38 Special 158 LSWC vs 158 LRNFP
 

I am sure that someone has tried these in a reliable ballistics medium such as ballistics gel so I am wondering how they compared. I shoot a bunch of these at normal 38 Special velocities of around 875fps from my 4" guns. Having decided that I will no longer cast I buy the 500 packs of the precast and load them exactly the same. Same vendor for both types usually Lasercast or Proofmark.

What I have noted and the driver of the question is the much greater effect that the RNFP has on our berms at 25 yards. This is very subjective but the crater and the debris spread is about twice the size of the SWC. It is even more pronounced if the berm is wet.

The meplat on the RNFP is a good bit larger than the SWC could it really have that much effect?

Thanks
Chip King

Haven't tried your brand, but the spent cast bullets I pick up off my practice range show no expansion from hitting the sand, unlike the soft plated or some of the premium HP.
IMHO, the splash in sand is not much of a terminal ballistics test other than a big fast bullet makes more splash than a .22.
Hard cast bullets seem to penetrate about the same in gel.

A lot depends on how soft the lead is and how it holds up
while going through the gel pack. if the tip of the RN starts to slide
to one side it may cause the bullet to tumble, causing
it to veer off course or turn sideways causing a larger surface
that will change penetration data greatly.

A RN with a FT will add a slight amount of more energy to a
target and should by right, not penetrate as much due to the
increased friction of the tip.

However I have had a 158gr RN and SWC at 777 +/-fps both go through four water jugs in one of my field test.

Ballistics gel is not reliable to anyone except the bullet manufacturer's ad department. Bullets are always shot into it square and level. It is consistant thru and thru. Thus , recovered bullets are consistant and presentable.

The human or animal body is not. There's skin , flesh , fat , organs , muscle , bones , etc of varying toughness.


Back when it was pretty much standard issue to every policeman across the country , the 158gr LRN was a notoriously poor manstopper. It bored a clean hole straight thru , unless it glanced off a bone. But it loaded easy and looked good in belt loops.

As to flat pointed bullets? I guess it would be akin to getting stabbed with a pointed stick , or a blunt stick. :D

From what I understand the shoulder of a SWC will tear a nice clean hole through tissue instead of just move it aside like a LRNFP might.

While I agree that observation of the effect of each bullet type strike in sand or dirt, either wet or dry, is not really definitive. What does make a difference in terminal performance in any medium is meplat diameter. This is why handgun bullets intended for hunting have large meplats.

While many suppose that the shoulder of a SWC type bullet will cause full diameter cutting in soft tissue this is simply not correct. Tissue is deflected by the meplat causing a larger cavity than the full diameter of the shoulder, which doesn't touch tissue until the bullet speed drops near zero. The shoulder of the SWC is intended to cut clean full diameter holes in paper targets, just like a full WC, nothing more.

The SWC has a better coefficient of form, ballistic coefficient, and form stability than a full WC. This results in better accuracy at distances where the full WC would begin to degrade and even begin to tumble. This is generally accepted as being anything over 50 yards.

chipking,

The short answer is yes, the larger meplat diameter is what makes the difference.

No, I haven't tried it in gelatin, but old time gunmen, such as Elmer Keith and J. Henry FitzGerald, wrote about bullet shape and a large meplat and it's advantage in living tissue.

This has been buried by todays admen, and their writers, pushing high tech, and higher priced, hollow points and ultra high velocity ammunition. They aren't interested in 'what is the best for us' as much as 'what sells the most' for them and at 'what profit'.

SWC's were designed to cut nice clean, full diameter, holes in paper, while being easier to load than wadcutters. Other than that, the WC's beat them in every other use.

A Lead Round Nose will do that, a Round Flat will not having nearly twice the meplate of the swc. Yes it can make that much difference but neither dirt nor mud is the best test medium.

Thanks for all the responses which by the way lead right back to my original question. Has anyone compared the 158 RNFP and the 158 SWC at the same velocity in a verifiable, repeatable ballistics medium?
Thanks all
Chip King

In a verifiable medium, no. But I have cast & swaged 1000's of hp in different nose profiles along with different sized hp's.

Things I do know & learned:

Bigger meplats = bigger hp's
The more curved the bullet nose the better/easier to load in revolvers
The larger hp's of the rnfp bullet with their long hollow nose will expand to a larger diameter than their swc counterpart

I used to have a 358156 hp mold, & replaced it with these.

http://i162.photobucket.com/albums/t...pse3f5b1ce.jpg

Those are a 640 style 158gr rnfp hp's that will run circles around the 358156 hp that I used to cast. These 640's dominated the 156's enough that I sold the mold.

Another project that I'm going to work on this winter, making a rnfp nose forming die for the swaged bullets that I make.

http://i162.photobucket.com/albums/t...ps220be9fd.jpg

As you can see in the picture of the swaged bullets, the nose of the hp bullet has a wider profile than the solid swc nose. This was done to try to get more expansion at slower speeds (ie snub nosed velocities).

I do allot of testing with the 38spl and different bbl lengths. Currently I use:
1 2"bbl
3 different 4" bbl'
4 different 6" bbl's
1 8" bbl
1 10" bbl

That's 10 different barrels & 5 different barrel lengths that I test 38spl's with. That tends to allow me to get a real good look at how a bullet will perform.

I see Kieth's name come up in this forum all the time. He did excellent work & his bullets are legendary. But every bullet design (including his) has limitations. His swc has been around for decades & the 640 rnfp design for a decade.

The rnfp's have taken over & have dominated the semi-auto's. As shooters get educated about them they will take over areas of the revolver market. The 38spl should be one of those areas. The rnfp will easily outperform the swc with easier loading with speedloaders & their expansion to a larger diameter hp.

My all purpose 38 Special load is the 158 gr. RNFP. It is loaded from the Lyman Cast Bullet handbook (3rd Edition) with 4.9 gr. 231 and chronograph of my loads from a 4" revolver are at 906 fps the same as the Lyman book shows. This is 16,800 Pressure and is not a +P load. (The +P is 5.2 gr 231 at 18,500).

The 4.9 gr 231 load is listed as potentially most accurate load, and in nearly all my 38's it is. My 6" 686 will shoot it into 1.5" at 25 yds.