.550" vs .600"?

milestown said:

MagnumMania

Can you tell me more about your A191 reamer design and what you like about it. How does it shoot and how do the throats last in the magnum calibers ?

Thanks for sharing
Hal

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If you look up the specs on it you will see the base to shoulder length is shortened with the shoulder datum reduced. So, I design my reamers to suit. Throat length varies from cartridge to cartridge.
Now, the throat on the A191 300WM reamer has a throat that matches the 215g Berger and will not fit in a 3.4" magazine, in fact none of my custom magnums will. They are all long throated to suit heavy for calibre bullets. Normal 300WM throat length is .297", which places a 3.4" magazine length at a disadvantage from the start. Although fine accuracy can, and is, obtainable. 3.7" magazine length is perfect and what I use.
The throats are protected by the length of the bullets used and the elongated throat itself.
The case being tighter base to shoulder is what I am after, it is a positive all round with no drawbacks.

Cheers.

Small contours….. that's like a Bartlein 3B or Krieger/Brux #5 right?

Frank in the Laurels said:

NONE, don't drive yourself looney worrying about this technical of a question in my opinion while hunting..that little un-noticed breeze will have a much greater effect in my opinion.

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This........

Personally I'd go with the heavier contour to get that extra weight out front. I have a unwritten rule of not going sub .6" at the muzzle and no more than .65" (unless I'm going with the 375's-458's)

No.

What about amount of taper, like how fat is the barrel near the chamber end. The difference between .6 - .55 is only .05.

All of my barrels are on the heavy side, like muzzle diameters of .65 for .20's and more for 6mm to .30 caliber.

I have a .300WM that once had a light 27" Palma contour but the back end of the barrel was too fat for the nice stock so I had the barrel turned down to a #5 contour and accuracy was unchanged. COAL for the .300 WM loaded with 178 ELDM's for rodent shooting is 3.47 inches. Taper is more gradual than abrupt Palma contour having long shank.

I carefully filled the gap between stock & free floated barrel with epoxy then refinished stock - looks real nice.

Theorizing about the weight of the .050": Let's give it 22" of the .050". Somewhere along the barrel is the average, I guess. For this I will choose .750". So we multiply .750 X 3.14 and get 2.355. Now we multiply 2.355 X 22 to discover we have a piece of steel 51.8". Now we multiply 51.8 X half of the .050" and get 1.29 cubic inches. The weight of steel is about .3 pounds per cubic inch so we multiply .3 X 1.29 and get .39 pounds. Now we multiply .39 to get ounces. .39 X 16 gives us 6.2 ounces.

The last barrel I had fluted was .621" at the muzzle. Twisted Barrel removed seven ounces by fluting. If I start with a six-ounce lighter barrel and flute it, I will net about 3/4 of a pound lighter rifle.

That's a lot of math for a guy who got a GED at age fifty-one.