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Joined: Feb 2005
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Campfire Outfitter
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Campfire Outfitter
Joined: Feb 2005
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If we drop back from 60,000 lb/sq in. to the much milder 50,000 lb/sq in. in the .30-06 with the 168-grain Sierra HPBT, for example, we don't lose very much in velocity or energy � from 3,041 ft/sec to 2,887 ft/sec (154 ft/sec less) and from 3,446 ft-lb to 3,109 ft-lb (337 ft-lb less).
By dropping back to 83.3% pressure, we drop back to 95% muzzle velocity and 90% energy. And these down-range differences diminish appreciably with the distance that the bullet travels. (Looking at it through the other end of the scope, we see that boosting the pressure doesn't buy us all that much in velocity and energy.)
Also, a bullet with a higher ballistic coefficient further reduces the down-range deterioration by "bucking" the drag more efficiently. IME most of the powders I use shoot much better at higher pressures. Why hamstring the 30-06 at 60K,when a modern gun will handle 65k just fine?
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Campfire Outfitter
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Campfire Outfitter
Joined: Feb 2005
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Ken Howell,
This idea is "engineering loads to chamber pressures no higher than 50,000 lb/sq in. (instead of 60,000 lb/sq in. and higher)" is archaic. Materials are better than when you were young. Swedish and some of the German steels used by Lowe of the turn of the last century were just as good as anything now....overall tolerances are better, or atleast much easier to hold, but quality of materials really isnt all than much better.... I beg to differ and I have job experience in iron ore metallurgy. Modern quality steel is much better than turn of the century quality steel.
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Campfire Sage
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Campfire Sage
Joined: Aug 2007
Posts: 115,424 Likes: 13 |
This is turning out to be a typical mixed-up Campfire thread, for more than one reason:
1) Modern high-BC bullets (commonly called VLD for Very Low Drag) do NOT lose more velocity when pushed faster. Instead the BC actually increases slightly at higher velocities.
2) Lower pressure doesn't necessarily result in more accuracy. It often used to, so much that "load under max" was common advice. But that advice began back when many powders, such as IMR4895, were designed to burn most consistently at less than 60,000 psi. Most of today's centerfire rifle powders are designed to burn most consistently at 60,000 psi or so.
3) If lower pressures resulted in greater accuracy, then benchrest shooters would be loading to 50,000 psi. They don't. In fact they normally load to over 60,000 psi.
4) Pressure isn't the main cause of barrel erosion. If pressure was the cause, the .308 Winchester would erodes barrels as quickly as the .300 Weatherby. Instead heat's the main culprit, and the greater the powder charge, the longer heat erodes steel on each shot. The easiest way to lessen heat duration is to use less powder, not more powder at lower pressures, one reason smaller cases are becoming more popular for longer-range shooting. (The other, of course, is VLD bullets that don't slow down faster when pushed faster.)
Dear Mr. Barsness, I had 10 more pages planned for this thread, and your letting the cat out of the bag prematurely [bleep] that up. Shame on you... Travis
Trump being classless,tasteless and clueless as usual. Sorry, trump is a no tax payin pile of shiit. My young wife decided to play the field and had moved several dudes into my house
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Joined: Aug 2007
Posts: 115,424 Likes: 13
Campfire Sage
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Campfire Sage
Joined: Aug 2007
Posts: 115,424 Likes: 13 |
Now I'm ascared.
deflave and deBrent are agreeing! You gots to be a doctor or dumber to disagree with my logic. Travis
Trump being classless,tasteless and clueless as usual. Sorry, trump is a no tax payin pile of shiit. My young wife decided to play the field and had moved several dudes into my house
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Joined: Aug 2007
Posts: 115,424 Likes: 13
Campfire Sage
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Campfire Sage
Joined: Aug 2007
Posts: 115,424 Likes: 13 |
Thanks for the education. Looks like something interesting to investigate that I've ignored at my peril, now to try to find the time. Never imagined BC could increase to that extent given the practical constraints of bullet design. If you want a real education, follow this formula: Shoot different bullets at different speeds at different distances + look at the target = experts aren't always experts. Travis
Trump being classless,tasteless and clueless as usual. Sorry, trump is a no tax payin pile of shiit. My young wife decided to play the field and had moved several dudes into my house
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Campfire Ranger
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Campfire Ranger
Joined: Feb 2001
Posts: 24,239 |
It appears as if Mr. Ackley did us all a great dis-service with all his fooling around with cartridges.
Should we dig Mr. Weatherby up and burn him at the stake?
And that foreigner, Lazzerini, or some such.......... you can tell by the name he was up to no good.
Never holler whoa or look back in a tight place
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Posts: 115,424 Likes: 13
Campfire Sage
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Campfire Sage
Joined: Aug 2007
Posts: 115,424 Likes: 13 |
It appears as if Mr. Ackley did us all a great dis-service with all his fooling around with cartridges.
Should we dig Mr. Weatherby up and burn him at the stake?
And that foreigner, Lazzerini, or some such.......... you can tell by the name he was up to no good. They key to success when using a Weatherby cartridge, is keeping 'er around 50K. If you don't understand this, go get a PhD. GFY, Travis
Trump being classless,tasteless and clueless as usual. Sorry, trump is a no tax payin pile of shiit. My young wife decided to play the field and had moved several dudes into my house
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Joined: Dec 2002
Posts: 22,276
Campfire Ranger
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Campfire Ranger
Joined: Dec 2002
Posts: 22,276 |
Haven't read the whole thread, but I think the .220 Howell is a pretty interesting cartridge. And it looks like you can load it to 50ksi and still have the case full of powder, depending on what powder is selected.
Not real sure if you can do the same with a 7 mag or .300 win mag, let alone one of the Ultras. And I just don't like the idea of air space in the case when running a big boomer.
"...the designer of the .270 Ingwe cartridge!..."
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Campfire Ranger
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Campfire Ranger
Joined: Jan 2001
Posts: 28,433 Likes: 10 |
Sshh, don't tell Ken - but you can still load it to 65 kpsi if you want and it will embarrass a laser beam.
Gunnery, gunnery, gunnery. Hit the target, all else is twaddle!
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Joined: Aug 2007
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Campfire Sage
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Campfire Sage
Joined: Aug 2007
Posts: 115,424 Likes: 13 |
Yeah, the .220 Howell is where it's at...
Travis
Trump being classless,tasteless and clueless as usual. Sorry, trump is a no tax payin pile of shiit. My young wife decided to play the field and had moved several dudes into my house
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Joined: Dec 2000
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Campfire Ranger
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OP
Campfire Ranger
Joined: Dec 2000
Posts: 29,348 |
Pressure isn't the main cause of barrel erosion. � heat's the main culprit, and the greater the powder charge, the longer heat erodes steel on each shot. � the temperature that�s inseparably associated with the pressure. We don�t instrument test barrels to measure and to record temperatures, so we measure and record pressures in test barrels, and measure the associated temperatures in other laboratory paraphernalia (where we find, inter alia, that the temperatures associated with double-base powders [mixtures of nitrocellulose and 20�40% nitroglycerin, with an oxidizable stabilizer such as mineral jelly] are 400� F to 1,200� F higher than the temperatures that are associated with single-base powders at the same maximum temperatures). Accustomed to measuring and recording pressures instead of temperatures in test barrels, we say as a matter of interior-ballistics short-hand, that it�s the pressures that erode barrels. But as John has just said, it�s actually the higher temperatures inseparably associated with these higher pressures that erode barrels.
"Good enough" isn't.
Always take your responsibilities seriously but never yourself.
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Campfire Tracker
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Campfire Tracker
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Posts: 3,081 |
What case is the 220 howell based on?
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Joined: Dec 2000
Posts: 29,348
Campfire Ranger
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OP
Campfire Ranger
Joined: Dec 2000
Posts: 29,348 |
Sshh, don't tell Ken - but you can still load it to 65 kpsi if you want and it will embarrass a laser beam. No, you can't, and no, it won't. If you load it to 60,000 lb/sq in., you get a muzzle velocity of about 3,400 ft/sec and a muzzle energy of about 1,900 ft-lb � but the bullets fly apart just a few yards from the muzzle. Those little gray blobs that I've seen are neither very attractive nor very effective.
"Good enough" isn't.
Always take your responsibilities seriously but never yourself.
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Joined: Dec 2000
Posts: 29,348
Campfire Ranger
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OP
Campfire Ranger
Joined: Dec 2000
Posts: 29,348 |
What case is the 220 howell based on? The .25-06 shortened to 2.400 inches, with a 0.375-inch neck and a 25� shoulder angle. Gross water capacity is about 62 grains.
"Good enough" isn't.
Always take your responsibilities seriously but never yourself.
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Joined: Dec 2003
Posts: 86,365 Likes: 36
Campfire Oracle
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Campfire Oracle
Joined: Dec 2003
Posts: 86,365 Likes: 36 |
Now I'm ascared.
deflave and deBrent are agreeing! You gots to be a doctor or dumber to disagree with my logic. Travis Now, where did I say that I disagreed? Try to keep up, but in the meantime, GFY very much.
If you take the time it takes, it takes less time. --Pat Parelli
American by birth; Alaskan by choice. --ironbender
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Joined: Dec 2003
Posts: 86,365 Likes: 36
Campfire Oracle
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Campfire Oracle
Joined: Dec 2003
Posts: 86,365 Likes: 36 |
Now I'm ascared.
deflave and deBrent are agreeing! Happens all the time. You just don't pay attention You make an excellent point. It's true that I often don't pay attention to your posts. Consider yourself lucky that you were following deflave.
If you take the time it takes, it takes less time. --Pat Parelli
American by birth; Alaskan by choice. --ironbender
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Campfire Regular
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Campfire Regular
Joined: Jul 2013
Posts: 598 |
With all due respect, it is very easy to see who has killed critters here and who has not.
A university degree does not earn respect, while killing, hunting experience and bush knowledge always does.
Who gives a rip about contrarian arguments? Probably those who are armchair hunters.
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Joined: Dec 2000
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Campfire Ranger
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OP
Campfire Ranger
Joined: Dec 2000
Posts: 29,348 |
Haven't read the whole thread, but I think the .220 Howell is a pretty interesting cartridge. And it looks like you can load it to 50ksi and still have the case full of powder, depending on what powder is selected.
Not real sure if you can do the same with a 7 mag or .300 win mag, let alone one of the Ultras. And I just don't like the idea of air space in the case when running a big boomer. Yes, you can � and with delightful results. I ran the numbers to be sure and to get some pertinent specifics, then typed a long, detailed response to your post � � then fumble-fingered it into outer space.I'll get back onto it tomorrow. 2 tard rat now. 'Tain't easy bein' senile! G'night!
"Good enough" isn't.
Always take your responsibilities seriously but never yourself.
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Posts: 9,473
Campfire Outfitter
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Campfire Outfitter
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Ken, forgot 60,000 psi, that's underloading most cases...
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Campfire Tracker
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Campfire Tracker
Joined: Aug 2006
Posts: 3,009 |
Since I have no way of knowing what pressures my hand loads are creating, I strive for that magic velocity Mr. Barsness wrote an article on. 2700 fps.
Any deer hunting load producing 2600 to 2800 with reasonable accuracy has been good enough for me to keep the freezer full.
Find a copy of Mr. B's article from Handloader 244, Dec.-Jan. 2007 issue entitled, "The Perfect Velocity" and quit worrying about pressures we mere loonies can't measure.
"An open message for all Democrats; "Look you are nothing and your work is worthless. Anyone who chooses you is detestable." Isaiah 41:24 (HCSB)
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