School me on wildcats

The place to discuss ammunition, reloading, ballistics, loads, and chamberings.
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First Shirt
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School me on wildcats

Post by First Shirt »

As we've discussed here before, the Senior Minions are saving their pennies to buy left-and-right-handed ARs, and would like to build 6.5 Grendel uppers for them. Their desire for a 6.5 Grendel upper is based purely on performance, and doesn't take into account the availability of parts, reloading components (brass, mainly), or other bottlenecks in the logistics chain.

So I got to thinking (always dangerous, I know!), about options. There is a company selling AR barrels in Six5, which is a 6.8 SPC necked down to 6.5mm (.264 neck ID) and trimmed to 1.620 (which makes it a 6.5x41, vice 6.5x39 for the Grendel), which, they claim, will equal or exceed 6.5 Grendel performance with 100-120gr bullets.

Upside: Uses regular 5.56 bolts, which are readily available in right-or-left hand configuration. Easier to find replacement or upgrade parts. Offers equal or better performance compared to the Grendel (the Six5 operates at 58K psi chamber pressure, versus 52K for the Grendel.), and components, especially brass, will be easier to find. It's tons easier to find 6.8 SPC mags than 6.5 Grendel mags.

Downside: No commercial availability at all, and a serious lack of load data. The aggravation of having to size and trim new brass for reloading.

What am I missing?? I know the Minions would really like a Grendel upper, but do the plusses outweigh the minuses??? I'm seriously trying to talk myself out of this, with a conspicuous lack of success.
But there ain't many troubles that a man caint fix, with seven hundred dollars and a thirty ought six."
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Lokidude
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Re: School me on wildcats

Post by Lokidude »

Grendel is built on a 7.62x39 case, yes? C products, and a couple others, have mags for x39 readily available most all the time, for not unreasonable dollars. As to wildcats, you're going to experience all new bottlenecks, such as having to fire-form brass, looking up load recipes with little to no manufacturer support, etc.
workinwifdakids wrote: We've thus far avoided the temptation to jack an entire forum.

But what the hell.
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First Shirt
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Re: School me on wildcats

Post by First Shirt »

That's the hangup, no load data. There's no fireforming, it's just a matter of necking 6.8 SPC brass down to 6.5mm (.264 ID). And no commercial loads. So it will be a strictly handloads-only propostion.

Granted, I don't think either of The Minions has ever fired a factory load in their current hunting rifles, but if push came to shove, they could find and shoot 7mm-08 ammunition.

But if we go to Six5, factory ammo is a non-player.

Damn, I hate it when I have to THINK!!!!
But there ain't many troubles that a man caint fix, with seven hundred dollars and a thirty ought six."
Lindy Cooper Wisdom
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PawPaw
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Re: School me on wildcats

Post by PawPaw »

First Shirt wrote:That's the hangup, no load data. There's no fireforming, it's just a matter of necking 6.8 SPC brass down to 6.5mm (.264 ID). And no commercial loads. So it will be a strictly handloads-only propostion.

Damn, I hate it when I have to THINK!!!!
Once you get into wildcatting, it's a whole 'nuther obsession. Before long you'll be thinking "What IF... I neck down a .50 BMG to 6mm and run it though a 7 wist barrel so I can use those long, lovely DTAC bullets?"

Load data, believe it or not, is generally not a problem. Simply find the closest cartridge you can find to it and use starting load data. Experimentation is the incentive to wildcatting, and you can't have one without the other. In your case, I''d use the starting data for the 6.8 SPC, simply because the difference in the neck would be the difference between eenie and meenie.
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Yogimus
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Re: School me on wildcats

Post by Yogimus »

just muzzle-load while drunk. Every shot is a wildcat!
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First Shirt
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Re: School me on wildcats

Post by First Shirt »

PawPaw wrote: In your case, I''d use the starting data for the 6.8 SPC, simply because the difference in the neck would be the difference between eenie and meenie.
I am SO gonna show them this, just because it tickles me!!! Thanks, PawPaw, you've made my day!!!!
But there ain't many troubles that a man caint fix, with seven hundred dollars and a thirty ought six."
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Greg
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Re: School me on wildcats

Post by Greg »

First Shirt wrote:
PawPaw wrote: In your case, I''d use the starting data for the 6.8 SPC, simply because the difference in the neck would be the difference between eenie and meenie.
I am SO gonna show them this, just because it tickles me!!! Thanks, PawPaw, you've made my day!!!!
Looks pretty cool. Seems like it could be a better 6.5mm round for the AR platform than Grendel. Should be easy for some enterprising manufacturer to standardize, too.
Maybe we're just jaded, but your villainy is not particularly impressive. -Ennesby

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PawPaw
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Re: School me on wildcats

Post by PawPaw »

Greg wrote:
First Shirt wrote:
PawPaw wrote: In your case, I''d use the starting data for the 6.8 SPC, simply because the difference in the neck would be the difference between eenie and meenie.
I am SO gonna show them this, just because it tickles me!!! Thanks, PawPaw, you've made my day!!!!
Looks pretty cool. Seems like it could be a better 6.5mm round for the AR platform than Grendel. Should be easy for some enterprising manufacturer to standardize, too.
As in all handloading, go slow and ramp it up slowly. Sometimes the difference between safe and unsafe us very close when you get to the higher loads. Be careful, but don't be afraid to experiment. When you get to your goal, stop there.

Do all the smart things, measure brass after every shot, until you are sure that you're in safe territory. If you start getting brass stretching, either in OAL or in head diameter, stop right there and back down, you've gone too far. You'll learn to see the warning signs.
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First Shirt
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Re: School me on wildcats

Post by First Shirt »

Hey, PawPaw, you got an AR that you want to experiment with?

Sounds like you know more about this than I do.
But there ain't many troubles that a man caint fix, with seven hundred dollars and a thirty ought six."
Lindy Cooper Wisdom
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PawPaw
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Re: School me on wildcats

Post by PawPaw »

First Shirt wrote:Hey, PawPaw, you got an AR that you want to experiment with?

Sounds like you know more about this than I do.
Negative, Ghostrider, the pattern is full.

I learned about wildcatting during my castbullet phase, which is wildcatting standard calibers. Same principle. Have you ever loaded a .30-06 with Red Dot? Or a .30-30 with Bullseye? You learn interesting things about pressure, and bullet performance. And yes, to answer the question, you can safely both load a .30-06 with Red Dot and a .30-30 with Bullseye.

What I am interested in is the .250 Savage, or necking a .223 Remington up to .257 caliber, (or both). Probably before the year is over, I'll have a bolt-action in .250 Savage. I believe that with today's good powders and today's good bullets, it will be a whitetail slayer extraordinaire.
Dennis Dezendorf
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