Reviving a Wildcat: 6x61mm Brogne

[Squid556]

This thread serves as a document of my venture into the unknown. I had little to go on while researching this project. Now all future owners of this rarity will have at least some baseline saved forever on the internet.



Story starts with the 7x61 Sharpe & Hart. For the uninitiated, it was the 7mm Rem Mags predecessor. A .532 bolt face, belted magnum to come out of the 1950s. It brought glorious magnum 7mm performance to the public. Until the 7mm Rem Mag overtook it in the 1960s

At some point in the 60s I assume, an Ohio gunsmith named Ralph Brogne started chambering custom rifles in a necked down 7x61 S&H case called 6x61. I do not know if Brogne himself came up with this cartridge or not, scarce info here.



So here we come to the star of the show. A 6x61mm magnum wildcat. It probably predates the .240 Weatherby slightly, while having similar ballistics. One is longer and skinnier, the other is shorter and fatter. Before this, the only 6mm magnum I’m aware of was the .240 H&H ,which didn’t have much of a widespread acceptance.


6mm ARC / .243 Win / 6x61


.25-06 / 6x61 / .264 Win mag

Chambered in the timeless post war Yugo Mauser, an Interarms Mark X. Beautifully crafted by Brogne.




I was fortunate enough to have dies for this. I’m assuming Hornady is able to make more of these hopefully.



Now the problems begin….How am I supposed to know what recipe to use? Did some digging through my Cartridges of the World book, reloading manuals, and internet searches. Found that this cartridge is most like the .264 Win mag and .240 Weatherby. I chose a powder seen amongst those two. Then decided on an appropriate bullet. And with the help of some friends, plugged that info into Quick Load. Comparing two different peoples Q.L. findings, against load data for the similar cartridges….. I made an educated guess that I could use IMR 7828 powder with a ceiling of 56-59 grains.

Then normal handloading practice applies. I reduced the 56 gr by 10% and made cartridges from 51 up to 56. Making sure to wear safety gear and inspect the rifle / ammo each shot.



No pressure signs at 56 gr IMR 7828. I could have kept going but decided I was happy here considering all the holes touched at 50 yards. Recoil was prominent but not painful. Effect on target…… devastating. The estimated 3200 FPS my 100 grain interlock was traveling did things to a water jug I have never seen.



This cartridge basically takes the “fast killing” 200 yard zone of .243 Win and doubles it. Creating a 400 yard whitetail laser. Barrel life is probably short but who cares, this ain’t a target rifle.

Final data:
100 gr Hornady Interlock 3.000” OAL
56 gr IMR 7828
CCI LRP
Norma Super 7x61 Trim 2.410”



Thanks for reading. Would be great to see other magnum 6mm stories below. Maybe some other Brogne rifle owners too!

 

[Creedmoor]

Looks like fun. Have you ever thought about investing in QuickLOAD software for loading data?
Quality is about 12 miles from my family's farm in Maryland.

 

[Squid556]

Looks like fun. Have you ever thought about investing in QuickLOAD software for loading data?
Quality is about 12 miles from my family's farm in Maryland.

After this venture I’m heavily considering it. Might use it as much as a learning tool more than a reloading tool.

 

[Creedmoor]

After this venture I’m heavily considering it. Might use it as much as a learning tool more than a reloading tool.

I think it was money well spent, the more info you give it. The more you get back.
It also makes it easier to see what results you will most likely get when goofing with unknown powders in a certain size case and bullet.
Did you try to form cases before you gave a paycheck to Quality? Lol

 

[Squid556]

I think it was money well spent, the more info you give it. The more you get back.
It also makes it easier to see what results you will most likely get when goofing with unknown powders in a certain size case and bullet.
Did you try to form cases before you gave a paycheck to Quality? Lol

I considered including this in the OP but since you asked ….

The rifle came with 20 new 7x61 cases from Quality Cartridge. Later I sourced 80 new Norma 7x61 cases from a shop on gunbroker. Yeah they were salty!

Took a new case, sized it…. Wouldn’t chamber in rifle.

Realized with this set up, the case wants to stop .007” before being fully sized. So you really gotta give it some muscle to ensure these are sized right.

Both virgin and fired cases do that.

There is quite a difference between the two

Personally I find the 7x61 quite sexy (despite the belt) and wouldn’t have messed with it at all.

 

[Creedmoor]

I considered including this in the OP but since you asked ….

The rifle came with 20 new 7x61 cases from Quality Cartridge. Later I sourced 80 new Norma 7x61 cases from a shop on gunbroker. Yeah they were salty!

Took a new case, sized it…. Wouldn’t chamber in rifle.

Realized with this set up, the case wants to stop .007” before being fully sized. So you really gotta give it some muscle to ensure these are sized right.

Both virgin and fired cases do that.

There is quite a difference between the two View attachment 376029

Personally I find the 7x61 quite sexy (despite the belt) and wouldn’t have messed with it at all.

Yep, my 17 Heebee when forming cases it leaves a donut on the neck as to headspace it for fireforming. Does the shoulder crisp up after firing.
I'm sure all of those cases were expensive, nothing is cheap from Quality.
With a 19 Badger we have I was going to order a set of forming dies, it was stupid money. I sent Jimmy Leahy, the 19 caliber guy 900 ( hopefully a lifetime supply)
30 carbine cases to form for me.
I cried to pay him, but it was a much better deal than to order a set of dies.

I don't know the oal of the belted case your shooting, but I would be tempted to lube up a 7mm mag case and run it in the sizer die.
The shoulder reminds me of a 300 Savage case.

 

[Squid556]

Yep, my 17 Heebee when forming cases it leaves a donut on the neck as to headspace it for fireforming. Does the shoulder crisp up after firing.
I'm sure all of those cases were expensive, nothing is cheap from Quality.
With a 19 Badger we have I was going to order a set of forming dies, it was stupid money. I sent Jimmy Leahy, the 19 caliber guy 900 ( hopefully a lifetime supply)
30 carbine cases to form for me.
I cried to pay him, but it was a much better deal than to order a set of dies.

I don't know the oal of the belted case your shooting, but I would be tempted to lube up a 7mm mag case and run it in the sizer die.
The shoulder reminds me of a 300 Savage case.

Ah yes the woes of wild catting.

That 300 savage is another one that really piques my interest.

I hadn’t tried to form from anything else. If I did the 264 win mag would be my choice, but even those are probably expensive and rare. I’m hoping Norma keeps making the parent case for a long time.

With all the learning I’ve had to do, it makes me want to make a wildcat myself. Despite having all the cartridges we need now.

 

[Creedmoor]

Ah yes the woes of wild catting.

That 300 savage is another one that really piques my interest.

I hadn’t tried to form from anything else. If I did the 264 win mag would be my choice, but even those are probably expensive and rare. I’m hoping Norma keeps making the parent case for a long time.

With all the learning I’ve had to do, it makes me want to make a wildcat myself. Despite having all the cartridges we need now.

Yes, it always seems what's new in the cartridge world is something that's old and given a new name.
Years back I ordered a few hundred 256 Winchester cases and they shipped me 264 Win cases. I sent them back and nowadays I kinda wish I would have kept them.

 

[Michigan Slim]

I'm a fan of the Interlock in the .243. I'm interested in hearing how it does for you.

 

[Creedmoor]

I'm a fan of the Interlock in the .243. I'm interested in hearing how it does for you.

I'm going to guess with that size case, explosive.. lol

Heads shots are going to be dramatic.

 

[Hookeye]

Had a 7mm Rem Mag yrs ago. Liked it
But have been thinking of maybe a 257 or 264 mag Ruger #1.

They have a 6.5 prc B in stainless this yr, 24" instead of 26. The .257 weatherby mag B models had 28" bbls. Personally the 26 i think looks best.

But havent seen a 24" version yet

 

[Creedmoor]

Had a 7mm Rem Mag yrs ago. Liked it
But have been thinking of maybe a 257 or 264 mag Ruger #1.

They have a 6.5 prc B in stainless this yr, 24" instead of 26. The .257 weatherby mag B models had 28" bbls. Personally the 26 i think looks best.

But havent seen a 24" version yet

Either one of those would work for me also. I would rather it be a Browning 1885.

 

[Michigan Slim]

Either one of those would work for me also. I would rather it be a Browning 1885.

I had wanted a No. 1 since I was old enough to lust. I finally was in a position to get one a couple years ago. So I got two!
I got into cowboy action and fell in love with the long range competitions. That led me to the Sharps and 1885's. Both .45-70 and then .38-55. I have more single shots and lever guns than any other types by far.

 

[Creedmoor]

I had wanted a No. 1 since I was old enough to lust. I finally was in a position to get one a couple years ago. So I got two!
I got into cowboy action and fell in love with the long range competitions. That led me to the Sharps and 1885's. Both .45-70 and then .38-55. I have more single shots and lever guns than any other types by far.

Gotta love levers. Long ago I bought a used #1 in 45-70.
My grand father would give me a Browning lever each year for my birthday.
Then Browning came out with the BPCR rifles.

 

[two70]

Yes, it always seems what's new in the cartridge world is something that's old and given a new name.


I'm going to guess with that size case, explosive.. lol

Current cartridge design seems to mostly be removing the largely un-needed belts from old belted magnums and shortening them a bit too allow for extremely long bullets.


I'm going to go with really, really explosive. I've seen what a 55 grain BT from .243 Win will do to a squirrel, I'm guessing this 6mm will do similar to larger targets.

 

[Creedmoor]

Current cartridge design seems to mostly be removing the largely un-needed belts from old belted magnums and shortening them a bit too allow for extremely long bullets.


I'm going to go with really, really explosive. I've seen what a 55 grain BT from .243 Win will do to a squirrel, I'm guessing this 6mm will do similar to larger targets.

The belt was for a few things, you can use it to headspace and to add more brass in the web as to help keep primer pockets from blowing out. Now they've learned just to add more brass at the rim to beef it up. Like the Dan Wesson 360 brass, I use those to form 22 Jet and 256 Win Mag cases if I need them.
They have a much heavier web in them.

The rimmed cases are used a lot in wild cats for the reasons of easier extraction and a heavier web to keep primers where they belong.
Thats the killer with 22 Hornet sized cases, 1 to 3 reloads a bit warm is its in the trash with them. 218 Bee and the family of super small cases are still popular because of it.

Thats the reason I have so much fun with the tiny 17 caliber center fires.
Flat, fast and explosive on impact and no huge boom down the valley that annoys some land owners.
Lots of fun.

 

[two70]

The belt was for a few things, you can use it to headspace and to add more brass in the web as to help keep primer pockets from blowing out. Now they've learned just to add more brass at the rim to beef it up. Like the Dan Wesson 360 brass, I use those to form 22 Jet and 256 Win Mag cases if I need them.
They have a much heavier web in them.

The rimmed cases are used a lot in wild cats for the reasons of easier extraction and a heavier web to keep primers where they belong.
Thats the killer with 22 Hornet sized cases, 1 to 3 reloads a bit warm is its in the trash with them. 218 Bee and the family of super small cases are still popular because of it.

Thats the reason I have so much fun with the tiny 17 caliber center fires.
Flat, fast and explosive on impact and no huge boom down the valley that annoys some land owners.
Lots of fun.

The belt was popularized by the long, slender .375 H&H which had such a shallow shoulder angle that the belt was needed for sure headspacing. It proliferated from there because the .375 H&H was the most readily available large case to base new magnum cartridges upon and because shooters came to associate belts with magnums. For most cartridges with a belt, the belt was little more than a marketing ploy during the magnum craze. Off the top of my head, the H&H, .458 win mag, and .458 lott are the most prominent cartridges that actually need to rely on the belt for headspacing. Considering that the 9.3x62 only has a 2 degree sharper shoulder angle and functions perfectly fine without a belt, I'm not sure the .375 H&H really even needed it.

 

[Creedmoor]

The belt was popularized by the long, slender .375 H&H which had such a shallow shoulder angle that the belt was needed for sure headspacing. It proliferated from there because the .375 H&H was the most readily available large case to base new magnum cartridges upon and because shooters came to associate belts with magnums. For most cartridges with a belt, the belt was little more than a marketing ploy during the magnum craze. Off the top of my head, the H&H, .458 win mag, and .458 lott are the most prominent cartridges that actually need to rely on the belt for headspacing. Considering that the 9.3x62 only has a 2 degree sharper shoulder angle and functions perfectly fine without a belt, I'm not sure the .375 H&H really even needed it.

Thanks, I'm not as well versed as you in the early belted cases.
I own three 700's and a SG mod 70 in 338 WM, two 300 WM and a 7mm WM that Ive never shot.
I like the mass the belt adds to the bottom of the case, I would bet that at one time is was needed. It most likely would have been eliminated long ago just over the extra manufacturing costs verses not having the extra steps it take to form the belt.
One really learns what brass to use and what cases have primer pocket issues when you play with the little tiny cases that can go from mild to wild with a few tenths of a grain.