Home Forums Hunting & Shooting Ask The Gunwriters Why aren't bullets pointed at both ends?

I�m outta my league here with folks such as Ken and Sitka Deer, but I have a few thoughts/questions on the topic:

1. A bullet pointed at both ends would be long for it�s weight � at what point would the SD and BC be compromised?

2. Comparing two bullets of equal weight, a bullet pointed at both ends will have less bearing area for the rifling to act on and offer less of a gas seal. Less bearing area could also allow the bullet to cant in the bore.

3. I question whether laminar flow can exist in a rifled barrel.

� The shape that's most stable in flight is the sphere -- but it's not aerodynamic enough to be a good bullet. It's also the shortest for its weight -- one factor in its stability.

� The shape that's most accurate is the cylinder -- but it's not aerodynamic enough to be a good high-velocity rifle bullet.

� The cylinder with an added ogive makes the accurate basic bullet aerodynamic.

� The main advantage of the "boat" tail at supersonic velocities is the eye appeal that undergirds customers' confidence.

� The shape of the ogive is important for aerodynamic flight. The shape of the base is important for clean, simultaneous exit from the muzzle.

By God!! We are finally getting to the crux of the matter here!!!
My question is, as a consumer, how can I tell when my confidence is being undergirded, and is that a good thing or a bad thing? Does undergirded come in degrees of undergirded, like insanity, or is it more like pregnancy, one is either undergirded or not undergirded?? Is it possible to be overgirded??
Anxiously waiting a clarification.

TIC

Royce

The best confidence is that which has been eroded, subsequently researched, and ummm...re-undergirded. Anything else is blind faith.

I prefer bullets with a high BC because, well, that seems better than a low BC. That said, I don't get to cranked up over a BC of 0.3 as compared to a BC of 0.4.

Ken ... do the math .... .154 squared times pi equals .0745" squared (inches squared). Gee, just as I typed!



I do however agree with your opinion of laminar flow. But am curious on how you can say gas cutting would be more prevalent if the contact area of bullet and barrel remain the same between both types of bullets. To say they are different are an apple and oranges type of thing.

Sorry, 'gadro -- I'm more persnickety with my terminology. When I learned my wee modicum of math back around the Pleistocene, a number squared equaled so many (different number) square inches. So I misread what you typed, I guess. Is your use of "squared" a term of the new math?

Understood ... just when I use units in chemistry I'm used to using them as written (ie. inches followed by a superscript 2). But when talking construction and such I usually use square feet and not feet squared.

Such when reporting data where I may have 5,000 events / cm^2 ... is said normally "five-thousand events per centimeter squared" also is often refered to as "five-thousand events inverse centimeters squared". Depends on with whom your talking too, and the environment, on how each gets used.

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I've read several posts on this board about getting great groups immediately after a new barrel is installed. My limited experience has been that a new barrel "settles in" and starts grouping after several rounds have been fired........maybe 70 rounds (give or take) . What has been your experience?
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Any thoughts? Anyone?

HogWild

HogWild,
I think after about 70 rounds, you've probably cleaned the rifle enough times for bullets to "wear in" on a clean bore surface, smoothing out the tooling marks in the new bore. You can accomplish the same thing by "breaking in" a new bore, cleaning completely after each shot. Your first few rounds will have a lot more color on the patches, but as you progress, the first patches from a few more rounds will be a lot cleaner.

Regarding the pointed bullets at both ends, if a flat portion is better for the gas to push against in a boat tail, would a concave (hollow point) in the rear bullet be any better? Or is this too much gas on an already gassy subject?

WinMike: A "rebated boattail" seems to be something like that at Swage.com. Although, just because they cite the advantages of the design as precluding laminar flow doesn't mean laminar flow actually exists.



The phenomenon does seem to exist, however. The Corbin website cites the Lapua rebated boattail, originally designed to combat laminar flow.



Jaywalker