Better Components —-> Decreased Accuracy

Tim

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I’m not exactly as......meticulous.....as some when I reload.

Edit: this is all regarding 6.5CM in a precision rifle.

I don’t count the firings on my brass. I check cases against a Wilson gauge, but don’t sweat things if case length is a couple thousandths +\- I use Hornady dies, not the high dollar Forster. My press is a Lee. Powder +\- 0.2 grains....you get the idea.

I’ve been getting wonderful accuracy, so why change, right?

My LGS was out of my normal Winchester primers, so bought the more expensive FGGM primer.

that got me wondering if I could squeeze any more performance with better processes. So, I....

- annealed the cases
- trimmed, chamfered,
- cleaned primer pockets
- ensured perfect charge weight
- used the “better” primer

I did NOT change the sizing or seating dies and used the same powder and bullet.

and my results took a dump. SD in the high teens vs my usual 6-7. Misses on steel that had been getting almost boring with prior loads.

Unfortunately I didn’t have paper to shoot for actual groups, but I was missing 10” steel at 500 that usually is just my warm up.

So, I’m going back to loading with a a cocktail in 1 hand and an eye on Dancing with the Stars.
 
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So, all joking aside. I suspect the primer pocket cleaning and/or the chamfering as my culprits.
 
You’d ha e to work up a new load with a new primer. I was using federal match primers before, they worked well and I grouped well, but I switched the cci450 and luckily they made the same load shoot better.

I can get on board with that, but the SDs going to hell really threw me.
 
ANY component change will affect the outcome, sometimes dramatically, sometimes subtle. You may have hit the jackpot and changed primers and lot numbers of powder or bullets all at the magic moment. Either go back to the "old" way or begin workup all over again...

You'll need to shoot some paper and forget about the steel for a while until things settle back down.
 
Precision rifle loading is all about consistency. You had a consistent process before and now you’ve gone and changed it!
 
I would bet that a slight difference in the initial spark and adding annealing both account for the change.

Adding annealing took much of any springback out of your necks, lessening neck grip on the bullet. That and the slightly more or less spark.

High teens SD isn't bad, but did your mean velocity go up or down or did it not change much. If there was only one variable changing and it was annealing, my initial instinct would be to tweak the powder charge up a bit. Given that you have changed two variables it might be up or down.
 
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I would bet that a slight difference in the initial spark and adding annealing both account for the change.

Adding annealing took much of any springback out of your necks, lessening neck grip on the bullet. That and the slightly more or less spark.

High teens SD isn't bad, but did your mean velocity go up or down or did it not change much. If there was only one variable changing and it was annealing, my initial instinct would be to tweak the powder charge up a bit. Given that you have changed two variables it might be up or down.
I would bet that a slight difference in the initial spark and adding annealing both account for the change.

Adding annealing took much of any springback out of your necks, lessening neck grip on the bullet. That and the slightly more or less spark.

High teens SD isn't bad, but did your mean velocity go up or down or did it not change much. If there was only one variable changing and it was annealing, my initial instinct would be to tweak the powder charge up a bit. Given that you have changed two variables it might be up or down.

annealing, Lessing the neck tension? I don’t know if that’s accurate. It softens the brass, so annealing before sizing, isn’t working the neck as hard... and once sized, should have the same neck tension, and a more consistent neck tension
 
annealing, Lessing the neck tension? I don’t know if that’s accurate. It softens the brass, so annealing before sizing, isn’t working the neck as hard... and once sized, should have the same neck tension, and a more consistent neck tension

Hmmm, good point!

If the final step is to open the neck back up with an expander ball or mandrel, yes it would springback less and result in less grip on the bullet.

On the other hand, if the neck sizing is controlled using only a bushing, less springback will result in a greater interference fit, but actual grip could be either more or less. There are several variables that contribute to how much force is needed to overcome the grip and release the bullet, but my instincts tell me interference fit and work hardening are the two that contribute the most.

Either way, adding annealing to the process should result in more consistent grip. That and more precise powder charges make be suspect the Holy Grail is just a few tenths away.

Or here.

IMG_20191101_202707428.jpg
 
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Any change in the components, including a different lot/batch number can change the way it preforms.
The loading manuals tell you to start at the beginning if you change something.
 
So, all joking aside. I suspect the primer pocket cleaning and/or the chamfering as my culprits.

I like to cut all my primer pockets to the same depth, it helps with consistent primer ignitions. From reading over at the snipers hide, about the only brass prep I do is trim, anneal, and cut the primer pockets. I'm using LC brass in my 223 & 308 ARs and get consistent 3/4 MOA using SMK bullets.
 
I'm anal about brass prep, even with high dollar brass. I'll generally buy 200-300 pieces of brass from the same lot at a time for any new caliber I have depending on the intended use. For some special uses I'll buy 500-1000. All of that brass will get primer pocket uniforming, flash hole deburring, necks uniformed with a mandrel, full length sized with a bushing die and trimmed. I don't weigh brass. After the first firing the brass only gets full length sized and trimmed. I use bushing dies and record bushing size for the new lot. I will fire all of that brass one time before I consider a change in bushing size. I only have one rifle that I turn necks for. I only have two rifles that are Ackley improved that requires blowing out the brass. I rarely anneal because if you do it wrong you ruin the brass and might as well throw it away. The reason for all this is for initial consistency of the brass. I want to start off with everything the same. That way when I develop a load the only other considerations are powder, primers and bullets.
 
I weighed and sorted primers and bullets and loaded 50 that way and 50 with unweighed/unsorted primers and bullets.
I’m not exactly as......meticulous.....as some when I reload.

Edit: this is all regarding 6.5CM in a precision rifle.

I don’t count the firings on my brass. I check cases against a Wilson gauge, but don’t sweat things if case length is a couple thousandths +\- I use Hornady dies, not the high dollar Forster. My press is a Lee. Powder +\- 0.2 grains....you get the idea.

I’ve been getting wonderful accuracy, so why change, right?

My LGS was out of my normal Winchester primers, so bought the more expensive FGGM primer.

that got me wondering if I could squeeze any more performance with better processes. So, I....

- annealed the cases
- trimmed, chamfered,
- cleaned primer pockets
- ensured perfect charge weight
- used the “better” primer

I did NOT change the sizing or seating dies and used the same powder and bullet.

and my results took a dump. SD in the high teens vs my usual 6-7. Misses on steel that had been getting almost boring with prior loads.

Unfortunately I didn’t have paper to shoot for actual groups, but I was missing 10” steel at 500 that usually is just my warm up.

So, I’m going back to loading with a a cocktail in 1 hand and an eye on Dancing with the Stars.

I did similar "experiment" by weighing and sorting primers and bullets. Also I always clean primer pockets but loaded 50 where I did not with "random" weight primers and bullets. The dirty primer pocket rnds with random bullets and primers shot tighter groups than the weighed and sorted rnds. This stuff will make you pull out your hair. That's why my gunsmith keeps talking me out of building a 6PPC. He does not want to contribute to the further deterioration of my mental health.
 
The one thing that did the most to improve my SD in 223 was to turn the necks.
 
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