[LordJim]

Tolerances is my guess. One could even go so far as to ensure that the casing and the bullet are matched to the barrel/chamber of a particular gun.

-
Jim

[myopicvisionary]

First is the use of match grade bullets as in this case Sierra Match King HPBTs. All bullets are weighed and segregated. Second all cases are weighed so that case volumes do not vary. Runnout is checked to ensure that bullets are perfectly straight in the case. Basically, its a blueprinted round.

[George]

thanks, weigh empty then full to check volume?

[stephpd]

Myopic is correct. Using the best parts and being consistent with everything.

This should be the goal in every round that is reloaded. That match grade ammo uses very consistent parts and attention to detail for each part. With boat tail bullets being the most aerodynamic is the best place to start. But the routine of checking each part for the rebuild is what makes some ammo much better then the regular stuff on the shelf.

Not only are bullets sorted by weight but so are the cases. Start with a regular case and trim to length. Then weigh and sort by headcase and weight. Deburring the flash hole will also help to give the primer the best chance of a uniform burn. Checking for run out of the brass will also improve groupings. Seating the bullets with a competition seating die will keep the bullets straight while inserted into the case and give a more accurate COL.

Being able to improve on this is even more then possible by marking the orientation of the cartridges as to how they sit in the chamber of the rifle. Using cases fired from that rifle and only using an end sizer will make the cases fit that chamber better then any store bought ammo can be made.

Trial and error with what powder to use as well as which weight of charge can make big differences. A change of just 1/10 of a grain can make a difference. COL is also important. You want a few thousandths of an inch clearance between the bullet and the rifling in the barrel. Bullet sized for the barrel which requires slugging the barrel. 1/1000 of an inch difference can have dramatic results in performance.

That reloaders can make better cartridges then what can be bought off the shelf and for different targets is the ultimate in reloading. Match grade bullets are good for paper but not the best for all types of animals. Being able to choose the right bullet for the target is possible with most stuff off the shelf. Weight, shape and composition of the bullet will all have an effect on trajectory and how the bullet behaves on impact. Match grade ammo is designed for paper targets. That the companies make bullets for everything from varmint to cape buffalo shows that these need to be considered as well. Do you want a bullet that explodes on contact or drive deep before mushrooming? Or drives deep without mushrooming?

I'm just getting started into reloading and these are my goals. To make the best cartridge possible for my gun and have a selection of different weight, shape and composition for each type of animal that I'll likely hunt. I'll also apply these same principles towards handgun loads as well.