I was fortunate enough to have taken a tour of the Lehigh Defense facility in PA.  My firsthand observations of ballistic testing confirm what has been presented in various youtube videos.   It's amazing that near perfection of bullet performance can be achieved in so many of their offerings.  I also noticed Kevin Underwood has several options including the XP line.  Although price is a major factor, each projectile seems to be a miniature "work of art".

That sounds like a fun tour.  Don't know much about their products, but I have seen them mentioned here and there on the web

Have you seen the video Tnoutdoors9  just did on their new extreme penetration ammo,  It has great penetration, if you are looking for $1.50 per round ammo that will go through 36 inches of ballistic gel and some 1 gallon water jugs and keep going.  I think all they did was figure out a way to charge premium defensive ammo prices for FMJ performance.

YouTube

Actually it was 22" in ballistic gel with denim.  That is over penetration, but it is also occurring with the XP extreme penetration round in 9mm, a caliber known for deeper than average penetration.  I would not be using that offering for duty or self-defense purposes rather it may warrant consideration for hunting or woods carry. Additionally, increased cavitation was noted with an increase in volume of the permanent wound cavity when compared to FMJ performance.

Lehigh Defense offers an extreme expansion as well as a controlled expansion round that may be better suited for defense purposes.  Honestly, I believe these particular loadings may be a better option if over penetration is a concern.  The XP bullet was designed to be an improvement on the classic Elmer Keith bullet where deep penetration is highly desirable.  Additional wound capability is noted when compared to hard cast lead.

LD also found a sweet spot between expansion and penetration for the 380acp.  The XP in this caliber penetrated about 17" in ballistic gel with 4 layers of denim.  The permanent wound cavity was 1.0-1.25" in diameter and resembled a hollow point cavity; however, the cavity was three times the length of some of the best hollow point designs.  Until now, because of the XP, I will consider the 380acp acceptable for defense use.

The rifle bullets that I witnessed ballistic gel testing, including 300blk in extreme expanding subsonic, controlled chaos, and controlled fracturing where remarkable as well.  The 5.56 offerings were impressive to say the least with massive energy dumps observed.  The on-site ability the constantly tweak engineering by modifying changes to the CN machining process offers a unique advantage to traditional processes.

To say that the bullets/rounds at $1.50 are overpriced is far from the truth.  They are selling premium ammo,made from premium components, with premium performance, at a premium price.  The also have some designs that are available only to the military and excluded from law enforcement as well as civilian sale.

https://www.youtube.com/watch?v=betFqFCwcYo

https://www.youtube.com/watch?v=JrEmQNe-TrA

You can also check out the video on youtube of their new 78gr 300blk close quarters ammo.  They filmed the video a few days before we visited but the clay blob was sitting on a table.  Needless to say, the close quarter ammo is not just an over-priced gimmick.  The damaged table support was sitting in a corner and the 16' ceiling still had remnants of splattered clay.  The addition of aluminum to a 300blk round produced some impressive damage.  This technology is also available for the 45-70 round, a personal favorite of mine for hunting in the Northeast.  Velocities of 3000fps with aluminum construction are hard to overlook.