25 Grendel or 25 BR

[LRRPF52]

Just got in some Blackjack 131gr .257 ACE samples to start playing with.

I've always wanted a quarter bore since my Grandpa loved .257 Roberts, but I want it in an AR15 of course.

I've been looking at 6mm AR, but think this might have a chance to beat it.




.330 G7 1000yd verified BC, really meant for 25x47 Lapua and 25 CM.

Longer than any 140gr class VLD/SMK/Scenar bullet I have in 6.5mm.

Wouldn't suffer from anemic plate impacts of the 6mm at distance, or the recoil of 140gr 6.5mm, but brings BC superior to most 140gr 6.5mm and definitely smokes 6mm BCs, even the DTAC.

I'm doing some mocking up right now.

[BCHunter]

What do you expect for coal? And how much case capacity do you anticipate with it?

[biodsl]

Subscribed.

[LRRPF52]

What do you expect for coal? And how much case capacity do you anticipate with it?

To load this in a Grendel case and have the projectile shank/boat tail meet the case neck/shoulder, it will need 2.370" COL minimum.

In a BR, it looks like we can get it shorter since the neck/shoulder on the BR is 1.238", and the BR has way more neck support/long neck for feeding stability of the concentricity.

I don't want to suffer from the problems that I think are happening with the .224 Valkryie in gas guns.

Also looking at 25 WSSM, which would duplicate or exceed 25x47 potentially.

I need some BR brass with dies to expand and what not.

The only bullets I'm finding with a higher BC than this 131gr ACE in the 6.5mm realm are:

* 147gr ELD-M at .351 G7
* 150gr SMK .713 G1/.360-ish G7

I don't like pushing past 130gr, so this ACE is on the edge, but has insane BC for weight. Seems like a beautiful little bullet for the AR15 that will retain energy extremely well, while suffering from very minimal wind deflection. We need more COL though I think.

[Huckleberry75]

Miles and Logan know how to create beautiful bullets. Those Aces are ..well, Aces!

[Sticks]

This outta be good.

[sneaky one]

I think I'll sit down with BFT- I have an idea for a midsized AR- to handle the 6.5-47 Lapua, a new .257 cal. round, the one that L 52 is thinking of.
And a few that are just longer than the Grrr.

The .257 is already loaded from Sharps, co. for AR's. should be an easy dimensions swap on the computer. This could get interesting.

Think-- AR 12, or 12.5

Just talked to BFT, we'll start on it this week. I'm stoked!

[grayfox]

That Sharps "25-45" AR is a necked up 223 case...
I like the idea of starting with the grendel case. Less anemic-ness.

[SightedIn]

Just to confirm, when you say 25 BR are we talking a 6mmBR necked to 25cal?

[LRRPF52]

Just to confirm, when you say 25 BR are we talking a 6mmBR necked to 25cal?

Yes. I really think that case will be ideal for low recoil and sufficient mv to get this bullet going.

With the 25x47 Lapua and 257 Creedmoor, they're already smoking 6.5 CM performance, as well as 6 Creedmoor, and a 131gr will actually move the plates so ROs can see it.

The 6s don't have much retained energy to swing plates or make a big splash on steel once you get out there.

I love the 6mm for the areas it shines, which are varmint, TGT, cutting paper at distance, low recoil, super flat trajectory.

The .257 ACE 131gr gives you the best of both worlds between 6.5mm retained energy, but super flat trajectory and lower recoil of the 6mm when shot from -08 cases.

-08 cases are a non-starter in the AR15 frame, so I think the 257 BR combination would feel like shooting a Grendel, but doable from a smaller rifle chassis and mags.

For optimum projectile/brass arrangement, it's going to require a COL that no AR15 magazine or receiver set can handle currently.

For loading long in Grendel, it won't require much at all to get neck tension. Bushing dies will work.

Mocking it up in Grendel, it already has some neck tension in Lapua factory virgin brass.

[SightedIn]

Ok yeah that sounds pretty awesome. My only question is that isnt a 6br bolt face a .473? Can that fit in an ar15( as opposed to a ar10)?
Actually scratch that i just remembered the 30AR fit in an ar15.
What bolt would you use? Some sort of .473 face but ar15 bcg carrier hybrid?
Got my interest totally piqued here

[grayfox]

For optimum projectile/brass arrangement, it's going to require a COL that no AR15 magazine or receiver set can handle currently.

For loading long in Grendel, it won't require much at all to get neck tension. Bushing dies will work.

Mocking it up in Grendel, it already has some neck tension in Lapua factory virgin brass.

So are we talking use of a windowed mag? or will this have to be single loaded?
Or re-barrel a howa mini and use its mag length?

[go4shoot]

I'm hoping for a lot of bullet manufacturers are going to jump on the 25 caliber and produce some new high bc bullets.

[bj139]

Ok yeah that sounds pretty awesome. My only question is that isnt a 6br bolt face a .473? Can that fit in an ar15( as opposed to a ar10)?
Actually scratch that i just remembered the 30AR fit in an ar15.
What bolt would you use? Some sort of .473 face but ar15 bcg carrier hybrid?
Got my interest totally piqued here

458 SOCOM bolt should work. Same case head size as 30-06.

[SightedIn]

458 SOCOM bolt should work. Same case head size as 30-06.

Sounds like a plan lets build this thing! Well LRR would actually be doing the building😎