I know that there isn't really a place for this but also know some of you want to talk about it.
The 30RAR. Just my opinion here, they messed up when they made the rim size .492.
If you want to use other 284 or 6.5-284 brass with a .473 rim then take some and shorten it and neck it down to check the case capacity. Try it first and decide if the case capacity is worth it. Figure out how hard it will be to push the shoulder that far back. How tough will it be to get custom dies made? Try it with the 450 bush master cases too. Before anyone that can produce the cats will, they will check it out every way possible.
Paul, I agree with some of the comments you made on arfcom. There should be a standard IF the cats are done. The designs need to be done by someone that knows enough to keep the ogive in front of the case mouth at the very least.
Lots of things to consider including parts and brass availability.
Will any mag other than a RAR mag work without spitting all of the cartridges out at once?
Consider using RAR brass is 2gr capacity over the BRX worth the trouble?
Consider 284 brass has the same capacity as the BRX, worth the trouble?
Will Remington ever sell parts?
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woohoo Wrote:. . .
The 30RAR. Just my opinion here, they messed up when they made the rim size .492.
. . .
I agree. And, continuing this gross oversight, they failed to neck the case down to what's hot: 6.5mm and 6.8mm.
Oh, what could have been.
I'm actually looking at using Lapua 6.5x284 brass. I've been drafting the case dimensions this morning. Shoulder needs to come forward, and I'm looking at a shoulder angle that will provide a more efficient burn. The RAR has a 1.530" case length, while the Grendel has 1.520", so I don't think ogive length is an issue since I can load a 130gr VLD to 2.310" in a Grendel and mag-feed, but the short .284 would be better served with dedicated mags with a longer allowable COL, like 2.310, with 2.320" internal mag length. That places some serious QC considerations on magazine manufacturing, but we already know that PRI and HK have made such mags.
The .450 Bushmaster and .30 RAR are descendants of one of the most under-appreciated and relatively unknown cartridges-the .284 Winchester, which should have gained more popularity than it did, since it fits in a short action.
Wilson has already made some 30 RAR guns, and there are catters on AR15.com who are anxious to do 7mm, .358, .257, and 6.5mm. It has the potential to be one of those 21st Century chamberings that will take the AR15 into a solid big game hunting rifle, that is also lightweight and low-recoiling. I think there are other aspects of the operating system and recoil system that need to be addressed more like an AR10, but Remington/DPMS really did that with the hybrid bolt, and AR10 extension with center feed ramp, as well as the beefier upper receiver.
Is 2 gr of capacity worth it? Actually if you use 284 or 6.5-284 brass there wont be that much difference between a BRX and a 6.5-284 short cat.
Go ahead and make a case the way you want it using the brass you plan to and measure the case capacity.
In early 2010 I did what you are doing now. A 6.5 BRX using Lapua brass has 42gr capacity.
XcountryRider
Unregistered
woohoo Wrote:I know that there isn't really a place for this but also know some of you want to talk about it.
The 30RAR. Just my opinion here, they messed up when they made the rim size .492.
If you want to use other 284 or 6.5-284 brass with a .473 rim then take some and shorten it and neck it down to check the case capacity. Try it first and decide if the case capacity is worth it. Figure out how hard it will be to push the shoulder that far back. How tough will it be to get custom dies made? Try it with the 450 bush master cases too. Before anyone that can produce the cats will, they will check it out every way possible.
Paul, I agree with some of the comments you made on arfcom. There should be a standard IF the cats are done. The designs need to be done by someone that knows enough to keep the ogive in front of the case mouth at the very least.
Lots of things to consider including parts and brass availability.
Will any mag other than a RAR mag work without spitting all of the cartridges out at once?
Consider using RAR brass is 2gr capacity over the BRX worth the trouble?
Consider 284 brass has the same capacity as the BRX, worth the trouble?
Will Remington ever sell parts?
We have another possible source of uppers and bolts. I say possible because they are in the early investigative stage of getting samples. If they can manufacture the bolts and uppers then yes it maybe worth it to go the 30RAR route. Especially if it does not require cutting brass and turning necks.
XcountryRider
Unregistered
LRRPF52 Wrote:Are you saying you found 2.0gr difference between the short 6.5x284 and the BRX? 2 grains is a bit of powder to me, especially if we're going slower-burning, but if the 6.5 BRX runs fine from PRI mags, then that is a major plus.
Are you cutting the case length down from 1.560" for the 6.5mm? There is a ton of neck to work with on that brass.
I'm wondering if a 6.5mm CAT off a 30RAR would need special mags or if 30RAR mags would work. If they would work then it might be easier to convince someone like ASC to build a 30RAR mag?
Can 450 bushmaster brass be used.
Seems like your 800 series bolt would do well with it.
Would 6.5-284 dies milled down at the bottom work
Black followers have been made that center feed the 450 with stock steel mags and run well.
Just as good as 450 mags.
Sig mags work with the 450.
The 450 is a real hammer under 200 yards.
A 6.5 going 2800 fps would reach out a lot farther.
450 brass is good quality and not as thick as 284 brass and might hold a little more powder.
Would need much trimming since they're 1.7 inchs long.
