Assuming primer pocket and case weight uniformity and deburred flashhole, what is the most crucial to accuracy?

Bullet seating depth, charge weight, neck tension?
Something else?

In other words when working up a load which is the first variable you work on?

I generally vary the seating depth first. But does charge weight affect harmonics as much as seating depth? If that were the case then either could be the first controlled variable.

Yet an old BR shooter once told me that vertical group spread was a factor of charge weight and horizontal spread was a variance of neck tension.
Have you ever heard that? So maybe neck tension is important but I would venture not for the hunting ammo.

What say you guys?

Vertical spread can be caused by heating up the barrel from round to round. Horizontal spread can be caused by pushing or pulling on the rifle while releasing the trigger.

The thing that contributes most to accuracy is getting all the bullets to go through the same little hole in the target.

-- Sorry . . . we've sort of beat this one to death.

Sorry, Genghis.

I should have done a search first. Turned up one in March and one last August with some good information.

We sure don't want the boards to get like the gun rags with the same info year after year.

To answer your question in three words...

The shooter's ability.

ricciardelli says "To answer your question in three words...The shooter's ability." If you have taken care of this factor, the next most important component is good, concentric, accurate bullets!!

OK, getting a bit more serious now . . .

I don't think it's so much one big thing but more a lot of little things that seem to gnaw away at the group size. Let's argue here that powder choice is pretty much witchcraft. There ain't no "magic powder" -- find one that works for you and develop a load.

Charge weight affects accuracy. At some point the barrel harmonics come together with all the components. I've individually weighed each charge -- even double weighed on a digital and beam scale. I'm hearing that bench shooters claim it's more about charge volume than charge weight. Last loads I had just got tossed from an RCBS Uniflow -- I got a couple groups at .338" without a lot of fussing on a lot of the details.

My standard deviation on velocity comes way down when my cases are fully filled with powder. There's been some discussion in here regarding the affect of the charge position relative to the primer -- shooting downhill, etc. My standard deviation dropped to below 10 fps when I slightly compressed my charges in .223 Ackley. I'd like to be able to say that this improved my groups -- but it didn't. I think velocity and harmonics affect accuracy more than standard deviation.

I think neck turning is important. Getting the neck concentric so that the bullet sits in the middle of the bore axis and so that the brass releases the bullet uniformly is essential. Varmint Al thinks that neck turning can reduce group size by 50%.

Varmint Al's Reloading Page is worth a look see:

http://www.cctrap.com/~varmint/arelo.htm

Some would weigh brass and bullets. The bench rest crowd does this. I spent $200 on a digital scale so I could weigh brass and bullets . . . It's still a whole lot of extra work. If you turn the necks on the brass that changes the weight of the case without affecting the case capacity. There's the rub . . .

I just sorted a heap of range pick-ups by head stamp. So now I have 300-plus cases marked LC for Lake City Arsenal. The dates and head stamps vary all over the place.

I have some 300 cases of Winchester brass -- all the same mfg lot, all fired the same number of times. Winchester is supposed to be some hot, accurate brass. I don't have any data to compare Winchester with any other brass. We're working on that one.

Put a micrometer on the brass and get it all the same length. I try for 0.0005" plus or minus. That's half a mark on the micrometer -- one side or the other. Varmint Al polishes the mouth of the case with stainless steel wool after the burr has been removed. Al uses moly coated bullets too -- and doesn't want the coating scratched.

Getting the bullet seated to a uniform depth with uniform neck tension and without scratches, dings, nicks is important.

Consistent primer seating depth . . . uniforming the pocket, deburring the flash hole. You know all this.

Shooting small bore (.223 Ackley), I find it's important to keep the bore clean. I scrub out at about every 10 to 15 rounds. Use the right jags, patches, brushes, a bore guide, etc. That seems obvious, but I see a lot of guys pushing weird stuff through the bore.

Temperature affects accuracy. Keep the loads out of the blazing sun. Let the barrel cool off between shots. Brass is a great conductor of heat, and the case sitting in a hot barrel transfers the heat to powder rapidly. I think that leads to vertical strings.

All the reading I've done -- which is getting considerable these days -- suggests that getting an accurate load requires the systematic elimination of variables. I think there's a lot to that.

Once you get to the bench, you want to ensure that the gun sits in the bags the same way each time, that it's sitting "flush" and not pinched or shimmed. The sights should come onto the target without your having to prop the gun.

Eye relief needs to be uniform. Starring through the scope for more than about 30 seconds produces eye fatigue.

Breath control is as important at the bench as it is for virtuoso flautests. If you hold your breath for more than about 15 seconds you're going to start to tense up.

Some like to pinch the trigger with thumb/forefinger against the trigger guard.

-- OK, that's a start . . .

[ 06-14-2002, 20:51: Message edited by: Genghis ]

I find that being consistent in all aspects of loading, shooting, etc. is the greatest benefit.
Good technique is desireable but even reproducible poor technique is correctable, randomness is not correctable.

Cheek weld, shoulder to buttstock pressure, grip, sight picture, bullet weight, powder charge, OAL, case weight, primer pocket depth, runout, fouled barrel, shooting position.

Once all things are the same the only variables left are environmental.

There are many shooters that simply can't do the same thing twice in a row, they have an irresistible urge to change something each shot and try to observe the effects.

I know what your asking without getting into the philosophical side of it.

My vote goes to seating depth. I believe you can pick a load and primer within reason and build an accurate hunting cartridge just by using seating depth.

I AGREE ON THE SEATING DEPTH,ALONG WITH ALL THE OTHER RESPONCES SUCH AS NECK TURNING,POWDER CHARGE ,CASE LENTH, AND MOST OF ALL THE SHOOTERS ABILITY. I HAVE FOUND THAT EVERY GUN LIKES A CERTAIN BULLET SEATED TO A CERTAIN DEPTH WITH JUST THE RIGHT AMOUNT OF POWDER TO PRODUCE TIGHT GROUPS

What are you saying, Snowy? You have to be CONSISTENT or what? This subject has been beat to a bloody pulp and stomped into an unrecognizable red mudhole, with everyone chasing everyone elses tail, screaming their favorite song at the capacity of their lungs and pissing on any suggestion other than the one that is chic at the time.

Time to think in global concepts rather than individual issues and not recite the status quo liturgy. That litany is becoming deafening. The whole is alway much greater than the sum of the parts. Don't be a member of the FLOCK, become Johnathan Livingston Seagull and soar beyond the mundane and trite world of recitation and experience the exhilaration of true freedom to explore new and different things.

Makatak

The powder and bullet is far more important than the other variables.If you find the right bullet and powder combination the rest will help to fine tune the load but with the wrong powder or bullet you will not get good groups no matter what else you do.

Thanks to those that offered the useful advice.

I didn't intend to ruffle feathers. Perhaps I phrased the question poorly.

I'd say it's pretty obvious that everyone tries to control variables like shooting and loading technique, range conditions, bore condition, and case dimensions for the sake of consistency.

But load development is not about keeping everything consistent. It is about choosing a variable to methodically manipulate while holding all others as constant as possible. To make that choice you must prioritize.

Since it makes sense to first manipulate the variable you think contributes most to accuracy (or methodically eliminate the ones that destroy it), it was a simple question about your personal methodology. Just a short prioritized list of five or six DELIBERATELY MANIPULATED variables to optimize in the ORDER you address them was all I was looking for.

For example, when bullet depth is optimal, then you have to decide what to optimize next, and next and so on. They can't all be tested at the same time.

Just reeling off a list of accuracy factors without assigning weight and priority to them is useless.

Flippant and asinine responses are worse, of course. I've never understood why people waste their time writing them when they contribute nothing.

Let's let this one die. Check, please...

[ 06-15-2002, 07:37: Message edited by: steve y ]

All the variables have to be assessed. You do each one in turn, in your mind, sometimes without conscience thought, until you arrive at a conclusion.

You have to constantly evaluate until you decide where to start, then start. We all have our sacred cows as to which is the most important to us and we will defend our position to the death, that is human nature.

I have found seating depth will contribute a great varience AND powder charge AND case capacity AND bullet weight AND twist rate AND powder type. I tested nothing but a primer change and went from a bug hole to over one inch difference. I just finished testing a BR4 and a Rem 9 1/2 for varience. BR4's had twice the ES and twice the SD and larger groups, BUT, if I change the seating depth by a few thou or increase the powder charge by a few tenths, that varience could just as easily go the other way.

My advice, as I so eloquently stated above, is not to get stuck in the rut. Pick ONE variable to test at a time, whatever you feel comfortable with, just pick a starting point and go from there. Every rifle is unique. What shoots in my 22-250, even if it is exactly the same as yours, will be different. Sometimes we get lucky and can use the same data and get the same results but you still have to tweak the load if you want....or not. Check your own feathers, by the way.

This site has a wealth of good information, just as much total bullshit and a hellofalot of my way or the highway, get the fu** out, you got shitferbrains. I keep looking for that easy way but haven't found it yet. The road to knowledge never is an smooth one and just as soon as you think you're the smart one, Murphy's law jumps up and knocks you on your butt. It's so easy to say the words and they sound so...Marvelous, and you can prove them so easily, they must be true. The problem is, what did you just prove. Welcome to the wonderful world of reloading. Makes Alice in Wonderland look like a sunday school picnic.

Makatak

Now that Ive re-read the ORIGINAL question, ignored the rest of the posts and scratched my first reply.

It seems like most guys like to try to get the seating depth right first and then work on the charge but the other way around might be a better approach, I dont know and that is a good question.

About component selection. My biggest reason for loading at all is so I can select the bullets that I desire instead of having to settle for some stinking FMJ load for varminting or a ballistic tip for big game because that was all the store happened to have at the time. So thats where I start, for me the specific purpose comes before accuracy even enters the picture.

Also, even though all guns are different I still think that "to a point" a little research can go a long way in powder selection without wasting time and resources trying to re-discover what many others have already learned. There are lots of excellent suggestions in the forum and manuals for types of load specific powders. Anyone else see it this way or am I missing the boat?

[ 06-15-2002, 20:38: Message edited by: Wstrnhuntr ]

Being a steady shot and the crown of you muzzle?? would be fair contributers to accuracy.

As well as dry ammunition

As for mechnical reasons Id say seating depth and load consistancy. As for shooters reasons I'd say trigger and breatheing control.................J

Hey steve y, HAHAHA Don't let them get to you. Your questions seem reasonable to me and definitely worthy of discussion. Just scroll past the responses that contribute nothing of value.

quote:

---

Originally posted by steve y:
Assuming primer pocket and case weight uniformity and deburred flashhole, what is the most crucial to accuracy? Bullet seating depth, charge weight, neck tension? Something else?

In other words when working up a load which is the first variable you work on?

---

Givens:
1) Lots of actual Trigger Time through Dry Firing and actual shooting prior to the Load Development.
2) A rifle "capable" of good accuracy for the task at hand(trigger, barrel, etc.).
3) Fully Prepped, Partial-Full Length Resized and Weight Sorted cases from the same Lot.

My first variable is determining what is a SAFE MAX amount of Powder to use.

I like to start with a Match Grade bullet Seated 0.005" "INTO-the-Lands" (using a specific group of cases, primers and powder) and work up to find the SAFE MAX Load. I'm watching the Casehead and Pressure Ring Expansion values, plus the other standard Pressure Indicators, as the Load increases.

Once I determine where the SAFE MAX is for that Test Lot, I look at the Targets for "signs of grouping" close to the SAFE MAX. Then I run another Test Lot with that specific amount of Powder and the same components, but vary the Seating Depth(second variable) at 0.010", 0.020" and 0.030" "OFF-the-Lands".

If this goes well, then I "might" try one more series with different Primers, but it is usually just not necessary.

I'll repeat the above for 3-6 different Powders depending on the particular caliber. This gets a good many bullets through the barrel which is also a great benefit to knowing if you have a potential good shooting rifle or not.

Then I pick the 1 or 2 best Powders and focus on using them to develop my actual Hunting Loads with bullets designed to perform properly on the specific game being hunted(being able to use the correct bullet design for the task at hand is the most serious variable).

If that first "weight" of Match Grade bullet doesn't want to shoot well, I'll look to see if there is another weight Match Grade bullet I'd consider using during early Load Development and try them(like a 165gr instead of a 150gr in 30cal). If there isn't such a bullet available, I'll go on and try the specific Hunting Grade bullet I'm wanting to use and see how well it does. Occasionally they will surprise you and shoot as well(and rarely better) than the Match Grade bullets.

Of course the reason for starting with Match Grade bullets is to establish an Accuracy Benchmark for the specific rifle.

It takes the vast majority of a summer to get all that shooting and target analysis done. By then I either have great confidence in the final Hunting Load, or that rifle doesn't get to go hunt.

Seemed like a fine question to me.

Good job HotCore. For the life of me it seems like people want to answer different questions than the one that's asked. If this were an essay test there would be a lot of F's right out of the chute. I thought it was a great question and have wondered the same thing. Your post made me frown though because I'm not sure I've got the time to put into load development the way you do. I wish I did! And I guess since I posted, but didn't answer the question, I get an F too.

Roger

STEVE Y,
Since I don't want to upset anyone with a complex answer, I'll just say the single most important thing is the six inches between the shooters ears. Have fun all.

[ 06-16-2002, 07:47: Message edited by: BigBob ]

Ya know over the weekend, I changed my mind, from Seating depth to powder weight. Just kidding. Seriously, I know alot of people get tired of the same old posts. But you got to remember, new people come into the forum everyday. And to some, rehashing an old discussion is pretty interesting. To the older members, they get agrivated and bored and end up saying "do a search". About every aspect has been agued in some magizine, book, and of coarse word of mouth. Just about every post, even the old timers, you could write, "refer to American Rifleman volumn so and so, or handloader mag. or the Barnes handbook, etc, etc."

So this weekend I was interested, I took some old coreloks, I had a load for already and set the depth to an extremely low COL. I picked a powder and found a load that was decently accurerate. I had done the same with seating depth and kept the low static and got good results. I have kept the load and seating depth static and changed primers with good results. So I came to the conclusion this hobby will drive a man crazy.

Eye sight or the lack of it. We will all succumb to that problem.

Match grade bullets,full length size brass every time with bushing dies, no expander, seat bullet straight ,then seating depth, and powder.

ALL OF THE ABOVE, Steve Y, all of the above. It is a just variation on the same theme. Mozart would have loved it. Match bullets work great for both paper punching and bagging your beast but you've seen the where that can lead. My 22-243, when it was worth a damn, would not shoot Hornady 53 HPM's no matter what I did, but it would shoot Sierra and Rem 52 match and the old Noslers and most 50 to 60 grain varmint bullet into nice small groups, but that doesn't mean the Horn's were bad bullets, just this rifle didn't like them. I have rifles that shoot best into the lands and some that need a lot more jump. One powder works best in one rifle and won't hit shit in another of the same caliber. Primers will make you just as crazy as me.

I'm running some seating tests now from into the lands by about 0.005" to 2.35" in a 22-250 using Sierra 52 match and H414 at about 48,000 psi, WLR primers and one round blew the primer and give a velocity of 3900 plus fps. Each charge was weighed, each case was weighed, each neck was turned, each bullet was checked for seating and all the fired rounds were showing about the same velocity, different shaped groups and sizes. I don't have a clue why this one went "off" on me. I stopped right there and started measuring everyting is sight. The only measurment out of whack was the VERY large primer pocket and the smell of burned powder coming from the wrong end. When you play in the field of dreams sometimes you get a bastard wanting to play.

Take a look at the reloading pages for the caliber your working with and look at the different velocities and groups by just a change in the amount or type of powder. That will give you some idea that there ain't no easy way.

But shooting is fun isn't it and so is reloading and testing and investigating and doing new things. College was fun but hard work, but an "A" was a lock if I did a little studying. Grad school was easier because I had built on a solid foundation and approach to learning, but with a different way to solve problems and so it is with this sport. You just have to find your own way using all the information available.

Don't throw it out just because it doesn't happen to work in your toy, the way someone says it does in their toy. For them it works, for you the "Gremlins" are messing with you. Don't let them win.

Your next rifle will be just as different, but may be easier to develop a load for. It still boils down to beginning with a bullet, a primer, a powder charge, a case and some arbitrary seating point, and an end point YOU have selected as your goal.

Enjoy your trip. Makatak

What contributes the most to accuracy?

Answer: The nut behind the trigger!

Well said Gungadin!

Sorry my feathers got ruffled guys.

What appears to some be tedious redundancy is actually the very essence of the hobby. If the subject of accuracy has been done to death the entire forum is moot.

Let me give an a conservative illustration an average load development possibility in a new rifle.

Bullet weights or styles - 4
Powders - 10
charge weights- (4.0 gr in .5 gr increments)- 9
Primers- 2
seating depth- (.040" in .005 increments)- 9

That 6480 possible combinations to eliminate. At 2 groups of 5 rounds for test firing you must load 64,800 rounds to methodically develop a load. The barrel is gone long before that.

FWIW,
I start with once fired, fully-prepped cases.

Then I do something most probably don't.
In the bench guns, I use only ball powders. I can throw to a tenth, and when weighing it makes trickling easier too. That confines me, for better or worse, to about three powders per chambering.

I choose bullets based on twist rate and reputation. Mostly Sierra MKs and Berger at the moment.

With seating depth, I start in rifling and back out .005 at a time. If I find a sweet spot then I narrow it to .003. That may be straining on gnats, though, as runout due to bullet shape is can be .002".

I start with mild charges but when depth is optimized I might wiggle a couple grains in either direction a half-grain at a time, trying slight depth adjustments as I go.

At the moment I'm in a primer rut with Federal. No complaints there. Though after best load is determined I will try CCI BR.

As somebody posted before, it's amazing how long one rifle can occupy you during load development.

Plus there is knowing when to be satisfied. I think I may be starting to waste my time on a couple of rifles.

Thanks to all. Steve