Friday, July 18, 2008

Bullet seating, the final event

In the first five installments of this epic work, we look at all the steps of reloading reasonably accurate rifle ammo, right up this point:


Here we sit with a rack of nicely prepared and primed cases, all loaded with perfect powder charges. All that’s left is to seat the bullets and box them up. How hard could that be?


Bet you thought I would say it’s way hard, then spend a thousand words telling why in detail. Actually, it’s mostly way easy. The hard part is deciding exactly how far in the case to seat the bullet. The bit where we press the bullet into the case? The die deals with that once it’s properly set up. Just load the press and push the handle down!

No, the next thousand or so words will be about setting up the die, mostly. Also, maybe a little about seating depth, and a little about cartridge boxes. Oh.... some about labels too.

Come to think of it, I’ll probably just be babbling along for a while.

Before we can set up the die, we must decide how deep to seat the bullet. This is one subject that can keep reloaders gathered late around the camp fire. Everyone has an opinion, and the weird thing about it is.... most are right. The reason is simple. Every rifle, every bullet, and every load has a sweet spot where the bullet needs to be seated for best accuracy. Arguing about where that spot resides is silly.

Finding the perfect load for a rifle usually means changing one detail at a time, making little adjustments and testing till the recipe is refined. Once all the other factors are worked out, precision shooters will often haul their reloading gear right to the range and test seating depths. Making changes a few thousandths of an inch at a time till the ‘sweet spot’ is found for that load and bullet.

Since we are not loading for precision rifles here, but military surplus weapons, I’ll approach the subject differently.

While a bench rest shooter might be concerned solely with how far his bullet seats compared to the barrel lands, Hi Power match shooters and Mil-Surp hobbyists have magazines to deal with. In addition to that, Military rifles often have long throats the bullet must jump before entering the rifling. Seating to touch the lands, if even possible, usually means the cartridge will not feed from the magazine.


We also have to consider another factor. Cartridge handling and durability are an issue.

Bullets seated too shallow can fall free if not treated carefully. On the other side of that coin, bullets seated too far out might engage the rifling on chambering, followed by pulling the bullet out of the case if the bolt is opened. An action full of powder is not a pretty sight!


In my humble opinion, rifle cartridges in the .30 caliber arena should have bullets seated at least one half the neck deep for reliable handling in a target shooting environment.

If defensive or hunting use was the goal deeper seating would be in order. Military loaded ammo usually has bullets seated full depth, at the least.

(The following directions and tips are for setting up a standard RCBS seating die. Specialty seating dies require following the makers directions.)

My methods are really pretty simple. First, mount the die in the press. At this point leave the die very loose. Loose enough that it won’t be doing anything to either the case or bullet when the ram is raised.


Now we insert a case into the shell holder on the press ram. (I like to use a spare case for this step, rather than a match prepared case.)

Raise the ram till the case is fully inside the seating die. If there is any hint the die is impacting the case, lower the ram and unscrew the die a bit. If the die does not touch the raised case, then screw the die down till it just does, then back it off ½ turn and set the lock ring.



The goal here is to have the die fully support the case as much as possible while seating the bullet. Skipping this step, or seating with the case only partially in the die, can contribute to the bullet being seated in a non-concentric manner. Non-concentric means wobbly and wobbly is baaaaddddd.

Now bullet meets case for the first time. With a charged case mounted in the shell holder, set your bullet of choice in the neck. It probably won’t stay there straight as the neck is sized smaller than the bullet diameter. It had better be, anyway, or you grabbed the wrong bullets!

The bullet will probably have to be guided with one hand as the press ram is raised and the assembly runs into the die gently. Take care not to pinch your fingers! The average press can snap your finger like a toy, and it really, really hurts. I know. I don’t want to tell how I know, but I really, really know.

As the bullet and case enter the die for the first time, make sure the seating stem is backed well off. We don’t want to fully seat the bullet here, just nudge it into the case. This will take repeated attempts, tweaking the seater stem a bit at a time. Go slow, and have a bullet handy to match up with the subject, using it to judge how deep in the neck our bullet is being seated.

If this is the first attempt with this rifle, I would be checking the fit against the rifles magazine. NOTE: Do not load the rifle in the house! There is no need to even have the bolt in the rifle! Just check for fit and then dump the magazine floor plate to release the round. Do not even take the risk of chambering the round.

Once the maximum length is found for the magazine, load development can begin in looking for maximum accuracy.

If this is an established load (and the load this article is based on..... is) then I use another method. I set my vernier caliper to the desired over all length and lay it on the bench. Each step of setting the seater, I try the loaded round against the caliper as a gauge.


Bumping the seating stem a few thousandths at a time, continue matching to the gauge till it just fits. The last couple of thousandths should be carefully measured and rechecked after the seating stem is locked down. The act of locking the stem will usually change the depth by a thousandth or two, and must be accounted for.


The seating die is now set up! Go ahead and seat the rest of the bullets!

Whoo Hoo! The set of match ammunition is now finished!

NOW what do we do with it?

How about we box it up properly, and mark it properly?



Good quality cartridge boxes are worth investing in. They can last almost a lifetime and serve to protect the time we’ve invested in or precision ammunition. They also keep the ammo racked in a way that lets us label it properly.

One of the problems facing hand loaders is keeping track of the details. This isn’t factory ammo, and we can’t just go to the store and buy another box. Safety demands we track everything we do. Common sense tells us we can’t hope to duplicate a winning load without knowing what we did.

Logs books are a must, but labeling the ammunition is key as well. Some people like to number their loads, and then log the data. Others simply mark up the box with the load data and skip the log. My choice: Both, of course. I log the load as I shoot it in testing, and I mark up all the load information on the box, or a label inside the box. Sometimes I place a detailed log sheet inside the box, and often I write the load data on the test target and save that as well.

In labeling the ammo box, and just about everything else for that matter, here is a tool worth its weight in gold:


It's an electronic label maker. A family member gave me this several years ago at Christmas. My first act was to label her dog (as 'Dog', naturally). The second label went to her other dog (Dog #2). After that it got interesting.

These can be purchased for around $20 now, and have a multitude of uses. I label powder, bullets, ammo, spare parts, and just about anything else. It lives on the loading bench and gets used often.

Looking at the box shown above, we see it’s labeled in a way that will let me duplicate the load as long as I keep the cases in that box, and that box mated to the rifle.

Now, I know some smarty is going to notice a word on the box I haven’t used yet. Comparator. This is a device that allows the hand loader to set up every new load and bullet combination to the same distance-to-lands as the sweet spot requires. It looks like a big machined nut, but in each flat is a hole exactly at the marked caliber. It fits on the bullet right at bore diameter, where the bullet will strike the lands as it proceeds down the barrel. This is the spot on the bullet that must be referenced to recreate the distance-to-lands with any bullet desired.



With the comparator on the bullet, measure the length from the cartridge base to the far end of the comparator. Now we have a number that can duplicate in developing a new load for that rifle.

That little tidbit finished, it’s time to wrap this up.

In the six parts of this series I’ve tried to lay out some methods I use to work within my hobby. If they are helpful, then great, it’s all been worth it.

To new reloaders, I offer this advice: Buy some manuals and read them. Read them before you begin hand loading. Read several and compare them. If you can find an experienced reloader willing to teach, do that too. Take your time, be careful, and never push the limits. Don’t go on the hunt for the most power, the highest velocity, the tiniest bullet...... etc. It’s wasted time. Hunt instead for accuracy and reliability.... there the gold will be found.

Next up: A post with results! Taking the ammunition made during this series of articles and comparing it to military surplus 8x57mm. We'll see exactly what doing this work will achieve, besides having fun and the pride that goes with building your own precision ammunition.


Brigid said...

You make it look so easy, not like the art form it can be.

If it gets a bit cooler out, I may try my hand and some next weekend.

Fun on a workbench. :-)

BobG said...

"Buy some manuals and read them. Read them before you begin hand loading. Read several and compare them."

Some of the best (and neglected) advice on reloading.
I've been reloading for 20+ years, and must say that is an excellent series of posts. I only reload pistol ammo these days, so my reloading is a little less complicated.

pdxr13 said...

Your words about a clean bench and lack of distraction are right on. A loading room/closet needs a door that can be closed and locked if you are called by nature or the phone/door needs answering. Adult beverages, smoking, being tired, recovering from the flu, are all incompatible with finishing safe cartridges that you can have complete confidence in.

There are loads that fill less than half of the cartridge, allowing a double-load of powder to be charged without spilling out the neck. Avoiding this kind of load is good practice, but while the charged cases are in the loading block a strong light can be shined on the open necks and the level of powder can be examined. A double charge will be obvious. Any variation in powder level is cause for putting the suspect charge on a scale to confirm/dismiss before inserting a bullet.

Thanks for this series.