best barrel length/twist for a long range .270?

[mattri]

Looking for a barrel to shoot .270 win acuratly out to 600 yards. Would like to shoot the heavier 150-160grn high bc bulets and the lighter 100-115 varmint rounds as well. Is there an optimal length to look for? 26, 28 30"? Is there a twist that would allow this large of a spread in weight? Thanks, Matt.

 

[ChrisNZ]

If you're going to the trouble of rebarrelling Matt and you want to use a long action/.473 rim, why not go 6.5/06? More efficiency/flatter shooting/less recoil/better bullet choice by far.

Chris-NZ

 

[mattri]

Looked at the 6.5-06 but have decided on the .270. Any suggestions re barrel length and twist?

 

[TonyR]

The Sierra Manual bases all of its 270 Win load data on a 26 inch barrel with a 1:10 twist for bullets between 90 and 150 grains. Same twist for the 270 WSM and 270 Weatherby Magnum. 24 inch barrel for the 270 WSM and 26 inch for the 270 Weatherby. I used a 1:8.5 for the 142 grain bullets in my 6.5X284 and I use a 1:9 for the 180 gr bullets in my 284 Shehane. You might be able to get away with a slower twist like a 1:11 which would work all the time for the light bullets if you only shoot the heavy bullets in warm weather or high altitudes. Berger lists a 1:11 for its .270 130 and 140 gr VLDs.

 

[kendoka66]

My two cent,s, I am now working with a Remington & 700 CDL with a 24" barrel,It loves The 130 and 140 VLD,s from Berger. I have been shooting a Savage long action mated to a Shilen barrel 1 - 10 twist 26" heavy barrel S/S. I have about 850 rounds thru it. It has been a good shooting rig. Trouble with the .270 is there are not a lot of match bullets to chose from.The rifle is a .270 WSM by the way. Our range is 500 meters only so that limits me to the shorter ranges. the 135 Sierra,Bergers130,140,150 is about it. The Sierra Game Kings shoot well also. I use RL.25 and Mag Pro mostly.

 

[mattri]

Great replies, thanks.

Am looking at a 26" SS barrel with a 10 twist.

kendoka66, have you tried the lighter bullets with that barrel?

 

[JabaliHunter]

26" 10 twist should be ideal for 150 VLD hunting bullets. Don't think I would go longer in a hunting setup unless you can get away with it by using a falling block action...

 

[RonAKA]

10 twist will be safe. You biggest issue with lighter bullets will likely be the throat length. You may want to consider a shorter throat that seats the long heavy bullets deeper, that still allows you to get the light short ones out to the lands.

 

[mattri]

Thanks for the good posts.

 

[Larryh128]

I used a pair of 270 wins for years as my main hunting rifles with kills to 446 yds on whitetail. 24-26 inch barrels will give you the best velocity. I mainly used 130 gr Ballistic Tips @3100 fps BUT 140 gr Accubonds @3000 fps were slightly more accuarate. Either IMR or Hodgden 4831 are really the best accuracy powders. Up to 57 grs (130) in IMR 4831 or up to 59.5 (130) in H4831. H4831 is preferable in cold weather so that was always my hunting choice. I personally wouldn't mess with 150's because you can't drive them hard enough to be anywhere near flat to 300. A 10 twist has been the best & probably an 11 twist would be slightly better for the 130gr or lighter.

 

[Obtunded]

Actually, your timing is good... There is a company out of Canada (Matrix Ballistics) that has started to produce high BC .277/6.8mm bullets in 165 and 175 grains.

I obtained samples of both and they are a very nice bullet. The owner of MB (Marshall) has been developing these in concert with a long range BR shooter and the early results are extremely impressive in terms of BC. The 175 has a BC (based on their 1000 yard tests) of .700

They were using a 6.5-284 case, so it is a 6.8-284. I imagine the vernerable 270 case would do a nice job with these, particularly the AI Version.

1:8 seems to the the optimal twist, but this is not standard twist rate for most 270 barrels.