Sierra Gamechanger bullets.

[Deputy819]

@tbrice23
The average I got for the 6mm Sierra's was 1.162 (Hornady dial-caliper/not Mitutoyo )
Compared to the 6mm 87gr vld Berger's I have @ 1.06 they were quite a bit longer.

 

[Deputy819]

They may very well group great. Only one way to find out. I just tend to get a little disheartened initially when the sum of my numbers equals a word like "Marginal"....which sounds too much like "Doubtful"....which sounds too much like "SUCKS".

 

[Canhunter35]

Run the formula minus the plastic tip? It looks the same length if it wasn't for the tip

 

[Deputy819]

Yeah, I don't know. I wasn't sure if that tip could/should be considered a "phantom" part of the overall length of the bullet.

 

[Canhunter35]

See what it gives you for stability then try them and let us know. I'm betting they'll work. You own them anyways, might as choot'em

 

[JJMoody]

May have been mentioned, but aren't these "just" a Game King with a tip? I'd imagine most of the data for GKs oughtta work. I could be wrong.

 

[Gene R.]

I would love to see Sierra make a long, sleek, 170-175 grainer for, the .270 WSM that equals, the Berger 170 grain EOL at, .660 BC ! That would be a real, long range,.. "Game changer" !

I would be happy with a 160 or 165 that would be stable in a 1:10 with high .500 bc. Retain energy and buck wind for use in my factory 1:10 270 win, 270wsm. But we know the market won't dictate that for Sierra.
Gene

 

[den]

JBM - Calculations - Stability - JBM Ballistics
this one has an input for the tip length

 

[Deputy819]

Thanks! I'll go home and run that when I'm off the clock.

 

[highdrum]

I would be happy with a 160 or 165 that would be stable in a 1:10 with high .500 bc. Retain energy and buck wind for use in my factory 1:10 270 win, 270wsm. But we know the market won't dictate that for Sierra.
Gene

Most people have found the 165 matrix vld to suit your exact needs stated. Says they require a 1:9, but they work in 1:10 especially if there is a little elevation involved.

 

[Deputy819]

@den
The JBM model gave me a gyroscopic stability factor of 2.223. According to that I should be good to go. Now I just need to CHOOT EM!

 

[False]

Well now I know why they are 90 gr. I bought a box of the 6mm. The SMK 95gr shoot well and these have similar BC. With a 9 twist barrel, 90gr is probably the biggest they could go.

Does it say 9 twist on the box?

@tbrice23
The average I got for the 6mm Sierra's was 1.162 (Hornady dial-caliper/not Mitutoyo )
Compared to the 6mm 87gr vld Berger's I have @ 1.06 they were quite a bit longer.
View attachment 102800

 

[Deputy819]

No reference to twist rate on the box...

 

[False]

Interesting. The 95gr SMK 6mm specifies 9 twist.