Twist for 140 Amax

[oldfatguy]

Trying different bullets in a 260 Rem with a 1:8.5 twist barrel. The label on the box of 140 Amax says they require a 1:7.5 twist rate. Anyone used them in a 1:8.5?

Thanks,

OFG

 

[427Cobra]

Re: Twist for 140 Amax

Your fine, my 1/8 twist 260 shot them very well .015 off the lands

 

[turbo54]

Re: Twist for 140 Amax

8.5 does the 140amax and 140hpbt at ~2750 through my 22.5" 260 right nice.

 

[oldfatguy]

Re: Twist for 140 Amax

Thanks for the replies. Now to pick a powder to start. Probably H4831 SC.

OFG

 

[Rob01]

Re: Twist for 140 Amax

H4350. It's the go to powder for the 260 and 6.5 Creedmoor.

 

[oldfatguy]

Re: Twist for 140 Amax

Thanks Rob. Have a pound of H4350 per the Hodgdon manual for the 142 SMKs, but neither the Hornady nor the Nosler manuals have any 140gr loads listed for H4350.

OFG

 

[Rob01]

Re: Twist for 140 Amax

Use the 142 data and work up. Also look up in the Reloading Depot at the top of the page and look in the .260 load thread.

 

[luvtolean]

Re: Twist for 140 Amax

It should shoot fine on a typical AL day but it can get slightly on the edge for stability factor depending on DA.

Mess around with twist in Shooter and you'll see it.

 

[oldfatguy]

Re: Twist for 140 Amax

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body">Use the 142 data and work up. Also look up in the <span style="color: #CC0000">Reloading Depot </span>at the top of the page and look in the .260 load thread. </div></div>

This is the most useful thing I've learned about in a very long time.

Thanks,
OFG

 

[Jig Stick]

Re: Twist for 140 Amax

an 8 twist has the best stability factor for 140s

 

[JWV]

Re: Twist for 140 Amax

I exclusively shoot the 140 Amax out of my 260AI. I use an 8 twist CBI barrel and use 42gr of H4350 (fairly light load) and COAL to 2.835. I do believe the velocity was around 2860 fps. I think your 8.5 twist will be alright. Just get some velocity on them.

 

[majohnson2]

Re: Twist for 140 Amax

I went through the same a few months ago, never found the answer. Maybe you can find the reason. I don't think it C.Y.A.

http://www.snipershide.com/forum/ubbthre...183#Post3391183

 

[leadbullet]

Re: Twist for 140 Amax

I have an 1-8 twist benchmark barrel that shoots the 142 SMK and 140 Amax the same at 950yds with 43.5 gr of H4350 in lapua brass, .015 off the lands.
reloading for the .260 is very easy and this caliber likes almost everything.

 

[Paulyr450]

Re: Twist for 140 Amax

In my 260 with an 8 twist barrel it shoots the 142 smks,139 lapuas and the 140 smks really good. I tried the 107 smks and they sucked. I use h4350 like everyone else. Good luck

 

[BoilerUP]

Re: Twist for 140 Amax

260 and any 139-142gr bullet:

42.0-43.5gr H4350

Works good, lasts a long time

 

[bama1]

Re: Twist for 140 Amax

My 1 in 8 will not shoot 140's of any kind. I can drill Berger 130 and 139 scenars but amax, sst, Sierra gk or 142's mk will not get below .8. Period.