I've got roughly 300 pieces of 300wm brass, of varied manufacturers.

I know this will add a variance to my loads, but how much?

How much will that matter to me?

I'm not exactly going for tiny groups on paper, I really have no desire to be a benchrester much past 500 yards, and I would use my 308 for that.

I want  to pop a 12" balloon out to 1000yards, and an 18" balloon to about 1800 yards, simple as that.  Shooting will be done makeshift prone out on pubic land, and honestly just for light hearted fun.

With the current covid conditions and a depression coming, I really don't want to spend money that I don't need to.  Think I can get by with the varied brass?

Sort by headstamp, if you want to load all to the same specs, you may have to work up the load for each due to internal dimension/material  differences and they still may shoot to a different point of aim...but if you keep them grouped and used by headstamp they should work fine...

Like mentioned above, segregate different brands. Some may have greater or lesser internal volume from the rest which can and will throw your shit off.

Don’t expect minute of angle groups.

Agree with the rest.

It isn't likely that you will be on your goals with mixed brass.

I will go a little farther. It isn't likely you will be on your goals unless you have enough of any one headstamp to get into a closed-loop learning curve.

A change in the middle of a load development may not show up at say 300 or less, but from there out it almost always does.

I goofed myself up lots of different ways when I was younger, traveling all the time, and in a rush I would shoot a match with mixed leftovers. Even with the same headstamps, those mixed batches didn't cut it at 600 yards.

If you plan on a one off event, don't worry have fun. If you want to be able to hit 1 MOA at 1000+ yards after just a few foulers and sighters, then you will find it takes discipline in component management as well as brass prep.

Don't know what bullet you are using, but consider a near best-case scenario: a 338LM driving two 300gr Berger OTMs with a G7 BC of .471, one at 2800fps and the other at 2790fps. Ignoring wind, these two bullets, driven with an ES of 10fps, will have impacts 11" apart vertically at 1800 yds. Any crossing wind drift will be exaggerated, and you are shooting at a somewhat round target.

IOW with little more than a 0.6 MOA difference due to MV difference, even if one bullet hits the second is unlikely to do so.

IME only blind and unusual luck will keep your ES to 10fps when using different headstamp cases. Can't predict the unknowns, but an ES of less than 25 is extremely unlikely.  You'll be chasing the last shot's POI in circles.

Beyond what Dryflash says, if I were forced to use those cases I'd weigh the cases within each headstamp, trying to stay within the same lot of the same headstamp, and hope I had enough. But I personally I wouldn't waste the money on bullets and powder using mixed cases at 1,000yd to a mile.

You say you don't want to shoot tiny groups on paper but then talk about shooting MOA out to 1800 yards. That usually requires pretty high level precision.

I guess what I meant, was beyond my 300 yard bench, I would enjoy "ring the gong" style shooting, rather than seeing how I group on a piece of paper. The ballons are a gong replacment, cause I ain't walking a piece of steel a mile out, and back. It will be all for fun, me and the girl, maybe a buddy, or just me, on state land.  Not competition, not formal in any way......Pure podunk fun.

The ranges I mentioned are just what I have available to me, I was stating what was possible, not exactly what I expected to do right off.  I ain't a total newb, I have the knowledge to begin, I'l find my limits as I go, and I know I'll be learning more as I play. But I'm just getting in the mood, and figuring out where I wanna start.

As it sits, I've owned the gun now for about 3 years and shot all factory ammo within 300 yards.   I got it the way I like it, and I wanna try something new, beyond my 300 yard bench.

The Covid Depression has me limited.  I'm laid off, wanting to play, not wanting to dump a lot of cash into this right now. I do have some play cash available, but I'm kinda trying to figure out the best place to put it. Brass. match primers, dies, more bullets/powder?  If times looked more promising, buying a couple hundred cases wounldn't be a big deal, but they ain't cheap.


I've gradually picked up a spattering of components over time, and have enough to load some of something, lol.  Just trying to decide where to go with things. I knew that varied brass would be a veariable, but I didn't know how much.  

I have

1k winchester magnum primers
5 pounds of reloader 22
400 178gr Hornady Amax
200 225gr Hornady ELD match
RCBS FL die set

I just dug out the brass, to do a sort/count.

I will make a suggestion, meant to help, not to criticize your goals and dreams.

Find yourself a heavy bbl 223 with a 7 twist and learn to shoot the best you can at 300 or whatever the easy access range would be.

Then, when you have a chance, see what you can do at 600 with the same loads you use at 300.

This way, even when resources are tight, your rifle skills come cheap so you get more trigger time per dollar. Force yourself to shoot in both dead air no wind days to get good dope, and then go out in real switchy wind and see what you can do.

You have to eventually shoot on stuff that teaches you both your POI and group size to get better sooner, not just hit/miss.

If at all possible, find a mentor. Go visit a High Power Mid Range match of some sort. Go see what it takes to hit 97% on a ten ring from slings or rests. You will learn much faster from those guys than you ever could on your own.

I appreciate your suggestion, I really do...and totally agree.

I'm plenty familiar with POI and group size, MIL and MOA.  I really get all the trigger time I want.

Don't get me wrong, I don't think I'm a pro or nothin, But I'm a bit past that stage.  The easiest access range to me is 50-100-200-300 yards, because I own it.  It's basically in my back yard, and I've been shooting it for 35 years or so. What I'm looking for is to expand my horizons a bit. I've spent most of my life shooting my 300, and spots like this don't open up too often. The other spot I have to shoot could offer me up to roughly 2100 yards if i want to find the line, and will probably only be usable for the next few years,  I'd like to play with that and see what I can do.  I built this bolt gun hoping for the opportunity.

I don't shoot 223 anymore, they just gather dust now.  This whole expedition will be preempted by a couple 308's that have been hobbies for a while now. One isn't capable of playing this game, but it's a bloody solid semi-auto 300 yard gun and I'm sure it will stretch a bit further.  The other was built and loaded for these longer range same reasons, maybe a bit shorter max distance, and only on my 300. I'd like to push it to 800 or so yards. I just didn't have any question on the 308 brass, I have about 4000 of those, all the same.  I know that was all the same.....I watched the 60 spit it out. It holds 1/2MOA or so to 300 yards, and I'd like to push it to it's max.

I also expect to learn some wind.  my 300 is pretty well sheltered by forest.  I can only see an inch or two drift on the most gusty of days.

I'm limited on resources only really now, and only really on 300wm.....and all because of the Covid.  I have plenty of 308 stuff, and until now I could buy whatever I wanted.

I watch a few 1000 yard (and quite longer) shoots every year from afar. Not really the "get a mentor"  type.  I've seen the effort that guys go to to achieve results.  I don't want to be a competition shooter, I don't think it would enjoy it much.  I expect I'll put up some paper now and then, but I really just want to pop balloons.  I have no doubt that I'll be able to get the 308 to hit, but the 300 is a bit more of a challenge right now with my limitations.

What I'm trying to decide, is if the brass is where I want to lay down the cash, or somewhere else.

Load some what you have and see if it performs to your needs

I would sort them if it were me.  Varying case capacities across the different brands could cause issues if you are loading near max levels.  Not to mention that if going for best accuracy (which you are) it's not conducive to success to mix brass.

I hate to be wordy but I feel like I need to say this.  Loading precision rifle ammo is a different endeavor than loading bulk pistol or AR blasting ammo.  With those you can get away with mixing headstamps, etc. and still do OK. On the other hand trying to load consistent sub-MOA ammo is very dependent on EVERYTHING you use and do.  My "process" has many steps and some would consider it to be a bit tedious but I find if I deviate at all my accuracy suffers.  Even concentrating on maintaining consistent pressure on the press handle is a factor.  In the end yes, the brand of brass you use is as much a part of the "recipe" as the type and amount of powder/bullet/primer and so on.  As I already stated this is not so important in general pistol/rifle ammo.  My .45 brass bucket has several different headstamps and I load 'em all the same and they shoot fine.  But I'm not trying to hit balloons at a mile with my 1911.  You will find if you really get into this just how rewarding it can be.  Especially if you have even a little OCD in you're blood.