To add on to this.....
Shared as part of the BRK Ghost review..... https://www.airgunnation.com/threads/brk-ghost-review.1274213/page-26#post-1523881
www.airgunnation.com
And as I commented that I'd test here....https://www.airgunnation.com/threads/hollowpoint-skiving-serration-on-slugs.1316203/
Credit to
@Motorhead as I saw him do it first and shared about it online a couple years ago...
I started shooting these .20/18.9s not long after they came out, and struck slug gold! Absolutely amazing slug. Theyve become my número uno for prairie dog pesting at a couple of the areas (where there's nothing behind the dog colony). As I've noted though, they tend to poke a hole versus dead-right-there a pest. I've had them go clean through big euro doves, wing joints included. And they usually go through and through the dogs and keep bouncing, kicking up dust like a rock skipping on water. Even a head shot on a dog out to 100yards doesn't stop the slug. So I've always assumed very minimal, if any expansion.
After the discussion a few days ago I decided to give the ole Motorhead Phillips tip a go.
A Ph-1 was the ticket. There was concern raised about base deformation when using a hammer and hard table, etc. So I just pushed them against my thumb. I'd rather they stay accurate, even if it means no expansion, so wasn't too keen on the idea of doing something to them that would make them shoot less accurately.
Made myself about 40 of them in just a couple minutes.
Here are the first couple.
First order of business...are they still accurate?
This pipe is at 95 yards on my back irrigation berms. This is three shots (whiter marks above and right are bird crap).
Yep, still accurate!
First experiment......
I figured a liquid laundry detergent bottle full of water would be sufficient to stop them. Thick plastic and about 6 inches of water....I was also mostly curious about long range effect so placed the jug at 95 yards. Shot it three times, kaWHOP, kaWHOP, kaWHOP. Went downrange.....and all three went through both sides of the detergent jug and kept on going.....quite surprised that six inches of water and two thick plastic sides didn't stop them.
Second experiment.....
Maybe more water? Filled two 1 gallon zip lock bags with water, nearly to bursting, and laid them down, one in front of the other at 95yards. Only shot once here. Went through both bags! This was around 10-12 inches of water. KaTHUMP on impact!!!! Interesting thing to not here is that the final layer of Iplock baggie has two holes in it, so a petal had to have broken off in the water of the second bag.
Third experiment.....
Bars of soap, set them down, front to back, at 93-94 yards.
Took one shot with a Phillips head slug and gathered up the soap. The shot was a bit off center...but served to contain the slug. It was just barely stopped by the fifth bar.
This is the wound channel....
Slug travel is top to bottom here.
Slightly different angle, slug travel is again top to bottom, can just barely see the slug in the closest bar.
Slug travel is bottom to top in this photo..
And now we need a control.....ie what does a non-Philips head slug do in the same conditions? So i had to take two shots here as the first one hit a bit high and figured it'd miss the soap bars. You can see both holes here....
Here is the wound channel for the non-Philips....
Your can see the high shot grazed the first couple bars but it missed the later bars and kept going. Slug travel is top to bottom here. This unmodified slug also stopped in the fifth bar, and just started to bulge out he far aside of the fifth bar.
Left is the slug that was shot without modification. Right is the Phillips head slug.
And a close up of the expansion...
Quite obvious that they'll expand more when aided by the Philips. Since my Phillip indentations were quite shallow, I can only assume they'd get a full petal if the Phillips marks were deeper into the head of the slug. Seems like I remember Scott may have even shared that the four edges of his Phillips bit to make it deeper.
So, of you want expansion, this seems the easy/cheap way to get it. The fact that it doesn't ruin accuracy is the best part.
Super fun experiment.