7mm/08 1:11.5" twist

[Con]

Guys,
When was the change made from 1:9 1/2" to 1:11 1/2" twist in the 7mm/08 ... particularly the Stevens 200.

Where the stagger feed Stevens 7mm/08s faster or slower twist?
Cheers...
Con

[DGD6MM]

Change= afew years back. Faster twist 1-9.5.

[Cycler]

It was at least three years ago and no one knows why. Savage refuses to explain their reasoning despite numerous e-mail, phone and snail mail requests from me and other forum members.

This topic has come up several times in the past with the same conclusion; we don't understand why they did it and they won't say.

[Con]

Okay, a few weeks back a friend bought a new Stevens (actually 3) ... and one was a stagger feed 7mm/08. Barrel is coming to me, so I'm hoping its a 1:9.5". If its a 1:11.5" ... I'll shoot some groups with 175gr Woodleigh and if they tip ... send the targets to Savage with a 'please explain' letter. ;) I'm in Australia, and the importer apparently got hold of a large shipment, seems a few older stagger feeds were in there.
Cheers...
Con
PS: Has the Stevens 200 been discontinued in USA?

[Jamie]

If its a 1:11.5" ... I'll shoot some groups with 175gr Woodleigh and if they tip ... send the targets to Savage with a 'please explain' letter. ;)


I am sure they will explain it by telling you the twist is too slow for that length bullet and to try something in the 140 grn range.

[hotbrass]

+1

Stevens 200 is alive and well.

[Con]

I am sure they will explain it by telling you the twist is too slow for that length bullet and to try something in the 140 grn range.


So can they recommend a 140gr projectile for elk sized game shot at anywhere from 10 yards to 300yards and often in thick scrub? Most shots are well under 100 yards, angles often cant be chosen and shot placement can be dicey in scrub. ;) ;D
Cheers...
Con

[hotbrass]

Your the one getting the barrel. If you want to hunt elk size game or use heavier bullets, then you are probably getting the wrong barrel if it is 1:11.5. Which is your problem, not Savage. ::)

[Jamie]

U would think anything in the 130-140 range that said Barnes or Partition would be enough. If that is not heavy enough order a barrel with a faster twist.

[DGD6MM]

I had a 1-9.5 laying around till about 2 weeks ago, sold it to CoverDog over on 6BR. I have a brandnew Steven's centerfeed 7-08 with 1-11.5 twist. I know it will do what I want. I agree with Jamie on the 130-140 grain bullets.

[Cover Dog]

DGD6MM....nice barrel, the first thing I did was double check the twist. As you said 9.5. I haven't shot it, just cleaned it, but it looks to be a nice barrel.

[diriel]

Any of you ever hear of JBM? It is a free online ballistics program, that also has a bullet stability calculator. This is put together by Bryan Litz. I just ran the numbers on an 11.5 twist barrel at top velocity. Care to guess what I found? The 140gr barnes Tripple shock will not really even stabilize at 100 deg F. at sea level. Now if you pile on some additional temp and a LOT of elevation above sea level it will just barely stabilize. What it amounts to... Savage messed up real bad. This is not some good ole boy spouting crap, this is some of the brightest minds around; scientifically saying: No-No bad Joo Joo!

http://www.jbmballistics.com/ballistics/calculators/calculators.shtml

Run the numbers for yourselves. What it amounts to...the Savage 7mm-08 is setup as a VARMINT RIFLE Only.... serious hunters need not apply.

Happy Hunting!

[Con]

My interest is academic ... my Stevens already has 243Win/308Win and 358Win barrels. I grabbed a 7mm/08 at a cheap price ... but despite it being 2010 ... the barrel came off a new staggered feed Stevens. Old stock that was shipped to Australia no doubt. Maybe I've lucked into a 1:9.5" ... I'll know better next week.

But the twist is wrong ... lead will not last forever in ammunition and as noted the 140gr monolithics are in theory pushed by the 1:11.5", even the 120gr TTSX may be marginal. If I use it ... heavy game will be chased with a 140gr Nosler Partition which I know will work.
Cheers...
Con

[hotbrass]

Any of you ever hear of JBM? It is a free online ballistics program, that also has a bullet stability calculator. This is put together by Bryan Litz. I just ran the numbers on an 11.5 twist barrel at top velocity. Care to guess what I found? The 140gr barnes Tripple shock will not really even stabilize at 100 deg F. at sea level. Now if you pile on some additional temp and a LOT of elevation above sea level it will just barely stabilize. What it amounts to... Savage messed up real bad. This is not some good ole boy spouting crap, this is some of the brightest minds around; scientifically saying: No-No bad Joo Joo!

http://www.jbmballistics.com/ballistics/calculators/calculators.shtml

Run the numbers for yourselves. What it amounts to...the Savage 7mm-08 is setup as a VARMINT RIFLE Only.... serious hunters need not apply.

Happy Hunting!


Its not the weight its the length and distribution of mass that dermines twist requrie. Barnes are all brass and are therefore longer than regular lead bullets.

11.5:1 will stabilize lead normal 140 grain boat tails and spitzer bullets. I just go through reading Litz book. Good read for ayone intested in learning about ballistics long range or short.

[diriel]

Yes. It is a combination of Bullet Length, and weight. Mainly the length. Temperature, and elevation above sea level also affect bullet stability. I do not have the book, but have done extensive RL and Web related research. JBL has quite a bit of info linked on it that pertains to this subject. Feel free to play with the JBL stability calculator, it is enlightening.

[hotbrass]

Got the software.

Read the book and you wont use the term "weight" in the same way ever again since it is the least important factor in stability.

[Jamie]

Its not the weight its the length and distribution of mass that dermines twist requrie. Barnes are all brass and are therefore longer than regular lead bullets.

11.5:1 will stabilize lead normal 140 grain boat tails and spitzer bullets. I just go through reading Litz book. Good read for ayone intested in learning about ballistics long range or short.



HB is correct, it is the length that determines stability needs and Barnes bullets are usually longer than most others per given weight because they do not contain a lead core. Example would be the 50 gr Barnes VG bullets. Barnes says they need at least 1:10 to stabilize. I started to mention it in my earlier post but most of the time too much info just starts up arguements.

[diriel]

/shrug, 11.5 twist 7mm barrel is still strictly for VARMINT shooting, as it simply will not suitably stabilize hunting weight bullets WELL :)

HB I am not arguing with you. You say Tomato, I say Tamato. Do the math and tell these folks what an 11.5 twist barrel is good for.

Have a good one

[DGD6MM]

I bought my 7-08 to shoot 120-140 grain bullets, mostly 120 range. Like I said, I know it will do what I want. I also believe I can get a 140 to shoot 1moa. Anyone else? This is a hunting rifle and not one of my target rifles. I strive for the utmost accuracy that I can get out of any of my barrels. I knew what the 1-11.5 was about be fore I decided to get rid of the 1-9.5. There is always after market for those that believe they need a faster twist. ;D

[diriel]

DGD,

For a 120gr flatbase bullet you are mostly stable in that 11.5 twist. Much beyond a 120 flat base and under most circumstances you will be just barely stable, if stable at all. You WILL begin to see some key-holing in the 140gr bullets as you approach Sea Level, and the temps drop much below 80 deg. F.

HB stated a couple things that are true, but he did so in a way that purposely obscures things more than helps. These are some facts guys:
-- Most of the time: a greater amount of WEIGHT will equal a Greater Amount of MASS.
-- A greater amount of mass will make for a longer bullet most days.
-- A longer bullet is definitely harder to stabilize, and requires a tighter barrel twist to do so.
-- Temperature definitely will affect stability. The higher the temp, the easier it will usually be for a bullet to stabilize. A bullet that is "stable" at 120F. may very well not be stable at -40F. OUT OF THE SAME GUN, WITH SAME AMMO!
-- ASL = Above Sea Level. The higher above sea level you get, the less dense the air gets. Yes, the air gets thinner. The thinner the air is, the easier it is to stabilize a bullet. So a bullet that is stable at 5500 ASL may very well NOT be stable at 100 ASL. It makes a tangible difference.

What this all amounts to? For YOUR individual circumstances, a Gun and Ammo combination may very well SEEM stable. It may shoot admirable for you day in and day out! But if you take that very same gun and ammo, and take it to a different part of the earth entirely it may suddenly "And for no good reason" start spraying bullets in a pattern a stage coach shot gun would envy!

Stable means you can take it any place, any time, and shoot and be good to go. Period. No excuses, no apologies, no harm, no foul. If you can not do that, you are not stable. You would be semi stable at best. But hey, if it works for you, That is What Matters Most! To You! :)

Have a good one,
Gary