Neck tension variation
- Thread starter Ucsdryder
- Start date
Help Support Long Range Hunting Forum
MagnumManiac
Well-Known Member
I use them for foulers.
I don't do this with non-precision rounds I shoot.
If you anneal every firing, you should have already sorted your cases, so they should be consistent from case to case with neck tension.
Cheers.
I don't do this with non-precision rounds I shoot.
If you anneal every firing, you should have already sorted your cases, so they should be consistent from case to case with neck tension.
Cheers.
CBH Australia
Well-Known Member
Are these for expected to get target precision?
Long time reloader having done thousands of rounds on a single stage press.
Lately I am expanding my knowledge and trying a bit more equipment.
What you describe might still be hitting 1moa, so long as they are not loose,
.
I've had trouble with my new rifle not getting the result I would like.
I'm now going down the path of trying Lee Factory Crimp dies. There are various threads here. For a small cost they might firm up the grip on your necks. It's not neck tension as such but a simple fix that will see the projectile doesn't come loose or cause problems in the field.
If you are looking at precision , I don't have experience with annealing , but then there is neck turning and bushing dies that might help neck tension.
Annealing would help any load and case life but it probably requires a bit more outlay.
Mikecr
Well-Known Member
It would be better to determine why, and fix that.
Seating force is frictional. In itself, variances hurt nothing other than causing a battle to hit desired seating depths (CBTO).
If you reduce seating force with a dry lube [in the neck/on the bullet], friction variance should be reduced to a point where you can detect neck tension variance (a smaller variance). With that, if tension variance is ugly, and your load likes lighter neck tension, you can reduce neck interference (as sized) and/or anneal necks. Be sure to load develop any tension changes though.
The best dry lube in this application is the carbon layer provided with shooting. Don't over clean that, or things only get worse.
DoneNOut
Well-Known Member
I started wiping the bullets with Hornady One shot case lube before seating and its helped the seating force stay more consistent. Just use the leftover lube over sprayed on the loading block and wipe with fingers real quick just prior to seating.
lancetkenyon
Well-Known Member
Anneal and use an expanding mandrel each time, and this should help tremendously.
QuietTexan
Well-Known Member
It sounds like you're on the edge of a very deep rabbit hole... unless of course you're already down here, in which case welcome to the other side of the looking glass. If you don't want to jump in here, then yes just set the abnormal ones (be that hard or soft) aside and use as foulers, or intentionally shoot them together to see if this is something that shows up on your target.
If you want to jump in, I would suggest that you watch the entire AMP Press demo video in this link. I'm not saying you have to buy an AMP press, but because he uses an electronic sensor he can show a computer screen report that traces seating pressure. A K+M Force Pack does a similar thing, but it's harder to actually show in real time:
https://www.ampannealing.com/amp-pr...HnWhtOFR-Kqo74aKzYztdhPq9up0YvnkaAgaHEALw_wcB
Unless you are already doing several of things people holler "that's not necessary" about as reloading steps (turning, annealing, mandrel expanding, use a bushing/honed die, pin gauge your necks, arbor press and inline seating, use custom barrels, own your own reamer, etc) I'm not sure chasing this down is where to best spend your money, time, and energy to solve right now versus upgrading other parts of your process. But yes, variable seating pressure is real, it makes an impact on target, and can be quantified through a variety of measuring tools.
Ucsdryder
Well-Known Member
- Joined
- Jan 23, 2016
- Messages
- 1,571
I looked over the edge and said nope. I'll set the obviously easy seating and hard seating bullets aside for foulers. Heading out Friday for a good Antelope tag then in 3 weeks for a good bull tag. I love shooting out to 1000 as much as the next guy, but in the end I'm shooting a light weight 7 Saum HUNTING rifle with the purpose of killing stuff. Thanks for all the replies.
dok7mm
Well-Known Member
I have pretty well conquered neck tension by turning necks, annealing every firing and setting necks with a mandrel, but there are always a few cases that go into the fouling box for unknown reasons.
Mikecr
Well-Known Member
It's important to understand WHAT is real.
Seating force is mostly frictional, and friction itself does not affect results.
With cases sized to the same length and interference:
I can coat a few inner necks with tungsten disulfide to greatly reduce seating force.
I can take a few inner necks to squeaky clean to greatly increase seating force.
Mix em up, shoot em across a chrono, into a group, -no difference.
A smaller portion of seating force is affected by tension.
There is currently no way to measure neck tension (hoop tension).
The best we can do is normalize friction, so that we can see variance in tension, and then adjust that.
This can be done with neck sizing LENGTH, and this does show on target.
I can directly raise or lower MV, with actual neck tension adjustments, independent of overall neck friction/seating forces.
But of course you can't adjust tension with bullets already seated.
I used to have a K&M arbor press with force measure, but built an electronic version with a better approach around 20yrs ago.
I use a load cell inside a mandrel die so that I can take measure in a pre-seating operation. I adjust tension and repeat measure until matching the batch. When it gets to be a battle, it's time to process anneal (I dip anneal) the whole batch.
It's after this that I seat bullets and ensure correct CBTO with each.
vancewalker007
Well-Known Member
- Joined
- Mar 30, 2013
- Messages
- 991
If you are not annealing at least every other usage, doing so will usually clear these inconsistent tension issues right up. Until then you can set these aside and shoot some against the ones you think are correct to see if there is any noticeable differences.
QuietTexan
Well-Known Member
I think we're saying the same thing in that the validity of using seating pressure differences to catch an outlier before shooting is predicated on the assumption that the other parts of the process are consistent enough that you're detecting actual tension-induced differences and not friction differences based on poor cleaning, sizing, chamfering, etc.
The seating pressure number by itself doesn't mean much, and can be increase/decreased using different brass prep methods. But when running a batch though where every case has been consistently prepped, then if seating pressure on one particular case is different then that outlier in seating pressure would seemingly be caused by a tension difference.
Mikecr
Well-Known Member
True
If you're a target shooter looking for one hole groups instead of 1/4" groups, yeah probably. But for hunting, a waste of time. I don't do foulers either since I don't want to waste money on throw away ammo that is probably just as good as the others. I always start with a cleaned barrel too, target, hunting, what ever. I always clean rifle after shooting.
