270 MSR wildcat

[Constructor]

It's a .277 hunting cat based on 6mm Dasher brass developed to shoot 130-140gr bullets out of an AR15. 130 Berger Classic hunters(BC .497) run 2750-2800 out of a 20" barrel. The 145 ELDX with a BC of .536 hit 2650. 10 rounds fit in a 15 round 6.8 mag. 250-300fps faster than a Grendel.
5.56, 6.8, 270 MSR

 

[Hellbender]

What bolt are you running? Standard AR bbl extension or big one like Oly WSSM?

 

[Constructor]

What bolt are you running? Standard AR bbl extension or big one like Oly WSSM?

750XD bolt. Standard OD extension but lug design is different. We have been machining them since 2009, I designed them in 2007.

 

[Hellbender]

Oh, now I know who you are! Yes, I'm familiar, good stuff!

 

[madolive3]

I've been looking for a caliber to rebarrel my Valkyre, this may be it.

 

[Jsmith2631]

Well damn.....my new grendel is supposed to show up next week. Now I want this!

 

[madolive3]

Barrel bolt and dies on the way

 

[ShooterwithNoName]

I've considered picking up this cartridge if I decide to play around with another small frame widcat. I ran the 6mmAR Turbo40 for about a year. It was an impressive little cartridge, but being built in an AR was it's weakness imo. I've gotten really great accuracy from ARs, but I've moved all my AR builds from precision to HD/hunting setups.

That being said, if I were to wake up tomorrow and decide to build another wildcat upper, it would be 270MSR. I already have a ton if .277 bullets, suitable powder, etc. Excellent Washer brass can be had second hand for decent $$.

The ability to move out of 6.8spc territory and push 130-140gr bullets up to 2700fps or so would be a really awesome hunting rig imo.

@Constructor, do you suggest going to 20" barrel length for those planning on running 270MSR? I run all shorter 12.5"-18" on my hunting ARs anymore. Have you ran it in anything shorter?

 

[Constructor]

I've considered picking up this cartridge if I decide to play around with another small frame widcat. I ran the 6mmAR Turbo40 for about a year. It was an impressive little cartridge, but being built in an AR was it's weakness imo. I've gotten really great accuracy from ARs, but I've moved all my AR builds from precision to HD/hunting setups.

That being said, if I were to wake up tomorrow and decide to build another wildcat upper, it would be 270MSR. I already have a ton if .277 bullets, suitable powder, etc. Excellent Washer brass can be had second hand for decent $$.

The ability to move out of 6.8spc territory and push 130-140gr bullets up to 2700fps or so would be a really awesome hunting rig imo.

@Constructor, do you suggest going to 20" barrel length for those planning on running 270MSR? I run all shorter 12.5"-18" on my hunting ARs anymore. Have you ran it in anything shorter?

No, most of the guys are using them to hunt mule deer and elk and longer distances. An 18" would only lose 60fps from the 20". Anything shorter may need a mid gas and I think there would be a lot of unburnt powder spewing out the end of the barrel.

 

[ShooterwithNoName]

No, most of the guys are using them to hunt mule deer and elk and longer distances. An 18" would only lose 60fps from the 20". Anything shorter may need a mid gas and I think there would be a lot of unburnt powder spewing out the end of the barrel.

Got it, it looks like a really great hunting cartridge for small platform ARs... I'm a .277 fan, I use my 6.8spc almost exclusively nowadays for hunting. But I'm in WV so most of my hunting is coyote, whitetail and very rarely a black bear. So it fits the bill for me perfectly and I can always find quality reloading components just about anywhere.

 

[Khavic]

Just getting started with pressure testing my 270 MSR with BLC -2 and 115 CC. It's shaping up to be a bug holes shooter. Great design Constructor.

 

[FrozenMinnesotan]

Old thread. But are reamers available? Would like one in a bolt gun

 

[Constructor]

Old thread. But are reamers available? Would like one in a bolt gun

Honestly there are several calibers that will fit in a bolt gun that would be easier and perform better. I have the only reamers and do not rent them out. I'm sure JGS or one of the other could make a set, it a 6mm Dasher necked up to .277 a simple wildcat.

 

[FrozenMinnesotan]

Honestly there are several calibers that will fit in a bolt gun that would be easier and perform better. I have the only reamers and do not rent them out. I'm sure JGS or one of the other could make a set, it a 6mm Dasher necked up to .277 a simple wildcat.

Ok. Ya I kinda figured. Probably go another route anyway

 

[MBPD 444]

Honestly there are several calibers that will fit in a bolt gun that would be easier and perform better. I have the only reamers and do not rent them out. I'm sure JGS or one of the other could make a set, it a 6mm Dasher necked up to .277 a simple wildcat.

It would be a great candidate for the Howa Mini Action.