Odd Speer Gold Dot G2 & Hornady Flexlock Question

[Spartan1980]

Does any of the SMEs have an idea of the anticipated shelf life of the "new" polymer tipped ammo? Specifically I'm wondering if the polymer tip will "degrade" over time such as hardening, shrinking, etc. I keep my carry ammo for long periods, thankfully don't need to shoot much of it and I'm looking at re-stocking for basically a lifetime supply. If there are no anticipated issues I'll go with these since they are now priced the same as the older versions. I keep my ammo stored inside the house or in my underground storm shelter which is pretty temp stable at reasonable temps year round so the ammo itself is not really in question, just the long term stability of the polymer tip has me curious.

[bfoosh006]

Good question. I had not considered this at all.

what about the modern harder plastic tipped rifle ammo as well ?

I would tend to think a decent "shelf life" ... but the above question... makes me wonder...what about any plastic shrinkage over time for the "harder" rifle tipped ammo as well ?


I am going to have to look at some of the old boxes of Nosler Ballistic rifle bullets I have .

[Evil_Ed]

I would think UV and other sunlight exposure issues would be the main cause of shrinkage, brittleness, etc? In theory, just keeping them boxed in a darkened area should be good to preserve the polymer for a while...but good question, I wonder.

[Hambo]

I was going to post my guess, but I think a call to Hornady, Nosler, or Speer is a better idea.

[OlongJohnson]

I'd be careful about what polymer the Hornady tips are in contact with for any length of time. I had some in Beretta sand-resistant mags for a couple years and the Hornady bullet noses were sufficiently sticky coming out when I unloaded the mags as to be non-functional. I think they'd be OK in other mags, but they were dragging on the inside of the B mag to where it took a couple seconds for the stack to rise when each one was pushed out of the top. Would not have run in a pistol at all.

In general, I assume that any soft polymer in contact with any other soft-ish polymer for the long haul will be a problem. Never know what the problem will be, but I've had enough things turn to gooey slime that it's safer to go for prevention.

[Spartan1980]

I'd be careful about what polymer the Hornady tips are in contact with for any length of time. I had some in Beretta sand-resistant mags for a couple years and the Hornady bullet noses were sufficiently sticky coming out when I unloaded the mags as to be non-functional. I think they'd be OK in other mags, but they were dragging on the inside of the B mag to where it took a couple seconds for the stack to rise when each one was pushed out of the top. Would not have run in a pistol at all.

In general, I assume that any soft polymer in contact with any other soft-ish polymer for the long haul will be a problem. Never know what the problem will be, but I've had enough things turn to gooey slime that it's safer to go for prevention.

What do you think was the deal with these mags causing some sort of polymer incompatibility? I thought these mags were steel coated with a PVD coating of some sort. If it was the mags, that's just weird. I'm thinking something in the storage environment or maybe lube residue caused the tip degradation. Or it could just be exactly related to my question.

To the O/P: I doubt that these rounds in handgun calibers have been out long enough for any of us to have any experience to really know. As mentioned polymer tipped rifle rounds have been out for a long time and I've never heard of problems, but I just thought I'd throw the question out here to the SMEs here as it's something I've never seen discussed or mentioned.

[OlongJohnson]

What do you think was the deal with these mags causing some sort of polymer incompatibility? I thought these mags were steel coated with a PVD coating of some sort. If it was the mags, that's just weird. I'm thinking something in the storage environment or maybe lube residue caused the tip degradation. Or it could just be exactly related to my question.

The tips don't really appear degraded, but the interaction of the tips with the coating was notable. I do remember when the mags were brand new, the bodies tended to feel grippy/sticky in the humidity of Houston at the outdoor range. Not like something would adhere to them, but extra-high sliding friction. They were commonly referred to as "sand mags," so maybe better in a sandbox than a swamp. Also, they (about four of them) were supposed to be 12-round factory mags (for a 96), but one took so much force to get the 12th round in that it swelled and wouldn't slide into the gun smoothly, and they all ran best as 11 rounds. Annoying for such a big gun when the USP Compact .40 mags take 12 with USP-like reliability.

It's all down the road, as the 96D was one of the first guns to go in the dempanic.

Other examples of the phenomenon I referenced are a Nikon camera body that sat in its original box, bagged in the original poly bag as supplied by Nikon, for several years. All the soft-touch polymer on the camera that was in contact with the bag is sticky now. A low-end example is a Harbor Freight angle grinder where most of the tool is covered in soft touch that is now disgusting sliminess after about eight years in a garage. I keep acid-free paper under the butt pads of rifles in the safe so they don't interact with the rubber padding that's in there.

[the Schwartz]

Does any of the SMEs have an idea of the anticipated shelf life of the "new" polymer tipped ammo? Specifically I'm wondering if the polymer tip will "degrade" over time such as hardening, shrinking, etc. I keep my carry ammo for long periods, thankfully don't need to shoot much of it and I'm looking at re-stocking for basically a lifetime supply. If there are no anticipated issues I'll go with these since they are now priced the same as the older versions. I keep my ammo stored inside the house or in my underground storm shelter which is pretty temp stable at reasonable temps year round so the ammo itself is not really in question, just the long term stability of the polymer tip has me curious.

The concern you've expressed is part of why I've never cared much for the engineering principle of ''let's plug the JHP expansion cavity with a piece of elastomer before it gets plugged so that it won't get plugged up''.

Elastomers do degrade over time as a result of contact with environment factors such as heat, pollutants, chemicals, and mechanical cycling. The elastomers used in these bullets' (Gold Dot G2, Hornady Critical Defense and Duty, etc) expansion cavities oxidize over years-long time frames and that has got to have an effect on the compressive and tensile strengths.

The performance of these newer ''pre-plugged'' JHP designs is a function of the compressive and tensile strength of these polymers, so I suspect that as these polymers ''age'' (degrade) their performance will also change as they typically stiffen, harden (embrittlement), and degrade (shrink, deform). Put another way, these pre-plugged JHP designs have what is essentially a 'shelf-life' due to the presence of the polymer plugs. Besides exposure to atmospheric O₂, these designs are also going to be exposed to extended periods at elevated temperature next to a human body, corrosive sweat, temperature cycling during different seasons, and chemicals, lubricants, and solvents used in maintaining the guns in which these designs will reside. None of this can be good for the elastomers being used and can only serve to accelerate the rate at which these polymers degrade.

Call me '''old-fashioned'', but I'll be sticking with the proven conventional JHPs without a polymer insert.

[Spartan1980]

@the Schwartz thanks.

You hit on the EXACT thought I had when asking. Long term properties that is.

I'm skeptical too and thinking of the target market for these rounds it's not unreasonable to think that LE agencies would go through their inventory and be reordering at least somewhat regularly. I think I'll also stay with what we know works. Ammo properly stored will last probably 100 years, I won't but my daughter will still be protected.

[0ddl0t]

Obviously best practice is to rotate out your carry ammo long before it ever becomes an issue. As to your question, accepted MIL and SAE shelf life varies from 3-25+ years depending on the material. Some examples:



Aflas 25 Years
Butyl Rubber 25 Years
Chloroprene (Neoprene®) 15 Years
Ethylene Acrylic (Vamac®) 15 Years
Ethylene Propylene 25 Years
Fluorocarbon (Viton®) 25 Years
Fluorosilicone 25 Years
Hydrogenated Nitrile 15 Years
Nitrile (Buna-N or NBR) 15 Years
Polyacrylate 15 Years
Polyurethane (Polyester or Polyether) 5 Years
Silicone 25 Years
Styrene Butadiene 3 Years