Reloading: Seated, Crimped & Sorted
- By Wheelwrite
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- Last updated: 19/05/2017
The moment we’ve all been waiting for! We finish our ammo build. From our reloading manual we have selected a near factory duplication load with regard to performance and bullet design and weight. The cases have been prepared, sized, primed and charged with propellant. We made reference to a COL (Cartridge Overall Length) in last month’s edition, so we will start with a sound safety procedure for a first time reload by making a dummy check round. Using a case of the same brand, we carry out all the prep work as before but refrain from installing a primer or powder charge. We can now use this to help set up the bullet seating process.
Select the bullet seating die from your set and inspect the seating punch that was supplied. The internal profile should be shaped to make contact with the radius of the ogive of the bullet, rather than its tip or meplat. If you have any doubt, then check with your supplier or a colleague with reloading experience. A punch (plug) that engages on the tip can distort the bullet and will inevitably cause inconsistencies in its seating depth. Note that some dies have a two piece floating plug assembly that is inside, but not connected to, the punch locking ring, such as the excellent Hornady New Dimension Custom Die Sets. Here, great care must be taken to ensure that the floating plug insert remains within the punch body when initially setting the die.
Place a case from the subject batch into the shell holder, cycle to the top and screw the seating die into the press until it lightly contacts its neck, then back the die off by between half and one turn. Lock it in place. Wind the suitable seating punch to the top of the die body. Half cycle the press; place a bullet from the subject batch squarely on the neck of the case and cycle to the top. Screw the punch down until it contacts the bullet. Open the cycle slightly, wind the punch down a turn or two and cycle again. Remove the dummy and measure the overall length. Repeat the process as necessary. When the overall length is about .020” longer than the specified COL for this assembly, remove the bolt from the rifle and test fit the round.
Repeat this seating/testing cycle until you can just close bolt. Remove the round and run an ink mark around the ogive of the bullet. Chamber the round again and close the bolt. You should have a clear witness mark around the ogive just above the neck of the case. Confirm the overall length of the dummy and then further seat the bullet until the dimension is reduced by approx .010” to .012”. Lock the seating punch in place. CLEARLY mark this dummy round with a memorable reference mark or label and quote the details in your reloading records. You can now reload the batch of charged cases. Measure the first loaded round from the batch, just in case! Eyeball each bullet for damage, before placing it on the neck of the case.
If your chosen bullet has a cannelure (crimping groove) then the COL may be determined by its position. (If the position of the cannelure does not match the ideal position for the desired COL and there is sufficient neck tension for safe assembly, then the rounds can be assembled in the manner described above). Otherwise, you will need a seating die that has a roll crimp in order to deal effectively with this bullet design. We set the seating die body as before and start with the seating plug set at the top. Having placed the bullet on the neck of the case, we incrementally adjust the plug deeper until the lower rim of the cannelure is just below the rim of the neck (that is, with MOST of the cannelure still visible). We now back the seating plug out a few turns and wind the main die body deeper, until it touches the rim of the neck. Now wind the seating plug down until it contacts the seated bullet.
After locking it in place, we half cycle the press and commence incrementally screwing the main die body deeper by no more than a quarter of a turn at a time. Examine the assembled round after each adjustment. The visible part of the cannelure will slowly reduce and a slight radius will become visible on the neck of the case. The crimp is complete when you can no longer feel the rim of the neck when you run the cartridge between your thumb and forefinger. Any further increase in the crimp is only going to add damage to the rim of the case neck.
Remember that we have set and locked the dies to work with a specific set of components and conditions, as noted in your reloading records. Any changes in these, whether to the make (headstamp) or condition (number of reloads) of brass, bullet weight, make or design, or in the rifle to be used and a new die setting procedure will be required. Whenever a new batch is to be assembled, regardless of changes, or the lack of them, make sure that the dimensions of the cartridge and its fit in the rifle are correct. Imagine having to dismantle (pull) a whole batch of loaded ammo because the position of the locking ring had changed or the new brand of bullet was seated too deep for safety?
We’ve already discussed this topic but it is worth a second airing. If the budget permits, get yourself a suitable chronograph or scrounge the use of one from a friend (on a “you bend it, you buy it” understanding!). A record of the velocity of your newly assembled cartridges will give you an invaluable base for possible future ammo development. It also enables you to compare your real data with that in the manual for the same recipe. If you are using the ammo on game, then the energy calculation based upon your actual readings will enable you to ensure that you are above the legal minima for the species and region of the country.