Is the difference worth my time?

[PHINPAD]

I am loading for .223 using a 80gn with 22.1 grains of Swiss RS40.

I use a RCBS Chargemaster but then using a set of Gem Pro scales and a fine trickler I get the exact weight I am looking for. This takes time and I am wondering if the difference between the lowest weight and the highest weight that the RCBS is throwing would make much difference at 600 yards.

Out of 12 throws today the lowest was 21.94 gn and the highest was 22.16 gn

(I am happy that there is no draft / electrical fields and the scales get a good hour to warm up before use).

Any assistance gratefully received.

 

[Evan]

You have to honestly appraise the rest of your equipment and your skills to have an answer.

I lean towards no, it isn't worth the loss of convenience to tighten down accuracy to the last kernel because I'm very unlikely to shoot the difference. I need to shoot more and learn the wind better before I need a 0.25" improvement in vertical dispersion at 600 yards.

 

[dsculley]

It really depends on the node you are on. If you are in the middle of a wide node then it may not make a difference. The only way to know is to test. I would use a blind bag test. Load 20 rounds each way. Get 2 identical containers. Give the 2 sets of ammo to a friend making sure they know which set is trickled to exact weight and which is thrown. Have them mark the containers 1 & 2 and place the ammo in the boxes so they know which is which but you don't. Go shoot the two sets round robin at two targets preferably at the range you will be shooting. Evaluate the targets to see if there is a difference. After you have finished your assessment of the targets, you can then find out which set was 1 and which set was 2. By not knowing which set is which, personal opinion will not influence the results or assessment of results.

By shooting the sets "round robin" they will both be shot in the same conditions, so a wind or other condition change will not affect just one set. For this test, you don't need to adjust the scope to hit the x-ring, you simply need to maintain the same point of aim on each target throughout the test. It doesn't matter where on the target the groups are located, as long as you are maintaining good form and the same point of aim for each shot.

 

[Uncle Ed]

You have not told us the type shooting you are doing, the type rifle or the make cases you are reloading.

And my point being the more case capacity varies then super accurate powder charges will not help anything. And the powder weight accuracy depends on the quality of your cases and how uniform the cases are in volume.

I primarily use Lake City 5.56 cases that are a higher quality and uniformity than Remington or Winchester cases. And they are fired out of a AR15 and a Savage bolt action. And I bought my RCBS Chargemaster to speed up the reloading process and not strain my bifocals looking at a beam scale pointer.

Bottom line, if you are not prepping and uniforming Lapua cases for benchrest accuracy, I would not worry about the weight variations your RCBS Chargemaster throws. And my opinion is from someone who does not shoot in competition and has average off the shelf factory rifles.

Below are the case weight variations between the brands of .223 cases and how many cases in the sample.

Below is the average ,223 H20 capacities of three averaged cases.

 

[K9TXS]

I agree with Uncle Ed. What type of shooting you are doing?

The only rifle I load for now is 20 Vartarg. I form all my cases from LC brass which takes a good bit of time. I hunt ground squirrels once a year and may start with prairie dogs next year as well. However, I do go several times a month to the range and shoot 100 to 300 yards using the same type of rest that I hunt with.

I have a standard charge weight of 18.5 grs I use in both rifles. I always throw 18.2(+-) and trickle up to 18.5. It does take longer doing it this way, but I know I always have the exact load for both rifles. My chambers are slightly different so I have a different seating die for each rifle.

I tried the RCBS Chargemaster many years ago and didn't care for it all and went to my current method.

This does take more time doing this way, but hey, I'm retired and now I have time.

 

[PHINPAD]

Thank you for your replies. I like the sound of loading 20 each way and seeing what the results are. If nothing else it will give me another excuse to get to the range.

I am currently shooting a magazine fed bolt action. In a fortnight I will be shooting an F/TR at 300, 500 and 600 yards.

 

[ToddKS]

@PHINPAD I would 2nd the suggestion to load and test. This is what I have been doing and as a result I have eliminated/changed some things that were taking additional time because I could find no quantifiable difference between things done one way vs. another. In one case I found the faster solution actually produced better results, but mostly I discovered that I was just spending more time to get the same result. I spend a lot less time loading than I used to. I am loading for PRS style matches.

 

[watercam]

FWIW I load manually with a tuned scale and manual trickler using Varget powder for the most part. I am able to throw a charge, trickle to the kernel and seat a bullet in about 27 seconds. The electronic route takes about the same amount of time if you count seating the bullet. My SD numbers in a Palma rifle are in the 5-7 range so I am very happy. I have more time than money these days so saving $800-$1200 means more barrels and bullets.

 

[Ned Ludd]

The best approach, as mentioned above, is to load a few rounds each at the high and low ends of your charge weight range, then shoot them on two different targets at least 300-400 yd downrange without changing the scope setting once it is dialed in. Measure the velocity and carefully compare the size/shape/position of the groups.

Alternatively, you can simply fire 10 or twenty shots that cover the full charge weight range in one string, measure the velocity, and look at the ES/SD values for the string. In the small .223 Rem case with 80-90 gr bullets, I can typically achieve no better than about 15 to 25 fps ES over a 10-shot string. For F-TR matches at 600 yd, I would like to keep the ES for a .223 Rem load below about 30 fps for 10 shots if possible. That is usually sufficient to keep all shots within the X-ring in terms of vertical dispersion, again - solely based on velocity/ES. If your ES is in the 30-40 fps range (or higher), you might want to tinker with the load a bit to see if you can reduce it.

Having said that, if you do find unacceptably high ES values, it still may not necessarily be due to charge weight variance. You charge weight range as listed above is 0.22 gr (22.16 gr - 21.94 gr), which is almost exactly 1% of the median total charge weight. That means you are weighing powder with roughly +/- 0.5% variance. If your average velocity with the 80s is 2900 fps, that means you can make a crude estimate of 2900 fps +/- 15 fps solely based on your charge weight variance. Although there are many other factors that give rise to velocity variance, this rough estimate of the effect of your charge weight range on velocity is still within an acceptable region. In other words, it may not yet be the limiting source of error in terms of velocity variance. Only determining your actual ES/SD can definitively answer the question one way or another, but it may be that the precision to which you are weighing powder is not the limiting factor.