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223submoa

223submoa

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Good Evening Everyone,

I'm prepping to try my hand at an OCW load workup. I have my brass cleaned, sized, and primed. My question is, how much variance is normal in cases? If i fire a 5 shot group that has 3 cases that are 1.742 and 2 that are 1.743 would i see any tangible effect on precision? What about overall length? Does a thousandth of an inch or two make any noticeable difference? Thanks for any input.
 
The effects of wind, temp , humidity and human error will out do what 1/1000 of an inch variance will do to your accuracy .

You would be better off to weight sort your cases , for .223 I'd probably sort by .3grain variance .. Yes this does mean weighing all your cases
 
Make sure your case length is less than the max length, for safety reasons. For performance/accuracy reasons, case length does not matter at all and you won't be able to detect *any* difference.

If you are going to shoot your .223 at 1000 yards it is probably worthwhile weighing your brass. If you are going to shoot it at 600 yards and less, don't bother. (Go ahead if you want to, it certainly won't hurt anything - and it also gives you to chance to find a defective case too - but you can skip over this step without compromising your ammo).

It is normal to see several thou variation in C.O.A.L. of your loaded ammo. Some bullets with very uniformly made tips (e.g. Bergers, or any of the plastic-tipped bullets) will land in perhaps a 5 thou range. Other bullets with less uniform tips (e.g. Sierra) can easily see a 10 thou range. The _important_ dimension, which is the distance between the cylindrical portion of the bullet and the rifling, will be much more uniform than this - you can measure this with a bullet comparator if you have one, or just take my word for it that this isn't terribly important. Note that bullets with crappy tips (I'm looking at you Sierra!) shoot very very well at 600 yards and beyond, so don't let that bother you.
 
thats not alot so I do not think it will be noticeable but it is important to keep them all the same, I found uniform neck thickness,seating depth and charge weight to be more critical
 
Last edited:
Grant Shave said:
It is my opinion your reloading technique is as important as your shooting technique, I reload as if I am competing even if I am making gopher loads

If you are looking for consistent and accuracy loads then you must do all you can every time you reload, now there is some tolerances that have less effects than others

heres what I do and I do this even for new brass before I fire it, full length resize, trim length to what ever the shortest case length in the batch is, I neck turn until I have removed a little brass off all the way around the entire neck ( you will usually never do this part again for the life of the brass), I use a primer pocket uniformer to ensure consistent primer seating depth, and it works great for cleaning pockets on fired brass, chamfer in and out side of necks
if working with fired brass I clean the inside of the necks with a brush in a small drill
I weigh every load and I use a bullet comparator for checking seating depth, I do not weigh brass but I do not think you will go wrong by doing it

its alot of work but at the end of the day it will not be your loads that let you down and if you find you get that unexplained flier, put it in the junk pile or do what I do and throw that piece of brass away
I have found case length critical on my custom guns more so than a factory, how often you need to trim to length will depend on how hot of loads you run
Click to expand...

You sound just like me however I don't tend to do as much trimming. I haven't quite gotten the hang of neck turning and am afraid to remove too much material. I do weight sort my brass though.

After the first time weight sorting my brass I ended up shooting one of my best groups ever. For that group of 5 shots, my chronograph registered an ES of only 3 fps!!! I also pour my powder on a labratory scale and pour my powder to the single kernel. I also measure using a comparator to the ogive rather than bullet tip.


There are two types of accuracy that affect trajectory and precision:

Internal and External

Internal is removing as many variables as possible to improve precision BEFORE the bullet leaves the muzzle. The level of precision in your reloading plays a big part on the success in this area.

Skill and knowledge of the shooter plays into both areas.

external of course being all of the environmentals, geography, etc that affect the trajectory AFTER the bullet leaves the muzzle.
 
Thanks for the info guys. I wasn't sure if these slight variances would make a difference or not. You've put my mind at ease. I'll post how the OCW test goes when I complete it.
 
As long as you are using brass from the same lot, variations in weight will not affect what matters...

Internal case volume.

If you truly want to sort your brass, firefore then measure the actual case volume. Weight is NOT a good indicator of this.

You will find many times more benefit from a quality digi scale for weighing your charges. This will have a massive impact on your groups. Using a scale from a reloading company is pretty much a waste of time given the inherent error of these scales.

for peak accuracy, I weigh my charges to UNDER 0.1gr. Most reg scales have a built in error of +/- 0.2gr so 4 times what you need.

A good seater is also critical if using longer heavier bullets.

Jerry
 
Thanks Jerry. Do you have any recommendations for a reasonably priced, quality scale?



Mystic Precision said:
As long as you are using brass from the same lot, variations in weight will not affect what matters...

Internal case volume.

If you truly want to sort your brass, firefore then measure the actual case volume. Weight is NOT a good indicator of this.

You will find many times more benefit from a quality digi scale for weighing your charges. This will have a massive impact on your groups. Using a scale from a reloading company is pretty much a waste of time given the inherent error of these scales.

for peak accuracy, I weigh my charges to UNDER 0.1gr. Most reg scales have a built in error of +/- 0.2gr so 4 times what you need.

A good seater is also critical if using longer heavier bullets.

Jerry
Click to expand...
 
I think the only real benefit to having everything exactly the same is the pursuit of true accuracy where you take all variables out of the equation so the only thing left to do to those .2 groups is adjust the optic. I am not there yet though.....
 
Mystic Precision said:
As long as you are using brass from the same lot, variations in weight will not affect what matters...

Internal case volume.

If you truly want to sort your brass, firefore then measure the actual case volume. Weight is NOT a good indicator of this.

You will find many times more benefit from a quality digi scale for weighing your charges. This will have a massive impact on your groups. Using a scale from a reloading company is pretty much a waste of time given the inherent error of these scales.

for peak accuracy, I weigh my charges to UNDER 0.1gr. Most reg scales have a built in error of +/- 0.2gr so 4 times what you need.

A good seater is also critical if using longer heavier bullets.

Jerry
Click to expand...

I use an Acculab VIC-123: Accurate to +/- .02gr - Many more times accurate than most scales that limit you to .1-.2

It will pick up changes to the individual kernel of powder.

I wouldn't exactly call it reasonably priced though. It is a professional laboratory scale though apparently Acculab went out of business though. We are talking the 400-1000$ range for these level of scales.
 
Mystic Precision said:
As long as you are using brass from the same lot, variations in weight will not affect what matters...

Internal case volume.

If you truly want to sort your brass, firefore then measure the actual case volume. Weight is NOT a good indicator of this.

You will find many times more benefit from a quality digi scale for weighing your charges. This will have a massive impact on your groups. Using a scale from a reloading company is pretty much a waste of time given the inherent error of these scales.

for peak accuracy, I weigh my charges to UNDER 0.1gr. Most reg scales have a built in error of +/- 0.2gr so 4 times what you need.

A good seater is also critical if using longer heavier bullets.

Jerry
Click to expand...



ceriksson said:
I use an Acculab VIC-123: Accurate to +/- .02gr - Many more times accurate than most scales that limit you to .1-.2

It will pick up changes to the individual kernel of powder.

I wouldn't exactly call it reasonably priced though. It is a professional laboratory scale though apparently Acculab went out of business though. We are talking the 400-1000$ range for these level of scales.
Click to expand...

Interesting.

Last time I checked, which was quite a while ago, benchrest competitors were using powder measures to dispense their loads. Are they now using high end electronic scales? If not, are powder measures repeatable to less than .1 grain?

I think we can agree that most benchrest competitors take ammo uniformity to the limit.

I remember reading an article in Precision Shooting some years ago that described some testing that showed weighing charges to a finer degree than a powder measure had no improvement in accuracy. I don't remember the details though.

This would seem to contradict the recommendations above for lab grade scales.

I have no dog in this fight (ok, it's not a fight, but you know what I mean). I'm just pointing out some stuff.
 
neck tension!! what was that! did you say neck tension?? or was that neck tension? NO I meant consistent neck tension, or did I say neck tension?? no I meant consistent neck tension!!!
I started weighing brass one time, and got about ten pcs done when I started to think, I know that a dangerous thing when reloading, where is the difference in the weight from one piece to the next?? so if it is in the head where brass is thickest what would that have to do with pressure when the round goes off??? pretty sure the BIG deal is pressure!! so that was the last time I weighed a pc of brass. I'm pretty sure case volume is more important??? What I have found through experience is as my brass gets more fireing's my groups open up a little and I attribute this to hardening of the necks causing different grip tension which will effect PRESSURE! I have not resorted to anneiling yet as again I'm leary of consistency in the results, so I limit the amount of fireing's before replacing. I have found that a lot of the anal steps that shooters talk about are exactly that, ANAL. I believe it's all about PRESSURE when the round goes off! and I'm finding that some things we stress over are not that important if they don't affect pressure too much. I can see why Bench guys "throw" their loads, maybe one or two granuals of powder doesn't affect the pressure nearly as much as neck tension or some other variables??? I also live by the saying " if Lapua don't make it I don't shoot it" I think that eliminates a lot of brass prep. I would rather be shooting than loading so take this all as more internet opinion!!!
Marc
 
TwoTone said:
Interesting.

Last time I checked, which was quite a while ago, benchrest competitors were using powder measures to dispense their loads. Are they now using high end electronic scales? If not, are powder measures repeatable to less than .1 grain?

I think we can agree that most benchrest competitors take ammo uniformity to the limit.

I remember reading an article in Precision Shooting some years ago that described some testing that showed weighing charges to a finer degree than a powder measure had no improvement in accuracy. I don't remember the details though.

This would seem to contradict the recommendations above for lab grade scales.

I have no dog in this fight (ok, it's not a fight, but you know what I mean). I'm just pointing out some stuff.
Click to expand...

Like I said before, it is all about the elimination of variables. I didn't say that a given variable always makes a lick of difference to the accuracy of the shot, but it is one less variable to worry about. It allows me to start thinking about other things like neck tension, trimming, case consistency. It never ends lol....

I'm sure that if some precision shooters had all the money in the world, their reloading room would look like something out of NASA with guys in lab coats and shoe covers working to produce perfect reloads.

And all I can say is that my group sizes and velocity consistencies through the choronograph vastly improved with the new scale both in powder measurement and case sorting. It works for me so I will stick with it.
 
TwoTone said:
Interesting.

Last time I checked, which was quite a while ago, benchrest competitors were using powder measures to dispense their loads. Are they now using high end electronic scales? If not, are powder measures repeatable to less than .1 grain?

I think we can agree that most benchrest competitors take ammo uniformity to the limit.
Click to expand...

Ammo made with thrown powder charges is very accurate. So accurate in fact that short range BR shooters (100y, 200y and sometime 300y) use thrown charges and achieve the very best centrefire rifle accuracy.

*BUT*, thrown powder charges have some variability in the charge weight (for example - my Redding BR-30, which is a good but not top of the line measure, throws most charges of Varget to within a 0.4 grain window; however if I throw and weigh 50 charges, there will usually be an extreme spread of 0.8 grains or even 1.0 grains from heaviest to lightest charge).

Different weights of powder charges usually causes a bit of spread in the muzzle velocity (how much depends both on the powder, and the specifics of the load; in some loads, there is very little change in m.v. over a charge weight spread of 0.5 grains. In other loads, there can be a larger spread of m.v. caused by the same 0.5 grain spread).

I remember reading an article in Precision Shooting some years ago that described some testing that showed weighing charges to a finer degree than a powder measure had no improvement in accuracy. I don't remember the details though.

This would seem to contradict the recommendations above for lab grade scales.

I have no dog in this fight (ok, it's not a fight, but you know what I mean). I'm just pointing out some stuff.
Click to expand...

What you have read is true, BUT, the effect of powder charge weight variations (spreads in muzzle velocity) usually does not show up in short range accuracy testing. If you want to shoot at 1000 yards, a large spread in m.v. will cause vertical stringing on the target at 1000 yards that does not happen with the same ammo at 600y, 300y or 100y. So for long-range ammo, it can be helpful to keep your charge weight variation as tight as reasonably possible.
 
rnbra-shooter said:
....What you have read is true, BUT, the effect of powder charge weight variations (spreads in muzzle velocity) usually does not show up in short range accuracy testing. If you want to shoot at 1000 yards, a large spread in m.v. will cause vertical stringing on the target at 1000 yards that does not happen with the same ammo at 600y, 300y or 100y. So for long-range ammo, it can be helpful to keep your charge weight variation as tight as reasonably possible.
Click to expand...

That's a very good point.
 
Here is my vertical spread at 600yds with consistent powder pouring.

Ignore the groups at the top and bottom of the target, they are different loads.

The string in the middle consist of about 20 rounds. The width is due to moving point of aim to shoot several groups. Groups were about .5 moa on average. The one on the right middle is closer to .25


Target 2.jpg by ceriksson, on Flickr
 
Everything matters if 1) you have a great rifle and 2) you shoot far enough.

If you shoot only to about 300 yards and have a factory rifle - don't bother to weight sort. If you can put at least half your shots from a 10 shot group into 1/2 MOA at 300 yards, then you should definitely be weight sorting.

Weighing empty cases is a waist of time unless you are cherry picking and segregating the most consistent from a lot.

A small round like a 223 needs to be twice as perfect as a 308 to get the same results. As for weight sorting, the best way to do it is to first ensure all cases are the same length. Reason being - if 2 cases were identical in all respects other than length - they would weigh differently. So starting with cases that are the same length is the first prerequisite.

Assuming all your cases are the same length - then yes weight sorting is better. The best way I have found to weight sort is to simply write the weight on the side of the LOADED ROUND with a sharpie. After you have weighed them all then put them into the ammo box in order.

Why write it on the LOADED ROUND? Well knock over your weight sorted ammo box by accident and the rational might begin to make sense. If at that point it doesn't - then you should not bother to weight sort.

Weighing the loaded round is really the same as weighing just the cases because everything in the case is as perfect or close to perfect as most reloading scales can detect.
 
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