Nothing yet
. I will go to the range later on this week. I will probably use group 1&2 at 300m. I will post my results here.
Headspace variance- now what?
- Thread starter marchx
- Start date
. I will go to the range later on this week. I will probably use group 1&2 at 300m. I will post my results here.I know winning in the wind videos, f class john as well. I watch Erik's videos to laugh. This guy just makes me laugh, his appearance, his accent. He's a funny guy.
This being said, I don't really think that setting a die in Co-ax press is rocket science. It's difficult to make a mistake here. The thing is that you set the bump using a benchmark case. The problem here is that other cases may not react the same way the benchmark case did.
Yep that's why I asked . When you put a load on anything there is going to be some give , flex , deflection . When it comes to presses that tends to be in the linkage . On standard presses to remove this flex you need the die and shell holder to make firm contact at the top of the stroke . If that sizes your case to much you need a shim ( feeler gauge ) in between the die and sell holder the appropriate size to make up the difference or use Redding competition shell holders which allow you to size up to .010 longer in increments of .002 depending on which of the 5 shell holders that come in the set you use .
The COAX is a whole different animal and I don't have all the answers for you when using that press because I don't use one . I will say it seems to do a better job then most standard presses when it comes to this issue . Although a +/- .001 is not the best one can do , it's pretty darn good when not doing anything else to resolve the issue .
As far as annealing twice , I'm not sure that will help . First if you can set the temp of your annealer to 750* . Doing it twice only gets you to 750* twice , what will have changed ? will it be twice as 750* as the first one ? Second having it in the 750* longer seems to say the same thing . Will it be more 750* if you hold it longer in the heat ? 750* is 750* , the only way either of the above helps is if the neck and shoulders are not actually reaching the desired temp or the temp/s reached is not consistent .
That all said and again assuming your machine can be set up to be consistent . Your cases should be sizing consistently as well . I heat my cases to 750* but only to stress relieve which that temp works just fine for . I also get incredibly consistently sized cases , I mean even after years of doing this it still blows my mind I can get +/- .0005 with 90+% all coming out exactly the same . My point is if your machine and or your process is consistent so should your sized cases be unless you are introducing some press flex/deflection into the sizing process .
If you have a few cases to sacrifice ( they don't have to be the good ones you are using now ) Go ahead and anneal them the same as your other ones but this time size them to make the press do that cam feel he described in the video . If they come out more consistent then you know backing the die out in introducing that press flex .
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DJSBRS
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I recommended annealing twice. The assumption was that doing it twice you would get additional stress relief perhaps with no softening of the brass. If you want to lower the hardness you would have to go to a higher temp. It's guess work if you cannot measure hardness. I would increase the time in small increments measuring shoulder bump at each level. A red glow is about 1050F. The shoulder bump inconsistency may not be related to annealing?
What's the length with the bump gauge before sizing or annealing. If they are different lengths and the die is pushing them back a certain amount, they may have different springback.
Your Data: Worst bump is 3 thou more than the 60% group. What's the target show you? Are the worst bump the longest before annealing and sizing?
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1. it is unlikely that 3 thau variance comes from annealing. As mentioned before the cases were all 99% underannealed. Annealing it twice at the same 2.6 s would not make any difference. You just won't reach the temperature level where recrystallisation of brass begins.
2. the target does not show a thing I did not load the brass yet. Will do tomorrow.
3. I will shoot group no. 1 and group no.2 at 300m, so I don't expect the groups to be spectacular.
That would be my immediate reaction. Second is the case-lube that you use on sizing and your application method. Not all lubes were created equal and that and/or application inconsistency can have a large effect on shoulder bump.
On the issue of annealing effects, I came across an interesting situation last year. A very experienced gunsmith and rifle load developer who offers the latter service commercially to buyers of precision custom rifles turned up on the 100 yards bench range to check out some 6PPC in a BR rifle. The owner has taken the rifle to him after groups had overnight doubled or tripled in size at a low barrel round count. He'd (the gunsmith) checked everything out thoroughly on the rifle including doing a scope swap and couldn't find the cause, so began to believe it was the ammunition despite the rifle's owner being a very competent and thorough handloader who'd assured him that he'd not changed his methods or components in any way, not even new powder or bullet lots. So the tester ran his own PPC handloads through the rifle, and Bingo!, groups were now again in the ones or twos. Definitely the owner's ammo. Then it turned out that the brass had been annealed in an AMP machine, and for whatever reason, that was it - significant change for the worse.
I've no idea why that should be, whether the very unusual nature of full BR case preparation and its equally esoteric relationship to a BR rifle chamber changes something, or whether the annealer wasn't working properly and/or operator error, but one thing I do believe is that annealing for the sake of it on every reloading is not the inherently great practice that so many enthusiasts for case-annealing obviously believe. Brass quality and behaviours under resizing and firing stresses / changes are critical to results. Why inject another possible variability unless there is a proven need? Although I anneal some larger cases used in F-Class cartridges every five or so firings purely to extend case-life, I've yet to anneal a single 6BR case. Buy a couple of hundred Lapua, measure and batch plus some 'clean-up' neck-turning as required and shooting them in a good no-turn chamber, those cases last the life of the barrel and shoot as well for me at the end of that barrel and set of cases' life as they did at the beginning. I'm an only so-so BR competitor, and if I was in the running for national small group records, I might think differently, but to be honest I doubt that.
Reasonable consistency is one thing, zero shoulder position variance is quite another! You're likely to be sadly disappointed if that's your expectation.
I bump shoulders for every cartridge 1-1.5thou, and I've never needed to anneal shoulders for this.
I always measure every single bump, and I never have issues with that amount of bump.
For the life of me, I don't see how annealing shoulders would be beneficial, outside of prior to fire forming.
I also never bump, and never body size until the brass is FULLY fire formed, at least 3 firings, and that's about the time I send FF'd brass off to have a custom body die made.
I see no reason to be FL sizing new brass, and never letting it reach final form/baseline.
Otherwise, how do you even know what you should size, how much?
In my view, the chamber is THE best die, and I want my sizing dies to compliment that.
For the OP, I think you're creating this problem with unnecessary actions.
I always measure every single bump, and I never have issues with that amount of bump.
For the life of me, I don't see how annealing shoulders would be beneficial, outside of prior to fire forming.
I also never bump, and never body size until the brass is FULLY fire formed, at least 3 firings, and that's about the time I send FF'd brass off to have a custom body die made.
I see no reason to be FL sizing new brass, and never letting it reach final form/baseline.
Otherwise, how do you even know what you should size, how much?
In my view, the chamber is THE best die, and I want my sizing dies to compliment that.
For the OP, I think you're creating this problem with unnecessary actions.
You live in the US, so you can happily send your fully fireformed brass to have you custom body die made. For me it's 3 months of lead time and VAT+customs when the die arrives. If FL sizing is unnecessary, what would you do? neck size up to 3rd firing?
Yes I would. Up through the 3rd firing.
wkdickinson
Gold $$ Contributor
FWIW - I was having a similar problem (Peterson brass, Annealeez, COAX, Redding Type-S w/o button, Imperial sizing wax). I found that the issue was the way I was lubing case (getting lube on the shoulder) and just doing a full stroke on the press when resizing. Here is what I do now:
- Anneal
- Dunk case neck in Imperial "Neck Lube" (graphite)
- Carefully lube only the case body below the shoulder with Imperial sizing wax, on my fingers
- Push the case into the sizing die fully and hold it there for a 5-count, before lowering the ram
- Finish neck with mandrel
Similar problem. The only time I collapsed a shoulder was when I put too much lube on the case. The excess lube was accumulating in the shoulder area of the die. Had to be a big buildup to severely collapse a shoulder. Cleaning the die solved the problem and being more careful lubing cases. The buildup had to be way more than a few thou. This kind of buildup would mess up shoulder bump.
This is on my bucket list
nooo. I will fix my induction annealer. easy to use, no flame. precise as to 0.05s.
I appreciate your input. I didn't mean to sound impolite- I am sorry if I did. The thing with propane torch is that local laws here and most lease agreements forbid use open flame devices inside apartmens. This is why I chose induction annealer and it's very comfortable piece of equipment (if it works).
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