Pros/Cons of 30 vs 40 degree shoulder?

[Mike Matteson]

Any of my guns (factory or custom) are single shot or converted to single shot, with safety and ejector delete.
If the case was a short 6br variant at 60deg, I would likely have a rattle with feeding. I believe a 6.5x47 will be as short as I can go with such a high shoulder angle. The tray on my BAT is exactly centered for .473 case head cartridges.

Before I built a WSSM variant, I watched people struggle with feeding of that animal. I went with 35deg shoulders there.
But Bruce Thom at BAT built me an action FOR the WSSM and it feeds like butter on a biscuit. So if a 6.5x47 works in 60deg, I'll change my WSSM to that as well.
The WSSM is a short-fat cartridge that well demonstrates efficiency -as claimed. It's design dimension ratios hold the powder back, and I have to turn efficiency way up in QL (weighting factor) to calibrate with my load.
There is something to it, as my 26WSSM Imp can smoke a 6.5x284 (10gr higher H20 cap) with same bullet and barrel length.
My accurate barrel life is also ~1850rnds, where a 6.5x284 is ~1200.

Even if satisfied with a standard cartridge, for reloading, case improvements including lower body taper and higher shoulder angles, can greatly increase case life. This, by reducing stretch and sizing requirements, leading to less brass movement/trimming. With capacity gain you could, if you wanted to, back off a bit on peak pressure to gain even more in brass and barrel life.
And as far as fire forming to fit the chamber, we all do that anyway. A case is fully formed by your chamber (your best die).
It helps to do a deep body dip anneal before 1st firing.

Mike: I kind of wonder about that. My feeling was that the cases were anneal at the factory. In reading into what you are saying I need to anneal to start with. I am starting off with new cases. For concentricity I trimmed to length, cut the neck for thickness, then size to .002" neck tension. I have to step down 4 times to achieve the neck size. So it looks like I need to anneal probable after the 3rd step, before the final sizing. (6mm/280AI) I am all ears.

 

[Hugnot]

One of my favorite rounds is the 6mm AI with a 40 degree shoulder and next to no body taper. I fireform either 6mm Rem or 7X57 cases necked down to 6mm. Feeding is real slick thru a LA Ruger M77 MKII, velocites 125-150 fps more than 6mm Rem. It uses about 99% case capacity with 87 grain VMax bullets loaded with VN1165 or RL23. Boosting case capacity & the sharper shoulder seem to work with slower powders & 87 grain bullets.

Case trimming is less.

I have read and expect it to be true that upon making cases with shoulders like 40 degree an unacceptable number of cases have folds in the shoulder area. This causes waste and reduced $ gain, so it appears that 30 degree or so shoulders are made instead.

 

[dennisinaz]

Nobody is arguing that. The problem is in forming the brass

 

[coop2564]

I don't recognize this term?

Why you would believe some of these statements by Hornady is crazy. It is not beneath them to create some form of BS in order to push their products above other manufacturers. Hornady's cases are soft period. Automated manufacturing with steps which involve pushing the shoulders back does not respond well using soft brass. If they used tougher, slightly harder brass they wouldn't have the problems they suggest. It's much more complicated than this but this is an effort to be short winded...

Didn't say I believed or agreed with them only that's their stance. 4:00min mark.

 

[dennisinaz]

If they use tougher, harder brass things would be even worse

 

[Mikecr]

They should talk to Weatherby about their process for double radius shoulders (something we can also do).
They likely form the neck first and shoulder last.

Fire forming is not difficult in a true Ackley chamber, as there is built in crush at the neck-shoulder junction, to remove headspace, just for this operation. A false shoulder can also be installed by the reloader with a mandrel and bushing.
You may have some failures, cracks where the original body-shoulder junction was. This is either due to poor factory case forming, or because a reloader did not pre-anneal correctly.

You should be ok for most cases, and you should be rewarded with extra brass life to make up for a few lost.
I had a 6Dasher for a while, Lapua 6br parent cases, never lost one to a problem. This was brown box muntz metal alloy (very hard).

 

[Mike Matteson]

They should talk to Weatherby about their process for double radius shoulders (something we can also do).
They likely form the neck first and shoulder last.

Fire forming is not difficult in a true Ackley chamber, as there is built in crush at the neck-shoulder junction, to remove headspace, just for this operation. A false shoulder can also be installed by the reloader with a mandrel and bushing.
You may have some failures, cracks where the original body-shoulder junction was. This is either due to poor factory case forming, or because a reloader did not pre-anneal correctly.

You should be ok for most cases, and you should be rewarded with extra brass life to make up for a few lost.
I had a 6Dasher for a while, Lapua 6br parent cases, never lost one to a problem. This was brown box muntz metal alloy (very hard).

My question is: I am stepping down a 280AI case to 6mm. It takes me 4 time with bushing to achieve the 6mm neck size. I believe you are stating that the case should be anneal before sizing the case to be fire form it. I don't care about extra steps. That life. I already have some many steps one more doesn't trouble me. I am just trying to confirm that you feel that anneal the case before the first firing. It also been stated that annealing should be done before sizing the cases, which I totally agree with that, because of heating the case changes it some.
Here my steps: Set case length and trim all to same length, Cut the necks for thickness, Reduce the necks to 6mm from 7mm, Clean the flash holes, set primer pocket depth, Do a volume weight check. Clean and dry the cases as need. Then load and fire form the cases with bullet into the lands. De-primer case, anneal, clean case. set to sizing and load again. Missing anything?

 

[DUCKMAN11]

I anneal before I even de-prime. It's the first step for me after I pull the trigger and I anneal every time I reload. Consistency comes from doing every step every time. That being said....I don't neck turn every time for obvious reasons. I'm sure I'm doing an unnecessary step but if done correctly it's not going to hurt accuracy or brass life.

 

[L.Sherm]

I've never had a problem fireforming probably 1,000 223 into 20VT and 20SCC( 20VTAI), 200 6PPC into 20PPCAI, 100 6BR into 20BRAI, 200- 06 into 6.5x06AI 100 280 into 280AI. Plus making probably 1000 17 cal Badger cases from 30 carbine cases.
All with pretty d$$$ good accuracy too.

 

[L.Sherm]

Here's forming 20PPCAI cases for an example.

 

[Mikecr]

I am just trying to confirm that you feel that anneal the case before the first firing. It also been stated that annealing should be done before sizing the cases, which I totally agree with that, because of heating the case changes it some.

Annealing should be performed before any big change, to prevent cracking.
Like I would probably anneal necks before going 28cal to 26cal, then anneal again before going to 24cal, and then anneal from upper body through necks before fire forming.
Pretty rare that I ever anneal again from there, as there are no more big changes.

 

[Mike Matteson]

I anneal before I even de-prime. It's the first step for me after I pull the trigger and I anneal every time I reload. Consistency comes from doing every step every time. That being said....I don't neck turn every time for obvious reasons. I'm sure I'm doing an unnecessary step but if done correctly it's not going to hurt accuracy or brass life.

You only turn for thickness once.

Annealing should be performed before any big change, to prevent cracking.
Like I would probably anneal necks before going 28cal to 26cal, then anneal again before going to 24cal, and then anneal from upper body through necks before fire forming.
Pretty rare that I ever anneal again from there, as there are no more big changes.

Thanks! That's adds some additional steps, but that's ok. I finally got the rifle the last time I was in Montana. I was headed back to Mexico-North and didn't have time to load for it. The Smith fired it a couple of times to test it. So I only worked over 5 cases at that time. So I will mark those case that have been fired, and they will get anneal before being used again. In setting up the next batch, I will anneal as stated and record them. Watch and see what happens and what goes on and when I have problems with the case. That will a good study. I have almost 500 280AI Peterson case presently, with less than 10 that have prep.

 

[Mike Matteson]

I anneal before I even de-prime. It's the first step for me after I pull the trigger and I anneal every time I reload. Consistency comes from doing every step every time. That being said....I don't neck turn every time for obvious reasons. I'm sure I'm doing an unnecessary step but if done correctly it's not going to hurt accuracy or brass life.

DUCKMAN11: I started to answer you and it got posted before I finished. De-primer with only with a de-primer die, no sizing goes on. I anneal every time before sizing. I also set and recheck and cut my cases for length every time after resizing. I have the equipment to do it quickly. Cutting the necks for thickness is only done once at the original start of setting up the case to start with. I make that a 2 step cut. A partial cut and finish cut for thickness. So concentricity and accuracies in reloading is my goal. I have generally over a great many years been able to achieve 1/2" groups @ 100yds with the rifles I shoot. I won't keep them if I can't. At the same time I held my shooting to 500yds or less in the field. Now with new rifle I have had set up I am looking 700+yds to shot at Ground Squirrels and now P. dogs. I have and used a 220 Swift from the middle 70's for my ground squirrels shooting.

 

[Mike Matteson]

I've never had a problem fireforming probably 1,000 223 into 20VT and 20SCC( 20VTAI), 200 6PPC into 20PPCAI, 100 6BR into 20BRAI, 200- 06 into 6.5x06AI 100 280 into 280AI. Plus making probably 1000 17 cal Badger cases from 30 carbine cases.
All with pretty d$$$ good accuracy too.

Thanks at the same time. I note that.