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Author Topic: .270 Winchester  (Read 2479 times)

Offline JimP

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.270 Winchester
« on: February 10, 2008, 12:15:20 AM »
Some folks say this cartridge is just a 30-06 necked down from .308" to .277", but I've noted that the brass of the .270 WIN is .003 longer than the '06 brass. Someone once told me that this was because the "parent" case of the .270 WIN was the 30-03 Springfield, but I have not been able to verify that. My handloading books tell me the .270 WIN was introduced in 1925 in the Model 52 Winchester, and was the favorite of longtime gun-writer Jack O'Conner. It trades position with the "aught six" for the #1 and #2 slots for most popular (as in selling the most boxes of shells each fall) deer cartridges every couple of years. This a good thing, as factory ammo is always easy to find.

I've owned (and handloaded for) my .270 for over 10 years. I've taken 10 deer with it, at ranges from 15 feet to "way out past Ft. Mudge". The previous owner, my Grandfather, figured he'd gotten 52 deer with it, and countless coyotes. I once watched him roll a running coyote in the MIDDLE of a section, on the third try. The range had to be between 600 and 700 yards, as the fenceline the 'yote was running for was the property line dividing the secion in half. I couldn't even SEE what he was shooting at, at first. And at the time, the gun wore iron sights. I asked him how he could do that, and he said "you have to know how to shoot, and how the gun shoots. It'll drop the bullet so much at such and such range........" He bought the gun "new" in (IIRC) 1958 from a hardware store for $125 (again, IIRC) with 2 boxes of shells, on the condition that he let the store owner leave it in the store window until fall. The hardware store no longer stands, and the town it was in is no longer incorporated, but that rifle still shoots 1" to 1.25" groups at 100 yards, and puts deer in the freezer, year after year.

The factory ammo is supposed to generate 3,100 f/sec with a 130 frain bullet, and 2,800 for the 150 grain. This is out of a 24" test barrel, and I have noticed most of the cheaper factory rifles on the racks of gun stores have 22" barrels. Good luck getting advertised  velocities out of them.

My rifle has a 24" barrel, and I have chronographed 130 grain factory load (Winchester Super X) at an average vel. of 3106 f/sec. I have been unable to duplicate this with any of my handloads, with 3,050 f/sec being about the best I could do (with both 54.0 grains H414 and 58.0 grains H4831sc). After doing a little reading on Ballistic Coefficients in the backs of the vaious reloading manuals I have, I decided that Heavy for Caliber, High Ballistic Coefficient Bullets woud do no worse at close range, drop slightly less at mid to long range, and pack a lot more punch at long ranges. I also had someone tell me heavy for caliber bullets work better in older guns (something about throat erosion). So I started working on a 150 grain load....... It turned out that my rifle likes Sierra's 150 grain Gamekings. 58 Grains of IMR 7828 will launch one at about 2950 f/sec, and consistently group them in 1"-1.25". I have pulled off some really amazing shots with this load in the field, and the Sierra Gamekings have peformed very well. They are about the softest/lightest constructed big game bullet available, yet have the mass to get the job done. I have shot 3 deer in the chest (facing straight at me) at under 50 yards, and none of the bullets made it past the diaphram into the guts (MESSY!). They pretty much entered the "boiler room" and detonated, making hash out of the heart and lungs...... On the other hand, I have hit 2 deer at 400+ yards standing broadside to me and the bullets entered, passed through the heart and went out the far side, leaving an exit wound big enough to put your thumb in. However, TANSTAAFL: recoil on these 150 grain hot loads negates one of the virtues of the .270 Winchester- the 130 grain loadings kick signifigantly less than the 30-06. And brass life is shorter. I don't make the rules- it's just physics.....

There are bullets as light as 90 grains available for handloading, so you can practice on prairie dogs all summer long without bruising your shoulder to badly. I like the 110 grain Hornady V-Max in front of 47 grains of IMR 4064. Yes, I KNOW there are cheaper, more efficient ways to kill prairie dogs, but if you can loop up, drop into "rice paddy prone" and cut a grass rat in half at 350 yards, putting a bullet through a deer's chest at the same distance is not that difficult. "Beware the man with 1 gun: he probably knows how to use it."
The Right to Keep and BEAR Arms is enshrined explicitly in both our State and Federal Constitutions, yet most of us are afraid to actually excercise that Right, for very good reason: there is a good chance of being arrested........ and  THAT is a damned shame.  III.

Offline iiranger

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Re: .270 Winchester
« Reply #1 on: January 23, 2009, 10:57:30 AM »
#1. Amen
#2). '06 brass usually lengthens a bit when necked down from .30 to .27. How much. Jack O'Connor lead me to believe when I was young and knew nothing, this measurement was to allow for about all to be expected...
#3). .270 was standardized at 55K CUP while the '06 was standardized at 45K CUP the standard of the earlier day... (1906 vs. 1926)... Of course there will be shorter case life. Easy to live with for the increased performance. And screwing a new barrel into an $18.00 springfield from DCM, cheep, cheep, cheep... Those days are gone. Oh welllllll... Happy New Year.

Offline JimP

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Re: .270 Winchester
« Reply #2 on: January 28, 2009, 11:20:38 PM »
".270 was standardized at 55K CUP"  SAAMI specs........ not as concrete as the laws of physics, which have no fudge room........ they are kinda like the sign at the edge of the cliff that says "Warning- Steep Cliff Beyond This Point" ......How far beyond?  If you find out by falling yer ass off it, you can't sue us, because you were warned, that is how far........
The Right to Keep and BEAR Arms is enshrined explicitly in both our State and Federal Constitutions, yet most of us are afraid to actually excercise that Right, for very good reason: there is a good chance of being arrested........ and  THAT is a damned shame.  III.