Need help from those who have modified the meplat of the SMK.

[Michael Eichele]

To all,

Due to the lack of expansion of the 190 SMK in soft tissue from 308 velocities (2657 to be specifec) between 100-600 yards, I have made an effort to modify the bullet's meplat to help it open up a bit. The original bullets from the box are an average of 1.355" long, some being much shorter and some a bit longer. I uniformed the tips and made them all 1.340" long. The nose is square now. Then I opened the tips up (the hollow point) from 0.020" to 0.040". The old meplat diameter was 0.055" and is now 0.060" wide. My questions to you who have experimented are these:

1: How much better can I reasonably expect they will open up and expand when hitting the rib cage of a deer size critter?

2: What percent of my BC can I expect to sacrifice (loose?)

3: I cant remember the 3rd question so I will ask later.

Thanks for your advice.

 

[James Jones]

I haven't tried trimming the SMK's but I have done the Berger VLD'sand it helped the expansion ALOT it also made the bullet group a little better at long range , I'm guessing thats do to the meplat making the BC more uniform. I personaly woulden't worry to much about the tiny loss in BC , it would be hard to judge how much loss in BC you would have due to not knowing exactly what had changed.

The SMK's have a bit thicker jacket than the Nosler , Hornady and Bergers that use the J4 jacket material so they will always lag behind a little in the expansion department.

Have your tried the Bergers? the 190's have a very high BC and I think that even if you trimmed the meplat back further than needed that the BC would still beat the SMK's and the thinner jacket would also help with the expansion

 

[Michael Eichele]

Thanks JJ,

No I havent tried the bergers yet. I would love to but dont have the time to order them and experiment with them before I leave for the next hunt. I figured the BC loss would be minimal but was curios. If I remeber right the last time I used this load I was getting about .560 from my rifle without any meplat modifications. I cant imagine my long range groups getting any better! This was always my most solid load. I could count on at worst .5 MOA from 100-1000 yards any day of the week. This load also dropped less and drifted less and had more energy at any range than any other load I had for that rifle. I gave it up though for its lack of expansion. If my mods help, it may just be the perfect load.

Thanks again!

 

[Michael Eichele]

BTT._

 

[AJ Peacock]

Regarding your question of how much trimming the meplat affects the BC. I didn't look for it, but I seem to remember Shawn posting something to the affect that uniforming the meplat changed the POI at 1000yds around 1MOA.

Thats from memory, so take it with a grain of salt.

HTH

AJ

 

[Michael Eichele]

10" at 1K inst bad. I will do some tests out to 740 yards this week. I will know a bit more then and will post the results.

 

[Mikecr]

Based on the numbers given and going from .055 to .060 meplats(not much at all), I figure .006 loss in BC(to .554).

 

[Michael Eichele]

Ok, so we have disscused the BC differences, how about the ability to expand by opening the hollow point from .020" to .040"? Any ideas there? Bear in mind I havent had any problems with expansion when I hit skull or shoulder bone just ribs and lungs. I am looking for expansion in the ribs. I know I went out yesterday and shot a steel gong at 300 meters and they sounded like they hit alot harder than normall. Maybe it was my imagination. Who knows!