rebated rim on larger case the ultimate AR round?

S

steve garrett

Well-known member
since nosler made a rebated rim for the 22 nosler. others claim issues with bolts that are made to accept cases fatter than the 6.8 spc, namely the 6.5 grendel cases. I have always though the 6.5 BR case would make the ultimate AR 15 case. Its and its fat and holds a useful up big step up in power.

I think the 224 valkyrie is kinda a joke because they actually shortened the 6,8 SPC case. What if they made a rebated rim 6.5 BR case and sized it down to fit a 6.8 SPC bolt? does anyone know if this would work?
 
There are larger extensions and bolts out there to run the BR case, then you get into reduced magazine capacity. I see the rebated rim as a negative personally. Valkyrie is showing up in people's amgands now and doing what it is supposed to.
 
I think rebated rim cartridges have a harder time catching and stripping from the magazine. I don’t know the diminsions of the 6br case but I believe it has a .308 bolt face however the 6ppc uses a 7.6x39 bolt fsce (same as Grendel) I think it would be the ideal case to rebate the rim to a 6.8 bolt face diameter then neck down to 22cal band throw some big bullets. But there is the 6mm AR already and it is basically a 6ppc with a little longer body. But they didn’t rebate the rim so it uses Grendel bolts and Those are the ones with problems.
 
The Bushy and SOCOM are both rebated to 473, 308 size, they are loaded to lower pressures because of the bolt thrust issue with the big cases. They will break STANDARD size AR15 bolts if loaded hot. This is the reason the SOCOM isn't getting SAAMI approval as the prof loads break things. Apparently the Bushmaster is just small enough to pull it off. You won't pick up much bolt life with a rebate as you are still hitting the bolt with the pressure only in a smaller area. Not good.

I talked at great length to the guys that submitted the SOCOM and contrary to popular believe by the sour grapes guys it isn't one of the big boys blocking it. It just comes down to parts breakage. Wilson with his bigger bolt/cut BCG is able to go hot but like the WSSM it will take a massaged upper to get it done.

With new steels and the new era beefed up bolts we are getting much better bolt life out of the PPC bolt head sizes and that is a plus. Between Ritch and I we've shot thousands of rounds on STANDARD 7.62X39 bots and never broken a thing. Looks like it might really be the fact that guys try to tun these into magnum cartridges and it just doesn't work that way. A Grendel/LBC is not a 6.5 CREED no matter how you cut it.

There is a cartridge out there being developed that will run with the better bolts but it will not be rebated that should run with the 6 BR. Just a matter of time and dollars. Of course once again not with the convenience of OTC ammunition but for the addicted that is no big step for the steppers here. If you want to play you have to pay in one way or another.

Greg
 
I guess the question is by running a .473 sized case, is the problem simply too weak of bolts? or if the bolts always held is there a way to run the bushy or socom full house other than that or is the barrel extension also a concern?

both those cases are rebated full size cases, it would seem like using a smaller bolt would fix the issue. no one has rebated a standard bolt face that I know of. They did it with the .473 bolt face because it was so common and allowed use of larger cases with standard bolt faces. nolser has been the only one to do it with the 22 nosler so far.

GLS, so there is something in the works? how soon do you think we will see it? any other details
 
Steve garrett just brought it up too and I was wondering the same thing. With these cases that are breaking bolts is there ever also damage done to the barrel extensions?
 
More wall thickness is needed o the 473. Better steel and enhancement to the lugs and walls do help. You can push the BUSHY and SOCOM a bit with those but not a lot. They are huge and the thrust goes up with the cross-sectional area of the case not-the bolt face size. To harness them you need an AR 10 size extension and a big bolt ala Wilson now. You put a BUSHY in a standard AR10 and it is one bad beast. We've done it and it is unreal.

Nosler was stupid going to a 45 MM case.All they did was take a 22X6.8 case and put a big rim on it. Picked up about a grain of capacity and have those rebated rims that get bent and damaged in a heartbeat compared the the standard 6.8. Sexy it is, usable not so much.

Yes there is some stuff in the works on the wildcatter level and it will be several months before anything pops up if it works at all. Computer says yes and the physics looks good.

I've seen severl bolts go away from pictures guys sent me and so far no one has had any damge to the extension. I know of one guy out East that has broken a couple 6.8 bolts of known good quality with no damge to the barrel. You want a 243 Winchester in a 6.8 case you will need to work for it and your wallet will pay for it.

Greg

Historical note. When the 6 PPC first showed up they were turning and rebating the rims to 223 size so the BR guys wouldn't have to alter their bolt faces from the 223 size they had been running. Now the process of bushing a big one or opening up a little one is common now no one does it any more. I know there were some guys shooting DCM High Power with the rebated 6 PPC before they could get bolts to fit.
 
Originally Posted By: GLShooterMore wall thickness is needed o the 473. Better steel and enhancement to the lugs and walls do help. You can push the BUSHY and SOCOM a bit with those but not a lot. They are huge and the thrust goes up with the cross-sectional area of the case not-the bolt face size. To harness them you need an AR 10 size extension and a big bolt ala Wilson now. You put a BUSHY in a standard AR10 and it is one bad beast. We've done it and it is unreal.

Nosler was stupid going to a 45 MM case.All they did was take a 22X6.8 case and put a big rim on it. Picked up about a grain of capacity and have those rebated rims that get bent and damaged in a heartbeat compared the the standard 6.8. Sexy it is, usable not so much.

Yes there is some stuff in the works on the wildcatter level and it will be several months before anything pops up if it works at all. Computer says yes and the physics looks good.

I've seen severl bolts go away from pictures guys sent me and so far no one has had any damge to the extension. I know of one guy out East that has broken a couple 6.8 bolts of known good quality with no damge to the barrel. You want a 243 Winchester in a 6.8 case you will need to work for it and your wallet will pay for it.

Greg

Historical note. When the 6 PPC first showed up they were turning and rebating the rims to 223 size so the BR guys wouldn't have to alter their bolt faces from the 223 size they had been running. Now the process of bushing a big one or opening up a little one is common now no one does it any more. I know there were some guys shooting DCM High Power with the rebated 6 PPC before they could get bolts to fit.

so the PPC case can be rebated. wouldn't the valkerie made way more sense on a rebated grendel case?
 
Originally Posted By: steve garrettOriginally Posted By: GLShooterMore wall thickness is needed o the 473. Better steel and enhancement to the lugs and walls do help. You can push the BUSHY and SOCOM a bit with those but not a lot. They are huge and the thrust goes up with the cross-sectional area of the case not-the bolt face size. To harness them you need an AR 10 size extension and a big bolt ala Wilson now. You put a BUSHY in a standard AR10 and it is one bad beast. We've done it and it is unreal.

Nosler was stupid going to a 45 MM case.All they did was take a 22X6.8 case and put a big case head on it. All it di was pick up about a grain of capacity and have those rebated rims that get bent and damaged in a heartbeat compared the the standard 6.8 variants. Sexy it is, usable not so much.

Yes there is some stuff in the works on the wildcatter level and it will be several months before anything pops up if it works at all. Computer says yes and the physics looks good.

I've seen several bolts go away from pictures guys sent me and so far no one has had any damge to the extension. I know of one guy out East that has broken a couple 6.8 bolts of known good quality with no damge to the barrel. You want a 243 Winchester in a 6.8 case you will need to work for it and your wallet will pay for it.

Greg

Historical note. When the 6 PPC first showed up they were turning and rebating the rims to 223 size so the BR guys wouldn't have to alter their bolt faces from the 223 size they had been running. Now the process of bushing a big one or opening up a little one is common now no one does it any more. I know there were some guys shooting DCM High Power with the rebated 6 PPC before they could get bolts to fit.

so the PPC case can be rebated. wouldn't the valkerie made way more sense on a rebated grendel case?

I suppose it could but the Valkyrie is no Grendel since it's a 6.8 base just like the 22 Nosler. You would gain zero in rebating it as you would just have a Nosler. Although technically the Nosler is a 30 REM/HAGAR base not a 6.8 because of the 45 MM length. The V is a neutered 22X6.8 and a one trick pony to boot hobbled by a twist rate that most here would find abhorrent in the varmint world.

The rebated PPC was to handle a shortage of PPC bolt face guns out there. It was not to "improve" the cartridge at all.

Greg
 
Originally Posted By: GLShooterOriginally Posted By: steve garrettOriginally Posted By: GLShooterMore wall thickness is needed o the 473. Better steel and enhancement to the lugs and walls do help. You can push the BUSHY and SOCOM a bit with those but not a lot. They are huge and the thrust goes up with the cross-sectional area of the case not-the bolt face size. To harness them you need an AR 10 size extension and a big bolt ala Wilson now. You put a BUSHY in a standard AR10 and it is one bad beast. We've done it and it is unreal.

Nosler was stupid going to a 45 MM case.All they did was take a 22X6.8 case and put a big case head on it. All it di was pick up about a grain of capacity and have those rebated rims that get bent and damaged in a heartbeat compared the the standard 6.8 variants. Sexy it is, usable not so much.

Yes there is some stuff in the works on the wildcatter level and it will be several months before anything pops up if it works at all. Computer says yes and the physics looks good.

I've seen several bolts go away from pictures guys sent me and so far no one has had any damge to the extension. I know of one guy out East that has broken a couple 6.8 bolts of known good quality with no damge to the barrel. You want a 243 Winchester in a 6.8 case you will need to work for it and your wallet will pay for it.

Greg

Historical note. When the 6 PPC first showed up they were turning and rebating the rims to 223 size so the BR guys wouldn't have to alter their bolt faces from the 223 size they had been running. Now the process of bushing a big one or opening up a little one is common now no one does it any more. I know there were some guys shooting DCM High Power with the rebated 6 PPC before they could get bolts to fit.

so the PPC case can be rebated. wouldn't the valkerie made way more sense on a rebated grendel case?

I suppose it could but the Valkyrie is no Grendel since it's a 6.8 base just like the 22 Nosler. You would gain zero in rebating it as you would just have a Nosler. Although technically the Nosler is a 30 REM/HAGAR base not a 6.8 because of the 45 MM length. The V is a neutered 22X6.8 and a one trick pony to boot hobbled by a twist rate that most here would find abhorrent in the varmint world.

The rebated PPC was to handle a shortage of PPC bolt face guns out there. It was not to "improve" the cartridge at all.

Greg

wouldn't a rebated grendel case and its short length mean the case wouldn't need to be shortened and would hold more powder than the valkerie? its already shorter than what they shortened the 6.8 case. maybe it was marketing because if they did that people would say thats nothing new the 22 grendel has been out there, and why not just shoot a grendel anyways.
 
Once again you gain NOTHING rebating the rim. I already shoot a 22 LBC/Grendel. It has higher capacity as you mentioned and will run above the V.with ease as does the 22X6.8.

Greg
 


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