Pleasant surprises with my old .270 winnie

[Phil Rizzo]

That's not true, at all. Not sure where you read 560 is not stable, but the internet is full of wrong information. Most load development methodologies are just plain wrong, unscientific and not statistically sane, yet they persist.
The N500 series is their line of high energy powders and the 560 is a slow burning powder.
If it states a charge should fill to compressed and you aren't compressing you should, perhaps, look at your COAL vs Sammi spec.

N560 is twice as stable as CFE223. .97 vs 1.70

I can promise this in addition

That's not true, at all. Not sure where you read 560 is not stable, but the internet is full of wrong information. Most load development methodologies are just plain wrong, unscientific and not statistically sane, yet they persist.
The N500 series is their line of high energy powders and the 560 is a slow burning powder.
If it states a charge should fill to compressed and you aren't compressing you should, perhaps, look at your COAL vs Sammi spec.

N560 is twice as stable as CFE223. .97 vs 1.70

Higher load density promotes several desirable results. BUT!
N560 can't always be compressed. In fact, it tells me where it can, either a faster burn rate powder MIGHT be used, or the case size is minimal for the bullet. Depends on bullet size, and desired performance.
I've go some FF load results from N560 to show off, and there is no way my load density was higher than 90%.
I was 500fps under max, easily. You just never know.

It is hard to find, but R23 loves 30/06 based cartridges like 270, 25/06, 280 and the improved versions. It is stable. And fast, yet it burns cooler than H4831, a legend in its own right.

 

[Mr. Magoo]

I I've played around with heavy for caliber bullets in my .270 and .270 WSM. Once I hit 165 gr. on up, I get keyholes. Your elevation has a lot to do with it as well.

Yep. Before using the berger calculator I wouldn't have imagined stabilizing 170s in a 1:10 was possible even at my elevation.

 

[k jensen]

TL;DR: 1:10 twist .270 winchester at 7750 ft elevation can sling lonnnng 170 grain bullets seated super long with great stability at 2915 fps with a big charge of VV n560 out of a 22" barrel. Blew my mind how little case volume this powder takes up.

Rifle: late 80's Remington 700 ADL, 22" 1:10 twist barrel. (My first big game rifle) Brass: early 90s vintage remington. Primers: CCI large rifle.

Most bullets that would stabilize (or so I thought) in the 1:10 are not exactly high bc wonders so I've been seriously hankering for a 7 prc just to try to stretch my comfortable bullet energy range a bit. Alas, I'm a farmer (read not wealthy) and a tinkerer. My favorite thing to do is try to achieve great results with stuff I already have, on the cheap.... so while goofing around with berger's stability calculator I found that their 170gr elite hunter/ extreme outer limit bullets (.336 g7 BC) were rated as 'very stable' out of my 1:10 twist barrel *at my elevation* (7750'). So I bought a box to play with, and some VV N560 powder (next best thing to RL26).

These bullets are 1.5" long, but my mag box is incredibly long- I can seat as long as I want- and my throat is really long apparently, so seating depth with the burger's boat tail to body junction seated only .250 into the case neck still gives me about .70 thou jump.

Worked up a load starting at burger's indicated minimum and found it to be so light that it was clearly not pressuring up properly judging by how the firing pin dent looked on the primer. Jumping up a few grains, then some careful working up a loooong ways with a ladder test got me up to normal pressures and found a couple nodes. One a good ways below max, and a nice wide one from comfortably below max right up to max with the fps only varying 15 fps for 1 full grain.

Settled on the middle of the node @ 2915 fps. Brass looks great, primers look about like the factory Remington primers after firing, so far pockets are nice and tight still. Need to do some more testing but first groups are printing 3/8 to 1/2". The wind started howling by the time I was finishing up and they opened up to 1" but I think I found my load.


These bullets at 2915 out the pipe are still well over supersonic at 1800 yards, and retain 1432 ft lbs energy at 1000 yards, and 1700 ft lb at 800 yards.

The N560 is not filling the case like the load info I have says it should. 58.9 grains is only getting to just below the bottom of the case neck junction- far from compressed- book says it should be 102% case fill at the recommended max of 55. 5 grains.

With the less volumous powder and the super long COAL, I'm able to stuff way more powder in there without pressure than berger's load info says I should. Still a bit stumped as to why, other than possibly my remington brass must have much more volume than brass berger used to get their info.

Really digging this n560.

I got me to wondering: had anybody else has found such good results from this bullet/ powder combo?

I am using N560 in my 270 with 150 grain projectiles with 58.5 grains of powder. My rifle also has a long throat which means that I can seat the projectiles further out and increase case capacity.
I am no where near a compressed load at that charge rate. Awesome cartridge.

 

[Mr. Magoo]

I

We have two vintage Remington 270's here obes an ADL and the other, a BDL.
Finally shot out the BDL's barrel and replaced it.

I'm curious to know if you are aware that P. O. Ackley played around with the .270.
Maybe, A.I. (Ackley Improving) yours might give you that extra zing you're looking for.

Remember reading that he said the .270 wasn't worth ackley-izing, it was already too overbore- more powder wouldn't equal much more velocity with the powders available then (pressure limits).

This is not necessarily true today with the plethora of super slow burning powders. I will be doing an ackley version or possibly a Gibbs, before I get too old to care, just to be different.

I'm already a bit above most factory 7 mag loads.

 

[Phil Rizzo]

I

Remember reading that he said the .270 wasn't worth ackley-izing, it was already too overbore- more powder wouldn't equal much more velocity with the powders available then (pressure limits).

This is not necessarily true today with the plethora of super slow burning powders. I will be doing an ackley version or possibly a Gibbs, before I get too old to care, just to be different.

I'm already a bit above most factory 7 mag loads.

Look at the Sherman also, he gets the goods out of the case while maintaining adequate neck length. Dies can be purchased with the reamer and gauge also.
Or possibly the reamer and gauge can be rented