How do I get my extreme deviation or spread DOWN?

Mikecr said:
How do you know this?
Have you, anyone you've ever met, or heard of, measured neck tension(annealed or not)?
Click to expand...

Does this count? Probably not but when I started with my last 338 LM I was using a .366" neck bushing to be .002" under loaded neck size. After 4 firings I lost neck tension as I could push the bullets in by hand. I also noticed soot on the necks. I dropped to a .365" bushing and now bullets were secure but still had soot. So I bought my first annealing machine. I annealed the same brass and went back to the original .366" bushing, all bullets were secure again. Soot went away too. Since about 1/2 the seated bullets in that brass lot were loose and 1/2 still tight after 4 firings, and after annealing all were tight with the .366 bushing it surely means I had more consistent neck tension. At least from my view it does.

Jeff
 
All kidding aside, I can tell by feel ...if it's good enough for Virgil King, it's good enough for me. I know you'll laugh, but I use a Lee hand press and I can feel the difference when seating bullets. Work hardened brass looses it's elasticity and annealing brings it back. I hope I didn't offend anyone with my attempt at humor; especially you Mikecr, I have the utmost respect for your opinion on all things reloading.
Good luck!
 
The reason I ask is because I've apparently never hardened necks, and never have to anneal beyond initial.
Frequent annealing seems to me a bandaid I don't need.

I measure seating forces with an electronic loadcell and hardened mandrel. I measure every single neck just before bullet seating.
With my control/consistency in reloading, I can see any change in brass hardness. Yet with many many reloads of my cases I don't see it change. And I've never had to pitch brass.
My velocities, ES, and tune hold without annealing.

If you find that annealing improves anything, then you must be work hardening brass through excess sizing. Maybe you don't have any choice(or the choices were already made).
But annealing reduces neck tension on properly expanded necks(due to decreased springback). This may lead to heading for more sizing than needed(if not annealed), working the brass more, and self perpetuating a need for the cause..
People who don't expand necks think annealing increases tension, again because of reduced springback. But it's really only increasing seating forces, which increases seating variances. Annealed tension(grip) is actually less than non annealed necks provide when sized correctly.

Like reducing runout, it's better to avoid the causes, so I don't recommend bandaids.
 
Thanks Mikcr! That's incredible, now I have another excuse to experiment/shoot&load.
If you don't mind me asking, how tight is the neck on the rifle you're shooting?
Thanks again!
Steve
 
I have only one factory gun right now, a Cooper in 223. This one gives me 4thou total clearance over loaded necks. But it doesn't get easier to load than with a 223.
My other guns (in 6br, 6xc, 6.5wssm) have aftermarket barrels chambered with my reamers. Well I just sold the 6xc, but it provided 2.5thou of clearance. The 6br is tight, and I turn necks for 1.5thou total clearance. The 6.5wssm is fitted, I turn the necks for 1thou total clearance with it (does not require neck sizing at all).
The 6.5wssm provides for learning truths about some things assumed around here.
Related to annealing, I learned from it, and my measure, that firing does not harden brass -ever.
It is sizing cycles that hardens brass. Sizing being an amount that actually causes yielding(it's beyond spring back).
 
Thanks Mikecr! This is very interesting; especially that you're able to actually measure neck tension. Have you ever had a neck crack on you? If so, how many firings did you get before that happened?
Thanks again for the valuable information!
Steve
 
I've never had a case problem of any sort. My brass will last the rest of my life, and/or as many barrels, cut with my reamers, that I use.
This makes the cost of any brass meaningless to me.

I don't measure neck tension(grip). There is currently no tool that does this.
I measure seating force with a hardened mandrel from necks that are consistent in friction (carbon film present). When hardness changes(from initial lead dip stress relieving) I get a big step change from normal. I get necks that are weak in springback. But that's alright, a few fireforming/sizing cycles, and all settles to normal.

Now the 223 brass for my cooper is not turned, and there is a small bit of thickness variance there. ~1/2thou total. I'm sizing it pretty good and I see small variances in seating force measure with a few out of 50 I reload at a time. SO far I've been able to adjust to match by tweaking length of neck sizing. No problem yet, but maybe I'll tire of this if it turns into a problem trend.
I'll either lead dip to start over, or go to Lapua's newer brass at that point.

I have never tried frequent annealing, as I don't picture any good in it over my approach. But I can picture bad in it easy enough.
Annealing takes the stored springback out of your brass. Springback is all that grips bullets(not interference fit). When you reload you WILL expand necks, but bullets make terrible expanders. So necks should be pre-expanded to proper interference prior to bullet seating.This also pushes thickness variance outward, allowing straighter seating. When your seating forces to get too high, due to downsizing annealed necks without follow-up pre-expansion, seater stems wedge onto bullet noses and your seating depths go all over the map.
But, pre-expanding annealed necks for proper interference may not leave enough bullet grip, because there is lower springback to grip bullets with. Adjustments for this mean over sizing, under expansion, and the tail chasing begins..
Now you can develop a load with very light neck tension, caused by frequent annealing, but you won't have as many options to the tuning. Good for benchrest -when you don't need many options, bad for hunting cartridges, where you usually do.

I fine tune loads with tension adjustment(length of neck sizing), as set through seating force measurement -vs- results. Frequent annealing would mean giving that up at least, and for no more reason than a bandaid on poor planning up front.
 
I built a 6.5-284 for one of my return valued customers 5 yrs ago. I knew the man knew how to shoot and how to load. He had a Weatherby MK5 action, Bartlien bbl, etc. When it left my shop it would print a .118 ctc group. He came back in 2 yrs and it opened up to a 2in group and upon closer examination his deviation was over 250 fps! He wanted a new barrel. With only 450 rds I knew something was wrong. After pushing him and questioning him he admitted he had listened to the internet and installed a David Tubb firing pin spring and had a titanium firing pin installed. The strikes on the primers were indicating this.I Installed a factory spring that I modify a steel firing pin and he was back in business. Moral of the story,, sometimes its not the obvious as the previous 4 pages point out, The internet is a danger place, and do not fix it if its not broke!:cool:
 
You wouldn't think it would, given a primary explosive in primers.
But I've tested myself and discovered that different striking of primers absolutely changes results from them.
I also found there are a lot of things affecting primer strike.
 
Warning! This thread is more than 12 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Similar threads

M
Extreme spread / Standard Deviation
2
Replies
17
Views
13K
CRaTxn
C
F
Extreme Spread?
2
Replies
14
Views
5K
Kinks
K
The Trinity Kid
How do I get talked into these things?
2
Replies
22
Views
3K
The Trinity Kid
The Trinity Kid
Cowboyblaster
I may get beaten down here
3 4 5
Replies
58
Views
8K
Cowboyblaster
Cowboyblaster
S
Tweaking the Extreme Spread ES
Replies
0
Views
2K
su37
S

Recent Posts

Top