Sectional density .30 and .35 cal

[Teaman1]

Strictly out of curiosity and just for something to talk about (I don’t have many gun nerds for friends haha)
I’ve started shooting a 35 whelen this year and looking to hand load for it soon.
The sectional density for a 225 grain 358 bullet and a 165 grain 308 bullet have nearly identical sectional densities. Any body shot these enough to see if the penetration with these bullets (from a 35 whelen and 30-06) is about equal? I’ve always referenced sectional density but I’m curious if it holds true through the heavier calibers. Maybe equal in flesh, but the heavier bullet carries better through bone?
I don’t know but I hope some of you do. And if you don’t know, I’d still like to hear any thoughts haha

 

[AkMtnRunner]

Bullet deformity and weight loss from the initial impact will say a lot for how well the bullet will ultimately penetrate. Essentially, it is the expanded sectional density that matters since almost all expansion happens in the first couple inches of impact. This is why brass solids are used often for very large dangerous African game, to penetrate extremely well. Also, why lightweight copper monolithic bullets are successful on large game. On the other hand, this is why large bore rifles with soft bullets are so successful on whitetail deer that may only have 1-2 feet of tissue to work on.

It is all about getting the right balance. We are fortunate to live in a time of great options and flexibility.

 

[Wapiti1]

AKMtnRunner covers a lot of it. Sectional density only really applies to a solid of similar shape.

Amount of expansion and retention of weight dictate final penetration in soft tissue, and design (lead hardness, jacket thickness, mono-metal, etc.) dictates how it handles bone.

Jeremy

 

[Teaman1]

Important detail left out haha. I would be using partitions

 

[robtattoo]

I can't speak to .35 Whelan vs .30-06, but in a scaled down comparison:
My .308 kills stuff.
My .358 kills it deader.

 

[Teaman1]

I can't speak to .35 Whelan vs .30-06, but in a scaled down comparison:
My .308 kills stuff.
My .358 kills it deader.

Seems logical to me

 

[AkMtnRunner]

In the case of partitions, which shed more with higher velocity, I would bet the 358 cal bullet would penetrate farther since it'll likely be going slower than the 308. Same case and same bullet sectional density = slower velocity as caliber increases.

It should also be said that the 30-06 can push 200-220 gr soft points to penetrate much better than a 165 gr if it's so desired. Last I read up on many others' experiences, 180 gr in the partition bullet was a sweet spot for the 30-06.

There's been a lot written about the 35 Whelen and partition bullets, which you can find with google searching. I found the bullet reviews on midwayusa useful.

 

[Teaman1]

My problem is I read too much online. Got to where a personal minimum sectional density for elk was around .271, but I’ve found many people use 165 grain 30 cal every year for elk. I have read every article I’ve found on the 35 whelen and all the midway reviews, still looking for more haha. Had my heart set on trying to load 250 grain partitions for my 35, but a lot of people seem to have good results on elk with the 225’s.