7mm/08 twist

[cape cove]

I've decided to have my Browning BBR varmint barreled rifle changed. Throat is bad after 2800 rounds. My go to bullet has been the 168 Sierra MK in this 1/9.25 twist barrel and from a stone stock rifle it grouped .3-.4 MOA. Since I purchased this rifle in 1987 there have been many long for caliber bullets introduced. After using several twist stabalizer programs and plugging in many of the recent bullet weights and lengths I've come to a decision to get a 1/8.5 twist. My question is if I have to fall back to the 168 Sierra would this faster twist somehow compromise the accuracy of this bullet. Most of the twist programs would give me a optiomal twist of 1/9.7 for this bullet.
TKS

 

[elkaholic]

You will be fine with the 168

 

[MudRunner2005]

If you fall back on the lighter 168's, a 1:8 twist will be fine, and you can still shoot the 180 Hybrids and 195 Berger Elites.

Are you going to go with a varmint contour barrel? Your factory wood stock's fore grip can be opened up enough to handle a varmint contour with no issues. Some say it can't be done, but they don't seem to remember when Browning offered rifles with Christensen Arms carbon fiber full-bull large diameter barrels in their factory stocks back around 2000-2001.

 

[cape cove]

Thanks for the input guys.
Yes I'll be going with basically the same varmint contour as I had. I believe it's appx .890 at the muzzle. My stock is in great shape that's why I want the same contour, and aftermarket short action stocks for the varmint barreled Browning BBR are rare.

 

[cape cove]

My barrel maker has asked if I would rather have a 4 or 6 groove barrel. What are your thoughts on this.

 

[desertcj]

If it's a 4 groove ratchet rifled, that's what I would do over a standard 6 groove. I would take a 5 groove over either though. The practical differences are highly debatable and you may or may not even notice a difference from what I gather.

 

[MudRunner2005]

My barrel maker has asked if I would rather have a 4 or 6 groove barrel. What are your thoughts on this.

Tell him you want a Bartlein 5R 1:8 twist.

 

[cape cove]

Thanks again guys for the input
MR 2005
The individual ( J C Custom) doing the work for me makes his own barrels so that excludes a Bartlein but I will talk to him about the 5R rifling. Why would you choose this over a 4 or 6 groove barrel TKS

 

[desertcj]

Thanks again guys for the input
MR 2005
The individual ( J C Custom) doing the work for me makes his own barrels so that excludes a Bartlein but I will talk to him about the 5R rifling. Why would you choose this over a 4 or 6 groove barrel TKS

Does he really gun drill and rifle his own blanks? I find that hard to believe. If he won't use whatever blank you ask for, I would look for a new gunsmith. 5 groove rifling may produce less engraving pressure with the bullet as there aren't two opposing lands engraving on the bullet. 5 groove has a land facing a groove. The R in 5R means that the lands are ramped. This is along the same lines of less engraving pressure.

 

[cape cove]

Yes this guy is a barrel maker He sells most of his barrels to gunsmiths and doesn't normally do builds. He done a 25/06 for me last year. Great job and barrel. Very accurate. he lists 4 and 6 groove barrels for the .284
https://www.jccustombarrels.com/

 

[desertcj]

OK. If your set on using him and one of his barrels. Pick one. I'd probably just stick with 6 groove.

 

[cape cove]

TKS
Like I said i've used him in the past and he respects a deadline and did a great job for me.. I also know of others that really like his barrels. MR 2005 likes your post as well so a 6 groove it will be. I really appreciate you guys opinion.

 

[MudRunner2005]

6-groove has been the standard for many many years for most major manufacturers. I don't really think you can go wrong with anywhere from 3 to 8 grooves. Personally, I like and prefer 5R rifling, but I have plenty of hand-lapped 6-groove factory Remington barrels that shoot lights-out, too.