I’ve got all this once-fired Nato-LC 5.56 brass. I want to make as much of it as I can into match-grade ammo. So I start sorting it by head-stamp year but then I get to wondering if that makes any difference at all. As I’m sorting I’m noticing that even within a given year some headstamps look different then others and some have a different style crimp. So I’m figuring that there’s likely to be as much variation of critical dimensions between cases of the same year as ones from different years.
So I guess that’s my question: have you noticed any correlation between headstamp year and consistency of critical dimensions? Should I sort this way or skip that and proceed directly to sorting by case neck thickness / uniformity, case volume, case weight, etc.?
Don’t waste your time - process all your brass the same way. Before you even begin, cull out the defects - badly dimpled cases, off center flash holes, split necks etc. Size, trim chamfer/deburr, remove the roll crimp on the primer pockets etc so that you have the same external dimensions for all the brass. After that, sort by weight - i.e. 1 or 2 grain batches, this will take into account any variations of wall / webb thickness (read internal volume). Don’t even consider turning necks for a gas gun. LC brass is generally really good and pretty consistent. It does vary from lot to lot / year to year - but overall is of generally very good quality.
BTW - I don’t sort by weight for anything other that 600 - 1000 yd ammo. Anything from 100 - 500yds get loaded from the same lot with the standard processing. The LR stuff get a fair amount of extra care.
The federal American eagle 50gr varmint tipped .223 is amazingly accurate out of a 1/7 twist barrel.
By separating your LC brass by year will help keep constant seating depths when seating your bullets. That’s the only reason I do it, to not to have to sit and adjust the seating die up and down saves a bunch of time if your trying to get the same COAL on every round.
Separating 5.56 brass by any measure is largely a waste of time in my experience. There are a few flavors of brass that have significant internal case volume variances. But for the most part I mix ALL my brass together for precision shooting. (.223 only… .308 is a different animal)
You don’t get mixed AOL useing mixed brass? To keep all cartridges the same OAL I have to back my seating die off and adjust it down to make sure they are all say 2.200 if not some are shorter or longer than others. Not a lot shorter or longer but some.
On just plinking rounds I would say it doesnt matter but for accuracy a few thousands either way in COAL can make a difference depending on what the rifle likes the bullet set at. There has been a few test targets posted here that show this extremely well.
Maybe it’s time for me to get a new seating die. But I don’t know how that could adjust automatically for inconsistent bullet lengths and thicker or thinner bases unless all brass is trimmer to exactly the same length. I have yet to find a box of bullets in pistol or rifle that were all the exact same length. Some vary a great bit.
Maybe iam just thinking more of useing mixed brass IE mixing Winchester,remington and LC all together. I just separate everything now into groups. Including LC by year.
The cartridge COAL usually don’t vary due to the brass and trim length. Unless you’re crimping while you seat which I would highly recommend you not do. Somebody here can probably explain it better than me but crimping while seating can mess your COAL up and ultimately screw up your cases so I never went down that road.
Most people seat the bullet then separately use a Lee FCD to crimp. You’ll still have a slight variance due to the same bullets being off a little but not much.
What you are seeing is the difference in the ogives of the bullets. I have seen as much as .010 difference from SMK’s, but they still shoot lights out.
I love the LEE FCD its so simple to use… I own one for every caliber but 6mm Rem. ,havent found that one yet,dont think they make one. I wonder if the one for .243 would work ? Never thought of that.
Hey thanks, that will be my next purchase when I find one…I’ve got rcbs dies for my 30.06, that FCD should be a whole lot easer to find local. I don’t shoot it much though…6mm rem. is a different story even the brass is seasonal like factory ammo.
And of course thats the round I like best for the smaller S.texas white tail deer. I think a change to a more popular caliber is coming though. I sure don’t want to , but may be forced to in the future.
It depends on your rifle I have two AR15s and a bolt action .223 with a heavy 26 inch barrel. The bolt action gets the best brass followed by my A2 HBAR and the carbine gets the unsorted left overs. And Lake City brass is the best brass the tax payers can have made and I would never think of letting any of my AR15s chew the rims up on Lapua brass.
Just run a test of 50 cases, sort by matching headstamp and then weight sort and load, then load 50 without any sorting and see if you see any difference. Your the one pulling the trigger and it will be a learning experience about your rifle and ammo.
And if you want to load ammo with the least amount of neck runout then buy a Forster full length die with the high mounted expander. I converted my RCBS dies by buying Forster expanders and spindle assemblies and I’m getting .001 or less runout after sizing.