I have a pair of TAP Gamma Plus plates from way back when.  I just recently learned about their issues with delaminating, so I am looking to replace them.  The replacement plates I'm looking at are a Dyneema UHMWPE plate that come in a Polyurea (Linex) coating or a Nylon wrap.  I'm trying to weigh the pros and cons of each and come to a decision.  Here is what I know so far:

Polyurea:
 - Very durable
 - Chemical / Water resistant (my understanding is that UHMWPE's are fairly resistant to chemicals and pretty hydrophobic already)
 - Will make the plate heavier than one wrapped in nylon
 - Easier to clean

Nylon:
 - Less durable
 - Lighter weight (This is a big bonus to me)

I've read that neither offers a ballistics advantage over the other. However, I'm curious how true this is since Linex and similar materials are used as anit-spall on steel plates.

The two plates I'm considering offer the same ballistics protection but differ by 0.7 lbs per plate.  Price is the same.  In order to make the most informed decision, are there any additional factors I should be considering regarding the pros and cons of these two options?  Any direct, industry knowledge is greatly appreciated, so if anyone knows of a member to invite to this thread, please feel free to do so.

Thanks in advance everyone.

If you're sacrificing M855 resistance for the lightweight of a pure UHMWPE plate, then you should make the most of the weight savings.

Get they Nylon covers and save that extra 0.7lbs.

Thank you for the replies so far.  The back face deformation info is very compelling and worth considering.  

In regards to M855 protection, spydercomonkey offers sage advise.  It's not a decision made lightly but the additional cost is a tough pill to swallow when it comes to a truly light (<5lbs) M855 capable plate.  Any recommendations are certainly welcome.

It's a bummer that the Gamma + plates aged as poorly as they did since they seemed to be an all around, pretty good plate.  Relatively light, ceramic strike face and also reasonably priced.  Perhaps it was all to good to be true, given how the aged.

Battle Steel III+ multicurve plates, 5lbs/ea & $149: Battle Steel III+

They also make a lighter III+ plate (4lbs 9oz/ea, $129) but it's single-curve: Battle Steel III+ Single Curve

I've yet to see a test where a Battle Steel plate failed against a rated thread.
HTH...

Tomac

Thanks Tomac - I'll look into these.

You're welcome. I've owned both of their III+ plates & their IV plates and use the III+ multicurve in my PC's.

Tomac

There's always the Hesco L210 at 5.5lbs. Slightly over your sub 5lb, but not by much. But only 0.59" thick, and rated for M855 and rumored also M855A1.
Also below $200 a plate.

Thanks for the recommendation to look into Hesco.  5.5 lb is a little above the weight threshold I've set but I currently have a request out to Hesco for the test reports on their 3810 plate.  I'm curious to see what their test velocities and back face deformation numbers are.  At around 4 lbs, it might be a good contender.

If they give you their reports and it says anything about M855A1 testing, let us know. They officially say the 3810 isn't rated for it, but I'm curious if that is because it fails backface deformation or because it actually penetrates. And if it does penetrate, I'm curious to know if they discovered what barrel length M855A1 needs to be fired from in order to penetrate.

Will do.

I heard back from Hesco today.  They responded to my inquiry quickly but indicated they could not release their independent testing results.  It's a bummer since it's a good way to verify non-NIJ threat levels but I understand if it's confidential.  On another note, does anyone have experience with Hardwire LLC?  I was directed to check them out by a friend who works in law enforcement.  His department purchased some of their plates but he doesn't know much more about them.

Hardwire is a world expert in UHMWPE 'Dyneema' technology. They make some of the worlds lightest and thinnest II/IIIA dyneema armor, as well as hard armor, and protection for critical infrastructure. So beyond legit as far as a company goes.

Most of their plates are Level III (no M855) but they list their III+ plate as ceramic/UHMWPE and capable of stopping M855.

https://hardwirellc.com/pages/hard-armor

Their III+ is 3.9lbs; 'Call for Pricing' so no idea what the cost is. But based on the specs they look worth calling about.

https://hardwirellc.com/products/level-3-multi-curve-plate

Hardwire LLC are good people, doing cutting-edge R&D.  Proudly American designed, tested, and made.  I'm involved with some R&D with them; they're very good and always looking for improvements.

Thanks for the link.  The 3+ plates do have impressive specs.  Back face deformation for M193 is less than 20mm.  M855 also looks good at 23.4mm / 25.2mm and they are testing at 3250 fps.  I did notice that the 7.62x39 MSC test was 32.0mm and I wasn't sure if that was a little high.  It also looks like the test was on a Large Sapi plate.  Would results be similar on a Medium?  Overall though, they look like a very good option.  

Test Reports here: https://hardwirellc.net/_urlfiles/docs/certs/HW-RF2SA-2020%20STTR.pdf

Hardwire is extremely legit. Very innovative company, on the cutting edge of UHMWPE stuff.