Highest BC .277 bullets available

[Longtooth32]

There is a greater problem than just getting them to fly well. Marginal stability can shoot very accurately but it can lead to poor terminal performance because it will allow the bullet to yaw on impact and not open the bullet properly or tumble on impact.

Steve

This is why I did (could) not use your bullet on my Elk hunt. I only have a 1-9 twist on my 270 Weatherby. I could not stabilize your heavies ( I really wanted sectional density). My 28" Benchmark barrel spit out the 170 Bergers at 3225fps. Shot my Elk at about 280 yrds. Did not even take a step...

The bullet liquified the internals... the bullet did not even exit...

Picture of what we found...



Entry of bullet

 

[Lee Goodwin]

I am going to hunt with 180 grain woodleigh bullets, in my 270. Loaded to 2529 fps according to hodgdon data. There was a spot around 51 grains that looked promising as far as accuracy goes. As far as taking an animal...we shall see.

 

[Rhett Crider]

I am going to hunt with 180 grain woodleigh bullets, in my 270. Loaded to 2529 fps according to hodgdon data. There was a spot around 51 grains that looked promising as far as accuracy goes. As far as taking an animal...we shall see.

Doesn't look stable the way it's tearing through your target.

 

[Lee Goodwin]

Doesn't look stable the way it's tearing through your target.

Even 130 grain bullets were tearing up the paper like that. I think up was partially the hard masonite target, a desk top.

 

[OhYtD]

I can see this in a 270W, 270wsm,270rsum, or 270rum (wc) ---but man it is long to try for 6.8spc---ogive is .829, 6.8 case is 1.665 so minimum load length would be 2.494 (have to single load as that wouldn't even fit in a dremeled out magwell with cut out mag)

also, they recommend a minimum 1:8 or 1:7 twist for stability , its top end BC is .706, low end is .627 (below 1500fps), average is .662

a few other options that aren't so radical would be the 145eldx @ .536BC or the 150 ABLR @ .625 BC or the 150 VLD @ .518BC--I know the ablr wont work in my 6.8, not sure about the 145 eldx (ask x-man he has some) --the 150ablr works in my 1:10 twist 270W great

Glad to see someone is making high BC bullets for .277 caliber but the 6.8spc is pretty much left out of this bullet option for most cases

other issue is minimum expansion speed, the ABLR is 1300fps, most hunting bullets are 1600-1800, not sure where the EOL stands for minimums.

 

[Lee Goodwin]

If there was a way , safe way, to get to 2700 fps...I think there would be no worries out past 150. Probably gonna think hard at 150 yards before I squeeze the trigger.

 

[aushunter1]

Its not about weight to twist rate its more about projectile length!

Most 270's will handle most things up to 180's in a 1:10 with the exception of mono's

 

[aushunter1]

Also, 300 feet of extra velocity alone has VERY little affect on bullet stability!

Why not?
The faster they are pushed the spin rate should help stability, no?

Of course there is a point at which no matter how hard you push the length with overcome the FPS.
If your on the cusp of stabilisation then I see an extra 300fps helping a great deal!

 

[Lee Goodwin]

Even 130 grain bullets were tearing up the paper like that. I think up was partially the hard masonite target, a desk top.

 

[Hand Skills]

Its not about weight to twist rate its more about projectile length!

Most 270's will handle most things up to 180's in a 1:10 with the exception of mono's

It's true that the length of projectile is more important than the weight when considering twist rates and gyroscopic stability (SG).

Atmospherics play a part too, in that one can get away with less twist at lower atmospheric pressures (the higher you go).

At ~2000ft we have found the practical limit of a .270 bullet in a 1:10 twist to be about 1.250" - or about 150gr in most cases.

Velocity in FPS has little effect. In fact ballisticians use mach numbers (as in mach 2 or mach 2.5) to describe velocity. That's a difference of over 500fps. When shot out of a 1:10 barrel for example,a bullet's displacement PER turn will be very similar, whether the muzzle velocity is 2500fps or 3000fps.

 

[Lee Goodwin]

When I was loading these 180s in my 270, there was a spot at 51 grains of 7828 that would string shots some but the third shot would be about right on. Also 52.5 grains was some stringing but a better "grouping"...52.8 was hodgdon data max, so, I said, "max it is", and data says that should be 2529 fps. Last time out was 52.8 of 7828, and, I have decided to stop at that and hunt with it but try to keep my shots under 150 yards. I have only taken one deer outside of that range, so, I am satisfied.

 

[Lee Goodwin]

Plus the acquired knowledge of the folks in this web site is astounding!

 

[Trm82]

I picked up a Tikka 270 WSM hunting rifle recently and have been playing with mostly monolithic bullets. Its sub moa @ 3300 fps with a 130 gr .540 G1 bullet, which isn't bad for long range hunting.

For those who are interested here is a list of commercially available .277 bullets with G1 values greater than 0.5 listed in descending order, the list is likely to be incomplete, so feel free to add to it or add your experience hunting with em.

Weight gr / type / G1 BC

170 Berger hybrid hunting .662 (1:8 twist required)

150 accubond .625

140 cutting edge MTH .590 (1:9 twist required)

130 cutting edge MTH .540

145 eldx .536

150 vld Hunter .531

140 Berger classic Hunter hpbt .528

150 interlock .525

150 interbond .525

The 150vld bc is actually 0.518
And the 170 vldh says 1-9 twist now.

I also think the 150 ablr bc has been down graded from 0.625.