Case prep questions

[FallAirFever]

So I finally have my bench set up and I'm getting some brass prepped to load. What are your thoughts on these steps and do you do them each time you prep or just once?

- chamfer and debur
- uniform primer pockets
- uniform flash holes

I usually neck size my brass.

Thanks for your input!

[Dick284]

I only chamfer and de burr if I trim.

Flash holes and pockets are a one time only thing as well, once they are done the first time you’re fine for the life of the case.(I do use an old, dull pocket uniformer to clean the pockets though)

[260 Rem]

For new brass you can not go wrong by:
*deburr inside of flash holes
*chamfer and deburr
*NK or FL resize
You are then ready to prime, charge, and seat.
After first firing
*clean carbon off NK
*nylon brush inside NK
*NK or FL resize
*clean carbon from primer pockets with a primer pocket uniformer
*check case mouths for square and trim to uniform lengths if necessary (chamfer if trimming)
Prime, charge.............

[303carbine]

What 260 said, and after about 1/2 doz firings, anneal the cases.

[Pathfinder76]

I chamfer after trimming. The end.

[Armorman]

You can get pretty crazy with brass prep. Other than the most common steps that 260 Rem listed I also like to group/sort my brass by weight just before I'm ready to prime. I'll also check neck concentricity at that time. It's all about being as consistent as possible.

[DiabeticKripple]

For once fired brass I:

- Deprime
- SS Tumble
- Dry in the oven
- Neck or FL size depending on application
- Trim to length
- Chamfer and deburr

[Dubious]

I deprime full length size, trim (if it’s time) chamfer and debur (only if I trim) then stainless tumble for up to 3 hours depending on amount of brass with dawn and lemishine. Had the idea that that the tumble at the end would clean off any left over lube or brass bits from the rest of the process along with the old carbon. I air dry them now found that the oven turns them straw color.

[gunluvr]

Since I make a point of keeping my spent brass clean, I don't tumble first. I determine FL sizing die adjustment by carefully measuring with a headspace comparator. I set the shoulders back no more than .002". (I'm not a fan of neck sizing.) De-priming is also done here. So, after lube and partial resizing, I wipe off excess lube, then measure for trim length and trim if necessary. Then clean primer pockets, then deburr/chamfer if necessary. Then into corncob media tumbler for 3 hours. This absorbs any left over lube inside and out. After a toss in media separator, I blow each case out with compressed air to make sure flash holes are clear. I segregate cases by manufacturer.
You can wet tumble with ss pins and detergent if you like, then dry, but I've never seen a need to.
This is all my personal preference, others will do things differently.

[6MT]

To the OP, if you're only neck sizing, you will eventually have chambering issues.

[tranq78]

Originally Posted by 6MT

To the OP, if you're only neck sizing, you will eventually have chambering issues.

Noob question. Why is this?

I have heard neck sizing may be less accurate than FL resizing but what type of chambering problems?

Sent from my SM-G900W8 using Tapatalk

[Dick284]

Originally Posted by tranq78

Noob question. Why is this?

I have heard neck sizing may be less accurate than FL resizing but what type of chambering problems?

Sent from my SM-G900W8 using Tapatalk

Cases stretching and being unable to chamber, and thus require the shoulder to be bumped back.

And what’s this about neck sizing is less accurate?

Somebody is spinning bs, or you mis heard them. But I’d like the full story just because.

[260 Rem]

Originally Posted by tranq78

Noob question. Why is this?

I have heard neck sizing may be less accurate than FL resizing but what type of chambering problems?
Sent from my SM-G900W8 using Tapatalk

My theory is .....
Each time the brass is fired, it expands against the chamber walls and then springs back towards it’s pre-fired dimension. This repetitive cycle results in progressive work hardening which means it never springs all the way back to the prefired dimension...so the case is always “growing”. Coincidentally, the brass has a tendency to flow forward because that is the easiest path given the limitations imposed on it by the chamber walls and boltface. After repeated firing cycles (of course the greater the heat/pressure — AKA hotter loads —-accelerates the process), spring back at the tightest fit in the chamber (the datum point where the cartridge headspaces) ... is reduced until chambering becomes noticibly more resistant. At that point, the brass will need to be FL resized to recreate the headspace clearance. Although this remedies the headspace issue, it will occur again as the work hardening process continues with each “cycle”. Thus, it is common to need to FL size with increasing frequency as the brass continues to work harden.
Regarding the relationship between NK sizing and accuracy ... many feel that NK sizing improves accuracy because it results in the case fitting tighter in the chamber. I don’t think that is necessarily true.

[Pathfinder76]

Originally Posted by Dick284

Cases stretching and being unable to chamber, and thus require the shoulder to be bumped back.

And what’s this about neck sizing is less accurate?

Somebody is spinning bs, or you mis heard them. But I’d like the full story just because.

Neck sizing alone is the most antiquated unproven accuracy enhancing fairy tale in existence. If I want consistent brass, I MUST move the shoulder. Otherwise it is not the same as it was before and therefore inconsistent.

[Ariu]

Are you loading for hunting or bench shooting?
Is you brass new or fired? If fired, how many times? From your rifle or not?
How many rounds are loading?

If the brass is once fired from your rifle and if you are loading hunting loads then:
1. Deprime
2. Are you tumbling? If not, check and clean primer pocket. This step might be skipped if you are tumbling and primer pockets come out clean.
3. Neck size if fireformed or FL size if not
4. Trim to length
5. Chamfer and deburr

if you are loading a big batch or developing a load, then you might consider of dividing you brass by weight groups.

[Quest206]

- uniform flash holes - one time only
- uniform primer pockets - one time only
- chamfer and debur - only after trimming

If you are only neck sizing then you should invest in a case gauge. This will tell you when to full length size and when to trim. You should anneal to prolong case life as 303 carbine mentioned. Lee makes a collet neck sizing die that will uniform neck wall thickness so you have minimum runout. Best neck sizing die on the market IMO.

[FallAirFever]

So this particular batch of brass it has been fired in the same gun I am loading for. That's the reason I am neck sizing although Chucks point about moving the shoulder a bit for consistency sake. I guess this would be partial resizing???
I load for hunting but I do like to make these loads as accurate as possible without going way over board. I actually enjoy brass prep but wasn't sure if a couple of the steps were a one time deal or an every time thing I think I have my answer to that. But I am going to give some thought to neck sizing a few times then FL or partial resize...


My next batch of brass is Lapua and I'm wondering how to tackle this stuff.

[tranq78]

Originally Posted by Dick284

Cases stretching and being unable to chamber, and thus require the shoulder to be bumped back.

And what’s this about neck sizing is less accurate?

Somebody is spinning bs, or you mis heard them. But I’d like the full story just because.

I'm not saying I believe everything on the internet.

This guy is saying his neck sized ammo is inaccurate. He goes on to discuss chambering issues as the cause. His native language is Japanese but he communicates pretty well.

https://www.youtube.com/watch?v=pxSX8BN3VgI&t=138s

[tranq78]

Originally Posted by 260 Rem

My theory is .....
Each time the brass is fired, it expands against the chamber walls and then springs back towards it’s pre-fired dimension. This repetitive cycle results in progressive work hardening which means it never springs all the way back to the prefired dimension...so the case is always “growing”. Coincidentally, the brass has a tendency to flow forward because that is the easiest path given the limitations imposed on it by the chamber walls and boltface. After repeated firing cycles (of course the greater the heat/pressure — AKA hotter loads —-accelerates the process), spring back at the tightest fit in the chamber (the datum point where the cartridge headspaces) ... is reduced until chambering becomes noticibly more resistant. At that point, the brass will need to be FL resized to recreate the headspace clearance. Although this remedies the headspace issue, it will occur again as the work hardening process continues with each “cycle”. Thus, it is common to need to FL size with increasing frequency as the brass continues to work harden.
Regarding the relationship between NK sizing and accuracy ... many feel that NK sizing improves accuracy because it results in the case fitting tighter in the chamber. I don’t think that is necessarily true.

Interesting.

I've got a milsurp that causes bulges in the casing. This is apparently normal. The rifle was made before SAAMI ever existed.

A FL resize will probably wreck the case after a few uses.

I'm not even sure I can bump the shoulders because of the bulging. I don't have a collet die. I've got a Lee FL die, maybe back it off one full turn, gradually tighten, and see if that works?

[Smokinyotes]

For those that are just neck sizing just do a few and then try them and make sure they chamber in your rifle. When I was a newb Reloader I neck sized 100 243 win brass, primed, poured the powder seated the bullet to find out I should have done a F.L resize cause I couldn’t get the bolt closed.

[260 Rem]

Originally Posted by tranq78

I'm not saying I believe everything on the internet.
This guy is saying his neck sized ammo is inaccurate. He goes on to discuss chambering issues as the cause. His native language is Japanese but he communicates pretty well.
https://www.youtube.com/watch?v=pxSX8BN3VgI&t=138s

I watched a few minutes of the video before deciding that the chap would score about 2/10 regarding his understanding of reloading. I suggest you erase everything he said from your memory bank. NOTE: The scale I am using to assess his understanding awards a 1 if the reload goes bang and a 2 if it does not blow up
Tranq78, if you a member of SPFGA, there is a free Reloading Demo on April 15th.

[Full Curl Earl]

Originally Posted by chuck

Neck sizing alone is the most antiquated unproven accuracy enhancing fairy tale in existence. If I want consistent brass, I MUST move the shoulder. Otherwise it is not the same as it was before and therefore inconsistent.

That’s calling a lot of world class shooters out Chuck.
Consistent brass can only be obtained from forming it in the mold it will be used in. Neck sizing only has always improved group size for
me. You don’t neck size?

[Pathfinder76]

Originally Posted by Full Curl Earl

That’s calling a lot of world class shooters out Chuck.
Consistent brass can only be obtained from forming it in the mold it will be used in. Neck sizing only has always improved group size for
me. You don’t neck size?

This is not the norm anymore. And I’ve neck sized. Not any more.

[Pathfinder76]

A quick google search. He is a known competitor by the way.

https://youtu.be/lLG2kSrD40g

[gunluvr]

Originally Posted by chuck

Neck sizing alone is the most antiquated unproven accuracy enhancing fairy tale in existence. If I want consistent brass, I MUST move the shoulder. Otherwise it is not the same as it was before and therefore inconsistent.

Completely agree.

[260 Rem]

I expect that the top dogs are running chambers cut by reamers spec’d to match the dimensions of their FL resizing dies. Resizing is minimal which not only results in a tighter chamber fit, but also reduces the work hardening of brass.

[DLab]

https://www.ingunowners.com/forums/a...-resizing.html
Another knowledgeable opinion on the topic .
I full length size either with a FL sizing die or Redding body die,bushing die in combination ,depending on the cartridge.

[Pathfinder76]

This ought to cause a stroke or two.

[DLab]

Originally Posted by chuck

This ought to cause a stroke or two.

Thanks ,
That works better than my link to it.
To answer the OP's original question,
New brass I run them over a button or mandrel to straighten necks, chamfer and fire once or twice ,then size ,trim to length ,chamfer ,de-burr ,check the flash hole ,de-burr if necessary.
For Bench rest cartridge's that are neck turned I do a little more prep work.
I have experienced the problems associated with NK sizing only ,and have also seen it with other shooters.
You need the tools to be able to measure minimal bump at the datum line to set your dies up properly ,more critical for target use then hunting rounds.
IMHO it saves over working your brass in either application and more importantly makes my rounds more consistent in accuracy and chambering feel.

[Salavee]

A headspace gauge gets it right every time. I think a fired case provides the best replication of a particular chamber. Use a headspace gauge to determine a datum point on the shoulder, bump the shoulder as required and carry on. A mandrel neck sizing die is great for maintaining concentricity as well.

Neck sizing only is far from obsolete from my experience.

http://www.larrywillis.com/