Seating and Crimping. These final steps can be done with one or two dies, depending on the type of crimp.
Taper Crimp ... this is just firmly pressing the case neck against the bearing body of the bullet. Considered the best for accuracy. Mainly for bolt guns and single shot/break open actions. A taper crimp is applied with the Lee Dead Length Bullet Seating die. It is done in the same stroke, bottom of it, as seating takes place. Semi Autos and pump rifles usually require a Roll Crimp. This type crimp actually roll the edge of the case mouth over and against the bullet. The Lee Factory Roll Crimp die is used even for bullets with NO canilure. Thats the serrated ring around the bearing body of the bullet. Also if you carry your ammo in a pocket loose, you many want a roll crimp. A roll crimp is firmed than a taper crimp and will produce a little higher pressure with like components. Some autos and pumps with removable Mags vice a tube can sometimes get by with a firm taper crimp. You dont want the bullet to suffer "set back" by strong recoil or pressing against another bullet in a tube Mag. Set Back will change the C.O.A.L. and you will get vairying results in shot patterns and point of impact. Nothing wrong with roll crimping rounds
for a bolt gun. All Factory ammo is roll crimped as they dont know what guns it will be shot out of.
For my bolt .308s I use the taper crimp there for only the Seating Die is Required. A seperate crimping function MUST be applied to rounds that are only NECK SIZED. The neck sizing die does NO CRIMPING. By adjusting the Factory Crimp Die a taper crimp can be applied.
Just to go back and touch on the Case Trimming step. You will not achieve a good crimp, taper or roll, unless every case is the same length.
Pic 1 The two different 150gr .308 bullets I load with for White Tail Deer. On the Left is the Soft Point Boat tail. On the right is the Soft Point Flat base. Boat Tails really dont aid in accuracy under 300 yards. They stabilize better at long range and may not be fully stabilized at shorter ranges. The Flat Base is a superior performing bullet for shorter ranges, and even some longer range Match shooters use them up to 600 yards with great results. Depends on you gun. I will use the Flat base bullets.
Pic 2 is the Lee Dead Length Seating die. Depth is set by the Knob on top.
Pic 3 A fully seated round showing the C.O.A.L. I check about every third round to ensure consistant seating depth. Notice my digital micrometer shows lentgh to the 10/1000 th. Every bullet in this sequence seated to with 5 10/1000 of 2.7500
Pic 4 A charged case that has the bevel applied with the Zip Trim. The bullet sits on top and ready to be seated. Slowly lower the arm until the bullet enters the die and the apply firm, but not over agressive pressure at the bottom of the Stroke.
Pic 5 this is the info I put on every box of reloads. I know its a little fuzzy as I didnt reset the lens for CLOSE UP SHOTS ....MY BUST.
It is labeled with Caliber of round, Bullet brand and specs along with C.O.A.L., Powder brand, type, and load in grains, Brand of case, and Primer Mfg. with type of primer, and # of time these cases have been reloaded.
Now have 31 loaded rounds Ready to Shoot. They will be tested at my Sighting in range, for me its 75 yards. From year to year the same load tends to change somewhat. By that I mean can shoot a little worse, same, or even a little better than in the past. You want to know before You get a big
Buck in your sights during the season. AS this loading is tested in the Savage
Axis and Marlin 7X I will post results in the Going Shooting thread.