6BRA Ladder Increments

[Curious]

Im thinking of going up in 0.1gr increments from 29.8 to 30.8 with H4895 and 107 SMK's, does this sound about right?

Ive ran these charge weights safely, there is no pressure issues.

 

[Northridge]

the 107 sierra usually builds pressure slower than some other bullets in this cartridge, with wise pressure evaluation you may be able to creep further up the charge ladder safely and likely will find another spot barrel will shoot. many things can and do affect safe operating pressure work smart.

Shawn Williams

 

[KenOath]

Im thinking of going up in 0.1gr increments from 29.8 to 30.8 with H4895 and 107 SMK's, does this sound about right?

Ive ran these charge weights safely, there is no pressure issues.

Yep sounds about right.
Friend of my mine is shooting the 107 Siearras, 28” 236 Kreiger, 31.05gns 4895, CCI450s, no pressure signs..

 

[Curious]

Yep sounds about right.
Friend of my mine is shooting the 107 Siearras, 28” 236 Kreiger, 31.05gns 4895, CCI450s, no pressure signs..

What speeds are you seeing at 31.05gr Rushty?

 

[Alex Wheeler]

Do .2 first, then when you find the spot to focus on cover it with a .1 ladder.

 

[R.Morehouse]

Do .2 first, then when you find the spot to focus on cover it with a .1 ladder.

For the ladder where would you seat 103 VT's ??

 

[Alex Wheeler]

Good question. Guys have them shooting well over a wide area. I would still start .005 in and .005 off then go from there.

 

[KenOath]

What speeds are you seeing at 31.05gr Rushty?

2991fps avg with 105 Berger Huntings, just done some load testing on new Barrel yesterday with 103gn Copperheads and new batch of 4895 and they are cooking along speed wise for 5 shots with 28” barrel and Labradar:
30.4 avg 2997
30.6 avg 3013
31 avg 3041
Don’t know if it’s because I jammed them all .010” or a faster powder or the time of day I shot them that’s given me the variations in speed,Bergers were shot early morning Copperheads on dusk, can’t see a 2gn difference in bullet weight giving me that much more speed. Good news is groups were small as well as ES.

 

[retired]

how much less body do they have, less bore dia body, less bbl drag more speed ?

2991fps avg with 105 Berger Huntings, just done some load testing on new Barrel yesterday with 103gn Copperheads and new batch of 4895 and they are cooking along speed wise for 5 shots with 28” barrel and Labradar:
30.4 avg 2997
30.6 avg 3013
31 avg 3041
Don’t know if it’s because I jammed them all .010” or a faster powder or the time of day I shot them that’s given me the variations in speed,Bergers were shot early morning Copperheads on dusk, can’t see a 2gn difference in bullet weight giving me that much more speed. Good news is groups were small as well as ES.

 

[KenOath]

how much less body do they have, less bore dia body, less bbl drag more speed ?

The 103 has a bearing surface that’s around .020” shorter than the 105...