HUGE BC change with opening up the hollow point.

Michael Eichele · #1 10-13-2007, 11:56 PM

Just a small piece of info to file away if any of you decide to experiment with modifying the meplat of the SMK.

I was out the last few days testing the 190 SMK's after having modified the meplat in an effort to get some reliable expansion on game and found that I had lost a huge amount of BC. It went from .574 to .451 in my rifle all else being equal. The meplat only grew by .005" but I opened the hollow point from .020" to .040". I was so shocked I decided to shoot more of the 100% factory bullets and they flew right where they should but the modified bullets always hit 15" lower (same POI at zero). I didnt think they would change that much but it is what it is.

Regards.

mikebob · #2 10-14-2007, 12:08 AM

When that hipe came out I did some research on it and found an article from a benchrest shooter that came up with the same results as you, So i never got into it. In his article he stated he gained no accuracy either. I was wandering if you did or not

Michael Eichele · #3 10-14-2007, 12:39 AM

I havent noticed any real accuracy changes to speak of. Most of the shooting I have been doing has been in a tough wind, so most of my groups have been a bit more open than normal at longer ranges. The times I have shot them at 300 yards with dead still air, I may have seen an ever so slight increase in accuracy but I wouldnt read into that too much with the minimal time I have been able to shoot in dead air at 300 yards.

Bear in mind I didnt just uniform the meplats, I opened up the hollow point by 100%. I am sure this is where most of the BC loss is coming from.

mikebob · #4 10-14-2007, 12:54 AM

It was along time ago when i read that but I dont think his was that dramatic but same conclusion. I was trying to find it but cant remenber the name of the benchrest shooter it was. Are you going to try them on game to see if it expands better or are you going to drop it because of the bc loss. If it works better I might have to finally get mine out of the box.

davewilson · #5 10-14-2007, 04:34 AM

i'm getting ready to go shoot some 250SMK's that i've drilled the hollow point out to .047 i think it is. was hoping to do a bullet test at 1300, but we'll see how that goes. hopefully i'll get some come-ups and maybe a ballpark of BC.

davewilson · #6 10-14-2007, 06:46 AM

i wish i could tell you all about my shooting but when i went to leave this morning, i forgot to put the emergency brake on my truck and went back in the house to get something i forgot. of course the truck went rolling down a fairly big hill, across a normally wet area and bumped into the small stream where it's sitting now. needless to say i didn't go shooting.

Len Backus · #7 10-14-2007, 07:04 AM

:(:(:(:(