Thread: Frustrating arvo at the range. Powder charges.

I’ve been looking at loading using Eric Cortina’s method. @dannyb went down the same line I think.

I’m starting with the .223 as it’s more economical given the cost and availability of everything at the moment.

So a few weeks ago I set up a loading length of 1.923” and starting charge of 22gr of 2206H going up in .4gr increments. 5 shot strings with the crony to see what the speeds are and not worrying about group sizes. Crony is a Magneto V3.
SDs were probably averaging 30 and ES of 34 to 86 as I was going through the charge groups. Hit 24.0gr and SD drops to 2.8 and ES of 8. Bingo! Average speed 3021.

So today I thought I’d load for seating depth with 24.0gr 2206H and all going well I should fine a good node. I loaded 10 at the original length of 1.923”, the first 5 were to confirm speeds and SD and the second 5 to see if there was a change of group sizes after taking the V3 off. The seating depths were then adjusted at 3 thou increments for the remaining 7x 5 shot lots.

Well fuck. First 5 shot speeds ranged from 2947 to 3030 (initial 5 from the previous range day at 24gr were 3017-3025). So I chucked all 10 down and the average was 2975, SD 31 and ES 83.

So I’m thinking that the charge weight hasn’t been consistent between my two case loading sessions and going off the speeds it’s probably light of the 24gr load I shot previously. (Last time 23.6gr was averaging 2960 and SD of 27.7). I’m using Ohaus 5-10 beam scales and it is possible to have to weight on the beam sit in slightly different positions in the same notch. Also when it’s zeroed the fixed ‘0’ doesn’t line up with the ‘0’ on the screw weight which is annoying but doesn’t affect functionality.

So….
Is it worth looking at some decent electronic scales? I see @Bos has just asked that question so will keep an eye on that thread too.
I also didn’t shoot the remaining 35 rounds as wasn’t sure whether I’d be wasting my time. Also the bloody wind started getting up. So even though the powder weight appears to be slightly light, is it worth shooting the loaded rounds and seeing if there is a good node? Then increase the charge until the average is around that original 3021? Will a small powder charge change move the node much? Only other option being to pull all the projectiles and start again.

Ironically, after the first shot foulers it shot an 8 shot group at 100m just under .300”. I should just be happy with that but it would be good to achieve the total consistency as I’ll do the same with the .284 next.

Welcome to Handloading @Snowgrass,
Low extreme spreads do not gaurantee tiny groups as you have discovered, especially at short range. I am not familiar with the Eric Cortina method but do have some knowledge of the Audette ladder tests. Audette shot a series of single shots, with small increments of powder charge, on a target looking for areas where shots were closer together. These nodes showed loads that were likely to have good groups in spite of velocity variations. If you are getting 0.3" groups perhaps you should just test that load at longer range rather than worrying about velocity variations. My experience has been that the .223 does show larger velocity variations than larger cartridges like the .308. Just remember that the aim is accuracy, not low extreme spreads. The latter is not automatically and indication of the former.
Regards Grandpamac.

Sorting out your brass by weight is an easy thing to do. You will see the weight vary following a bell curve . And surely out of 50 or 100 cases you will see the ones that should be excluded from you group test and used for sighting in or shooting stuff that do not require accuracy.
The more complicated thing to control is consistency of neck tension.
With out venturing into neck turning, annealing and using expensive instruments to measure the seating force to push the bullet in the neck, any bullet that require a significant different setting force should be set aside. If you end up with a little lot like that , try to chronograph it and see what are the speed variation compare to the others.

0.3 " is pretty good accuracy , if it is just a factory gun with basic reloading tools.

It goes with out saying that all those tests have to be carried out with the rifle action properly bedded in its stock or at least with a consistent seating , no stress of the action screws on the action, good crown and reasonably clean barrel . ( although some rifle may shoot better dirty).

Originally Posted by Friwi

Sorting out your brass by weight is an easy thing to do. You will see the weight vary following a bell curve . And surely out of 50 or 100 cases you will see the ones that should be excluded from you group test and used for sighting in or shooting stuff that do not require accuracy.
The more complicated thing to control is consistency of neck tension.
With out venturing into neck turning, annealing and using expensive instruments to measure the seating force to push the bullet in the neck, any bullet that require a significant different setting force should be set aside. If you end up with a little lot like that , try to chronograph it and see what are the speed variation compare to the others.

0.3 " is pretty good accuracy , if it is just a factory gun with basic reloading tools.

It goes with out saying that all those tests have to be carried out with the rifle action properly bedded in its stock or at least with a consistent seating , no stress of the action screws on the action, good crown and reasonably clean barrel . ( although some rifle may shoot better dirty).

Thanks Friwi. Rifles a factory T3 with no modifications. Basic RCBS reloading set up but am using Wilson micrometer dies with arbor press which gives consistent seating depths. Will have a look at brass weights and have noticed a slight difference in neck tension while seating so will pay more attention and segregate in to different lots.

Ideally I’m looking at setting the rifle up as a longer range varminter and to learn a few things along the way. We do the odd competition at the local range as well out to a few hundred yards.

@grandpamac the Cortina method basically works on the theory you can tune any load by adjusting seating depth.
So basically do a charge weight ladder find you most consistent velocity node (lowest ES) then do a seating depth ladder to tune for accuracy.
I have never loaded for 223 so was waiting to see if anyone more experienced chimed in.
This method is championed by longrange pro shooter Eric Cortina and certainly he gets results, as have I but my experience is limited to 270win and above calibers up to 7mm rem mag.
Eric suggests not shooting your charge weight ladder at paper so as not to be suckered in to choosing a load that shoots a small group but has a large ES as this will likely be less accurate at long range due to the variation in velocity increasing exponentially the longer the range and therefore increasing group size.
Eric shoots PRS and bench and shoots some incredible groups out to 1000yards.
What I really like about his method is that he explains it in a way that made sense to me, I first started watching his videos when I was starting out in hand loading so a lot of the terminology was foreign to me Eric explains a lot in layman's terms which was easier for meto understand.
It's not for everyone and in reality is that level of precision even nessacary for a 223 with a max range for medium game well inside 500yards (my opinion no offense to anyone else) probably not. But it sure is fun and when you can understand what's happening and interpret what your group sizes are telling you it's quite fun.
Obviously there are loads of other variables that can be eliminated as mentioned above by @Friwi but again is it really needed for a 223, I wouldn't have thought so.

Thanks danny for explaining the basic concept. My reason for using this method was the same as yours being it seems to be easy to understand being I don’t have years of experience handloading. I thought the .223 would be a good (read cheap) way of learning the process and hopefully being able to see it work before starting on the .284.

The other side of it, as Friwi has highlighted, is once I try going to the nth degree of accuracy/consistency there’s a lot more aspects to consider and it may end up being overkill for what I’m ultimately going to be using the rifles for. I think I’ll look at some electronic scales anyway to try remove any inconsistencies there.

Originally Posted by dannyb

@grandpamac the Cortina method basically works on the theory you can tune any load by adjusting seating depth.
So basically do a charge weight ladder find you most consistent velocity node (lowest ES) then do a seating depth ladder to tune for accuracy.
I have never loaded for 223 so was waiting to see if anyone more experienced chimed in.
This method is championed by longrange pro shooter Eric Cortina and certainly he gets results, as have I but my experience is limited to 270win and above calibers up to 7mm rem mag.
Eric suggests not shooting your charge weight ladder at paper so as not to be suckered in to choosing a load that shoots a small group but has a large ES as this will likely be less accurate at long range due to the variation in velocity increasing exponentially the longer the range and therefore increasing group size.
Eric shoots PRS and bench and shoots some incredible groups out to 1000yards.
What I really like about his method is that he explains it in a way that made sense to me, I first started watching his videos when I was starting out in hand loading so a lot of the terminology was foreign to me Eric explains a lot in layman's terms which was easier for meto understand.
It's not for everyone and in reality is that level of precision even nessacary for a 223 with a max range for medium game well inside 500yards (my opinion no offense to anyone else) probably not. But it sure is fun and when you can understand what's happening and interpret what your group sizes are telling you it's quite fun.
Obviously there are loads of other variables that can be eliminated as mentioned above by @Friwi but again is it really needed for a 223, I wouldn't have thought so.

Thanks @dannyb,
I had a better look at the Audette method. It was as I suspected a series of single shots on paper at 300 yards or longer range to detect shots that were closer together in elevation. He was looking for harmonic convergance where the barrel vibrations compensated for vertical dispersion from the velocity differences from load to load. Crieghton Claudette was born in 1920 and died in 1992 and was for a time the Palma Match Captain so the method was probably developed by him and others in the 1950 to 1970 era. its strength is that it focusses on likely accuracy at range directly and its weakness was that it needed to be fired at longer range. The Palma Match is shot at 800, 900 and 1,000 yards or thereabouts so it is likely Crieghton tested at one of those ranges. Eric basically substitutes velocity for elevation which can be tested at short range. This is looking for flat spots in the progression of velocity together with smaller ES. Thanks danny this has got my mind going on this one and I think some tests are in order.
Regards Grandpamac.

One thing Cortina mentions constantly is how people struggle when the margin for error is beyond the accuracy of their equipment.

Iv been watching Cortina and Keith Glasscock for ages, notice they are using a Prometheus (thousands of $) and an A&D fx120i scale ($1500). AMP press $2500. AMP Annealer $2500 Jeez some of his videos hes been talking about searching for nodes at a 10/th of grain at a time.
Interesting viewing though.

^^ - yeah I think the EC thing is a bit too gear orientated.

An alternative approach is to look for a resilient load, this is one that is stable across a fairly wide weight of powder variation . . . Sort of like getting a wide node rather than a narrow one.

As has been said above, work within the limits of your gear.
I am happy to settle on an ES of 20fps (less is better but 20ish is ok)
To achieve this I do the following:
Anneal every firing
full length size.
Sonic clean brass.
Trim
Chamfer inner/outer case mouths
Weigh evey charge through my auto dispenser to .1gn below my desired charge then hand trickle the last .1gn till the scale just registers.
Dip the base of my projectiles in graphite powder to assist in seating.
I seat each projectile (for ladders I measure each one and back the die out before seating the next).

Often I achieve ES of much less than 20fps but as before 20fps is plenty for the ranges I hunt even 30fps would be fine.
When I have settled on a load I have usually verified it by shooting 15-20 rounds over a labradar confirming velocities and repeatability of grouping.
When loading a confirmed load I do lots of 50 and still weigh to .1gn below and trickle the last .1gn by hand, I will measure the first 3 or 4 rounds for seating depth to make sure I have the die set right then I might measure the odd one if it feels harder or easier to seat (I also mark the primers with a vivid and use them for zero checking etc (I don't get many of these).

I don't batch weigh my brass but I may try that with my next project to see if that improves things but in reality for the ranges I am prepared to hunt at I don't need to.
It's a lot of time and effort but I enjoy the process.
I consistently am able to tune loads that shoot 1/2 3 shot groups at 100 yards or better and that's plenty good enough for this old hacker.

ok...I asume you using projectile in the 60grn plus weight bracket???? because 24.5grns of 2206h has been my go to load for years with 50-55grn weights... its mild on the light stuff and not to hot on the heavier stuff....Dannyb knows what Im going to say next...LOL
you have found a load that sometimes throws great deviation ....and its accurate...SO......IF.....you forgot all about using a chronicgraph ever again and kept loading the same load...you would be a happy man........YES YOU WOULD......the projectiles hit where your aiming....job done.

Originally Posted by Micky Duck

ok...I asume you using projectile in the 60grn plus weight bracket???? because 24.5grns of 2206h has been my go to load for years with 50-55grn weights... its mild on the light stuff and not to hot on the heavier stuff....Dannyb knows what Im going to say next...LOL
you have found a load that sometimes throws great deviation ....and its accurate...SO......IF.....you forgot all about using a chronicgraph ever again and kept loading the same load...you would be a happy man........YES YOU WOULD......the projectiles hit where your aiming....job done.

Thanks MD, yeh I think my OCD will get the better of me eventually even though I’ll probably spend more time at the range trying to find a load rather than just using the rifle. Using 55gr Blitzkings. I have some 69gr Matchkings to put through at some stage.

Respectfully, you haven’t followed Cortina’s method, so you shouldnt be surprised that you’re getting different results.

Starting again, load from 22.0 to 24.0gr in 0.2gr increments. Only 1 round at each weight. Seat projectiles to mag length or 20 thou off jam. Shoot over a chrony and record velocity.

Use ChronoPlotter to plot the velocities against powder weight and look for flat spots as per the graph below.


Selecting the middle of the flat spot, run a seating depth test starting at the depth used in the powder charge test above, and seat progressively shorter CBTO at 3 thou increments. Shoot 3-shot groups and record velocities. Look for where both small groups and low SD coincide. That’s your load.

Originally Posted by gqhoon

Respectfully, you haven’t followed Cortina’s method, so you shouldnt be surprised that you’re getting different results.

Starting again, load from 22.0 to 24.0gr in 0.2gr increments. Only 1 round at each weight. Seat projectiles to mag length or 20 thou off jam. Shoot over a chrony and record velocity.

Use ChronoPlotter to plot the velocities against powder weight and look for flat spots as per the graph below.
Attachment 195381

Selecting the middle of the flat spot, run a seating depth test starting at the depth used in the powder charge test above, and seat progressively shorter CBTO at 3 thou increments. Shoot 3-shot groups and record velocities. Look for where both small groups and low SD coincide. That’s your load.

Ahhhh thank you for putting it in simpler English

Originally Posted by gqhoon

Respectfully, you haven’t followed Cortina’s method, so you shouldnt be surprised that you’re getting different results.

Starting again, load from 22.0 to 24.0gr in 0.2gr increments. Only 1 round at each weight. Seat projectiles to mag length or 20 thou off jam. Shoot over a chrony and record velocity.

Use ChronoPlotter to plot the velocities against powder weight and look for flat spots as per the graph below.
Attachment 195381

Selecting the middle of the flat spot, run a seating depth test starting at the depth used in the powder charge test above, and seat progressively shorter CBTO at 3 thou increments. Shoot 3-shot groups and record velocities. Look for where both small groups and low SD coincide. That’s your load.

Thanks for that gqhoon. I can’t remember where I got the powder charge run through method, but was mainly looking at tuning via seating depth the way EC was explaining it. That graph is a great way to visualise what’s going on speed wise. My initial concern is why there was a difference in average velocities between the 24gr loads today and the ones from a few weeks ago, all else being equal.
The other bug bear is not knowing what accuracy effects having the magnetospeed hanging off the suppressor is having. Just means having to double up on loads I guess.