Length of a Sierra 107gr Matchking

[madsebshooter]

Can someone tell me the length of a 6mm 107gr Matchking bullet? I had a 6x45 built around a tight twist Obermeyer barrel, hoping to shoot in cast bullet matches with it. Best I can get with the cast bullets presently available to me is 1.4" at 100 yards, and to get that I have to go down to 1600fps. So I'm thinking about getting a custom mold made, something that'll get a bit more bite on the rifling, a lead bullet as long as the 107gr Matchking. For those of you who might be interested in plinking here's a pic of the lead bullet I'm shooting now, it's the Eagan MX2-243. Mr Eagan has passed on, but I have the mold cutting cherry. Thanks

 

[Hatrick]

1.230"

 

[madsebshooter]

Thank you sir, .020" shorter than a 105 A-Max, yet Sierra recommends a 1/8 twist or tighter, and Hornady says a 1/9 will do for their bullet. Maybe it's the different types of ogive.

 

[Hatrick]

Thank you sir, .020" shorter than a 105 A-Max, yet Sierra recommends a 1/8 twist or tighter, and Hornady says a 1/9 will do for their bullet. Maybe it's the different types of ogive.

I have a box of each here, and the lots that I have are pretty close to the same length + or - a few thou. The amax is about .030 longer in the bullet shank, (part that engages the lands), than the smk. So the ogive design of the smk may require a little more spin to get through the air with no wabble. Both shoot well from my button rifled 8 twist, but I would not rule out the 9 without a try.

 

[madsebshooter]

Thanks guys, I got the twist on my Obermeyer measured, and it is 1/8. I'm getting better with the cast bullet too, after enlarging the borerider. I'm getting the same 1.5moa at 2300fps as I was previously getting at 1600fps, got more work to do. Anyone interested in following along can go here: http://castboolits.gunloads.com/showthread.php?t=121224 That 5 groove rifling makes things tough, but I'll get it to work.