Odysseus 2 Posted September 30, 2022 I'm not a lawyer and the following is my personal opinion. I'm sure everyone has a favorite self defense load and chances are it is not NJ compliant (for carrying). Looking into the law it seemed feasible to simply make my favorite load NJ compliant by making sure it no longer meets NJ's definition of a hollow point i.e. filling the tip with high temp silicone. Per the State Police: "Ammunition lacking a hollow cavity at the tip, such as those with a polymer filling, are not considered to be hollow point ammunition. An example of this can be seen with the Hornady Critical Defense / Critical Duty, Cor-Bon PowRball / Glaser Safety Slug and Nosler Inc. Defense ammunition." Yes, silicone is a polymer for anyone wanting to argue semantics. Although I'm not aware of any case law establishing this polymer filled tip exception there is the Roosevelt Twyne case. That in conjunction with the SP guidance gives me confidence to proceed in filling my own HP's. I have a couple pictures that I tried to upload but it didn't seem to work. I put it in the member gallery if anyone want to take a look. It shows a critical duty and my Underwood 10mm 155gr XTP. The only thing I'll add is that one would have to do their own due diligence to ensure the polymer filling doesn't negate any expansion properties of the bullet. With my load having a muzzle velocity of approximately 1500fps, the expansion has been very consistent despite the filling. Accuracy may be influenced but I'm not using these for competition. Quote Share this post Link to post Share on other sites
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Lostboy 105 Posted September 30, 2022 Good topic to branch off from yesterday talking about .22 and how hollow points are a much better option for stopping power. What if you jbweld (or other epoxy) fill them? 1 minute ago, samiam said: Why go to all that trouble when you can buy commercial ammo that is essentially what you would be making: hollow-points with the point filled in with a soft polastic material? If it's just to prove a point, I understand, but it could get expensive by the time youtr theory is judges legally sound (assuming that even happens). For some calibers, yeah seems like a waste. Quote Share this post Link to post Share on other sites
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JackDaWack 2,894 Posted September 30, 2022 Why would you want to fill the tip with something that would alter the ballistics of the bullet in a way that is not predictable? Sure you could fill the tip with a polymer, will it still expand though? At least manufactured ammo will have adequate testing. Critical defense/duty, was not filled to make it "non hollow point", it was done to INCREASe expansion upon passing through heavy materials that would clogg the tip and prevent expansion... and here were are talking about doing just that on purpose? Quote Share this post Link to post Share on other sites
Lostboy 105 Posted September 30, 2022 5 minutes ago, JackDaWack said: Why would you want to fill the tip with something that would alter the ballistics of the bullet in a way that is not predictable? Sure you could fill the tip with a polymer, will it still expand though? At least manufactured ammo will have adequate testing. Critical defense/duty, was not filled to make it "non hollow point", it was done to INCREASe expansion upon passing through heavy materials that would clogg the tip and prevent expansion... and here were are talking about doing just that on purpose? Maybe fill them with polyurethane foam. Lol 51 minutes ago, samiam said: I guess a stronger case could be made to do this for a caliber that doesn't have Hornady Critical Defense or equivalent ammo available. For example, filling the tips of Winchester Silvertip HP .22 LR. Still, if you were somehow caught with it, I strongly suspect that the legality argument would be need to wait until after the possessor was arrested and indicted. I also wonder a bit about how far a rabidly anti-2A prosecutor might try to push the definiition of "dum dum bullet" as cited in 2C:39-3(f). Now, Hornady, along with other firearms manufacturers and their associations would no doubt contribute to the defense of any charge involving commercial ammo of that sort, but for home-made stuff you might be largely left to your own resources. The real issue may not be getting caught with them, but what if you actually had to use them. I would think regardless of what ammunition you use, the coroner may be your worst enemy. Quote Share this post Link to post Share on other sites
RichP 115 Posted September 30, 2022 I think the key words in the SP website clipping are "hollow cavity in the tip". By that description, only the very tip would need to be covered, and the remainder of your HPs cavity can be left alone. With that said, Its likely not possible for the average shooter to adequately test their concoction for performance or more importantly, any reduction in performance in altering the bullet. Large ammo manufacturers can/do test for these things. For me, there is no reason to not use one of the ammos that is listed by name on the website as being legal, and has been tested 9 ways to Sunday. Quote Share this post Link to post Share on other sites
124gr9mm 857 Posted September 30, 2022 3 hours ago, Odysseus said: The only thing I'll add is that one would have to do their own due diligence to ensure the polymer filling doesn't negate any expansion properties of the bullet. With my load having a muzzle velocity of approximately 1500fps, the expansion has been very consistent despite the filling. Accuracy may be influenced but I'm not using these for competition. While I appreciate your efforts to work around the insane laws in NJ, I'd be hesitant to put untested, home-brew ammo tips in my gun. There's no telling what they're going to do to the flight path of the bullet, if they're going to come loose in the magazine due to violence of recoil, or otherwise jam up the works of a gun. "Proof of concept" is one thing, but companies spend countless hours testing their designs before bringing them to market, so I'd trust the manufactured ammo. Quote Share this post Link to post Share on other sites
Odysseus 2 Posted September 30, 2022 I opted to make my own because I'm not a fan of most commercial 10mm offerings. Few vendors choose to load the caliber to it's proper velocity. Most are watered down to the point that one might as well shoot a .40. NJ sure has a lot of folks terrified of prosecution and I understand it, to a point. It's a polymer filled HP, just like Critical Duty and just like PowRBall. All would be considered as illegal HP's sans the polymer. I've done a fair bit of expansion testing to date though admittedly it has not been exhaustive. I will continue this process. My personal preference is to take the de minimis risk of prosecution for HP possession over the possibility of collateral damage from a critical duty round that is underpowered yet penetrates an unacceptable 18". There's no critical defense in 10mm. I like to keep penetration on the very low side of FBI guidelines. We civilians have a much higher risk of being held responsible for collateral injuries than any Governmental agency...but I digress. Of course I could throw out all logic and use fmj's to guarantee compliance with NJ's mindless restrictions. Quote Share this post Link to post Share on other sites
RichP 115 Posted September 30, 2022 You could always buy 40S&W Critical Defense ammo, pull the bullets and drop them into you favorite 165gr 10mm loadings. Best of both worlds. Only downside is that you might have to work the COAL down for safety. Quote Share this post Link to post Share on other sites
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Odysseus 2 Posted September 30, 2022 2 hours ago, RichP said: You could always buy 40S&W Critical Defense ammo, pull the bullets and drop them into you favorite 165gr 10mm loadings. Best of both worlds. Only downside is that you might have to work the COAL down for safety. Good call. I hadn't considered that. Will look into it further. I would have to ensure the bullet behaves appropriately at the higher velocities. Oh, and I meant to say the critical duty penetrates 20", not 18. I've been carrying my setup in PA for many years and wanted to change as little as possible. I'm a month or so out from actually carrying in NJ so I have to sort this out pretty soon. Great forum btw. I'm new here but enjoying the site a lot. Quote Share this post Link to post Share on other sites
124gr9mm 857 Posted September 30, 2022 3 hours ago, Odysseus said: I've done a fair bit of expansion testing to date though admittedly it has not been exhaustive. I will continue this process. Good. Expansion testing is great, but there are plenty of bad things that an added blob of polymer could do to the function of a handgun. I'd hate for you to get a 'click' instead of a 'bang' when needed, or a 'kaboom' at any time... Quote Share this post Link to post Share on other sites
Odysseus 2 Posted September 30, 2022 I can say the accuracy has not been altered to any degree outside my shooting ability to 25yards. Based on 100 rounds. The plugs will not fall out - they are quite difficult to remove. This would have to be confirmed periodically in case of any shrinkage. The rounds have been left in a hot chamber for 5 minutes with no signs of melting or deforming. Expansion has been consistent (via eyeball not caliper) on all of the water-jug & wet magazine shots. Need to order some gelatin blocks. From a legal perspective I'm trying to limit the potential for over-penetration and unintended injuries to the innocent. NJ compliant choices are limited in the 10mm platform. Quote Share this post Link to post Share on other sites
JackDaWack 2,894 Posted September 30, 2022 3 hours ago, Odysseus said: I opted to make my own because I'm not a fan of most commercial 10mm offerings. Few vendors choose to load the caliber to it's proper velocity. Most are watered down to the point that one might as well shoot a .40. NJ sure has a lot of folks terrified of prosecution and I understand it, to a point. It's a polymer filled HP, just like Critical Duty and just like PowRBall. All would be considered as illegal HP's sans the polymer. I've done a fair bit of expansion testing to date though admittedly it has not been exhaustive. I will continue this process. My personal preference is to take the de minimis risk of prosecution for HP possession over the possibility of collateral damage from a critical duty round that is underpowered yet penetrates an unacceptable 18". There's no critical defense in 10mm. I like to keep penetration on the very low side of FBI guidelines. We civilians have a much higher risk of being held responsible for collateral injuries than any Governmental agency...but I digress. Of course I could throw out all logic and use fmj's to guarantee compliance with NJ's mindless restrictions. Why not just shoot .40? If over penetration is a concern, why essentially take a .40 and throw more power behind it? Quote Share this post Link to post Share on other sites
Odysseus 2 Posted September 30, 2022 44 minutes ago, JackDaWack said: Why not just shoot .40? If over penetration is a concern, why essentially take a .40 and throw more power behind it? Because power does not always directly correlate with penetration. Often slowing a bullet down results in increased penetration due to reduced expansion. This is seen with various .40 / 10mm loads. I happen to like a combination that delivers 700+ft/lbs of energy dumped in 10-12" of penetration. And yes, I'm aware of the various schools of thought on handguns and their limited ability to produce stretch cavities. Quote Share this post Link to post Share on other sites
Lostboy 105 Posted October 1, 2022 15 hours ago, Odysseus said: I can say the accuracy has not been altered to any degree outside my shooting ability to 25yards. Based on 100 rounds. The plugs will not fall out - they are quite difficult to remove. This would have to be confirmed periodically in case of any shrinkage. The rounds have been left in a hot chamber for 5 minutes with no signs of melting or deforming. Expansion has been consistent (via eyeball not caliper) on all of the water-jug & wet magazine shots. Need to order some gelatin blocks. From a legal perspective I'm trying to limit the potential for over-penetration and unintended injuries to the innocent. NJ compliant choices are limited in the 10mm platform. This makes me think of when I bought 500rds of that polymer coated target ammo and that nonsense shot about 3" left of every other ammo. I dont think a bit of epoxy, polymer, etc would stop a bullet enough for pressures to warrant a "kaboom". I bet if you filled the tip of a gun with a 1/4" of jbweld the bullet would blast right though it. I'll leave it for someone else to try though. Quote Share this post Link to post Share on other sites
JackDaWack 2,894 Posted October 1, 2022 47 minutes ago, Lostboy said: This makes me think of when I bought 500rds of that polymer coated target ammo and that nonsense shot about 3" left of every other ammo. I dont think a bit of epoxy, polymer, etc would stop a bullet enough for pressures to warrant a "kaboom". I bet if you filled the tip of a gun with a 1/4" of jbweld the bullet would blast right though it. I'll leave it for someone else to try though. I would be more worried about it causing a malfunction. Quote Share this post Link to post Share on other sites
RichP 115 Posted October 1, 2022 The trick is to allow enough non-compressible fluid into the cavity to disrupt the bullet/jacket. Will silicone allow for that under various conditions, hard to tell. It appears to me that the "insert" that Hornady uses is slightly more rigid than your average caulk. I would probably try to replicate the durometer of what they use as closely as possible, since I'm sure that they went thru many test cycles to determine what works best. IIRC, the Critical Defense bullets also have a different jacket to enhance expansion. Quote Share this post Link to post Share on other sites
Shocker 150 Posted October 1, 2022 I like RichP’s thinking and along those lines, the interwebz is saying the poissons ratio of silicon is only .2-.3. I think you want something closer to .5 (like natural rubber…or cork) so that any axial compression is matched with a radial expansion. Quote Share this post Link to post Share on other sites
Lostboy 105 Posted October 1, 2022 1 hour ago, Shocker said: I like RichP’s thinking and along those lines, the interwebz is saying the poissons ratio of silicon is only .2-.3. I think you want something closer to .5 (like natural rubber…or cork) so that any axial compression is matched with a radial expansion. Locktite construction adhesive. Lol all kidding aside, someone should make a video testing these theories. I don't have much video editing experience but I'll fire the gun. Quote Share this post Link to post Share on other sites
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Odysseus 2 Posted October 2, 2022 11 hours ago, RichP said: The trick is to allow enough non-compressible fluid into the cavity to disrupt the bullet/jacket. Will silicone allow for that under various conditions, hard to tell. It appears to me that the "insert" that Hornady uses is slightly more rigid than your average caulk. I would probably try to replicate the durometer of what they use as closely as possible, since I'm sure that they went thru many test cycles to determine what works best. IIRC, the Critical Defense bullets also have a different jacket to enhance expansion. Appreciate the analytical approach to the problem. While I have access to a durometer, I'm not sure I can produce a sample from Hornady's rounds suitable for testing. I'll look into it further. When looking at Hornady's bullet, the cavity is larger and the ogive differs from the XTP. Due to the multiple variables from one bullet to the next, I'm not sure if matching polymer hardness is the sole solution to expansion - though Shocker may be onto something with his radial expansion thought. It's certainly not a bad data point to collect. What started out as a redneck solution seems to be morphing into a research project. Maybe I'll ask my son to take this up for his engineering thesis... Quote Share this post Link to post Share on other sites
Krdshrk 3,872 Posted October 3, 2022 On 10/1/2022 at 12:36 PM, samiam said: I've got a recipe somewhere on my other computer for DIY (untried by me) ballistic gel. Want me to look for it? https://www.customcartridge.com/pdfs/BallisticGel.pdf Quote Share this post Link to post Share on other sites
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MartyZ 691 Posted October 4, 2022 On 10/1/2022 at 11:56 AM, Lostboy said: Locktite construction adhesive. Lol all kidding aside, someone should make a video testing these theories. I don't have much video editing experience but I'll fire the gun. here you go Quote Share this post Link to post Share on other sites