Impact velocity required for hollow point expansion

[x101airborne]

Afternoon all.

I am looking to load some light tissue opening hollow points that are not prone to fragmenting for the 38 Special in the +P range. I was wondering about the Hornady 140 grain hollow point Hornady # 35740. All I have found is "meant to open in a wide range of velocities". OK, does that mean it will open at 850 fps.... 950 fps..., what? I don't want to go hog hunting with a 38 special to have to find out. 

Although as an afterthought, I could trap some and shoot them with the 38. Seems a little rough ethically, but so would be getting killed cause I didn't test my ammo. I do cast some 358429 Keith hollow points but even their use on skunks tell me they shred badly (and no, I am not going digging for a bullet after that). If this bullet would not be the best choice, what would? All advice welcome. 

By the way, weapon is a Smith and Wesson police turn in 2 inch model "Lady Smith", similar to the Colt Undercover. 

[bigbrowndog]

I’ve had good luck with Federal Hydrashok 124gr I think,...38 spec. bullets from a SW 60 2”. Ive got a pig kill with it at about 10-15 yards. I’m waiting for dark right now on a ranch or I could tell you for sure. I bought them in bulk along with a bunch of 9mm, 38Super hydrashoks.

Trapr

[boolitdesigner]

Any decent hollow point cast in alloys from 35:1 to 20:1 lead to tin will work fine.................

[groo]

Groo here
The old school SJHP [like the Remmington MMM jacket] should work if you want a jacket.
The exposed lead is soft and should at least round over.
I want an impact speed of about 1000 for 38cal bullets [mostly for the ones where the jacket goes all the way to the HP like auto bullets]
Cast is a different thing as hardness can be adjusted to fit speed and the HP is often larger/deeper [like boolitdesigner said +1]

[ezekiel38]

GT Bullets has a cast hollow point 38 bullet that weighs in at 145grains. Alloy is butter soft 2-2-98 and is recommended for lower velocity 38s. I've shot a couple of hundred of these in a Kimber 2" and a Smith Model 15 4" and they shoot nice groups at 20 yds and right to point of aim. I just ordered another 250 a couple of weeks ago.

Might be worth a look see if you're rolling your own.

[ddixie884]

Try the speer swaged lead 158gr swc hollow point. Soft lead, big hollow point, crimp groove and available in boxes of 500. 5gr Unique, firm crimp, 850fps from a 4"

[x101airborne]

Thank you all.

[gamsek]

My January test with MP Molds 359 Hammer, with deep HP and cup HP, alloy was pure lead with 2-3%tin, 925fps info soaked soft paper.
Cup (shallow) HP is helping them to open - but not to much - as intended. Deep HP - perfect expansion. I get zero fragmentation with up to 5% of tin in pure lead.


With more tin (Sn), antimony (Sb) content or over 1200fps, my cast HP will break its petals/nose. Those are few examples of high (pure with 10%tin) tin content (at low velocity it delays expansion, at high velocity petals break) and one example of 1/3pure lead+2/3 ww which breaks depends on velocity, HP size and shape.

[boolitdesigner]

Very nice display of photos. Alloy manipulation will get you about any result you want. Blowing the nose off at higher velocities is not a bad thing either. It allows a user of a weaker caliber to gain killing power for the cartridge used that probably would be inadequate if a solid was used. That would be for thin skinned game a big bluff solid would do little to but punch a hole thru it.

[x101airborne]

Those are some GREAT pictures!! Thank you!

[Cholla]

As gamsek wisely points out, there's more to HP expansion than just Bhn. If you want a non-fragmenting HP, keep antimony contents low to nonexistent. Also, tapered HP cavities tend to expand more readily, in my experience.

Part of the problem is testing them. I firmly believe that there's no man made material that can duplicate flesh, hide and bone. Case in point-

These .45 caliber bullets were shot into a water tub at the illustrated impact velocities-





Now here's the same bullet that impacted a deer at around 1025 fps-



Obviously water is much more resistive than hide, muscle and intermittent organs.

Cholla

[DiamondD]

Gamsek and Cholla thank you both for taking the time to post those pics. Great posts.

[ddixie884]

Yeah........

[bradshaw]

With everyone throwing in on this----“how fast must a handgun bullet go to expand----it is time for folks to do their homework. Once upon a time it was believed and preached that a grossly subsonic bullet would not expand, so the best thing to do is to configure a meplat to maximize impact. Other than having the ballistic coefficient of a barn door, a bullet which bases its appetite for impact on the WADCUTTER, useful range of the WFN is mainly limited by DYNAMIC BALANCE----the ability to sustain stabile flight. As Fowler recently pointed out, a Long Flat Nose flies straight farther than a Wide Flat Nose. Although the WFN registers more impact up close, if you’re going to shoot long with it, better make sure your bullet has the wings.

To hollow point a bullet moves COG (Center of Gravity) rearward, improving long range balance. Hence, accuracy. And a hollow point of pure lead expands in meat well below the speed of sound.

The argument between cast and jacketed is dead. A generalized, cartoon declaration doesn’t answer literate, specific question. Get specific: WHAT IS THE JOB?

POWDER COAT adds a new dimension to cast, permitting softer lead without leading. Pure lead could be swaged, with or without half-jacket, then powder coated. I suspect the momentum of a heavy bullet----with big hollow point----may expand in the 700 fps zone. to shoot rats in the barn with a Super Redhawk Alaskan .480 Ruger, a pure lead Cup Point @ 400 might do the trick.
David Bradshaw

[Cholla]

Feb 11, 2020 18:48:59 GMT -5 bradshaw said:

<snip> Other than having the ballistic coefficient of a barn door, all bullet which base their impact appetite on the WADCUTTER suffer limited rate. Range limited not just by wind resistance. No, useful range is mainly limited by DYNAMIC BALANCE----the ability to sustain stabile flight. A Fowler recently pointed out, a Long Flat Nose flies straight farther than a Wide Flat Nose. Although the WFN registers more impact up close, if you’re going to shoot long with it, better make sure your bullet has the wings.

To hollow point a bullet moves COG rearward, improving long range balance. Hence, accuracy. And a hollow point of pure lead expands in meat well below the speed of sound.

<prune>
David Bradshaw

Thanks so much for this. I've often wondered if the WFN shouldn't more aptly be referred to as the WWSTN (Wadcutter With a Slightly Tapered Nose).

Are there any practical differences in a SWC and a LFN, ballistically and terminally?

Cholla