Swiss arms and barrel twist

[IntelGDR691]

Hello everyone,

I just bought a new Black special and I'm wondering what is the best ammo suggested (brand, bullet weight...) for the 1/10'' twist barrel.

I actually don't reload, but I'm planning to do so in a few months.

Thanks.

 

[MKb42]

gp90

 

[IntelGDR691]

Excuse my ignorance, what is the in weight of the GP90?

Is there an american equivalent...? (Win, hornady, fed...etc)

 

[MKb42]

all information easily accessible with google.

 

[blckgnznstuff]

GP90 is a 63 gr bullet. Good stuff. The Black Special was made to use it. "Swiss Ordinance" carried by The shooting Edge is the commercial version.
Trying to simulate the round in hand loads has been problematic for me. Maybe someone with more hand loading experience with the Black Special could chime in.

 

[mrsmitty]

55 or 62 gr should be good

 

[nickorette]

Your best bullet for these is the 52 or 53 grain seirra matchking bullets. All bullet weights above 55grains will give you sub-par performance unless you have the 1 in 7 twist barrel.

God knows why the Swiss 62 grain bullets work wonderfully, but every other combination of match 60+ grainers out there shoot like ####.

 

[esquif]

gp90 is the stuff made for the gun and will let it really shine

 

[Farlsincharge]

Your best bullet for these is the 52 or 53 grain seirra matchking bullets. All bullet weights above 55grains will give you sub-par performance unless you have the 1 in 7 twist barrel.

God knows why the Swiss 62 grain bullets work wonderfully, but every other combination of match 60+ grainers out there shoot like s**t.

These are my findings as well. I have had good luck with 55gr sierra spitzer boat tails. I have an average group at both 100 and 200 yards of 1.28 moa with many groups under 1 moa. Usually there is one flier that screws up an otherwise amazing group.

I find the swiss isn't very fussy as even surplus 55gr fmj's are around 2 moa, and the different powders and bullets I try don't provide very different results.

 

[beltfed]

I've seen excellent results with the 60 gr. Hornady V/AMAXs from a 1/10 twist

 

[Guerrilla]

MKb42

gp90
all information easily accessible with google

.

WOW ONLY TEN POST IN AND I CAN ALREADY TELL YOUR A #### CANT WAIT TO HERE WHAT COMES OUT OF YOUR MOUTH NEXT...

 

[unibomber]

55 or the Swiss 63 gr are great, and cheapest!and probably the most available, but you can shoot up to 69gr bullets in that twist.... according to Sierra info.

 

[beltfed]

...but you can shoot up to 69gr bullets in that twist.... according to Sierra info.

I had decent accuracy with the 69 gr. SMK until about 300m - after that they quickly fell apart. Those were loads I originally made for my ARs though, and I didn't invest too much time perfecting a 69 gr. load specific to the Sig, as I swapped the barrel for a 1:7.
Incidently, the 69 gr. SMK is almost identical in length to the GP90 round, so they should be excellent performers in the Sigs.