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MP-44
January 7, 2002, 07:33 PM
Why are there no .22 cal. centerfires designed to fire bullets with a high sectional density? If 6.5 or 7mm with a high SD worked on large African game it would seem that .22 cal. with a high SD would work on North American deer. I would think that if it were possible some American company would have marketed a round and a rifle to fire it in. Is there a technical reason?

Art Eatman
January 7, 2002, 08:04 PM
Not having my data books handy, all I can do is ask whether the 70-grain .22 bullets don't have a high sectional density?

Regardless, the rate of decrease in velocity with distance means a reduction in energy/momentum/whatever, and anything less than a perfect hit would give the same old bad result.

Closer ranges, smaller deer--not so bad.

As always, one's skill in guaranteeing proper shot placementl is of very high priority. "Clean kill" is part of the ethic.

Art

Jim Watson
January 7, 2002, 08:38 PM
What do you mean, "Why there are no..."?

A good many years ago the .224 Clark (.257 Roberts Improved case) shot 80 and 85 grain softpoints special order from Hornady at deer and antelope. Now you can get Allred bullets with double and triple jackets up to 90 grains. Surely that would do anything necessary to a deer. All you need is a big .22 with a fast twist barrel. And some money.

I guess the big companies do not see a market. Not since the .22 Savage High-Power and the .22 Newton were so often failures on big game because the bullets then available would not do the job.

MP-44
January 7, 2002, 09:19 PM
I am not positive but I believe a 70 gr. .22 has a SD well under 200. And even an 80 grain would be a far cry fron the SD of a 160gr. 6.5.

Art Eatman
January 7, 2002, 11:25 PM
And that's part of the "why", generally, folks use .257 and bigger for Bambi. :)

Art

C.R.Sam
January 8, 2002, 12:34 AM
Several wildcat .22 cartridges played with over many years would be quite adequate on deer. Many states had/have a minimum caliber of .230 for big game tho which pretty well relegates the little hit rods to varments.

A bit over 50 years ago had a barrel chambered for .22/06. Barrel life limited load and bullet developement. I do like hot rods and once in a while they bite me or my check book.

Sam

Long Path
January 8, 2002, 02:34 AM
I read an interesting article a while back about 100g .22 bullets being shot at 1000 yards-- if you could get the jackets heavy enough and find someone who could get the twists fast enough [1:6 or better], they claimed it was incredible what stability they had over long ranges, and with high velocities to boot.

--L.P.

MP-44
January 8, 2002, 04:59 AM
Don't get me wrong. I am not saying I want to use a .22 for deer. I was just looking through the ammo catalogs and noticed that the .22 rifle bullets were way behind other rifle bullets in sectional density. They have the sectional density of pistol cartridges. I was just wondering if there was a technical reason for this.

Al Thompson
January 8, 2002, 06:41 AM
Interesting point - I never realized the SDs are so low. The Speer manual notes that the 70 grain bullet has a SD of .199.

Methinks this is convention rather than decision.

Giz

Art Eatman
January 8, 2002, 09:27 AM
I guess it's just one of those facts of life. Insert Tab A in Slot B; repeat as necessary, and nine months later there's a Blessed Event. Short, fat bullets and very-thin bullets just don't have high sectional densities per the definition of sectional density and that's just the way it is.

Art

MP-44
January 8, 2002, 12:21 PM
Not to run this into the ground but is there an engineering reason that high SD bullets and rifles to fire them are not made? Just for the record by my clculations a 100 gr. 224 dia bullet would have a SD of .279.
I also noticed that 24 & 25 cal. have poor SDs( heavy bullets just are not available). But as you can see in the bullet catalogs once you get to 26cal. weight for dia. jumps up considerably. WHY, WHy, Why???? Marketing reasons or too much bearing surface on the rifling?
Someone has got to know.

Al Thompson
January 8, 2002, 07:34 PM
Probably history - the Brits considered (very broad remark here) anything .30 and under to be a light rifle. In the days of poorly made bullets, SD had to be high to gain performance. Note the gun writers of yesterday preferred larger bores and heavier bullets. The Keith/O'conner dbates come to mind.

The other factor that over rides all others is consumer demand. If enough folks wanted high SD .22 bullets and the rifles to shoot'em - they would be here. IMHO, most folks that like the .24 and under calibers use them due to lack of recoil and on smaller targets.

HTH!

Giz

labgrade
January 9, 2002, 03:54 AM
I dunno ...

I've got a couple reasons why I think it's so or not, but will wait another day or so to post my "reasonings," ...

Hate to appear too much the fool so fast .... ;)

Essentially, my "gist" would be is SD is based as a mathematical computation of length & diameter - must have both & too, a function of velocity - the bullet must withstand that speed ..... (& expand to be "reliable) ....

Outa here until I can be more "coherent" re this one ....

Steven Mace
January 9, 2002, 05:28 AM
Labgrade is correct. Sectional density is a function of bullet weight & diameter. You can play with the Sectional Density Calculator (http://www.realguns.com/calc/sectionaldensity) to see what different bullet weights do for any given caliber. Hope this helps!

Steve Mace

Art Eatman
January 9, 2002, 09:09 AM
In the context of hunting: The hotshot .22s are effective due to their very high velocities. Once you get much above 55 grains, the velocity begins a dramatic decline--and thus they become much less effective on varmints.

You get much heavier than 63 grains or so, for better penetration on animals such as deer, and you're then back to the "perfect hit" deal. Lower velocity means less energy, etc.

Long-range effectiveness on people or paper, that's a whole 'nother deal.

Art

bfoster
January 11, 2002, 09:34 AM
It isn't listed, but Barnes may still have the tooling used to produce the 125 grain bullet that was used in loading the 22 Barnes QT (quick twist). The bc should be .356.

Bob

Art Eatman
January 11, 2002, 09:52 AM
That Barnes QT, from a Swift, would hardly break 3,000 at the muzzle, if that much. Plus, the OAL would most likely preclude its use in the standard magazine-fed rifle. TANSTAAFL.

Specialty stuff. Works good for its intended purpose, but certainly not for what's thought of as "normal" hot-shot .22 uses.

:), Art

MP-44
January 11, 2002, 10:03 AM
I guess the answer to my question is its a sales problem not an engineering problem.

JimmyDee
January 12, 2002, 04:38 PM
In a given caliber, ignoring things like jacket thickness and voids, higher SDs mean heavier and longer bullets. Heavier bullets mean higher pressures and, ultimately, chamber pressure is the limiting factor.

Longer bullets, if they are to fit in magazines, have to be seated more deeply in the case and reduce powder space. Handloaders can seat bullets further forward and reclaim some of that lost case volume, but they are limited by length of the chamber throat.

SD is only one design consideration; the bullet's flight and after-impact behavior have to be considered, too. I guess there's a magic diameter-to-length ratio for bullets, but I'd guess that what's best for flight might not have good terminal performance or may have too much barrel friction. (There is such a number for ships and boats, but they're only expected to push through water; they don't have to plow their way across the beach to get to the water and then come apart in an expected fashion when they hit something.)

I guess what we've got is an economically efficient combination of engineering, tradition, and regulation.

Art Eatman
January 12, 2002, 05:34 PM
I'd say it's mostly Physics and Engineering. What benefit is there from higher SD in .22s, from what's commonly used? Same for 6mm...There are "working weights" of bullets, from .22 on up, which meet the demands of shooters. Since there's no apparent gain from worrying about SD, there's no particular demand. If there were, the .22 Barnes "QT" would be common, would it not?

What we now have all seem to work just fine for the primary intended purposes.

Art

Steven Mace
January 12, 2002, 08:17 PM
To illustrate higher sectional density bullets with a .224" diameter see below:

Bullet Weight versus Sectional Density

1. 100 grains = 0.285
2. 125 grains = 0.356
3. 150 grains = 0.427
4. 175 grains = 0.498
5. 200 grains = 0.569

Sure, a 200gr. bullet with a .224" diameter has what appears to be a great SD number but which case do you plan on seating down into?

Steve Mace

labgrade
January 13, 2002, 11:40 AM
The higher SD bullets would have their place in a sub-sonic/supressed application, but that "seating depth" thing would keep raising it's ugly head - perhaps in a specialty cartridge, etc.

Too, with the extremely long bullet for the caliber, the rifle's rate of twist would have to be tightened up for some stability.