Why is the .270 Winchester so under loaded?

[z987k]

Lol, 270 Win has been out for 100 years, nice thought though. However, show some numbers and I'll recant.

I doubt there's anything by caliber, but we've made a LOT of guns recently.

There have been more guns produced in the US since the 6.5cm was introduced in 2007 to today than from 1950 to 1987. What percentage of those are 6.5cm, I don't know. But I bet it's a pretty good amount.

 

[Vern400]

270 and 30-06 generally have the case capacity to safely load a bit above factory ammunition specs with the optimal modern powder.

You will always hear someone pushing 100 fps or more than anyone else on the planet and saying it's not at peak pressure. Very few of them have the equipment to Mic case head growth to confirm the story. Measurements probably won't agree anyway.

270 with a 150 gr lead copper maxes out at 3000 to 3100 fps depending on the chamber and barrel. Ironically it's essentially the same trajectory as a 6.5CM with a bit more punch.

 

[Garandimal]

My question would be, "What's the point?"

A 150 gr. at 2800 fps from a .270 Winchester allows for inexpensive spitzer cup-n-core bullets to take even large game at 400 yards.


GR

 

[Vern400]

3100 fps is redline with a 150, and beyond Red line with shorter barrels, or certain rifles.
But I suppose no one ever lost an animal because of it.

3000 fps is not "underloaded". The parent cartridge was designed for a 150 grain bullet running about 2750, circa 1906.

 

[Lou270]

The 7prc is a good case study of legacy vs modern factory velocities. The 270 for ex has a saami velocity of 2850 fps with 150 gr bullets. This was established years ago and people have been able to improve upon that when slow burning powders like h4831 became available and can substantially beat it with modern double base powders like rl26 and others getting 3000 fpsish. The 7prc which has a saami velocity of 3000 fps with 175 gr bullets was apparently set with rl26 (modern best case). Since Hornady cannot get reloader 26 any more their factory ammo is running closer to 2800 fps with 175 gr bullets and powders they can get. This is incidentally pretty close to what the 7rem mag gets in factory loads with 175gr bullets whose saami velocities were stabilized years ago as well. So, it is a reverse scenario

Lou

 

[Steve O]

The 7prc is a good case study of legacy vs modern factory velocities. The 270 for ex has a saami velocity of 2850 fps with 150 gr bullets. This was established years ago and people have been able to improve upon that when slow burning powders like h4831 became available and can substantially beat it with modern double base powders like rl26 and others getting 3000 fpsish. The 7prc which has a saami velocity of 3000 fps with 175 gr bullets was apparently set with rl26 (modern best case). Since Hornady cannot get reloader 26 any more their factory ammo is running closer to 2800 fps with 175 gr bullets and powders they can get. This is incidentally pretty close to what the 7rem mag gets in factory loads with 175gr bullets whose saami velocities were stabilized years ago as well. So, it is a reverse scenario

Lou

Yeah, you are comparing apples and oranges.

Different bore size and different case capacities.

Compare 7PRC to 7 STW, Nosler, Ultra Mag.

 

[Lou270]

Yeah, you are comparing apples and oranges.

Different bore size and different case capacities.

Compare 7PRC to 7 STW, Nosler, Ultra Mag.

Not comparing cartridges or performance. Just showing why older cartridges look “underloaded” in some cases

 

[Garandimal]

Hodgdon - lists a max charge for .270Win/150 gr./H4831/CCI-200 as 51,200 CUP (59,717 PSI)

This is essentially .30-06 SPG PSI pressure.

And, while this is below the 52 CUP that SAAMI stipulates for the .270 Winchester, it is also no where near the 65K PSI that SAAMI also stipulates for that cartridge.

They are pimping new wonder-cartridges in PSI, and the older ones in CUP, a fraud.


GR

 

[Formidilosus]

Hodgdon - lists a max charge for .270Win/150 gr./H4831/CCI-200 as 51,200 CUP (59,717 PSI)

This is essentially .30-06 SPG PSI pressure.

And, while this is below the 52 CUP that SAAMI stipulates for the .270 Winchester, it is also no where near the 65K PSI that SAAMI also stipulates for that cartridge.

They are pimping new wonder-cartridges in PSI, and the older ones in CUP, a fraud.


GR

That is no where near the whole story. 1st, there are cartridges that have random, and wild pressure spikes for no apparent reason- 7mm RM and 243win for instance, which is why some cartridges do not get loaded in manuals to max pressure.
2nd, old cartridges have lots of old rifles that can not, or should not handle modern pressure limits- the 270win is one of those cartridges. The manuals generally refer to that historic limit as the loads will be fired in all rifles. They aren’t arbitrarily downloading some cartridges to make others look better, they are using common sense- there are no “old” 7PRC rifles, and therefore all modern rifles and actions can handle full on max loads.

 

[Garandimal]

That is no where near the whole story. 1st, there are cartridges that have random, and wild pressure spikes for no apparent reason- 7mm RM and 243win for instance, which is why some cartridges do not get loaded in manuals to max pressure.
2nd, old cartridges have lots of old rifles that can not, or should not handle modern pressure limits- the 270win is one of those cartridges. The manuals generally refer to that historic limit as the loads will be fired in all rifles. They aren’t arbitrarily downloading some cartridges to make others look better, they are using common sense- there are no “old” 7PRC rifles, and therefore all modern rifles and actions can handle full on max loads.

The .270 Winchester - was born and bread in 1925 as a beltless magnum.

130 gr./3140 fps./24" Bbl. with the best powder of the day, in factory loads.

That you are unaware of this fact supports the wonder-cartridge PSI/CUP fraud.

Factories could be loading 65K PSI for the ole .270 Winchester, 150 gr./3000 fps./24" Bbl. with modern powders.

... but they don't.


GR

 

[Formidilosus]

The .270 Winchester - was born and bread in 1925 as a beltless magnum.

130 gr./3140 fps./24" Bbl. with the best powder of the day, in factory loads.

That you are unaware of this fact supports the wonder-cartridge PSI/CUP fraud.

Factories could be loading 65K PSI for the ole .270 Winchester, 150 gr./3000 fps./24" Bbl. with modern powders.

... but they don't.


GR

What are you talking about? Not one thing you wrote here has anything to do with what I wrote- which is the reason you don’t see 270win loads in most manuals that go to 65k psi.

 

[Lou270]

You do see higher velocities in 270 rounds like superformance that load 130s to 3200 and 140s to 3100 fps in the 270. They could make a 150 at 3000 and in fact federal used to but dropped it’s “high energy” product line. This is ex of using modern powders in a “old” round and also why you don’t see “superformance” prc, wsm, rum, etc. loads. Their “normal” saami velocity already represents about the max you can get with modern powders in a saami labs

Lou

 

[Garandimal]

What are you talking about? Not one thing you wrote here has anything to do with what I wrote- which is the reason you don’t see 270win loads in most manuals that go to 65k psi.

Doesn't change the fact that the .270 Winchester is a 65K psi cartridge, and can be safely loaded as such.

RL26 is an absolute rocket propellant in that cartridge.


GR

 

[z987k]

Doesn't change the fact that the .270 Winchester is a 65K psi cartridge, and can be safely loaded as such.

RL26 is an absolute rocket propellant in that cartridge.


GR

Double base powders like RL26 tend not to be temp stable. Lots of people are going to prefer temp stability over outright speed. Factory ammo has to not be loaded to the bleeding edge of pressure especially with something like RL26 or they're going to have a lot of overpressure rounds sold anywhere warm.
Also they don't make RL26 anymore so, that makes it rather hard to.

 

[JFK]

None of this makes a difference. I own 3 270’s and love them. I used to chase every fps I could squeeze out, at the expense of brass life and recoil and to the benefit of nothing. If you are loading 130’s, get to 3050ish fps and be done and go shoot it. I handload, so not overly concerned with what factories are loading, but in my experience factory ammo has been more than adequate. Ammo makers DO have to account for the fact that a guy could be buying a box to shoot out of grandpas old rifle, and putting max charges of a hot rod double base powder wouldn’t be the smart move for them. Even a slow 270 is faster than most other cartridges.

 

[MJB]

The 130 is the best weigh for the 270, load them hot and don't look back! My favorite caliber for yotes, pigs and deer.

I've killed big yotes at over 700yds with my hand loads solids and lead 130's. It's been a decade since I tested but it was 3200 something with no pressure signs. I'll check the recipe when I get out of the hospital.

 

[seand]

That is no where near the whole story. 1st, there are cartridges that have random, and wild pressure spikes for no apparent reason- 7mm RM and 243win for instance, which is why some cartridges do not get loaded in manuals to max pressure.
2nd, old cartridges have lots of old rifles that can not, or should not handle modern pressure limits- the 270win is one of those cartridges. The manuals generally refer to that historic limit as the loads will be fired in all rifles. They aren’t arbitrarily downloading some cartridges to make others look better, they are using common sense- there are no “old” 7PRC rifles, and therefore all modern rifles and actions can handle full on max loads.

243 win, 7rm, 6.5 cm, all have lower SAAMI MAP limit than 270 win.

Hodgdon lists pressure in reference data data for 270 win, multiple powders and they are right up there close to 65ksi - above the SAAMI MAP pressure limits for 243 win, 7rm, 6,5cm.

 

[onlybrowning]

My first hand loaded cartridge was a .270 browning A bolt medallion. I was fortunate as a young man to have someone walk through the process with me. I shot Factory loaded 130gr Core Lokts to 1” and 130gr Winchester Power Points to just a touch over that. I then loaded 130gr Nosler Ballistic Tips over H-4831 (then SC once it became available). At 59.0 gr it seemed to shoot best for me. I had a Leupold (gloss) VX I 4-12X40 on it. Man was I proud of that rifle at 18 years old.

A year or more (maybe several more) I chronographed that load. It was 3157 fps! I couldn’t believe it. I figured it was 2950 at most.

Ironically, I’ve not loaded anymore of them and the rifle sits in my safe. But..I always recall it as “fast” in comparison to what the data said. That factory barrel is 22.” The .270 is a legacy cartridge. May not be the newest, sexiest, or most efficient, but you can’t knock it for working.


Sent from my iPhone using Tapatalk

 

[Garandimal]

Double base powders like RL26 tend not to be temp stable. Lots of people are going to prefer temp stability over outright speed. Factory ammo has to not be loaded to the bleeding edge of pressure especially with something like RL26 or they're going to have a lot of overpressure rounds sold anywhere warm.
Also they don't make RL26 anymore so, that makes it rather hard to.

As stated, H4831 and a 150 gr cup-n-core bullet at 2800 fps kills everything it hits, dead.

No complaints.

Marksmanship and fieldcraft trump extended range shooting.


GR