.260 Remington Barrel Twist Questions

[fredr1980]

I'm in the process of putting together a DPMS LR-308 rifle in .260 remington and had a few questions about the Black Hole Weapondry 1:9 twist barrel in the caliber. I'm planning on mostly target shooting in the 500-800 yard range nothing crazy just hitting some 10" steel gongs out to that range, maybe farther once I get better at precision shooting but for now it will be in that range. I picked up some 142gr Seirra MK and some 139gr Scenars, based on what I have researched these seem to the the best for getting out to 800yards, have the best BC and wind would play less havok on these heavier bullets at those ranges. I've also researched barrel twists and it seems that these longer heavier bullets from Sierra and Lapua need a faster 1:8 twist in order to stabalize. My question is would Black Hole Weapondry's 24" 1:9 twist .260 Remington stabalize these heavier bullets or is this barrel best for lighter 120gr or less bullets? Please let me know what your opinions are on these barrels and twist.

EDIT: Forgot to add that I will be reloading my own ammunition. Been reloading for a while, so I should be able to get the best performance out of these bullets with the right barrel.

Thanks,
Fred R.

[Deleted]

No.
Recommended twist is 1:8. Solid CNC bullets need 1:7 or 1:7.5 but they take too much case space in the .260 rem. In any case it is not a bad idea 1:7.5 to reach a higher stability factor. Angular momentum wears off too so as you approach transonic range there is less of a jittery trajectory with the heavier loads.

[Deleted]

Sept 21, 2012 20:50:02 GMT -8 @sergiomartinez said:

No.
Recommended twist is 1:8. Solid CNC bullets need 1:7 or 1:7.5 but they take too much case space in the .260 rem. In any case it is not a bad idea 1:7.5 to reach a higher stability factor. Angular momentum wears off too so as you approach transonic range there is less of a jittery trajectory with the heavier loads. [/quote

How would you know? Have you personally shot a Black Hole 260 Rem?

I don't agree on the Angular momentum theory. Once a bullet is stabilized it does not become unstable until it goes subsonic.

[Deleted]

How would you know? Have you personally shot a Black Hole 260 Rem?

Yes I have. 308win as well.

No theory here, all practice and hard earned life long results.
As you approach transonic range the bullet starts to yaw and creates a
jittery trajectory specially the long range VLD and hybrid bullets they need more spin. A stabilization factor of 1.2 minimum is necessary but a bit more not a bad idea.
I would not do anything less than the recommended minimum by the bullet manufacturer that in this case for the OPs purpose would be 1:8.
Here is an example with the minimum recommended twist...
bergerbullets.com/Products/All%20Bullets.html

[Deleted]

Sept 22, 2012 7:48:44 GMT -8 @sergiomartinez said:

How would you know? Have you personally shot a Black Hole 260 Rem?

Yes I have. 308win as well.

No theory here, all practice and hard earned life long results.
As you approach transonic range the bullet starts to yaw and creates a
jittery trajectory specially the long range VLD and hybrid bullets they need more spin. A stabilization factor of 1.2 minimum is necessary but a bit more not a bad idea.
I would not do anything less than the recommended minimum by the bullet manufacturer that in this case for the OPs purpose would be 1:8.
Here is an example with the minimum recommended twist...
bergerbullets.com/Products/All%20Bullets.html

It has been my experience that twist rate charts are not always correct. There are to many variables to make them 100 percent reliable. Experimentation is the only way to prove or disprove your barrel.

[Deleted]

I agree there is no substitute for actual experience but also I do believe that at a minimum following the bullet manufacturer's recommendation it is the way to go.
In the end is not like we can 'test drive' every barrel before we buy it and it is better to be on the safe side.
So one should first consider what bullets one is going to use, what is the true purpose and then decide on the rest from the casing to the barrel and type of system needed to deliver that mail.

[GLSHOOTER]

Sept 23, 2012 18:51:09 GMT -8 @sergiomartinez said:

I agree there is no substitute for actual experience but also I do believe that at a minimum following the bullet manufacturer's recommendation it is the way to go.
In the end is not like we can 'test drive' every barrel before we buy it and it is better to be on the safe side.
So one should first consider what bullets one is going to use, what is the true purpose and then decide on the rest from the casing to the barrel and type of system needed to deliver that mail.

All well and good the big thing I look at is the recommendation of the manufacturers and then I will expend a bit of money and see for myself. I'm finding that just because the box says a 1:8 will work it is sometimes right and sometimes wrong. Velocity of the bullet will determine that the bullet may or may not work.

The luxury of getting old is that we have years to learn from experimenting. I'll certainly go off without a lot of guidance but a little rationale thought will help in any application.

Greg

[Brandon Sneed]

Sept 23, 2012 18:51:09 GMT -8 @sergiomartinez said:

I agree there is no substitute for actual experience but also I do believe that at a minimum following the bullet manufacturer's recommendation it is the way to go.
In the end is not like we can 'test drive' every barrel before we buy it and it is better to be on the safe side.
So one should first consider what bullets one is going to use, what is the true purpose and then decide on the rest from the casing to the barrel and type of system needed to deliver that mail.

Agree. Considering gyroscopic stabilization is a fundamental law of physics, there's at least a min point we go from. I'll admit that the poly rifling of a BHW barrel provides anew variable that is slightly different than an enfoeld or even another poly rifling style, however we're going to see the differences at distance (ie the transonic distance) rather than while still supersonic.

And of course you add an additional variable when wildatting a round (projectile specifically) at speeds it wasn't previously designed for. Things get interesting then.

Lots of fun there!

[Deleted]

Those are all good points.
I was going by the specifics posted by the OP. 142gr SMK and 800 yards and beyond. That is long range.
One can always consider the 123 Amax and 123 scenar that are great bullets and shoot flat but in 260 LR loads the 140 grainers are the norm.

[Brandon Sneed]

Sept 24, 2012 6:43:41 GMT -8 @sergiomartinez said:

Those are all good points.
I was going by the specifics posted by the OP. 142gr SMK and 800 yards and beyond. That is long range.
One can always consider the 123 Amax and 123 scenar that are great bullets and shoot flat but in 260 LR loads the 140 grainers are the norm.

Very true. I think that the twist rate of a Poly rifled barrel will stabilize a bullet a little differently due to the coeff of friction that affects velocity. The danger I see with this is under stabilization which results in key holes. Some have no issue with over stabilization but tht issue at distances we refer to above create a set of outcomes undesirable.

When I get my 260 barrel back from the t&e that crusader weaponry is doing to it at 1000-1200 I'd be anxious to test some of this as well.

Maybe there's something amiss with Ops barrel.

[Deleted]

Nothing beats actual field testing that is for sure.
As I said the norm is 1:8 minimum in 260rem tube guns and whether is Lothar Walter, Scheneider or even Pac-Nor poly rifling.

[fredr1980]

Thanks for all the information. I haven't checked the site in a few days. I think I'll be going with a .260 Remington BHW barrel as I have contacted sales and they stated that they should be able to have one made with a 1:8 twist.

Thanks again,
Fred R.

[dr69er]

Like 1shotzero said always go with the faster twist rate especially if you plan to use VLD style pills...
It is very unlikely to over stabilize a long VLD projectile...While at higher velocity twist rate can be
slowed down a bit without to much Ill effect, but at longer ranges you will likely need the faster twist.
Just my two cents, thanks.

[Deleted]

I know the OP has had his 1 in 8 for a while now. Considering this thread is a year old tomorrow.

[Old Desert Rat]

Sept 26, 2013 15:58:25 GMT -8 @rjohnson said:

I know the OP has had his 1 in 8 for a while now. Considering this thread is a year old tomorrow.

There's my dilemma.  I want to build a .264 black rifle for long range shooting, which means 500 and out, since my little AR in 223, pushing out 69 SMKs, shoots under an MOA out to 600).  That means I'll be shoving 138+ gr. bullets out.

This thread has all members in violent agreement that only demonstration answers the twist/stability question, especially since poly rifling may introduce a variable into the classic twist equations.

But nobody has posted in over a year, and as of the end of the posts, nobody had actually gone out and SHOT anything (at least that they posted about)!

C'mon, has nobody on this site actually shot a 260REM with heavy VLD bullets for groups?  What happened?