

Stay Tuned! Handloading tips are coming next.

Ammunition For Long Range: Part 1

Shooter: Bang!
Spotter: High .3 MRAD Left 1 MRAD
Shooter: Taking 3 clicks down, holding 1 MRAD right. BANG!
Spotter: Low 1 MRAD, Right 1 MRAD
Shooter: Screw it! This is impossible.
Spotter: No it isn’t. You’re using crap ammo.

This is just a few shots. It’s also a good example of what to expect if you don’t have your equipment set up properly and you don’t take care to select ammunition that performs up to the level you need.

I went out recently to burn up a big wad of ammo that had been sitting around unused. It was unused primarily because it’s inconsistent. Most of it was 1 round of this load and 2 rounds of that load. It was also mixed up in the box so it really was impossible to tell what was what other than chambering. I had about 100 rounds of 7mag and 60 rounds of .223 and 50 rounds of .308.

I was able to score hits at long range with the stuff but they were inconsistent hits. Doing it twice in a row was cause for real celebration. Like hitting the lottery twice. Holding the same way twice in a row almost never resulted in 2 hits in a row. There was wind to deal with too but almost all of the misses were low or high. I can live with windage being off. That’s the slot-machine like gambling vibe you get with long range and the hardest skill to build. You never know what mother nature will toss at you in that respect. Vertical dispersion though is normally a problem with deviations in muzzle velocity and projectile differences that are insurmountable. If you don’t have consistent velocities you’ll never get this down. Those velocities determine how far a bullet gets before dropping N number of cubits/inches/feet/etc…

My .223 ammo was thrown together for plinking use in an AR-15 at close range (< 100 yards) where the muzzle velocity differences weren't a big enough factor to care about. There were 5 rounds in the mix that I'd put together to test new bullets with and those were carefully loaded and I could tell those apart. The bulk .223 made groups about a foot wide at 500m. The carefully assembled target loads printed a 2" group at 500m.

My .308 ammo was loaded to fire-form the cases to my chamber and to see how far I could push the pressures. That being the case there were 1-5 rounds of several spec loads that were carefully assembled and a bunch of random ammo I needed to burn up to get the brass. As expected randomness in the loads produced undesired lacking accuracy. It was less bad because I took more care with these loads than the bulk .223 but it was still hit and miss.

Where things were really messed up was with the 7mag. There were so many recipes there it was nuts. Apart from that these were basically all loaded by my dad while he was learning to reload and he was a little skittish about max loads so they're all underpowered and since he was a hunter and thought crimping would be useful to him, the bulk of them were over-crimped. I did have 5 rounds of some new target ammo to test for pressure and velocity and those were like laser beams. At 500m it was a beer can size group. The other loads impacted more or less randomly around a beaten area of 20+MRADs. I might as well have been lobbing artillery. On the upside, I got 100-ish rounds of 7mag brass freed up and can turn my attention to getting a new stock of primers.

So what do you take from this experience? I knew what I was going to experience and I was ok with that. I only cared about burning some powder and finishing the break-in of my barrels (all 3 are new barrels). Next time I go out though I'll want the ammo performing to the need. I tend to shoot at 1MOA targets so I need ammo that shoots at .5MOA.

In the next episode we'll discuss retail ammo versus handload versus remanufactured versus Joe-Bob's "try these" loads. We'll also discuss some matters of statistics, component selection and then we may delve a bit into handloading practices.

Stay Tuned!

Getting Your Inputs Squared Away Part: 7

We touched on some of these before but we’ll go further this time.

Latitude: Within a couple degrees is fine for most people. As you move away from the equator it gradually becomes more important. We know that you won’t be sniping at 0 degrees latitude so don’t put that value in. It’s liable to cause some weirdness if you do. For me, I bounce back and forth between 33 and 40 degrees. For the most part I just leave mine at 35 or 37. This is a big part of Coriolis drift calculations so don’t guess. Approximating is fine. Guessing is not.

Zero Range: This is either in yards or meters, which ever you’re using. You don’t need to denote yards or meters, just put the number of whichever of those you’re using in there. If you’re zero’d at 250 yards then put “250” in the box.

A further note on zero range: I try to maintain a 100 yard zero on all of my guns. The scopes I use have enough “up” in them to get me out to the ranges I shoot. This means that I often use canted scope bases and eccentrics in my Burris Signature Series rings to add in extra minutes of angle. The side effect is my scopes are frequently set with the turrets adjusted 2/3 of the way toward the bottom. Sometimes more on the punkin’ slingers. Ideally you’ll want your optic in the center of its mechanical range while at zero for optical reasons. This is also a reason I use fixed magnification scopes and not adjustables. Fixed power usually nets a little more adjustability since you don’t have another set of lenses taking up space. If you can’t zero at 100 that’s fine but it’s a lot harder to actually do. A lot of people will go 2.5″ high at 100yrds/meters but what they have to do then is look up their drop to estimate a nice round number of cubits to call their zero. There’s so much guesswork in the “N number of inches high” zero’ing method that I recommend against it. It’s fine for hunting, not for target work.

Ballistic Coefficient: This is the most critical element to get right. You need to find the exact bullet you’re using either on the manufacturers website or in the Projectile Database tab of Ballistic_XLR. Many companies make multiple bullets in a given style with widely differing ballistic profiles. Be sure you get the right one. If you put in bad data and get bad results don’t blame the math. Users of sierra bullets need to pay special attention to velocity regimes when figuring out what your BC should be. Most other manufacturers give their BC’s as an average that approximates what you’ll see and it’s been my experience that this is a much easier way of doing things if in theory less accurate. Also note that Ballsitic_XLR ONLY supports G1 ballistic coefficients. If you put in G7 data it just won’t work right. If you’re not sure, a quick phone call to your bullet manufacturer will quickly provide accurate information. They’re all very helpful, especially Sierra and Berger.

Bullet Weight: This is the bullet weight in grains. It’ll be listed on the box the bullets/cartridges came in. Just the numbers go in the input box. No letters. This is important as heck for ballistic calculations to come out right.

Bullet Diameter Inches: This is the bullet diameter in inches. 5.56mm = .223, 7.62mm = .308, etc… Only put numbers and decimal points in there. No letters.

Bullet Length Inches: You can measure one with a micrometer or just look it up in the Projectile Database tab. Just like everything else this is pretty important. It governs much of the spin drift numbers so you’ll want to get it right. This is a decimal inch number. 1 3/4 inches is 1.75. Don’t put ” marks or letters in the box.

There you go. We’re done with the basic inputs. Metric users will probably want me to go over this in more detail and there are things I didn’t discuss like what happens when you have MRAD reticle and MOA turrets configured and other interesting edge cases that are actually pretty common. Those topics will be covered in future articles and via support.

Don’t forget to check the download link periodically for updated versions.

Getting Your Inputs Squared Away Part: 6

Time to get your muzzle velocities taken care of. This is why you needed the 50-100 rounds of your chosen ammunition. We’re going to assume that you want to get your butt to the range and start getting your data. So we will also assume that you have a chronograph and batteries for it and you’ve familiarized yourself with its operation. You’ve got your tripod and test mounted your chronograph to it and learned how to adjust it.

Grab some dry ice and stick it in the bottom of your cooler wrapped in a layer of cloth. Drop your wet ice on top of that. Your wet ice will now stay solid for much longer than it would have. Take your ammo supply and put it in a zip-lock bag and put that in the cooler. You’re going to need to let the ammo sit in there an hour or so to cold-sink. Grab your infrared thermometer and head off to the range after a quick stop at the drug store. Pick yourself up a box of Therma-Care brand heat wraps. There are other brands but TC heats quickly and evenly up to just short of 110 degrees and they’re very consistent which helps with safety.

The object here is to test 5 rounds at each of several temperature regimes. You want to gather each shots’ velocity. Start with a cold bore (this could take a while, you should have all day, maybe 2 days). Grab 1 round from the cooler and close it back up. Measure the temp of that cartridge with your infrared thermometer. You may have to measure several places on the case to get a consistent reading. When it comes up to 0 degrees F stick it in the chamber and touch it off as quickly as possible. You’re not target shooting so don’t bother trying for precision. I don’t even put a target up when I’m doing chronograph work. Leave the action open and let the bore cool for a few minutes. Grab a 2nd round from the cooler and when the temp comes up to 0F fire it. Rinse and repeat till all 5 0deg rounds are fired, noting each velocity in order.

After the gun is fully cooled off grab a 6th round and let it come up to 10 degrees F or 20 degrees F. With ball powders I’d usually recommend doing 10 degree increments. This is because I’ve found ball powders to be more routinely temperature affected. With stick powders 20 degrees has treated me well.

Once you’ve repeated this test at each temperature regime and worked up to ambient air temperature and you’re not needing the cooler anymore, pull any remaining ice and dry ice out of the cooler. You’ll now be working the other direction. Use the Therma-Care wraps to heat up ammo as necessary for each temperature regime. You’ll want to measure the amount of time it takes to get a single round up to temp for each temperature and then wait that amount of time for each following round in the shot string. This will help assure even heating.

As each set comes up to temp, fire it and log the data. Don’t get impatient here and let your barrel get warm. You don’t want it imparting additional heat to the system. Do this test for each temperature regime above your “station” temperature (whatever outside air is in the shade as an average where you like to shoot).

After you’ve burned through 40-100 rounds you’ll have a fantastically useful set of data for non-standard temperature regimes. Now you should take an additional 10 rounds at 60-70F and send those downrange and collect that data. You want more data points for your “station” temperature so we can sort out the standard deviation and extreme spread and average and get a useful number to put in as “the” spec muzzle velocity. There’s no harm in getting more data points for any particular temperature range. It’ll help the statistics be more useful to you.

Put the collected muzzle velocity data for all the loads in order into the Shot Log & Statistics tab of Ballistic_XLR and you’ll get some useful statistics. Standard Deviations over 10fps are getting near the too big zone. Extreme spreads over 20fps are also getting too big. Ammo should be velocity consistent or we’ll never get your elevation right at extreme range. Long range maybe extreme no.

You should have string data for 40,60,70,80,90,100 as a practical minimum. If you shoot where it’s really hot a lot (Oz) or really cold (Norway) then you’ll want to do some extra velocity testing in those conditions just to get the most accurate data you can.

Now take your noted 70 degree average velocity and add it in the appropriate box in column A on the Pocket PC inputs page. Take the average number for each temperature specific shot string and add that to the appropriate cell in the Muzzle Velocity Variation table on the Pocket PC input page for the appropriate temperature and velocity regime.

Ok, your standard and non-standard-temperature velocities are in MVV. Muzzle velocities are done man!

NOTE: If you only put in your 70 degree muzzle velocity in Column A and you leave the MVV chart alone then the MVV chart will make a lot of assumptions and do some BS math. The assumptions it makes are not far off what the average person should expect from the average load with an average case capacity and average bullet weight with average powder. That said, the numbers produced via guesswork have nothing to do with reality. By adding your numbers to each temperature zone you’re ditching my BS numbers and putting in real ones that will work.

Stay tuned for Part 7.

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