After seeing the behavior of the 180gr GD it seems that at higher velocities it starts to peel back its jacket and "tuck" the petals behind the core. The jacket doesn't come completely loose and the bullet retains its weight. So we have a case of retained weight, reduced meplat, and in theory increased penetration in the last half of its travel.

In the other hollowpoint tests I have noticed that the bullet does not gain much penetration with increase of velocity, as long as the velocity is within its range of performance. In some cases a lower velocity actually increase the penetration.

The case of 180gr is very interesting as we are able to push it to the point where the jacket is "tucked" behind the core...essentially turning it into a WFN as it's losing its energy. The initial wound cavity does not seem to affected compared to other hollowpoints (actually very impressive!). Without kabooming the gun I think the 180gr GD should benefit from point of "failure" velocities.

Thank you guys for the tips! This 10mm thing is very addictive! Already have to go replenish from underwood again haha

Wew lads I couldn't think of the last time I was so nervous about a purchase. I read up on all I could on the RZ-10 and made every precaution not to get into a stainless/stainless galling situation that were reported on the 1911 forums few years back. I made sure I did not use plain CLP and ordered milcomm tw25b and polishing compound ahead of time. Long story short didn't get to use any of them and ended up using a friend's Red Line assembly lube dispensed out of a nondescript nail polish jar. He swears by the pink gue and says if it's ok on cars it's ok on firearms (I had my doubts).

Field stripped and lubed the rz10 at the usual places and racked it couple dozen times. The slide/frame was TIGHT, so tight that the slide wouldn't retain the lube and kept being displaced out of the crevices after a few racks. The gun was wiped of the factory lube ahead of time before we applied the pinkish assembly lube. With each rack of the slide the displaced pink would turn black and made me more nervous about possible rough spots/burrs at contact points. We must have relubed the thing 3 times. It seemed it was loosening up by end of the night. 

Took it to the range today and shot thru it sig 180gr FMJ, underwood 180gr xtp and underwood 200gr HC. 90 rounds all together. I had a 3 failure to feed within the first 3 mags of Sig. I don't know if it was the ammo or the gun or me as I caught myself placing the thumb below the safety. Upon closer inspection the FMJ had small gouges and some of the rounds were more difficult to push out of the DW brand magazines. 

Luckily those were the only malfunctions and since I adjusted my grip to rest on the safety I have not experienced another malfunction. Yes I'm a noob when it comes with 1911. Only owned one other Colt that I didn't shoot a lot. The rest of the range session was uneventful except for the holy **** of underwood 200gr HC. I did not expect so much smoke!! Was like shooting the black powder 1860!

The recoil was stout out of all the rounds including the Sig ammo which tbh didn't feel that much different than underwoods loadings. I think the rz10 recoils more than the g20? Accuracy off hand I was getting 2-3 inches 5 shot groups offhand at 15yd, with the smaller groups going to the 180gr XTPs, flinching and bruised palm and all  . Some other tidbits...The gun was not field stripped and lubed per DW recommendation after each 50rds.There were also no signs of smileys in any the three loadings.

Overall really happy and relieved with the purchase! With more practice getting used to the recoil I should hopefully be capable and confident to make a good 30yd shot!

Yes definitely! I am super curious as to the various HC designs and what kind of retained energy is left after slight deformations from the initial impact. I read up a bit on brassfetcher website about this product called synbone. They come in generic shapes that allow consistent hits shot to shot.

Is there however something that is more readily available that is roughly equivalent to bone?

I'm not sure how easily and consistently obtainable that is since most real bone tests I've seen are pre packaged meat.  It's difficult to replicate similar strike angle shot to shot. But yea bone will be awesome if it can be consistent shot to shot.

I think it would be ok if the barrier is *slightly* more challenging than bone.

I have been binge watching lots of tests of 10mm. Nearly all of them start with denim or hard barrier and end in gel. I would like to discuss about a design that tests the penetration ability of bullets AFTER passing thru soft media. For example, how much hard barrier can an already expanded gold dot defeat after passing thru 12 inches of ballistic gel?

The test design must be easily replicated by everyone. So no bone sim plates. Maybe readily available 2x4.

1.5in deep 2x4 --> 12in ballistic gel --> 1.5in deep 2x4 --> ballistic gel or water jugs

12 inches should simulate the shoulder width of a decent size pig. And hopefully the 2x4 would be sufficient in simulating bone (not sure about this). This will answer several questions about effectiness of both JHP and HC on the "second half" of the animal. Also most serious hunting loads should be able to penetrate 16+ inches of ballistic gel and should be able to complete this at least in part.

  Any thoughts?

We need some solid barrier -> ballistic gel -> barrier test.

Wow thanks for the links! So in relation to bonded ammo, let's say the bullet holds together after the first bone, then opens up as it hits soft tissue, will the expanded bullet have enough energy to punch thru the second bone?  I can see it work in a bone -> tissue scenario but what about bone -> tissue -> bone?

It seems most are capable of 15-18 inch penetration in ballistic gel when expanded

Hello all! Glad to find such an active 10mm community. I'm getting (more) into 10mm...in the past been treated with mild range loads in my g20sf. I ordered a razorback so that should get a little more support and barrel length. Setting aside the velocity data for now, which factory round has the best bullet design to punch thru bone and poke two holes in a piggy?

While the soft tissue penetration is more predictable I'm not sure how these HC would hold thru hard barrier without getting destroyed.