Making 30-BR from Sig 277 brass

I make the die that does it in one shot it doesn't even need lube as shown.
But it's the only one in the world...so you won't be getting it done that easy.

The hybrid case for supers is a good idea.

The subsonic 30 Br not a good idea.
Too much case capacity
Which makes large velocity spreads and large vertical even at 100 yds.
Same problem with the 8.6 blackout too much case capacity.
The gun will have to have a 7 twist instead of 17 twist.
I'd use the heaviest brass with the smallest case capacity...like reformed LC military.
Or make my own brass cases,..or cut the case off and insert a brass cylinder to make perfect case capacity 90 to 100% and pressure up enough to get 100 % burnt in the barrel, for the subsonic 30 Br endevor....if ya want it accurate, your case capacity should be similar to the 300 blackout.
I'd go with the shortened 338 Spectre or shortened 338 ARC case necked to 30 cal with a 30° shoulder SR primer...that would much easier to get accuracy and good S/Ds in velocity...better than the 300 Blkout.

A fun experiment, if ya had a good lathe.

For the super...ya have to move the shoulder back...brass moves easier at 20°, then finish up at 30° ...45° shoulders are moved at 20° or 30° depending on the die.
Or the shoulder will collapse
You should have neck turning capability as the brass will be thicher down toward the case head. And annealing works here when needed.

Dies for case forming can be made from scratch on a good lathe...or modify existing dies. Lee dies are cheap...but the hardened surface makes it difficult to cut without sharp carbide tools.

Also going from really long case to a short case requires a bit more thought in die selection if trying to use available dies.

I went out into the shop and formed the 30 br case from the 6.8x51 hybrid case with the dies I have...well close without making another die.
It came up .100" farther on the shoulder to get it into print ....the die hit the shell holder.
So I'd have to ruin the die for it's original purpose or make another die to set back the shoulder the last .090" and finish with a factory 30BR die.
The one case is a 8.6 Blkout finished 3rd from left finished...I use hybrid cases on the 8.6 Blkout supers...we already know its not a particular accurate sub round because of too much case capacity...but with a 6.5 twist its accutate with supers.

Anyway this is what it looks like.
1 roughing forming die, cut off, next forming die.
And a finish 30 BR die ...which I do not have...then neck turn, anneal, to suit your needs.

45-90 said:

I went out into the shop and formed the 30 br case from the 6.8x51 hybrid case with the dies I have...well close without making another die.
It came up .100" farther on the shoulder to get it into print ....the die hit the shell holder.
So I'd have to ruin the die for it's original purpose or make another die to set back the shoulder the last .090" and finish with a factory 30BR die.
The one case is a 8.6 Blkout finished 3rd from left finished...I use hybrid cases on the 8.6 Blkout supers...we already know its not a particular accurate sub round because of too much case capacity...but with a 6.5 twist its accutate with supers.

Anyway this is what it looks like.
1 roughing forming die, cut off, next forming die.
And a finish 30 BR die ...which I do not have...then neck turn, anneal, to suit your needs.

Click to expand...

I know you've formed and used these hybrid cases for different calibers. And if I recall correctly you also do your own barrels??? I'm wondering if you've check inside the chambers after a number of firings and found anything like this:

Yes, it appears near the case joint, or a bit forward.
The brass is very thin and cracks causing high pressure gas to lightly ring the chamber.
It will also cause the case to stick into the chamber as the brass stays in contact with the tiny groove and the rest of the brass and steel head breaks off.
It will continue to happen until the chamber is recut. I've repaired two rifles so far...
I gotten quite a few rounds of super high pressure loads on mine, maybe 1000.
I haven't done a round count.
But certain calibers with 10,000 psi less have many more rounds on them.
So, if your running these at 80,000 psi plus on occasion...this seems to be a byproduct. Many hunters could get by a lifetime but if ya shoot alot with my older hybrid cases this is a problem...I heard the newer hybrid cases are thicker...but I don't have any of the new ones.

I'm also shooting the piss out of the new 7mm BC all steel case.
I built dies for it and am reloading both steel and brass cases for those times I don't need 180 gr match at 3100 fps in a 20" barrel.
It could be a 1000 rd max barrel great for most hunters, but others might want a little less performance and longer barrel life type of mix...so that's why the brass cases were made running 280 Ackley speeds rather than 80,000 psi on every shot.

So far I kinda like Federals all steel cases better...but I do not have enough rounds downrange...and they are more difficult to size. Since they are all steel the barrel should not have a tiny ring form...but other drawbacks may appear.
I like these cartridge case innovations, but a few problems need to be addressed.

It's not as big a deal for me cause I can fix it myself...but I wouldn't want to wait on a gunsmith, and his cost.

45-90 said:

Yes, it appears near the case joint, or a bit forward.
The brass is very thin and cracks causing high pressure gas to lightly ring the chamber.
It will also cause the case to stick into the chamber as the brass stays in contact with the tiny groove and the rest of the brass and steel head breaks off.
It will continue to happen until the chamber is recut. I've repaired two rifles so far...
I gotten quite a few rounds of super high pressure loads on mine, maybe 1000.
I haven't done a round count.
But certain calibers with 10,000 psi less have many more rounds on them.
So, if your running these at 80,000 psi plus on occasion...this seems to be a byproduct. Many hunters could get by a lifetime but if ya shoot alot with my older hybrid cases this is a problem...I heard the newer hybrid cases are thicker...but I don't have any of the new ones.

I'm also shooting the piss out of the new 7mm BC all steel case.
I built dies for it and am reloading both steel and brass cases for those times I don't need 180 gr match at 3100 fps in a 20" barrel.
It could be a 1000 rd max barrel great for most hunters, but others might want a little less performance and longer barrel life type of mix...so that's why the brass cases were made running 280 Ackley speeds rather than 80,000 psi on every shot.

So far I kinda like Federals all steel cases better...but I do not have enough rounds downrange...and they are more difficult to size. Since they are all steel the barrel should not have a tiny ring form...but other drawbacks may appear.
I like these cartridge case innovations, but a few problems need to be addressed.

It's not as big a deal for me cause I can fix it myself...but I wouldn't want to wait on a gunsmith, and his cost.

Click to expand...

That picture I posted was from someone on another forum stating this was his barrel after ~ 230 rounds fired using loads that were not particularly hot (relatively speaking), something like getting 2750 fps out of a 20" 6.5 CR barrel. I hadn't checked that part of my chamber as didn't seen any apparent need to, but when I saw that, I took my bore scope and took a close look and this is what I saw (97 hybrid rounds fired, almost half being very close to that 80k psi):



When looking at that other guy's photo and mine, my assessment was that gases were leaking by the joint much like we see when gases leak past loose primers and etch the bolt face. You suggest that "cracks" in the brass are the likely cause??? But to me, that just seems to uniform. And I can't detect any cracks the brass from the interior of the cases. I'm just thinking the design simply doesn't allow the contact between the SS and the brass to seal off in time properly where the gases flow by and out at the outer seam onto the chamber wall. That could be because the flexibility of SS and brass as it moves to make contact with the chamber wall doesn't seal off soon enough.



When I fire my regular brass, I find that grove has left an almost imperceptible ring on the cases at the same location as the joint on the outside of the hybrid case:



Given my theory about the lack of sealing, I wonder if a chamber that's a little tighter would solve the problem, or sizing the cases less. . . so that the seal happens quicker/sooner? I notice when I size these hybrid case I get a measurement of ~.4675 - .4680 and when fired they're at .470" (whether they're the thin or thicker case wall version). My regular brass measure .4690 when sized and .470 when fired. I'm really thinking that web area of the hybrid cases are having to move too much and less chamber tolerance should be addressed if these hybrids are going to be the primary use.

When I slip one of my sized hybrids into a new SAAMI spec barrel, they do feel and seem to have more than usual clearance???

I believe its the "joint" ... or crack in the sidewalk that's not sealing on my early hybrid cases...as others have been manufacturing these hybrid cases and different internal capabilities have been reported...I'm not sure what's out there.

My experience...After the first firing the "joint gap" is narrower and the case has to be trimmed to length.
Depending on the gap sealing quick or not at all...will result in how long it is before recutting the chamber.

Are the new hybrid cases experiencing this, or are they selling rejected cases to the public??

Need more reports from users of the latest hybrid cases and the military reports on this cartridge in their rifles and machineguns.

The 308s took the brunt of the abuse firing 25 rd groups with hybrid cases, excessively hot barrels.

They have pretty snug chambers but both had to be rechambered...but the rifling still looked good.

The 6.5 CM has a faint ring starting with little abuse and far less rounds...but the rifling is surprisingly getting a fair amount firecracking already. So it will need another barrel soon anyway.
I also use hybrid cases in 8.6 Blackout, and 375 Raptor...both fired alot but with 65,000 psi limit according to QL....but faint signs of the hybrid ring are showing up there too.

So, it may be only a matter of time before all chambers will need to be recut regardless of pressure used or chamber tightness...
High carbon barrels might be better than SS barrel material for the hybrid case...only a sample indication of that.

Installing a carbide ring in the chamber might be an answer.

Are the reloads with the tighter joint better then the newly fired cases with the wider gap?

I'm working with the 7 mm BC with all steel cases and reformed all brass cases no hybrid cases.
So far the Federal steel case doesn't have the hybrid case "chamber ring" problem.
Only on 3 reloadings.
But it takes more effort to size, and no commercial dies are made for it at this time.
I am over sizing it a bit but we'll see how long it all lasts.

I found some examples...as the chamber ring forms the thin portion of the brass and case head seperate....getting harder to remove from the chamber each time as the internal "chamber ring" progresses to get worse.

Then ya have to ream out the brass portion of the hybrid case...cause it ain't coming out, ...one time reamed clear down the the case neck.
And recut the chamber, counter bore, barrel tennon, etc, and re time the muzzle brake.
I can do that pretty quick at home...but it's still a hassle, that should have been solved before the consumer gets the hybrid cases.

Maybe it has been solved, and they are selling us the previous rejects...don't know.

The idea has merit but this hybrid application may not be answer...and if you can not do your own rifle work ...it's likely not for you...at this time.

Improvements must be made here, maybe they have, but not my early hybrid cases.

Are others with the new hybrid cases experiencing any problems with the 277 Fury or 6.8x51 in rifles so chambered?

Need more input on this subject from actual owners, and shooters of hybrid cases, and their rifles and experiences.

Still making hybrid cases for different calibers, but it's harder to recommend them for others, use sparingly if you can not do your own rifke work.

If the newer hybrid cases have not improved in this area over time its a thumbs down for the average reloader.

Maybe the new cases are better, and we can talk about forming them into other calibers...
Time will tell.

Tagging in as that's my barrel picture posted above, honestly it made me lose interest in the hybrid brass. If anyone wants a slightly used CTR barrel, let me know haha

Eric_F said:

Tagging in as that's my barrel picture posted above, honestly it made me lose interest in the hybrid brass. If anyone wants a slightly used CTR barrel, let me know hahaView attachment 8783022

Click to expand...

About how many rounds did you shoot with the hybrids ?

I need to look at mine. I probably only put 700 or so through it.

XP1K said:

About how many rounds did you shoot with the hybrids ?

I need to look at mine. I probably only put 700 or so through it.

Click to expand...

233 rounds

Mike Casselton said:

Makes me reconsider using the hybrid brass.

I was going to use a 16" carbon barrel due to the long life of the 30-BR.
If it's gonna screw up the chamber, it's a no-go for me.

Click to expand...

Yeah I also assumed this brass would be the key to super durability... turns out it's the opposite

I think im just going to buy some alpha srp to beat on.

Eric_F said:

233 rounds

Click to expand...

I'm about to pull mine out of the safe and look at it.

It's got a dark ring in it, but you can't feel it. At least not with a paperclip. Need to get a pick and see what it feels like. It looks like gasses are escaping around the steel head and starting to etch the chamber.

Thinking back on it, I set this barrel back and rechambered it not that long ago. I noted it in my book for this rifle when I did it, but I'm not that into tracking exact round count on this rifle. As a somewhat educated guess, I'd say this chamber has less than 300 hybrids through it. I think I'm done with them.

Thanks for checking and posting.
As we are building a case against the use of the hybrid case in its current form for average civilian use.

Are your cases marked 23 or 24 for the yr of manufactured...or the first batch like mine no markings but SIG the caliber?

I was wondering if this problem has been addressed by the manufacturers ...kind of doubt it...so far with reports coming in.

But I've seem the military firing long bursts from their 6.8x51 full autos and the can cover caught on fire with the sustained fire...not short bursts.
Question is how are their barrels holding up to such abuse?

So let's switch gears!
Making 30 BR cases from 7mm Backcountry all steel cases!
Went out in the shop to see if it's possible...
And yes it is!

I already have some specialty forming dies.
The top secret die moves the bulk of the shoulder in one pass.
Another to move it down to get the 308 bullet to fit the case.
Seating the 308 bullet.
Of course you'd have to neck turn, and run it through a 30 BR FL die.
But it's not too difficult I did this one in a few minutes.
So now you're ready for 80,000 psi loadings again...hopefully with no chamber rings.

I made dies to reload the 7mm BC both steel cases and brass cases.

You'd have to find a source for these Federal steel cases, other than factory rounds.... I wasted a steel BC case just to see what the steel case forming operation was like.
Back in the saddle again....?

45-90 said:

So let's switch gears!
Making 30 BR cases from 7mm Backcountry all steel cases!
Went out in the shop to see if it's possible...
And yes it is!

I already have some specialty forming dies.
The top secret die moves the bulk of the shoulder in one pass.
Another to move it down to get the 308 bullet to fit the case.
Seating the 308 bullet.
Of course you'd have to neck turn, and run it through a 30 BR FL die.
But it's not too difficult I did this one in a few minutes.
So now you're ready for 80,000 psi loadings again...hopefully with no chamber rings.

I made dies to reload the 7mm BC both steel cases and brass cases.

You'd have to find a source for these Federal steel cases, other than factory rounds.... I wasted a steel BC case just to see what the steel case forming operation was like.
Back in the saddle again....?

Click to expand...

Which 6mm would be best to make from these? Very interesting.