My case prep

janfred · 2023-08-21T00:02:08Z

I reload because I want to shoot accurately. It is a means to an end, not the end itself. The days I enjoyed load development as a hobby is long gone. As a clever man once said, if you want the easiest way to do things, give it to a lazy man to do. So, as you can imagine, I have worked out a system for case preparation to do the least amount of work possible and still end up with accurate and precise cartridges.Step one, start with good components. In my case that is Lapua brass, berger bullets and S&B primers and whatever powder I can get. In most cases that is Somchem S335.Lapua .308Win brass has the most constant and even neck wall thickness that I have personally seen. The weight difference from case to case in a batch is less than the 3gr Nosler garantees with their Custom Competition cases and still cheaper. You may want to turn the necks if you do benchrest shooting, but for normal bisley, PRS, hunting or plinking you are wasting your time. On average my cases have a 0.015" neckwall thickness. A specific case's neckwall thickness can vary between 0.014" to 0.016" which gives a case induced total run-out of 0.002". You can turn all the cases to 0.014", but that is a lot of work for very little return.I have 3 rifles and every rifle has 600 cases. Every case I own has space in an ammo box and every box is numbered. The boxes are used in the numbered sequence in the rifle they were purchased for. That way I do not need to keep track of how many times they have been used as they are all the same until the sequence repeats. The cases are discarded when I change barrels or when one fails. Hence the required 600 cases per rifle. Expected accurate lifespan for a bisley .308 barrel is 6000 rounds. Ten shots per case seems fair.When I shoot, I take a cartridge out the ammo box, put it in the chamber, shoot it, remove the case from the rifle and place it back in the box. My cases are not ejected to fly through the air and fall into the sand. If the unthinkable should happen, the case gets picked up immediately and cleaned before it goes back into the box.When others hear how I size cases sizing the ridicule starts. I take the case as dirty as it came from the rifle and size it with a forster bushing bump neck die using a .336 bushing. The shoulders are bumped back 0.003". And no, I do not use case lube. And yes, I still use the original bushing I bought with the die back in 2016. It does not scratch case necks even after using it in this way for 10,000+ uses. And yes, the bolt still closes easily on the cartridges even after 10 uses without having to full-size or use a body die. I haven't used lube on 308 cases since 2017. I think this works because the carbon on the case neck acts as a dry lubricant. And because I am not sizing the body, I do not need lubrication there either. It also helps that I do not load to the ragged edge so the web expansion is kept to a minimum.After sizing 10 cases chosen at random are measured for length. If any are 51.1mm or longer, all the cases are trimmed with a Giraud 3-way trimmer to 50.9mm. Then they go one box at a time (50 cases) into a normal vibratory tumbler until the necks are mostly clean on the outside. I have three tumblers so can do 150 cases at a time. From the tumbler the flashholes are cleared of tumble media, case is inspected and then goes back into the ammo box primer side up. That way I can see the flash holes are clear and any media still in the case will fall out. I do not uniform, deburr or ream primer pockets. This is one of the reasons I uses Lapua cases despite the cost. I do not clean primer residue out of primer pockets. Tests I have done does not show any improvement in accuracy or velocity numbers. If there is a difference it is so small that I cannot measure it.I then prime the cases using a Lee hand primer. The case is removed from the box, primed, checked that the primer is below flush and then replaced in the box primer side up. This way I can easily see that all cases are correctly primed. When I charge cases, I remove the case from the box, charge with powder, seat a bullet and place the completed cartridge back in the ammo box. Job done.Let the questions begin...

Againstthegrains

(@againstthegrains)

Posts: 228

Reputable Member

I asked because I know a few guys who are sticklers for accuracy, that anneal each time they reload. The claim, is that the case neck hardening and therefor neck tension increases, cumulatively after each loading/firing cycle. By annealing each time, they have identical neck tension across all brass, no matter the age/number of cycles. They shoot oddball calibers, so they have to make sure the brass lasts a long time.

Posted : 22/12/2023 9:38 am

janfred

(@janfred)

Posts: 415

Reputable Member

Topic starter

This is where good quality components come in. It appears that Lapua necks harden at a similar rate. Provided I do not mix my cases, neck tension seems to be reasonably consistent over the whole batch from a subjective point of view. For all I know the hardness can be all over the place; as long as the ES/SD is within limits, I don't care

Also, the rifle was chambered with a custom reamer so the neck diameter is 0.342" and the base is at minimum SAAMI spec. The brass does not get worked as hard as with a standard chamber.

I think people tend to assign values to some reloading steps inconsistent with actual results.

Posted : 24/12/2023 6:38 pm

oafpatroll

(@oafpatroll)

Posts: 1106

Noble Member

I think people tend to assign values to some reloading steps inconsistent with actual results.

^This. A small fraction of reloaders I have ever met measure the effects of changes to a single variable let alone record it for subsequent analysis.

Posted : 25/12/2023 12:20 am

janfred

(@janfred)

Posts: 415

Reputable Member

Topic starter

To me one of the most irritating comebacks from some experienced reloaders is "just in case it makes a difference".

Posted : 25/12/2023 1:17 pm

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