7mm Back Country

[stokesrj]

The age of high pressure capable cartridges has arrived. 2025 is a watershed year with the introduction of and SAAMI acceptance of Federals new 7mm Back Country.
I’ve been working on the new infantry round which is the 6.8mm X 51mm or commercial equivalent 277 Sig Fury for a while now.

Both of these rounds operate at pressures that will destroy conventional brass cases.

The 277 Sig Fury uses a stainless steel case head and a brass case body formed into a case able to withstand 80,000 PSI. The 7mm Back Country utilizes a nickel plated steel alloy case also capable of operating at 80,000 PSI.

I think this new level of performance is here to stay. It may not be obvious why. So let me attempt to explain.

The trend is driven by suppressors. Suppressors drive towards short barrels. Short barrels kill ballistic performance. These new pressure levels restore short barrel performance.

I was just shooting both the 6.8x51 and 7mm BC at a test range in Nevada at extended ranges in high winds. I had no problems keeping my shots on an IPSC target at 905 yards in 17-20 mph full value winds.
The 6.8X51was a 16” barrel and the 7BC was a 20” barrel. Both out performed their standard pressure (62,000-65,000 PSI) counterparts from 24-26” barrels.
I have developed bullets that work for each of these calibers and in fact the Federal 7BC utilizes the 195 grain Berger Classic Hunter bullet in the SAAMI proof load which is loaded to 107,000 to 114,500 PSI for proof testing guns.

The 7mm BC is offered with our 195 grain Elite Hunter loaded to 3,000 FPS from a 24” barrel which substantially outperforms a 7mm PRC or 7mm REM Mag loaded with the same bullet. It does this with less powder and therefore less recoil.

The 7BC is essentially a 280 Ackley Improved with this new Steel Alloy case which Federal has trademarked as Peak Alloy.

The case is reloadable and I am working with Short Action Customs on dies. RCBS and others are developing dies as well and Federal plans to offer component cases to reloaders.

I’m not advocating anyone rush out and buy this chambering yet, but I do think it is worthy of keeping an eye on it.

[Gamsjagd]

I have listened to multiple podcasts on this, and they vary from Federal Cartridge industry schlubs flat out blowing smoke and bullshit to smaller rifle manufacturers claiming they couldn't get the rifles to shoot.

Ultimate Munitions claimed they spoke to multiple small manufacturers, even named some by name and none of them had any luck with velocity dispersion. Normals for the 280 Ackley, 7mm PRC and others were in the 8-30 fps, and this new 7mm BA is in the 80-150 range.

ADG Brass folks said the same thing about the cartridge in a podcast. Most of them are former Remington ammo engineers who started their own company.

I am really curious about the reloading process. I have heard that the steel must be ran through the die in excess of 40 times.

Clearly there is smoke and mirrors from both doubters and Federal.

[stokesrj]

There is more conflicting information than confirming information. I have spoken to 12 rifle manufacturers and the Federal engineers that developed the cartridge all in person. As I said I’ve also personally shot it. The SDs were below 15 which is standard for volumetric loaded ammo and precision is .5 MOA.
I’ve also personally talked with the brass plating engineer of the company that does the bright plating which is used on the Federal Premium cases, they are required to size, seat, and crimp 20% beyond nominal for each plating lot and he tells me no problem. There is also a lower quality plating used on the fusion line of cases which is a Mat finish with a lower RA.
Federal has been working on this for six years.

[MM]

Is this the future of all rifle cases? Will we see a 30-06 case made with the new alloy? This is a very interesting development and merits watching how it will catch on in the industry. I don’t currently hunt with a suppressor and don’t like shooting much past 300 yards so I won’t be an early adopter but I hope it catches on.

[stokesrj]

There is already a .223 version, there is .308 in the works that will outperform 300 WSM. But I expect trials and tribulations to come.

[Gamsjagd]

My questions as a consumer?

1. Can I really reload it?

2. I am guessing it will have a 500-1300 round barrel life, never know if you will be far out of standard or beat the standard. We destroyed a 7.82 Warbird barrel in less than 400 rounds, I think it was less than 300. What is the standard? I believe Hornady has published the standards of barrel life. I don't think anyone else has, so will Federal?

3. Can I reload it with normal reloading equipment?

4. RWS has done a lo of work to right size cartridge for silencers, even introducing cartridges in 308, 8x57, 30-06 and 300 Winchester just for silenced rifles. Why didn't Federal just do that?

[stokesrj]

Expected barrel life is 1200-1500 rounds.
It can be reloaded, it remains to be seen how many new problems will need to be addressed. RCBS and Short Action Customs are working on optimizing dies.
RWS simply used faster powders to minimize the loss of velocity when fired in a short barrel, but there is still substantial velocity loss. The 7BC increases muzzle velocity to a whole new level, never before achievable. A 20” 7BC will exceed 7mm REM Mag velocity from a 24” barrel and do it with a lower weight powder charge which results in less recoil.
The bigger picture is that all cartridges will increase velocity by 200 fps when using the Peak Alloy cases when loaded to 80k PSI. A 30-06 using Peak Alloy cases will outperform a 300 Win Mag using brass cases.

[Gamsjagd]

I hope that it works out. Kind of, 300 WSM in a 308 sounds amazing. I used to shoot F-Class and kangaroos, both are things that will destroy a barrel. I am not a ballistician or gunmaker. I used to be a military armorer, and I have an idea of what is going on with this stuff, but not 100%.

Ultimate Munitions is going to do a part B on their talk trash on the 7mm Broke Back Mountain in the next few weeks. More has come to light.

[MM]

This is very interesting to me and could be very useful. you could have a 30-06 or other standard cartridge at various power/pressure levels depending on need, 30-06 standard and 30-06 magnum for example. You could push a 110 grain bullet to almost 4000 FPS or a 180 close to 3000 assuming standard length barrels or use standard loads for up close woods hunting. I always thought burning out a barrel was more a function of volume of powder being burned and not pressure, but then I am not a ballistician. Bob, can standard bullets hold up to the pressures being generated or does bullet design have to be rethought? In any case (pardon the pun) i hope this technology catches on and becomes more available and not limited to one cartridge.

[stokesrj]

I’m currently studying bullet design requirements to perform at 80,000 PSI. I think it is prudent to beef up the jacket thickness in the base and boat tail portion of the bullet but we have not yet needed to do so for the 195 grain 7mm Elite Hunter. I also designed a 150 grain bullet for the 6.8x51 but it is for use by the AMU at conventional velocities. We have only taken it to 2900 fps in the 6.8X51 but so far it has outperformed all competitors at 1,000 yards but I have not yet tested it at full pressure.

[SPEEDY]

Looks like rifle manufacturers will have to start building stronger actions faster then I thought.
I'm of two minds about this from a hunting stand point, it's not needed for hunting, but if you could interchange between stand 308 and the upgraded version then you could just use the high pressure ones for occasional long range or big game use, and use the traditional cases for regular hunting so you don't cook your barrel out too fast.
So you have your 308win with 150gn pills for 90% of your hunting and then pop these cases in with a 220gn or 240gn pill at magnum velocity for a grizzly ect hunt, or change scopes and use VLD bullets fir long range mountin hunting.

[canalrifle]

This month’s NRA “American Rifleman” has cover article on “Federal 7MM Backcountry.”

[Chase723]

7PRC performance out of a 16” barrel and an extra round in the mag doesn’t sound bad to me. They also just released a video demonstrating the reloading process. Literally 1 small extra step. If you have a progressive press it’ll take an extra 3 seconds per round. I’m willing to give it a shot. I already ordered an R8 barrel for it.

[AxP]

7PRC performance out of a 16” barrel and an extra round in the mag doesn’t sound bad to me. They also just released a video demonstrating the reloading process. Literally 1 small extra step. If you have a progressive press it’ll take an extra 3 seconds per round. I’m willing to give it a shot. I already ordered an R8 barrel for it.

Hello.
What news can you share with us? Did you receive the Blaser R8 barrel in 7mm backcountry caliber?
All the best.

[AxP]

Anybody know, if 7mm Backcountry cartridge, is undergoing standardization by CIP? I suppose, this will be important step, for its adoption in Europe.