Wildcat Cartridges, What would you build?

[CBaker124]

Been a while since I’ve been on the hide. I’m still waiting on a build that I posted about on here a while back, which should be nearing completion soon so the anticipation has been killing me. In the mean time I’ve been trying to gather up some reloading equipment and components to keep myself occupied until then. I’ve also been brainstorming components do another build when this one is finished. The build I’m waiting on is a 300 PRC based on a Bat Vampire action and centered around the idea of a putting together a light weight all purpose 30 cal. I’m not sure which direction I’m going to go next but I’ve been doing some research on different calibers to try to decide. If you flip through a reloading handbook chances are you’ll probably come across quite a few cartridges you’ve never seen before or run across something you may have heard of but don’t know much about since it’s not commonly used or discussed, then you read the ballistics on it and you think to yourself, damn that is an extremely capable cartridge. I’ve come across several and it got me thinking, if you could create your own ultimate wildcat cartridge using anything out of a reloading handbook what would it be? We are seeing a lot of cool new cartridges come out these days and it seems like the parent case is usually something that’s been around for quite some time that’s tried and true then it’s tied into something a little more modern. And the possibilities almost seem endless. Im a sucker for .30 cals, so I was looking at the .340 Weatherby. The ballistics on this round are pretty impressive for the time period it came out, Weatherby introduced it to compete with the 338 Win Mag and I think they knocked it out of the park with the .340 WBY. With the right configuration of powder it can launch a 250 grain pill 2,900 fps and I’m sure if tuned correctly it could easily reach 3,000 fps. I know absolutely nothing about making Wildcat cartridges so I may sound like an idiot here lol, but If I were capable of building my own cartridge, I think I’d take the .340 Weatherby and get rid of the double radius shoulder and replace it with the 338 lapua shoulder and then trim the neck to get the proper cartridge length. Not really a wildcat per say, just modifying the case I guess but I’d love to see what a .340 WBY modernized like this would do. What would you build?

 

[TrevK]

They have already been done.. but I wanted something along the lines of the 25 creedmor and the 28 Sherman. Not a super crazy wildcat but definitely something I would have to load myself.

 

[memtb]

Done in 1990.....a .375 AI. There are many older design cartridges that benefit greatly with the AI conversion. Many, of the modern cartridges......not so much!

The .338 diameter bullets are a darn good performer on game, and have bullets designed for extremely high BC’s for great LR performance......an example being the .338 Lapua! I like your idea for the modification of the 340. You may get a slight performance enhancement, and rid yourself of that “double radius”!

I went with the .375 AI, with no regrets. It provided me with a caliber (.375) that is legal in most African countries for all of the big 5.....yet capable of using a factory round with minimal reduction in performance from the H&H ballistics, and a cartridge available most anywhere if the need should arise. It has been my “only” hunting cartridge since 1990. Good bullets, flat trajectories, high energy.....it simply works! memtb

 

[FuhQ]

Have you ever heard of the .300 Ackley Improved Magnum? It's basically a .300 Weatherby on steroids. You form cases from .300 Wby brass. I had mine built about 10 years ago. Awesome cartridge.

.280 Sherman is one I've been wanting to build for a long time.

I think a .25 Creedmoor would be an awesome cartridge for deer hunting. I have a new .257 Proof Research CF blank sitting here that's going to finish at 26" and it's got a 1:7.5 twist. Thinking about building a .25 CM Imp. (40º shoulder).

 

[Mike Casselton]

I'd probably build something on shortened 308 brass.
Make it about 1.6" long, use a small rifle primer and medium burn rate powders. Probably 30-ish grains of the correct burn rate through an 8-tw barrel.
I'd shoot 105 grain bullets of .243 caliber running just over 2800fps.

I'd also build a 30 caliber twin to shoot 110-125 grain bullets at 2800-2950 with something like H-4198.

 

[Steel head]

A shortened version of a 338 snipe tac that holds about 105-110 grains of N570
Aimed at getting a 285 solid at 3100-3150ish comfortably.

 

[brianf]

With all the cartridges out today, and the ability to order a barrel over the internet I don’t see a need to wildcat anything

if I want to go farther I’ll up my cartridge

If I want pure accuracy I’ll copy bench rest and F-class.


just my opinion

 

[Mr.BR]

I am currently toying with a 6mm with short neck and shoulder blown forward still fiddling with shoulder angles . Designed an built a compact bolt action that feeds from the Ar15 mags, hence the desire to get at least 6BR level performance out of a Grendel case and mag feed oal.

Still waiting for my copy of QuickDesign to help with the endevour

Maybe not quite this short of a neck ,but close enugh.

 

[brianf]

I am currently toying with a 6mm with short neck and shoulder blown forward still fiddling with shoulder angles . Designed an built a compact bolt action that feeds from the Ar15 mags, hence the desire to get at least 6BR level performance out of a Grendel case and mag feed oal.

Still waiting for my copy of QuickDesign to help with the endevour

View attachment 7693636

Maybe not quite this short of a neck ,but close enugh.

Interesting idea.

how much more velocity/capacity are you planning on over a grendel?

with the short neck do you foresee the bullet to far in the powder column?

thanks

 

[stello1001]

The only wildcat I want is a 22 dasher or bench rest but I don't reload yet haha...

Oh, I'd also love to hunt with a 6.5-284 norma

 

[Mr.BR]

Aiming for 39-40grain case volume so cca 5 grain more than Grendel .Will not be too crazy as i still need it 'robust' enough for mag feeding.

As for velocity, i hope 2700-2750fps with 105-107 bullets from a 20-22in barrels. chosen barrel length is going to compromise muzzle velocity

But like mentioned its meant for a specific rifle design , as its a very compact rifle and i have no intention of using 26-28in barrel.

Bullet deep in the powder column for me is a non-issue. It just means that effective 'boiler room' gains are comparably smaller than it seems

QuickDesign is great for Wildcating as you can export the design into Quick Load and play with internal balistics of your wildcats .

 

[CBaker124]

Done in 1990.....a .375 AI. There are many older design cartridges that benefit greatly with the AI conversion. Many, of the modern cartridges......not so much!

The .338 diameter bullets are a darn good performer on game, and have bullets designed for extremely high BC’s for great LR performance......an example being the .338 Lapua! I like your idea for the modification of the 340. You may get a slight performance enhancement, and rid yourself of that “double radius”!

I went with the .375 AI, with no regrets. It provided me with a caliber (.375) that is legal in most African countries for all of the big 5.....yet capable of using a factory round with minimal reduction in performance from the H&H ballistics, and a cartridge available most anywhere if the need should arise. It has been my “only” hunting cartridge since 1990. Good bullets, flat trajectories, high energy.....it simply works! memtb

Thanks Memtb, one thing is for sure Roy Weatherby knew how to make a cartridge pack some heat and that was 60 years ago. I can only imagine what he’d design with today’s technology. I like your approach on the 375. I’m planning on doing a compact rifle build on a Bat Bumblebee action when my Vampire build comes home and that’s kind of the same approach I’m going to take on this build and why I’ve been researching a few different cartridges. I’m kind of leaning towards 6.5-284 Norma.

 

[CBaker124]

Have you ever heard of the .300 Ackley Improved Magnum? It's basically a .300 Weatherby on steroids. You form cases from .300 Wby brass. I had mine built about 10 years ago. Awesome cartridge.

.280 Sherman is one I've been wanting to build for a long time.

I think a .25 Creedmoor would be an awesome cartridge for deer hunting. I have a new .257 Proof Research CF blank sitting here that's going to finish at 26" and it's got a 1:7.5 twist. Thinking about building a .25 CM Imp. (40º shoulder).

I sure have Mudrunner. There are quite a few cartridges based off of the 300 Weatherby mag. That’s actually what the .340 Weatherby is derived from, the 300 Weatherby Mag necked up to a 338.

 

[CBaker124]

With all the cartridges out today, and the ability to order a barrel over the internet I don’t see a need to wildcat anything

if I want to go farther I’ll up my cartridge

If I want pure accuracy I’ll copy bench rest and F-class.


just my opinion

Brian, that’s partially why you see so many wildcat cartridges and new factory loads today. Bench Rest and ELR shooters trying to get more out of a cartridge with less. Hence the reason why you see 6.5 Creedmoor, 6.5 PRC, 300 PRC, 6.8 Western, etc. sitting on the shelves at your local stores. Guys wanting more accuracy and distance without the added cost, recoil, etc.

 

[HogsLife]

7mm-300 Norma would be fun. Barrel life not so much, but those 250 rds would be awesome!

 

[Foul Mike]

I shoot a 6.5-06 and love it. 140gr. bullet at over 3000 fps. but I load it down some hoping for better barrel life.
I prefer 25-06 brass but also use 30-06 too so brass is not a problem.
I kind of wonder why it is not more popular but you do have to load your own for it. No factory shit for it.

 

[Schw15]

7mm practical 7mm rogue or 7mm-300 win mag. All great wildcats good performance too. Based off of the 300 win mag case

 

[iceng]

I've built a few over the years. Really depends what hole you are trying to fill. It's hard to reinvent the wheel, as there is almost no reason to wildcat, from a performance point of view. There are enough factory offerings and known cartridges to work.

I'm building a 375 raptor for a customer because a 375win wasn't enough, and a 375wsm / 375ruger were too much.

I designed and built a 7mm Super LR because I love 7mm, and couldn't find any data, or evidence anyone had done it. Custom reamer from Manson, does from whidden and now it's done. Works better than my 7-08ackley, by a small number which makes it irrelevant.

I have a huge 358 Torana, which is custom brass and launches 340gr @ 3000fps for my ELR / ULR stuff. Again, custom reamer, dies, and brass is also very unique as it doesn't exist anywhere (however the parent case was prototypes off a 460 Weatherby, but mine is not belted).

My PRS training gun is a 6 troll. 223rem necked up to 6mm, and Ackley imp. Or, 6x45ai. With a long throat. 87gr VMAX @2980fps. Nearly identical drop to my main PRS rig, but super cheap to run.

I have a few others I run. I even turned 300winmag brass into 458socom years ago just to see if it would work. Yes, it does.
Wildcats are great, and I love the idea of them, the only thing I will add is:

You will never reinvent the wheel, but at least learn how the wheel works before you try. Stay safe.

 

[Steel head]

My PRS training gun is a 6 troll. 223rem necked up to 6mm, and Ackley imp. Or, 6x45ai. With a long throat. 87gr VMAX @2980fps. Nearly identical drop to my main PRS rig, but super cheap to run.

I’ve always kinda though about doing something like that because as you say it’s cheap and effective.

 

[CBaker124]

I've built a few over the years. Really depends what hole you are trying to fill. It's hard to reinvent the wheel, as there is almost no reason to wildcat, from a performance point of view. There are enough factory offerings and known cartridges to work.

I'm building a 375 raptor for a customer because a 375win wasn't enough, and a 375wsm / 375ruger were too much.

I designed and built a 7mm Super LR because I love 7mm, and couldn't find any data, or evidence anyone had done it. Custom reamer from Manson, does from whidden and now it's done. Works better than my 7-08ackley, by a small number which makes it irrelevant.

I have a huge 358 Torana, which is custom brass and launches 340gr @ 3000fps for my ELR / ULR stuff. Again, custom reamer, dies, and brass is also very unique as it doesn't exist anywhere (however the parent case was prototypes off a 460 Weatherby, but mine is not belted).

My PRS training gun is a 6 troll. 223rem necked up to 6mm, and Ackley imp. Or, 6x45ai. With a long throat. 87gr VMAX @2980fps. Nearly identical drop to my main PRS rig, but super cheap to run.

I have a few others I run. I even turned 300winmag brass into 458socom years ago just to see if it would work. Yes, it does.
Wildcats are great, and I love the idea of them, the only thing I will add is:

You will never reinvent the wheel, but at least learn how the wheel works before you try. Stay safe.

Good post Iceing, you should post some pictures of those cartridges if you get time. That is the kind of stuff I’d love to learn how to do. I wouldn’t necessarily try to “reinvent” the wheel per say, but the wheel can always be modified and improved and that’s something I would be interested in trying with certain cartridges. Like the .340 Weatherby I mentioned above. Imagine taking a cartridge from 1962 that performed that well 60 years ago and applying some of the engineering designs and techniques from today to that case. I’d almost bet money if you modified it as I mentioned above you could get well over 3,000 fps out of a 250 grain pill and carry way more energy out past a grand. And you wouldn’t be changing a whole heck of a lot, just improving the cartridge more or less. I know that changes the game as far as data goes, but you should still have a pretty good idea where to start out at.

 

[Schw15]

Good post Iceing, you should post some pictures of those cartridges if you get time. That is the kind of stuff I’d love to learn how to do. I wouldn’t necessarily try to “reinvent” the wheel per say, but the wheel can always be modified and improved and that’s something I would be interested in trying with certain cartridges. Like the .340 Weatherby I mentioned above. Imagine taking a cartridge from 1962 that performed that well 60 years ago and applying some of the engineering designs and techniques from today to that case. I’d almost bet money if you modified it as I mentioned above you could get well over 3,000 fps out of a 250 grain pill and carry way more energy out past a grand. And you wouldn’t be changing a whole heck of a lot, just improving the cartridge more or less. I know that changes the game as far as data goes, but you should still have a pretty good idea where to start out at.

My buddy had a wildcat off of the 300 Weatherby. Load and shoot. It blew the shoulder out to a 40 degree I think and pushed the shoulder up. You could also make them from 8mm rem mag brass. Big performer 210 berger 3000 feet 22 inch barrel with a light loaf. He didn't push it. It was a 26 inch barrel before cutting down I think he hit 3400 with the 210.

 

[spife7980]

I’ve always kinda though about doing something like that because as you say it’s cheap and effective.

Ha! Just yesterday I was looking into the 6x45ai… and came to the realization that a straight br will not only be easier but it will also be better unless tied to a .384 bolt face

 

[Steel head]

Ha! Just yesterday I was looking into the 6x45ai… and came to the realization that a straight br will not only be easier but it will also be better unless tied to a .384 bolt face

Yea
It hard to argue against the 6BR

 

[oldiephrt]

Mr.BR Very interesting, any concern of keeping bullet aligned during feed from mag with a short neck?

 

[MJF]

I built a 6mm-06 as a versatile varmint, target and Antelope gun. It has exceeded my expectations in every way. As a reloader it was a fun process.

 

[Schw15]

One of my favorite wildcats I had when I was younger was a 6.5-280 ai. I also had 6.5-06 ai 6mm ai and 7mm stw ai. Alot of Ackley

 

[CBaker124]

Thanks for all the replies and positive feedback guys, I figured I’d get the gears turning for a lot of folks on here and you guys have came through with some really good stuff. It’s amazing what you’ll learn from people if you just ask. Hopefully we can keep this going, may be a good thread to reference for someone else interested in making a wildcat down the road.

 

[Mr.BR]

Mr.BR Very interesting, any concern of keeping bullet aligned during feed from mag with a short neck?

Yes that is definetly a fine line i will have to balance on, but like said waiting for the software so i can game some configurations and then strike a balance of MV gained vs neck lenght lost , that is the great thing about wildcatting in the computer first before any metal is cut.

Might end up with neck shorter than 6mm XTRA imp40 ,note these are all meant for semi auto rifles so with bolt action i might be able to get away with shorter neck and still have enough grip on the bullet

 

[Mr.BR]

Current bleeding edge of cartridge design

French 5.56x45 neckless, neck cut short to accommodate a 64g monolithic bullet, design is meant of be used in existing rifles ,mags and 5.56x45 chambers.

They are actually going to test fire it from an HK416 , and was already tested from a test barrel , point of the whole endeavor is to demonstrate that with proper bullet design there are still ways to go in 5.56 , of course end game would be a neckless cartridge with composite case like 6.8 from True velocity

Bullet is slightly modified and scaled down Balle D , 120y old design with better form factor than Werner Straight line.

Ballistics from a 14in barrel . Note considerable gains due to bullet used.
300m Velocity and Energy: M855 (1992fps/546) vs Neckless (2216fps/698ftlbs)
600m Velocity and Energy: M855(1224fps/206) vs Neckless (1631fps/378)
Supersonic Range: M855 (649m) vs Neckless (842m)

M193 / M855 / M856 (fired) / 70 gr VKO / 64 gr "5.56 mm D" / 7N6 / 5.45 tracer.

 

[Foul Mike]

I would bet that the 6mm-06 is faster than you need to go. My 6.5 is.
What brass are you using?

 

[Mr.BR]

I am playing with 6.5 grendel based design , meant to feed micro bolt action from ar15 mags.

Project on above picts is literally a IMI 5.56x45 bullet pulled , neck turned down to near zero and new bullet seated. This is some French development for the military, not mine. I just put it as an illustration that with long bullets sometimes you need a shorter case for more speed downrange when constrained by magazine OAL .

 

[elwarpo]

44 Warp - rimmless 444 marlin.
30-06 case necked up to .429 and 2.225" long. uses 444 marlin dies and load data but runs in semi autos. Have a couple of AR10s in in (rifle and pistol}
220 grains @ 2660 fps
335 grain @ 2120 fps
Drops hogs like a sledgehammer and uses cheap 44 cal pistol bullets.

 

[MJF]

I would bet that the 6mm-06 is faster than you need to go. My 6.5 is.
What brass are you using?

It is very fast. It will send a 87 gr V-max down range at 3875 fps+. It turns a Coyote inside out and varmints are just vanquished! For target shooting I use a 107gn SMK with Retumbo, in Winchester 25-06 brass. My target load isn't super hot. For load development I am 2 mills up from 100 yd zero at 600 yds on a 6" plate. I just moved to N Idaho so I'm looking for an area for 1000 yd shooting to finalize the SMK load. This gun replaced my .300 RUM and my .22-250. and is doing a pretty good job.

 

[iceng]

To people messing with extremely short necks to get extra capacity. Don't bother. You need to have specific projectiles and a very specific chamber to make them work. Basically, don't bother.

6mm Hagar, I've been wanting to play with that for well over a year, but sourcing components is a bitch. Yes creedmoor sports have it, and I'll buy dies and brass in a hear beat, but I'm struggling to get them out of USA. (I'm a gunsmith in Aus, i have almost every permit you can get, I even make semi auto rifles and suppressors here !).

I'll try to take some pics tomorrow of a few things I've done.

As for the 340wby. If I was to tackle it, id probably sharpen the radius a bit, and potentially look into body taper. It always was a solid performer. Perhaps look into the throat area and lead angle, may require a tweak for modern jackets and propellants.

 

[10X Rifles]

I'd probably build something on shortened 308 brass.
Make it about 1.6" long, use a small rifle primer and medium burn rate powders. Probably 30-ish grains of the correct burn rate through an 8-tw barrel.
I'd shoot 105 grain bullets of .243 caliber running just over 2800fps.

I'd also build a 30 caliber twin to shoot 110-125 grain bullets at 2800-2950 with something like H-4198.

It's a 30 BR.

 

[Scout37]

Been a while since I’ve been on the hide. I’m still waiting on a build that I posted about on here a while back, which should be nearing completion soon so the anticipation has been killing me. In the mean time I’ve been trying to gather up some reloading equipment and components to keep myself occupied until then. I’ve also been brainstorming components do another build when this one is finished. The build I’m waiting on is a 300 PRC based on a Bat Vampire action and centered around the idea of a putting together a light weight all purpose 30 cal. I’m not sure which direction I’m going to go next but I’ve been doing some research on different calibers to try to decide. If you flip through a reloading handbook chances are you’ll probably come across quite a few cartridges you’ve never seen before or run across something you may have heard of but don’t know much about since it’s not commonly used or discussed, then you read the ballistics on it and you think to yourself, damn that is an extremely capable cartridge. I’ve come across several and it got me thinking, if you could create your own ultimate wildcat cartridge using anything out of a reloading handbook what would it be? We are seeing a lot of cool new cartridges come out these days and it seems like the parent case is usually something that’s been around for quite some time that’s tried and true then it’s tied into something a little more modern. And the possibilities almost seem endless. Im a sucker for .30 cals, so I was looking at the .340 Weatherby. The ballistics on this round are pretty impressive for the time period it came out, Weatherby introduced it to compete with the 338 Win Mag and I think they knocked it out of the park with the .340 WBY. With the right configuration of powder it can launch a 250 grain pill 2,900 fps and I’m sure if tuned correctly it could easily reach 3,000 fps. I know absolutely nothing about making Wildcat cartridges so I may sound like an idiot here lol, but If I were capable of building my own cartridge, I think I’d take the .340 Weatherby and get rid of the double radius shoulder and replace it with the 338 lapua shoulder and then trim the neck to get the proper cartridge length. Not really a wildcat per say, just modifying the case I guess but I’d love to see what a .340 WBY modernized like this would do. What would you build?View attachment 7693366View attachment 7693367

I'd build a 284 wheeler.

 

[Mike Casselton]

It's a 30 BR.

Yep. I have one

 

[Iwillylike2shoot]

For me it would be a 284 prc (based on 300 prc) or a 7mm Sherman short. I have a local gunsmith who like the Sherman short and does a lot of them.

 

[delinquent pleb]

I’m thinking a 6.5Addiction (6,5x55AI…I may be wrong) will be in my future one day.

 

[Scout37]

Yep. I have one

Nice. Do you shoot F1 class with it?

 

[Mike Casselton]

Nice. Do you shoot F1 class with it?

No, it's just an old BR (score) barrel that will eventually kill some hogs and deer. That is, if I ever swap it with the 6-BR barrel that's on the rifle now.

 

[PinesAndProjectiles]

Make it about 1.6" long, use a small rifle primer and medium burn rate powders. Probably 30-ish grains of the correct burn rate through an 8-tw barrel.
I'd shoot 105 grain bullets of .243 caliber running just over 2800fps.

Sounds like a 6.8 SPC necked down to 6mm would fill this void.
Barrels are available through BHW or Ritch’s Precision Guns. Dies can be had from CH4D. Sizing is as simple as a pull of the press handle with 6.8 SPC brass.
I can push 58 grain VMAX at nearly 3400 out of a 24” barrel.

 

[Mike Casselton]

Sounds like a 6.8 SPC necked down to 6mm would fill this void.
Barrels are available through BHW or Ritch’s Precision Guns. Dies can be had from CH4D. Sizing is as simple as a pull of the press handle with 6.8 SPC brass.
I can push 58 grain VMAX at nearly 3400 out of a 24” barrel.

It's a 6-BR. Mine will send a 65gr flat based bullet at 3550 out of a 22" barrel. 55 and 58gr make 3800fps.

Instead of bothering with necking the 6.8, I'd build a fast twist 6 PPC or a 6 ARC and save time and a lot of money

 

[Dogtown]

Sigh...now you've got me thinking about ways to wildcat .300NM

 

[buggz]

44 Warp - rimmless 444 marlin.
30-06 case necked up to .429 and 2.225" long. uses 444 marlin dies and load data but runs in semi autos. Have a couple of AR10s in in (rifle and pistol}
220 grains @ 2660 fps
335 grain @ 2120 fps
Drops hogs like a sledgehammer and uses cheap 44 cal pistol bullets.

Oh, I find this very interesting!
Who makes these barrels?
I would like to try one for a Seekins SP10, currently .308

AND, handgun, yes!
T/C Encore?

 

[spife7980]

The Birth Of The .220 REDLINE – Coyote Stuff

coyotestuff.com

The .220 Redline Lives! – Coyote Stuff

coyotestuff.com

 

[waveslayer]

I had a new Lazzeroni Warbird built, getting 3120 with 215's if I go with 150 TTSX I'm well over 3400.

If you want a 30 cal wildcat, at least you can buy brass and others can share some load data. I hunt only with my Warbird

 

[CBaker124]

Hey fellas, since we’re on the topic of brass and such, anyone looking for brass and bullets get on graf & sons website. I just ordered some Peterson .308 brass and 230 gr. Berger Hybrid’s. They’ve got a lot of Berger stuff in stock right now and a fair amount of brass, including a lot of Peterson brass. They’re my go to for reloading supplies and they’ve consistently had a lot of stuff I’ve not been able to find elsewhere.
www.grafs.com

 

[Mr.BR]

Got to play with QuickDesign today

Green new chamber design ,blue 6ARC, this is still relatively normal neck length and gives cca 3grain more volume over ARC with same OAL , will likely further bump the shoulder , but first i have to export the design to Quickload so i can benchmark the different chamberings at least roughly before deciding to make one for real.

 

[nksmfamjp]

28 Sherman

28 Sherman Magnum!!!! Big fun!