Home Forums Hunting & Shooting Long Range Hunting The 6.8 WESTERN...

What bullet, speed are you thinking?

You want a shorter throat for long, sleek bullets, not a longer one.

"But it has to be NEW!"

The shooting industry is just as susceptible to the "newest and greatest" marketing strategy as any other. Fast-twist .270s will do well with us geeks but the low-information public won't pay attention like they would with a new chambering. This whiz-bang stuff doesn't really interest me; I enjoy available and affordable ammunition.

Honest question, wouldn't a longer free bore allow the longer bullets to be seated out further instead of intruding into the powder column? Seems like better case capacity, slower powders for overbore cartridges, less compressed loads, and lower pressures?

Bob

Sleek bullets with pointy noses have their ogive located further back than conventional bullets, so for a given OAL and distance from the lands sleek bullets require a shorter throat than bullets with more rounded nose profiles.

Said another way, with magazine length limiting how far out you can seat the bullet (when OAL is limited by mag length), pointy bullets require a much shorter throat to kiss the lands than round-nose bullets do. Or if mag length is not the limiting factor then there is limited case neck length to support the bullet, which also restricts OAL. Either way, when seating to longer and longer OAL, the more rounded the nose profile of the bullet, the sooner it hits the leade.

Good point Jordan. It was before I knew much other than a Krieger barreled 1-8 22-250 I got on accident made stuff fly when I hit them... that was my beginning of learning, RPMs count. Farese really drove it home when I started using BBCS.

This is great and all, but until bullet companies start asking a .277" round to shoot further, this cartridge (along with anything else in .277") will always be handicapped at longer ranges.

Even the .620 (.312 G7) B/C of that 165 ABLR isn't too impressive, considering its weight. That's assuming it is even an accurate B/C figure, knowing Nosler's reputation with jacking those numbers up.

I was thinking the same thing. Even the old 7mm 162 AM bests that ballistic performance.

Did a ballistic spreadsheet comparison b/t the ABLR's, 150gr./3100 fps v. 165gr./2950 fps.

Not much difference and the 150 shoots a little flatter.

The twist/RL-26 alone would allow the .270 Win to handle 150 AB/ABLR's at ~ 2900 fps.


Also did one on a fictitious 170 gr. NP at 2900 fps for the new cartridge.

It would be a beast, and don't think the .270 Win could push it fast enough to be useful, unless, as you mentioned, throated long.


This round seems to need really slick bullets to be useful, like the 175 gr. w/ BC(G1) in the .70's.

As mentioned, a .270 CM on steroids.




GR

That was my first thought, for a Freezer Queen M700 BDL.:

24" 1:8 twist .270 Win. with the 6.8 WESTERN throat, maybe AI.



Retro M40.




GR

It depends. They gave the CM a longer throat, so more of the bullet could be seated outside the case. Was that a mistake? The leade angle matters just as much. A long throat and steep leade don't allow long-tapered ogives any room. A short throat and a 1 degree, 30 minute leade angle, like the new "long range" rounds have, allow more room. A longer throat with the long leade allow long bullets to be seated in the neck of the case, thus increasing powder capacity, and potentially allowing for a more consistent powder burn. Magazine length ends up being the limiting factor.

IMO, yes it was a mistake. IME using a SAAMI reamer, the bearing surface of the 108 ELD has less than 1 caliber of shank (depending on lot number) in the neck of the 6mm Creedmoor when it contacts the lands. Using AIAW mags, I run out of neck long before running out of mag length. IMO the SAAMI 6mm Creedmoor throat length (considering the shallow leade angle) is not optimized for long, pointy 6mm bullets.

I think you may have mixed up your scenarios a bit. A short throat with steep leade doesn't allow rounded-nose bullets any room. A long throat with shallow leade angle doesn't allow long, pointy bullets to contact the lands before running out of magazine length (or if mag length is generous, then you run out of neck length to hold the bullet shank). I understand your point about longer throats, and this was a valid concern 20 years ago when bullets were shorter and more rounded than they are today. BobinNH used to chamber the 7RM with a long throat for just that reason (to seat the base of the bullet shank at the base of the case neck, often using NP or BBC bullets, IIRC). The point I was making is universal and does not "depend". When comparing bullets with long, pointy noses to bullets with more rounded noses, and assuming equal leade geometry, the pointy bullet needs a shorter throat to contact the lands at a given OAL than the rounded-nose bullet does.

It was called the 6.8 Browning right up to the time it was submitted to SAAMI.

I’ve been kicking around 7GPC too. Bought an 8” Hawk Hill sporter contour last year so it’s ready to go.

Interesting.

All under the FN Herstal roof.




GR

Sounds nuts but I keep thinking a 358Creedmoor would allow a 200 or 225gr AB to be seated to 2.8" unlike a 358winchester

That 165gr ABLR at 2900-3000 is suitable for anything that walks from 8-800 yards, all with very manageable recoil.

There is nothing in North America I wouldn’t shoot with it (although I would not choose it for big bears) and nothing in Africa I wouldn’t shoot with it if legal.

It’s basically like shooting a 7mm Rem Mag with 175s but with less recoil in a more efficient package. That’s about as close as you can get to the mythical “one rifle/one bullet for everything” combo. I’m intrigued.

U

Will a 1/10 spin that 165 ABLR....?
I have a seriously accurate .270win that’s 1/10 and would consider trying them if it will stabilize........

Rumor, that I never got confirmed, is that max coal was set to fit Browning's requirements.

Not a chance.

MAYbe the 150 gr. ABLR... but have heard instability from several that have run it through a 1:10 Bbl.




GR