Home Forums Hunting & Shooting Ask The Gunwriters Sectional Denisty

Sir,going to disagree with you,as Gary Sitton required a S.D. of .250 on game.

The bad part is that it doesn't even always work on solids. Compare flat nose solids and round nose, or even worse suppose one is wrong for the twist of the barrel and yaws, it can happen. Even a solid has to stay stabilized and nose forward to penetrate as expected due to SD.

I believe on of the most defining fenominon of sectional in the last 100 years has been duely noted in a particular caliber of moderate velocity shooting seemingly light bullets. Hunters worldwide have noted that when hunting with the 6.5 sweede and a 140 gr. bullet that penetration seemed somewhat surprising and unordinary. For instance.......many hunters noted that when compared with the 7X57 shooting 140 gr pills the 6.5 sweede shooting 140s was a notable difference. In the minds of many of these hunters that noted this strange 6.5 phenomenon the only satisfying answer from a physics standpoint had to be greater sectional density. It is my belief that sectional density is one important proponent of penetration and is useful though it is not the only proponent and there are other useful contributing factors such as weight and bullet construction.

Shod

SD is a number. Long bullets have it....short bullets don't.

Simple statements like that are the reason so many folks, including a lot of gunwriters and even a few editors, are so confused.
Length, per se, has nothing to do with SD.
It is a ratio of bullet diameter ( sectional area ) to density ( weight)
A long copper, brass or zinc bullet will not have a greater SD than a lead bullet unless it weighs more.

Simple statements like that have confused a lot of folks, including a number of gunwriters and even a few editors
Length, per se, has nothing to do with SD.
It is a ratio of bullet diameter ( sectional area ) to density ( weight)
A long copper, brass or zinc bullet will not have a greater SD than a lead bullet unless it weighs more.

SD means dick..end of story

For Elk, Deer, and Black Bear hunting I like to use cup and core bullets above a certain SD number so that I can use affordable bullets.

SD is a way to compare bullets in the worst case scenario, that is if they don't perform as advertised. As they said of the Russian tank corp during the cold war, quantity has a quality all its own, and SD measures quantity. It is very useful when you compare different calibers. For instance one of the reasons so many people don't like the 270 is because of the low SD of the 130 grain projectile.

I like to buy 500 of the same bullet at a time, then become very used to the trajectory of that bullet. I even discontinued 140 grain bullets in my 7X57 and use 170 grain Core-locs which were very affordable in bulk. Of course not everyone has 700 pieces of brass for their deer rifle, probably because of the budget busting expense of over priced bullets.

Even if I find a good deal on a "performance" bullet, like the Trophy Bear Claw Bondeds I am shooting in my .300 Weatherby, I still use a fairly high SD bullet. In that case 200 grain bullets.

I know lots of people who shoot very low quantities of big game rounds who spend insane amounts per bullet. To each their own.

One exception I have talked about before is my use of 180 grain Nosler Handgun Partions in the 35 Remington and 358 Winchester for Blacktail deer. Of course a 35 caliber bullet is pre-expanded for deer, and deer dont need much in the way of penetration, but I have never used that bullet when I had a bear tag with me. With this great bullet discontinued I won't be using them for that one purpose anymore. the 200 or so I have left will be used in my 357 Max.

siskiyou: I understand.

I'm staring at a pair of 130 gr 270 Nosler Partitions dug from the off side hide of a very big bull elk....which I think illustrates the point I was trying to make about bullet construction/design.