From that moment on he began to teach me how to work my Tikka and ammunition to a very high level of accuracy without a lot of pain or trouble that you too can apply to your varminting rifle. I was able to achieve 7 rounds into a group that was 2 bullet holes wide and 3 bullet holes high off a bipod and rear sand bag off a bench at 100 yards. This was a stock standard factory Tikka M55! You too can do this to improve your rifles accuracy and I intend to show you how.

Which Brass

No, this is not about weighing your brass cases! It’s who makes good quality brass. I seem to recall a recent thread on this topic in the forum or you can ask, about which brass to buy. If you buy quality brass and there is none better than Lapua you will have very consistent uniform brass that is well made and easy to prepare for reloading Winchester brass, by comparison needs a lot of work to bring it up to the same standard, but can be made to shoot just as well as Lapua. Better to spend the time shooting than trying to improve lesser quality brass!

Buying quality brass is almost like buying ready made BR quality brass that’s ready to go and it is so good you shouldn’t even need to think about neck turning; it is just so consistent and uniform. Most shooters agree that Lapua is the best, but do not forget that there are other brands that have a good reputation such as RWS, Norma, and Remington are also good choices. Since you are after the very best accuracy from your rifle buy the very best you can afford, far better to have 100 Lapua cases than 200 PMC cases. Think about it………

Accurising your Brass

Now this is the part where most shooters will say it’s not for me. If you want accuracy to be no better than say 0.5 moa as a general rule, then you can ignore this part. If you want more please read on.

The key to the accuracy is to ensure each and every stage of the reloading and ignition processes are the same for every shot. This is where you control the vibration patterns in the rifle during firing sequence and this is where the real problems of accuracy lie.

There are two tasks that need to be done and they are done only once. This does NOT include neck turning! Whew, they all say! The two steps all involve the improvement of the ignition process. You need reliable consistent ignition for accuracy.

Uniform the Depth of your Primer Pockets

You need to buy a primer pocket uniformer (with a carbide cutter for long life) for either large or small rifle primers depending on which you use. I’d recommend getting both. They will cut your primer pocket to a uniform depth and cut it square to the case head.

Imagine this, if your primer pocket depth’s vary by 0.005” (5 thousands’ of an inch) in your batch of cases and your firing pin sticks out of you bolt face by around 0.050” there is straight up a 10% variation in firing pin travel caused purely by the seated depth of your primers. This affects the firing pin strike to the primer which causes inconsistent ignition and reduces accuracy. You want to hit the primer exactly the same every time. So uniform those pockets!

From Top: K&M’s Small Primer Pocket Cutter, Large Primer Pocket Cutter and Handle

In the above photo, you can see on the middle Large Primer Pocket cutter a grub screw that allows for removal of the carbide cutter for replacement. By removing the drive shaft from the cutters main body, reveals a grub screw that is adjusts depth of cut by loosening the cutter screw you then wind the depth screw in or out to adjust the depth of cut. 99.999% of the time there is no need to adjust the depth of the primer pockets depth. The drive shaft is a standard ¼” drive and will fit most cordless screwdrivers for convenience.

Also you can use the cutter to clean out the residue each time the case is de-primed and this may cut a little more after the first few firings as the brass forms to your rifles chamber and this should stop after the brass hardens up. Cleaning out the pocket after sizing ensures each time the new primer is seated it will be exactly the same as the first time for the life of the brass.

De-burr those Flash Holes

Flash holes are sometimes drilled by the manufacturer, so the burr will be quite small, even and easy to remove, if the flash hole is punched like many manufacturers do, then the burr will be large and usually on one side. Either way burrs on the flash hole inside the case are bad news.

Any burr on the flash hole inside the case will have an effect on the primer flash and how straight it enters the powder column. A burr may deflect the primer flash off the centreline of the powder column in the case. Now because each case has a different size burr, each burr will cause a different flash into the gun powder which causes erratic ignition of the powder. By removing this burr in each case and creating a chamfered hole, will allow the flash of the primer to enter the powder column in a uniform manner creating a very consistent burn of the gun powder.

I like to think of these two steps as changing the ignition system of a cars engine from a points ignition system to an Electronic Ignition system for repeatable, uniform ignition of the fuel, which when you think about it a rifle and cartridge is a self contained fuel and piston or a single stroke, single piston engine…!

From Top: K&M flash hole de-burrer with the large flash hole de-burrer fitted, and the small flash hole de-burrer below

In the above photo, you have the flash hole de-burrer, the sliding brass sleeve slides into the case mouth to maintain alignment of the cutter to the case centreline, while cutting, and the steel sleeve around the cutter sets the depth of cut by coming to stop against the web on the inside of the case, cutting just enough to leave a nice chamfer on the flash hole. This tool is hand driven only, and you must clear the shavings regularly. The smaller cutter is for cases like the 6ppc’s, and other with small flash holes. If your cases have the small flash hole then get the small cutter as well. Since the depth of cut sleeve is slightly less than .224 cal, I think you can also get a .177 cal culler if needed.

Maintain Uniform Case Length

The final thing to do is to ensure that during the life of the brass, you need to monitor the overall length of the brass. If the brass in you ammo box varies by more 0.010” (ten thou) in length, then the longer necked cases grip the bullets more than the shorter cases. Longer cases have grip the bullet more and need more force to release the bullet. This causes differences in the amount of time that the bullet is inside the barrel.

As the barrel is whipping around during the firing sequence, if the time the bullet is in the barrel varies due to the grip of a case neck, your groups will be bigger. Not much bigger, but bigger anyway. Consistency is the name of the game. I like to trim when they get to be more than 0.005” (5 thou) for my hunting rifles and I always trim before a state level BR match. You will need to find you preferred threshold at which you trim your cases but keep them uniform and consistent. Another thing I like to do is use a case mouth de-burrer such as the one made by K&M to chamfer the inside of the case mouth to help ease bullets into the case without removing copper jacket material. Damage to the bullet is BAD! A regular de-burrer for the outside of the case is ok but not for the inside. A light cut is all that is needed for the inside of the case, but some rifles need a good chamfer on the outside of the case mouth to ensure reliable feeding.

In the photo below is the K&M inside neck de-burrer. This tool is adjustable for the amount you cut into you neck. You need only to do a slight cut certainly no more than 1mm along the inside of the neck. The “bent wire” you can see on the lower par of the tapered reamer cutter is a depth stop. There are 3 of these depth stops and they come to rest on the case mouth. The knurled knob is the locking screw for the reamer which slides in & out of the cutters body. This is a hand only operation and should be done every time you trim your cases to length.

The other de-burrer should be familiar and only used on the outside of the case. NEVER on the inside of the neck as it can leave small burrs even after you have de-burred. This is why I use the K&M tool A small 10x optical loupe (magnifier) from OPSM is a great tool for checking any small details.

From Top: K&M inside neck De-burrer and RCBS Case De-burrer

Remember, uniformity and consistency in everything you do will deliver the best accuracy from your rifle. The next article will go into reloading tips from the Benchrest world to help in working up a load for your rifle and accurised brass.