hollow point cavity filling/expansion aid

[Viking painter]

I have been reloading a lot of 9mm sd/hd ammo lately. Have about 3500 rounds finished and 1500 to go. I load on a lee classic turret press so it’s not a Dillion but fast enough for me as I just plug away at it in due time. My carry rounds are either hst +p 124 gr or 124 hornady critical defense. I like the little fancy looking “ expander ball” that hornady fills the cavity with to create rapid and controlled expansion, through testing found the thing actually works! Much like ballistic tips on vmax or varmagedon rounds and the such. So getting crazy ideas( turret pressing 3500 rounds= bora boring) I thought about this I have uv resin that is used to make fishing flies that is fluid until you expose it to uv light then it cures like a hard polymer, see where I’m going here. I know that homemade wildcat stuff like this should never be carried in a edc due to legal backlash by a prosecutor but for hunting rounds, why not try it? Turns out that this resin is really, really close to the consistency of the material used for ballistic tips on projectiles and bonus is, it is luminescent and glows in the dark. So I filled a few different projectiles, both 9mm and 300 blk, and going to do side by side expansion tests to see if this actually works. Tested for basic function and accuracy and everything was just as accurate as always. Thoughts? Am I just nuts, bored, or have some of my fellow reloading brothers and sisters thought about or attempted this before?

 

[Riomouse911]

Cool! I bet it could help keep fibers from clogging a JHP 9mm round and helping to initiate expansion as it drives forwards.

Stay safe.

 

[Ed4032]

This may work very well. The problem with hollow points is that they get clogged with material and become a FMJ round. We use hollow points because it causes the bullet to deliver all the energy to the target and not just pass through. Yes it makes a slightly larger hole but that’s not why we use them. Just test them in jell let us know how they turn out.

 

[41 Mag]

Oh my, tha thought of seeing 4 of those dots from tha business end of a revolver was the second thing that popped into my head, right after ... COOL..

I use a LOT of that UV glue myself making lures, and never thought of doing that. I have however considered using some of the Airsoft BB's in some of my cast hp's in similar fashion.

 

[dredd]

You had me Glow In The Dark!!! LOL

Interesting project. Looking forward to updates.

And just to muddy up the waters, are you adding much weight to the projectile?
Are you adjusting your powder charge?

 

[tightgroup tiger]

I'll pass on the glow in the dark, it would be nice if you dropped a round at night and had to find it. But it would be so nice for the bad guy to see me coming.

I'm looking forward to your expansion tests.

 

[Viking painter]

Cool! I bet it could help keep fibers from clogging a JHP 9mm round and helping to initiate expansion as it drives forwards.

Stay safe.

We’ll I figured that’s how hornady designed the critical defense round and with the composition of the resin being really close to what they use, theoretically it should work the same. When I get some time, I’ll do bare gel and clothing/gel tests. I am thinking more for hunting, especially getting .308 projectiles to expand better at 300 blk velocities.

 

[Viking painter]

You had me Glow In The Dark!!! LOL

Interesting project. Looking forward to updates.

And just to muddy up the waters, are you adding much weight to the projectile?
Are you adjusting your powder charge?

I know right, I am curious to see if they will trace at night, doubt it though. Still cool! Yes I measured projectile weight before and after filling and empty for the RMR jhp I got 124.1 gr, filled 124.4 gr so not much difference. Just used the same load I would if not filled, BE86 @ 5.6 gr 1.090 coal. The xtp only added .1 gr as it’s a smaller cavity but didn’t notice any difference in velocity or accuracy from normal. I run both of them with BE86 at around 1160-1170 fps to match most sd/had rounds. Good stuff!!

 

[Viking painter]

This may work very well. The problem with hollow points is that they get clogged with material and become a FMJ round. We use hollow points because it causes the bullet to deliver all the energy to the target and not just pass through. Yes it makes a slightly larger hole but that’s not why we use them. Just test them in jell let us know how they turn out.

I plan on doing bare gel and clothing/gel, it will be interesting. Hunting I’ve seen hollow points do the same thing with thick fur and skin like on wild pigs, some have just passed right through like a fmj. It could make a .308 projectile from a 300 blk work/expand a little better since most are designed for .308 velocities, I’m pretty sure with 9mm it will work good as well. As soon as it cools down a little bit here, I’m going to go out in the desert and give them a go.

 

[Viking painter]

Oh my, tha thought of seeing 4 of those dots from tha business end of a revolver was the second thing that popped into my head, right after ... COOL..

I use a LOT of that UV glue myself making lures, and never thought of doing that. I have however considered using some of the Airsoft BB's in some of my cast hp's in similar fashion.

I thought of airsoft bbs as well but I don’t cast my own and they wouldn’t fit in any jhp’s I tried. I think they would work good though. I’m thinking the uv glue might kinda act like rubber a bit with hydrolic pressure from it being compressed on impact will cause it to expand and push outwards on the petals on the hollow point causing it to rapidly expand. The xtp bullet is a known deep penetration design and might expand sooner and better than it does, also as I said in other comments helping 300 blk projectiles expand better? Mad science projects are awesome,lol!

 

[Larry in wyoming]

Power ball?
Was that the name of the ammo from back in the 90s that was built like this. It didn't really go anywhere at the time.
Cool project.

 

[Yankee1986]

Power ball?
Was that the name of the ammo from back in the 90s that was built like this. It didn't really go anywhere at the time.
Cool project.

Guessing this 9mm is vintage 2009 from the lot#.
Interesting looking when compared to the newer Hornady.
Starline brass, looks like this one round got some sort of double crimp? Only one in the box like that.
$27 a box/$1+ per rd, seems awfully high for 2009, I can see why they didn't stick around.

 

[Larry in wyoming]

Yep! I remember now. Made by the same company as glaser safety slugs

 

[eddiememphis]

Am I just nuts, bored...

I vote for both.

But that is where creativity spawns.

 

[Atavar]

The only question I have about all this is how thermally stable the elastomer is. Apparently quite a bit of heat is generated by air friction on high velocity rounds and early products had issues because of the plastic melting on the way to the target.

 

[tightgroup tiger]

Have you got to test the expansion consistency of those elastomer tips yet?

 

[Viking painter]

Have you got to test the expansion consistency of those elastomer tips yet?

I have finally got out to test them and the results are not what I was expecting. Without the tips, the expansion started at about 3-4” like one would expect from a standard hp bullet( these were the RMRs @ 1170 fps avg) and continued to around 8”, 2”-2 1/4” wound channel. Excellent expansion and penetration to 14”, these do live up to the hype! 112 gr weight retention from 124.1 gr. With the tips, the expansion started at 2” and continued to around 8” with around a 3” wound channel, explosive expansion ( kinda like a vmax) but stopped at 11”. 101 gr weight retention like it shedded the jacket and exploded. Expansion was slightly larger. For the 124 xtp bullet loaded to 1180 fps avg with open cavity, the expansion started at around 5-6” and made a 2-2 1/2” wound channel to 11” and penetrated to 21”, these are known as deep penetrating bullets and I see why! 122 gr weight retention and perfect expansion but not as explosive as RMRs. With the filled cavity xtp’s is where it got interesting and was exactly why I tried this experiment. Expansion started at 2” and didn’t stop till 7-8” with a 3 1/2”-4” wound channel! They stopped at 13” and we’re the size of a quarter! 114 gr weight retention and performance was that of my normal gold dot carry load. The pieces of resin tips I found were still intact for the most part and one was still on the expanded round, like it melted to it so they do hold up to the heat of being fired. I tested these on paper to see if it affected accuracy at all and they were the same as non filled with 1 1/2”-2” groups at 10 yds. The outcome of the experiment is, it works! Xtp’s are one of my most accurate bullets I use and probably a good choice for small critter control but don’t expand fast enough for a violent wound channel before they go out the other side and this helps them “explode “ like a varmint round but retain enough weight to hit the 12” sweet spot. All tests were done with 10% ballistic gel, 1piece of denim material and from a 4” g19 bone stock. Will post pics when my buddy sends them to me. Next try will be 300 blk subs and supers. Have a great day and happy holidays to all my brothers and sisters out there!

 

[RashQuestion]

Thanks for sharing your results!!! Very detailed!!! It's much appreciated.

Thanks Again and God Bless! Merry Christmas!!!

 

[film495]

interesting. I kind of wonder how this would affect a LSWC, like .38 Special since that is a popular projectile.

 

[reddog81]

Looks neat and it might have a similar consistency but that doesn’t mean it’s going to act the same. My first thought is that you’ve pre-plugged the hollow point and turned it effectively into FMJ.

 

[CoalCrackerAl]

I wonder how hot glue would work.

 

[zeke]

Silicone sealant filled to just the front of bullet, making sure there are no voids. Per highly unofficius testing procedure, about 10 years before Hornady's version, lowered the expansion velocity threshold by about 100 fps in 45 acp jhp's, and kept bullets from "clogging up". Purpose was to get reliable expansion from 3 in 45 acp. Am still using it for various pistol caliber "vermin" loads. Messy to do, and the rounds need cleaned up after curing. The silicone acts as a non-compressible fluid and works good at force transfer to promote bullet expansion. It wasn't an original idea, as got it from one of the first non-factory bullet testing platforms chat room. Most of my "vermin" loads are xtp's, and consider them excellent pistol bullets. Got some pretty dramatic expansion when combining the silicone with a tempered plus p 230 gdhp.

Never tried it in rifle, and not surprised if it would cause more dramatic results .

 

[Viking painter]

I wonder how hot glue would work.

I tried it and it didn’t change performance.

 

[Viking painter]

Silicone sealant filled to just the front of bullet, making sure there are no voids. Per highly unofficius testing procedure, about 10 years before Hornady's version, lowered the expansion velocity threshold by about 100 fps in 45 acp jhp's, and kept bullets from "clogging up". Purpose was to get reliable expansion from 3 in 45 acp. Am still using it for various pistol caliber "vermin" loads. Messy to do, and the rounds need cleaned up after curing. The silicone acts as a non-compressible fluid and works good at force transfer to promote bullet expansion. It wasn't an original idea, as got it from one of the first non-factory bullet testing platforms chat room. Most of my "vermin" loads are xtp's, and consider them excellent pistol bullets. Got some pretty dramatic expansion when combining the silicone with a tempered plus p 230 gdhp.

Never tried it in rifle, and not surprised if it would cause more dramatic results .

That was pretty much the same thing I saw from my test. The xtp’s had much more explosive expansion with the resin filled cavity and acted like a deep penetration varmit round. The uv resin I’m using is for making fishing flies and comes in three different hardnesses. I used the medium hardness so it would still have the fluid like/hydrolic properties to it like hornadys factory critical defense round. Just exactly your talking about. Next up is trying some 300 blk rounds to see if I can get better expansion with.308 bullets at 300 blk velocity which is a known fall back of some bullets in 300 blk. It will be interesting, will post back soon with results.

 

[lordpaxman]

Thanks for sharing those results. It’ll be nice to see the pictures.
I may have to use some of the leftover epoxy from my live edge projects and see if that would be an effective void filler.