Twist and Shout.... Or Weep

[Jcinnb]

OK,

I finally, on a whim, decided to measure my 25-06 twist, after reloading for almost a year.

I know.

I watched YouTube, broke out the cleaning rod, patch and tape.

Six measurements averaged 12.13"

So I am going out on a limb and say I ave a 1:12 twist rate..

From what I have read in the last two hours, this twist rate is best for bullets less than 100 gs, and even 100 is a stretch. Admittedly my best groups were some Nosler, I think 90s, but.....

115BT Noslers were a very, very close second. Does not seem to track with conventional wisdom. You know what they say, Ignorance is Bliss.

Do you guys think the same as regards an upper limit on bullet weight with this twist in the 25-06 caliber.

Better yet, what do you think, in plain terms for the simpletons among us, about 25-06 twist rate and bullet weight. I know I don't know.

Thank you very much!

 

[juk]

Most people say that a 1/9 AR barrel won't stabilize the heavier 69+ grain bullets. I've seen a few that shoot the heavier bullets well. I guess a bit depends on the bullet. For the most part though, the twist rate will dictate which weight grain bullets will shoot the best.

 

[rbernie]

Stabilization is caused by rotational RPM, effectively, using gyro effects to overcome aero effects and all sorts of other fun forces. You can alter the RPM by using a faster rifling twist per linear measurement, by driving the bullet itself through the rifling faster, or via a combination of both.

The RPM needs for a given bullet are influenced by its shape and length moreso than weight or any other factor. We commonly use weight as a simply way of viewing the problem, but the ogive shape, base shape, and all sorts of other factors can easily make liars of that simplistic view.

In short, bullet weight recommendations are just that - recommendations. One barrel might be fast enough to shoot a given bullet well then a seemingly identical gun's barrel will not. Boat tails will commonly cause issues at the raggedy edge of supersonic stabilization when flat base bullets of equal weight will not. VLD ogive designs will behave differently than less aero friendly bullets of equal overall weight.

You probably won't find 120gr pills to work well for you, but I'd expect 100gr to be fine as long as you keep the velocity up. If you can get 115gr BT's to work for you, then you're golden.

All you can do is try things and see what works.

 

[918v]

When you're on the verge of instability, changes in weather and elevation may ruin your day. Keep that in mind before you have a very expensive hunt ruined by a tumbling bullet.

 

[41 Mag]

Just curious as to the make of the rifle and or barrel which is on this rifle. In most cases with the 25 barrels I have dealt with they have all been in the 1-10 range. When I built my 25-06 AI I had the barrel made with a 1-9 twist to be sure I could stabilize the heaviest bullets I wanted to use. I can shoot custom bullets in the 130gr range just as accurately as I can 85gr bullets however I don't use anything lighter than 115 in it, with my standard loads being 120gr.

Unless your rifle was set up for varmint hunting and specifically to use the 80'ish grain or so bullets I don't know why it would be such a slow twist. That however is why they make custom barrels and such.

If one is building a custom rig you can go with what ever the barrel maker will allow, but in most cases one usually wants to go a bit faster than necessary. You can shoot the lightest bullets in a fast twist and usually get good accuracy to a point that velocity will start to take a toll, as well as longer heavy bullets. The opposite isn't always true however, where you get great results with light bullets in a slower twist but cannot achieve the velocity necessary for the heavier longer weights.

 

[Jcinnb]

Just curious as to the make of the rifle and or barrel which is on this rifle. In most cases with the 25 barrels I have dealt with they have all been in the 1-10 range. When I built my 25-06 AI I had the barrel made with a 1-9 twist to be sure I could stabilize the heaviest bullets I wanted to use. I can shoot custom bullets in the 130gr range just as accurately as I can 85gr bullets however I don't use anything lighter than 115 in it, with my standard loads being 120gr.

Unless your rifle was set up for varmint hunting and specifically to use the 80'ish grain or so bullets I don't know why it would be such a slow twist. That however is why they make custom barrels and such.

If one is building a custom rig you can go with what ever the barrel maker will allow, but in most cases one usually wants to go a bit faster than necessary. You can shoot the lightest bullets in a fast twist and usually get good accuracy to a point that velocity will start to take a toll, as well as longer heavy bullets. The opposite isn't always true however, where you get great results with light bullets in a slower twist but cannot achieve the velocity necessary for the heavier longer weights.

I do not know. I got the rifle off gunbroker, it is built on a Mauser action, the barrel is 24". I have learned so much about twist in the last week...I have to assume the rifle was built as a varmiter, based on the twist. I am thrilled with it as a shooter, no complaints at all, but I want to "know it all."

I have checked the twist two more times since my first post, and it is clearly 12:1. I do not know what type of barrel it is, or from whom purchased. I think I will break it down this afternoon and find out.

 

[Swampman]

It really doesn't matter what the BOOK says.

What matters, is what the RIFLE says.

In any case, if your rifle will shoot a 115 grain Ballistic Tip (length 1.207") with a boattail accurately, it oughtta shoot a 115 or 120 grain Nosler Partition (lengths 1.145" and 1.175" respectively) with a flat base, accurately as well.

This, pretty much means that, unless you hunt in California's "condor zone", you're set for anything that's sensible to hunt with a 25-06.

If you're sure the light bullet that cut your best group was a Nosler, it was probably their 85 grain ballistic tip varmint bullet, which performs great on varmints in my .257 Bob Ackley.

Either the 115 or 120 Partition will really flatten large hogs and if you're a fan of the 115 grain Ballistic Tip for big game hunting (I'm not), it'll hold good accuracy, velocity and energy out to as far as anyone could reasonably expect a 25-06 to be used for hunting.

Try your rifle out with the Partitions and if it shoots them as well as I think it will, you're set!

 

[joed]

Accept the rifle for what it is and shoot what it likes. There is no sense taking it apart as you may not find a name on it. I have a Krieger that is not stamped.

The fast twist barrels have been vogue ever since the military tried to breath new life into the 5.56 by getting it to shoot heavier bullets. Now anyone with a rifle wants a fast twist because they also want to shoot the heaviest bullet they can because heavier ones usually have the best bc.

What rifle owners should be doing is decide what they want to use the rifle for, than choose a bullet and twist.

If you have a fast twist your rifle may not shoot the lighter bullets well. None of the ones I owned shot light bullets as well as the heavier ones. I sold a really nice Savage rfile because it would only shoot a 69 gr match bullet accurately when I bought the gun for groundhog hunting with lighter bullets.

 

[41 Mag]

Well 1-12 it is, as mentioned it's nothing to worry about, it is what it is.


You should easily be able to work loads up using the 115's and possible even the heavier bullets, the good thing is your probably going to gain a touch of velocity to those type loads due to less restriction as the longer bullets head out the barrel.

With my AI version I considered going standard 1-10, but I knew from experience that at the longer ranges the heavier custom bullets I have don't hold their groups simple due to the velocity not being high enough to begin with. I went with the 1-9 to give them more spin, as well as a 28" barrel to gain al lthe extra velocity I could. All that said, I didn't build that rifle for a 100 - 200yd gun, I built it to reach out 5-600yds across my back pasture and still have enough whallop to put a big feral hog down. I can easily hit the mid 3300's with any of the 120gr loads I have as well as with the bonded 130gr bullets. I have some 142' as well, but simply could not get them up fast enough to stabilize with this particular case. It just don't hold enough powder.

Anyway good luck with yours, it should treat you right. I have always loved both my standard and now my newer AI version. THey are accurate and hit hard, and will take care of anything I am going to hunt.

 

[Jcinnb]

Hey, don't get me wrong, I love my rifle, just interested to know what is going on as I learn more.

I have loaded the all the bullets I have

75, 80, 85, 87, 90, 100, 110, and 115, Five rounds each. Max precision on brass as well as powder. Have them in a box, and ready to go. Probably Tuesday morning. Taking my .22 DSM (German trainer) to shoot between rounds.

My plan is to shoot, spotting scope, record, shoot the .22 until 4 minutes are up, then shoot again. Should be a 1/2 day event. Hopefully, something will jump off the page.

 

[greyling22]

barrels are like women: there are some rules of thumb, but in the end they're all different, and what works for most may not work for yours.