Fine tuning cartridges

[Apiidae]

My first post!

I have been reloading 38 special for cowboy action for about 6 months now. I am pretty happy with the accuracy, recoil, etc. of my cartridge so far.

I am starting to reload my 243 win now.

My question is, how do I fine tune for accuracy, for any cartridge?

ie. Do I pick a bullet I think I want. Then research and pick a powder. Trial and error the best powder load. Then trial and error the amount of crimp.

If after all of that I'm not getting the accuracy I want, where do start to change component brands/models of the cartridge?

ie. Would a Federal primer change accuracy compared to a Winchester primer? Would a Hornady 100 gr FMJ change accuracy compared to a Sierra 100 gr FMJ?

 

[Reefinmike]

Im no expert, but if you are aiming for great accuracy, Id find and stick with a bullet that is very consistent in diameter, oal and weight and buy them by the thousand and keep your "lots" separate. Pick a primer, any primer, and stick with it. Then buy multiple powders and stick with what is the most accurate. For 223, I bought 3 of the more popular powders(H335, win748 and varget), loaded up 20 rounds of each with the same bullet and test fired them all at the range. I put up a target with those 1" birchwood bright orange sticker 3 wide and 6 deep. loaded three of each load in the mag and shot the left, middle and right targets each with a different load, three shot groups. I went down all six rows and then after analyzing the target, H335 was a clear winner, win296 was close up and varget would do if I was in a pinch. All powders are different with different bullets so you just have to search and find whats best for your particular firearm.

For pistol ammo, I cast and size my own boolits for very consistent results and use HP-38(win231) for all loads... 380, 38spl, 45acp & 357 mag

also, Welcome to THR!

 

[Skyshot]

Every switch of components will have some effect on accuracy. Since every firearm is different, you are virtually starting with a blank canvass. If it where my .243, I would start with a couple of known go to powders like IMR4350 or RL19 and what ever primer you have a good availability of. Get two or three bullet types if you can and load ten rounds of each bullet using a good reloading manuals starting load charges. If you are using the same weight bullet like a 100 grn. for example. The starting charge recommended by any reloading will work across the board for the 100 grain bullet. So lets say you have some 100 grain Sierra boattails and some 100 grain Hornady SST's and some 100 grain Nosler partitions and your powder is IMR4350 and most manuals will have a starting charge of around 37 grains of IMR4350. Now I'm going to load ten rounds of each bullet with the same starting charge and with the same OAL(overall length of the round). Now go to the range and test fire those. When test firing, I'm going to try to duplicate the same conditions for each batch of loads, example will be either cleaning between each shot and letting the barrel cool or shooting all from a fouled barrel. It's up to you. For hunting purposes I want to shoot all shots form a cold clean barrel, if target shooting is the goal then I might want to shoot a foul shot before starting my group. Now one of those rounds is going to out perform the others. I would next take the best performing round and try to up the charge 5% or so and retest, you could also do the same for the other's on your next session. At some point you will arrive at very accurate and consistent loading. Be safe and just take baby steps when increasing the charges. Keep a journal of your loads and what changes you have done in charges and OAL. Be safe and good shooting.

 

[oldpapps]

Apiidae,

Sounds like you are doing everything right, not rushing into the unknown.

You have the basics under control and are now spreading your wings. Bottle necked cartridges add several elements to the process. None of them are extreme or difficult.

With your 38s you had little if any concern about the length of the brass (I never did). It just doesn't stretch very much. Bottle necked brass stretches with every firing and during the re-loading process. That is normal. Two things to worry about. As the brass gets longer, that brass comes from someplace. It is pulled from the case body, specifically just in front of the 'web', the junction of case head to side walls. As this area stretches, it gets thinner and thinner until it gives, head separation. A total PITA. This is a real problem and is real simple to prevent. Make a 'tool' out of a length of wire (I use a large paper clip), long enough to reach inside of the case to the head. Put a sharp hook on the end and drag it out rubbing the inside of the brass. Try it on new/once fired brass and see how smooth it is. When that gets a rough/gritty area, trash that brass.
Next is the actual length of the brass will get longer and longer. It can get so long that when the round is chambered, the brass pinches the bullet in the barrels throat. This is NOT good. How to fix this? Case trimmers of all descriptions are available. Not everyone is 'OCD' like me, I trim my target .223s every time I process the brass. It is not necessary to trim that often.

Another item that may be of benefit is to anneal the brass. I've been loading and shooting for over 50 years and of the bunches of re-loading I have done, I have annealed very few. Annealing will lengthen the usable life of the brass and some believe make for more consistent neck tension.

There are a few .243 auto loaders but few, so I will assume you are loading for a bolt action. Read up on 'Neck Sizing'. This too can/will lengthen your brass life span.

Now to that actual loading. The key is consistency. Start with a known proven safe loading with the bullet weight you want. Any little variation will make changes in your load. With experience you will soon learn what your weapon likes and how to improve upon it.

Remember, if you want greater speed, lighter bullets to a point then move to a know faster round. If you want greater smashing energies, move to heavier and faster bullets. Want more, move to a bigger, heavier round. The .243 is what it is and does an excellent job of it. Faster/harder hitting equates to more recoil/noise/greater stress on the weapon and brass.

Continue to study what you want and how to get there and you will develop good loadings for your weapon/s.

Good luck and be safe.

 

[Apiidae]

Thanks all for your advice. Looks like I have some research and shopping to do. I was mostly wondering how many variables I had to deal with. I will stick with the primers and brass I like, and play around with different powders and bullets.
I'm still not sure how much I need to worry about crimp. Should I treat my crimp like primers and brass, just pick a good 'feel' and leave it? Or does it eventually get fine tuned as well?

 

[oldpapps]

Crimping for a bolt actions comes down to the shooters preference in most cases. Yes there are some powders, the only ones I can think of right now are in pistol cases, that benefit from an increased bullet pull and auto loaders/pumps could suffer from set back.

I have loaded and shot bunches of 30.06 in M1 Garands, no crimp. Same for 308/7.62s out of M1As and many .223/5.56s out of ARs an Minis with no problems or need for a crimp. That doesn't mean that I won't need a crimp on the next batch.

Crimping requires one of three things. 1) Bullet must have a canalure, the crimp grove. OR 2) Bullet must have a crimp grove cast in it, for cast bullets. OR 3) Several names for them, Factory Crimp or Taper Crimp. A specially designed non crimping crimp die (now doesn't that make scene?)

The first two require the brass to be very close to the same length.

As long as you can't push the bullet farther in with your fingers, you should be fine with out worrying with crimping.

Safety first,

 

[Ifishsum]

I've had good luck with H414 in the .243, at least for lighter bullets. I started with that and found a good load so I haven't experimented with many others.

With a new cartridge, what I do is check a couple of loading manuals for a couple of likely powder candidates for the load I want to create, choose a primer and then I load up 10 rounds at the starting load, increase by .5 grains and load 10 more - on up to the max or maybe not quite. Label them carefully so they don't get mixed up at the range - then I shoot two five shot groups for each powder charge. Watch for pressure signs as you go up in charge to make sure you're not pushing the envelope, occasionally I stop before I get to the highest loads.

Normally one or two of those loadings shows clear accuracy potential over the others - at that point I'll usually load up another set of test cartridges around that charge range to verify my results, and maybe varying bullet seating depth to try and fine tune it even further. I don't change primers once I start load development, unless I need to for some reason. For a bolt rifle I have not yet found any kind of crimp to improve accuracy, but that doesn't mean it never will.

It doesn't have to be terribly complicated - I spend a lot more development time with my bench / target shooters than I do for hunting rifles.

 

[Apiidae]

Good and Good.

oldpapps; 'A specially designed non crimping crimp die' made me laugh. Did a bureaucrat invent this?

Last question. Semi related. The best I'm shooting is factory Hornady 95gr SST, from my Savage varmint, Nikon Monarch scope, on a bi-pod, 300 yards, 20 rounds, in a 5" grouping. Is that good? I never really see how accurate the average person shoots on the YouTube videos.

 

[Hondo 60]

How about bringing it in to 100 yds & see what you get there.
By 300, I can't hold the rifle still enough, so if I like it at 100, that's good enough for me.

 

[1911 guy]

You've gotten good advice so far. I'll simply tell you what I do, then incorporate it with what you've already gotten from the other guys here.

Pick a suitable primer that is easily available. In my opinion, it really doesn't matter which brand as long as you don't go swapping it out.

Pick a bullet suitable to the purpose you are using it for.

Check your manuals for the powder that allows for the most velocity with the least pressure in your caliber with your chosen bullet. Buy a pound.

Prep all your brass identically, to include trim length.

Load five with the minimum load, load five more with 1/2 grain more, etc, until max load. You're going to wind up pulling some of these, but it saves trips to the range.

At 100 yards, shoot for group size. No Kentucky windage, etc. You're testing the accuracy of the ammo in your rifle, not your ability to dope it.

Note where accuracy begins to increase and then decrease again. Note the charge on these loads. Lets say it starts to tighten up at B and begins to get loose again at D. That means your most accurate combination is somewhere around C. Next range trip, load another set of rounds with 1/10 grain differences, a half grain above and a half grain below C.

As you are shooting, watch for pressure signs. You probably won't get that far, but watch anyway. When accuracy begins to drop off, stop shooting, go home and pull the powder to reclaim the components for your second trip.

If you don't get any satisfactory results, select another powder or bullet.

Once you find a combination that your rifle likes, buy it in as large quantities as you can reasonably afford. Once supply dries up or lots change, you're back to the drawing board. At least with powder, you'll be somewhere close and have limited tweaking with lot variations.

 

[FROGO207]

^^^^^^^ Above post is pretty much how we all do it for rifle loading after a while I would think with minor variations in the workup routine. Then you can always try tweaking the other variables when you have the time to look for further improvements if you feel the need still. At least you have a reasonably accurate load to fall back on if specialized complainants you chose for better accuracy disappear someday.