Home Forums Hunting & Shooting Hunting Rifles The .270

Stick,

As you well know, a lot of folks refuse to accept that there is something out there that has an advantage over Ol’ Faithful, simply because the tried-and-true has always worked in the past. It’s not hard to imagine that we just might make some technological gains over a 100-year span, both in case and bullet design, all of which may lead to some subtle, but real, advantages over what was mainstream in 1925. Not only that, but certain trends over those 100 years, such as common twist rates for a given caliber, just might affect bullet development between then and now, resulting in current advantages for one calibre over another.

I find it works best to check emotional attachment at the door, and evaluate things based on merit. Can a guy kill game with a .270 Win and 150 gr Speer SP? I sure hope so, or he’s got bigger problems than BC to worry about. But do bullets exist now that give a guy an advantage over that .270/150 combo? Sure, they do.

Maybe a Ruger No. 1?

Never feed a narcissist. Self aggrandizing narcissists always derail themselves. Notice how it revealed its botched understanding of BC a few pages ago? The self aggrandizer will continue to defend its hole even after its defenses have been swept away, more aggressively to boot. Notice how it posts pictures that prove nothing (only that someone used a camera), and which are completely out of context. To be thought of as superior, and uniquely so, is the driving force behind the narcist. After all, they live in a world of self-grandeur and delusion. Once identified, they should become objects of pity, since they don't understand their own condition, much like a rabid dog that bites out of reflex, only knowing that it is miserable and must lash out.

Maybe........or a Browning High Wall.

MV stated to be 2567 fps.

The bullet’s vertical trajectory stays within a 12” vital zone.

I’ve killed and seen killed several ‘fleshy targets’, not just paper ones, with the 147 ELD, so that’s the bullet I’ll stick with. It has performed very well for me by creating a substantial wound channel and leaving a ~1.25” exit wound most of the time. I’d be happy to compare it with an ELD-M offering in .277”, for a more fair comparison, but there isn’t one. Which is sort of the point.

Only if you're in slingshot range.

These fuggers are probably on the negative side of B.C. values.

A Browning High Wall would be a good choice!

Berger VLD hunting/Nos Etip 130/Hrn 130 Inter bond or SST 130 in 270 all listed as .460 G1. Highest Alliant velocity listed is 3200 fps: 400 yd results: 2396 fps / 1656 ft-lbs / -16.7” or + 84 fps / + 114 ft-lbs / + 2.2” with respect to Creedmoor shooting boutique 130 gr “JLK” slug at 2900.

10glocks,

Before you dig any deeper, I think Stick was implying that despite a gain in mass, which is proportional to BC, there is no gain in BC (there’s actually a loss, instead) with that particular bullet, which implies that form factor was sacrificed for other design features. Compare with the 147 ELD, which has less mass and a higher BC value.

I’m pretty sure he was not implying that Berger doesn’t know how to calculate BC, as you stated above.

How about wind drift, which can present a greater challenge and be more meaningful at 400 yards than any of the other quantities you mentioned?

If you are comparing the performance of the 6.5CM to the .270 over normal hunting ranges , here are a few points to factor into your calculations:

1. Use a well-constructed hunting bullet that you can shoot through the shoulder of a deer without it blowing up before getting to the vitals, perhaps compare the 140 grain Accubond or TGK in .270 to a similar CM bullet
2. Use a muzzle velocity that a temperature stable powder gives you such as H4350 or H4831sc that will work well at -4 degrees to 100 degrees without significantly affecting your velocity , pressure and point of impact
3. Use the same length barrel 22" to 24"
4. Do not use a 200 yd zero. Sight your .270 in for 3" high at 100 yds and the CM for the same.
5. Use your accurate load of temperature stable powder which gives a moderate pressure, not the exaggerated published loads of factory loaded ammunition, nor maximum load
6. factor in that the .270 has 10 % more cross-sectional area than the 6.5 for a bigger wound channel
7. Give drop figures at 100 (+3"), 200, 300 , 350 yds
8. State what loads, projectile, barrel length you are using

Indeed the wind drift could be significant at 400, but depending on the actual wind conditions and the size of the “vitals box” you’re shooting at, the difference between a 270 slug and a higher g1 6.5mm slug may well be insignificant. The proposition that some have argued here, however, that the 270 is clearly outclassed by new cartridge developments is hard to support. As a rule, the 270 mitigates the higher BC advantages of more efficient case designs in 6 or 6.5mm by taking advantage of its greater case capacity in using newer, slower burning powders, like Reloader 26, IMR 7977 etc, to produce yet more velocity.

.277 vs .264 is only about 5% larger unexpanded, same if you use 1.5x for expanded differences.

Since you have all the answers, why not just present the data instead of asking Jordan to do the work?

I'm sorry, but your explanation doesn't comport with his statements:



Mass is hardly "largely meaningless." It is THE (only) numerator in the BC formula. No mass, no bullet. So it is largely the single most important factor in calculating at a BC, since the rule of thumb is that for a given caliber and given shape (design), a rise in mass always increases BC.



To me, that demonstrates that he doesn't know that other elements of the projectiles design can offset mass to produce a higher BC. It sounds like to me he's under the impression that more mass means high BC under all circumstances and that ain't always the case.



Given his posts and self-congratulating bullshit, yeah, it's easy to conclude that's exactly what he meant.

If that wasn't his intent, perhaps an effort to discuss the subject rationally and state his thoughts clearly would help. That's obviously asking too much.

10.24 % difference in cross-sectional area using formula pi x radius squared...... .0547 square inches for 6.5 (.264") v .0603 square inches for .270 Win (.277")

Use 3030 fps muzzle velocity, 24" barrel, 58 grains 4831sc, 3" at 100 yds, 140 grain TGK for .270. I don't have an accurate load for the CM using a similar single-based powder and a well constructed projectile.

Doesn't Berger use Brian Litz, ex-rocked scientist to calculate their b.c.s?

You got me there. Still not enough to make a real difference in wound channel.

Bullet construction/design would make more of a difference but then it's hard to make an apples to apples comparison on that because 1 make/model can be softer/harder or have different jacket thickness in different calibers.

Accubond in .277 140 may expand more or less easily than .264 140 grain Accubond.

Shoot a deer through the shoulders with any hunting bullet in either cartridge and he will be dead in the shadow where he stood at the shot.

It's all just a pissing match.

.264 lovers won't budge and neither will the .277 lovers. Myself I don't have a rifle chambered in either caliber.

Critters on the other hand can't tell 2 fugging bits difference when hit by either one.