Building a 270 short mag

[JBGrizzley]

So my most recent purchase was a Winchester Model 70 Extreme Weather SS in 270 WSM. I feel pretty good about it but i want to get more into customizing it if i can. Ive already got a Leupold VX-3i 4-14x40 30mm CDS scope and DNZ Game Reapers ready for it. Im pleased with the feel of the trigger as is but considering a Timney. It has the MOA trigger. Where Im hitting a roadblock is the barrel. I want to put a McGowan barrel on it, one to add some weight to it, and two i want a fatter barrel thats maybe shorter. So I want opinions on length (factory barrel is 24” i was wanting to cut down to 21”) and rate of twist (currently 1 in 10” was gonna stay the same with the McGowan but Im open to suggestions, my understanding of it is rate of twist is based off bullet size length and weight, however several different places on the internet lead me anywhere from 1 in 9” to 1 in 11”. Bullet will be a 130 grain Nosler Accubond) and as with the fatter barrel the channel in the stock will need to be bigger, the current stock doesn’t appear to have enough material in places for it to be cut for a free float with a bigger barrel, so Im considering a Bell & Carlson Varmint/Tactical or a Hogue Overmold. So whatever the final product comes out to be i would like to get cerakoted. Anyhow if you have any advice or suggestions on the parts post it up

 

[41magnum]

I did install #3 - #5 barrels for a heavy sporter back in my building days.
My personal .338 Win Mag wears a #4.
I used to install Shaw or Lilja or Shilen or Douglas for many of my customers, but nothing wrong with McGowen barrels, just their folks....25 yrs ago.
The barrel maker SHOULD help you with the twist.
I'd talk to a few, compare notes/prices, then decide, personally.
Cerakoting I believe also adds a little that the barrel channel will need room, unless I'm thinking of a different coating.
Sorry I'm not more help........I don't know much about these new composite stocks, I use wood, and if I want it heavy/wide I use laminated from Richards Microfit or Boyds.

 

[CBD21]

I put a shilen #4 contour at 25” long on mine and have been pleased with it.

 

[JJWise]

Cerakoting I believe also adds a little that the barrel channel will need room, unless I'm thinking of a different coating.

I don’t have any guns with cerakote personally, but I’ve heard the opposite. Cerakote is very thin and doesn’t really change dimensions of anything. My hunting buddy here has a 270WSM with a 22” barrel. It is VERY loud with a crazy muzzle blast and shoots about 100fps below advertised velocities. But if you reload you can probably mitigate a lot of the velocity loss by trying different powders, and 100fps isn’t going to make much difference anyways.