More 6BR newbie questions !

[dawgmaster]

I'll start off with a quick explanation of my situations, and then hopefully get some great feedback from you pros!

I want to start F-Class shooting this year...I have 2 semi-custom Rem 700s. Unfortunately, I just rebarreled my 6MM AI with a new 1in12...and now see I wish I'd gone with a 1in8".

My other 700 is a 22-243 Midd and I will change it into a 6BR in the next year.

My plan was to build a 6BR with a 1in10 for short-mid range. (shooting 80-95gr bullets) My smith thought best to go with a 1in8.
My plan on the 6MM AI was to eventually go 1in8 to shoot long range f-class with 95-108grnrs.

Do these seem like the right choices or do alot of short-mid range 6BR guys shoot with 1in12??

I'd perhaps just rechamber the 6AI to 6BR with the existing 12 twist...however I had 200 formed cases before the new barrel and now my headspace changed so I'm forming new brass as I go, so I figured I'd only shoot short-mid range f-class this year and form brass as I go.

Any advice or perhaps a better idea for getting the two calibres up and running?

 

[RonAKA]

I'm no expert, but I think the general logic is to pick your distance priority first, then pick your bullets, and last the bullets picked will tell you the twist - slowest twist that still stabilizes the bullet. Up to 200 and possibly 300 yards lighter flat base bullets likely have the edge. At longer distances you want the highest possible BC to minimize wind drift. The Berger bullet site has BC and minimum twist for each bullet. That is a good place to go next after you have settled on distance.

http://www.bergerbullets.com/Products/All%20Bullets.html

 

[dreever]

I agree with your Smith, go with the 1 in 8 which gives you the option to use the heavier bullet weights. I use 105 VLD's at all yardages in an 8 twist.

Danny

 

[MarkS]

8 tw would be best. If you want the extra punch for 1000 yds go with a 6 Dasher or 6BRX.

Mark Schronce

 

[SS427]

I agree with RonAKA. Figure out the distances and the bullet you plan to use and select your twist based on that. If you are never going to shoot a bullet heavier than say 80 grains, there is no reason to get an extremely fast twist barrel. This article written by Danial Lilja and posted on the Lilja website is why I think this. You can gets lots of opinions from who knows who off the Internet....but I just have a feeling Danial might be a little more credible.

http://www.riflebarrels.com/articles/bullets_ballastics/bullet_imbalance_twist.htm

If you plan to shoot a heavier bullet, or even think you might shoot a heavier bullet, get the faster twist. If not, go with the slower twist. There is a reason the benchrest shooters don't go with anything faster than about 1:13 twist with thier PPC rifles and that is because the slower twist is more accurate.

 

[Kenny474]

Most F-Class is 300yds and out as far as I know, so an 8 twist will be fine for it. Yes, you may get a touch more precision at short ranges (100-200yds) from a 1-12 to 1-14 twist, but you are also limited in bullet weight.

Go with a 1-8 for the 6BR, or consider a Dasher if you want to shoot to 1000yds. If you are only going to 600yds, a 6BR will do OK, but will start to lack a little at 1000yds.

The 1-12 6AI might be just the ticket for 300yd shooting with the right bullet. The screaming speed will make up for the lost BC at that range.

My opinion, or what I would do, develop a nail-driving load for the 6mmAI to use at shorter ranges, and chamber a 1-8 twist Dasher or BR for the longer stuff. I think the consistency of the BR case will pay off as ranges stretch and will be more consistent than most bigger 6mm rounds. But for shorter stuff, the 6AI may prove to be a great choice, as long as you can get it to be accurate enough. Then use the 6AI for 300yds and out to possibly 500yds if it will hold up that far, and use the Dasher/BR with 105-108's for 600yds and out.
You will have a very good combo this way, with a high velocity short range round, and a very consistent round pushing a high BC bullet for long range.

Good luck
Kenny

 

[dawgmaster]

Thxs guys,

All the advice is good...keep it coming!

Glad to get the opinion from kenny474...cause I'd hate to overlook or tear what might be a perfectly good combination apart. I was thinking more the 6AI would make the better long range rifle due to extra powder. But perhaps he's right on leaving it as is and rigging up a 6BR for long with the 8 twist.

 

[Erik Cortina]

No need to have two 6mm rifles! Specially if one of them is for long range! If you are going to use two rifles, keep you 6AI fir 300 then chamber the second for a 500 yards and out. A .284 Win is accurate, very competitive, and easy to load for. If not, then just forget the 6AI idea and build a Dasher with 1:8" twist that you can shoot all the way from 300-1000 yards. You will have a hard time making your 6AI shoot better than a Dasher even at 300 yards!