What IS the 1 in 10 twist good for?

[RugerIte]

OK we been hearing how much the more efficient twist out there are way better, and proven they are, along with the SPEC II chambering. There's a 2008 shooting report that convinced me done by the experts here who I feel are above reproach when they did their grand experiment.

So that having been said.

What IS the 1 in 10 twist good for?

I mean it as is there a bullet weight that it is best at as its a faster twist?

The 1 in 10 twist is from what I understand "Adequate" for the 6.8 SPC and allows for light to the 130 grain effectively, so does the 1 in 11 twist only at reduced pressures. Most loads will be slower in it though and you have higher pressures some what. Alleviated greatly by the SPEC II Chamber at least. Ok EXPERTS please correct any mistake or miss assumptions I made in this last paragraph.

[marinesg1012]

Unless you want to shot the heavy bullets (140 plus) subsonic I dont think the 1-10 does anything well....

[BillBond]

I have 1 in 10 LMT barrels with the SPC II chamber and some Noveske 1 in 12 barrels and cannot tell any difference when shooting 110 to 115 grain bullets.
Remington and SSA brass end up with the same small marks from the extractor and the ejector in four different guns.

YMMV

[Drifter]

If not pushing handloads to the max, and not shooting at extended range, I haven't noticed the 6-groove 10" twist in my Mini-14 (16.5" barrel) as a significant handicap versus the 4-groove 11" twist in my AR (18" barrel). Velocity with the SSA 85gr TSX TL factory load is 30 fps less in the Mini-14 (reamed to Spec II), but this is probably due to the barrel being 1.5" shorter. Accuracy is a little better in the AR, but this is likely due to the platform.

I understand the reasoning of the 11" twist being better (especially for handloaders), but any advantage probably goes unnoticed by users of factory ammo shooting at 200 yards or less.

If buying a new AR barrel, I would certainly get 11" twist, but I'm not ditching my 10" twist Mini-14. It has four 1-shot DRT kills on deer using factory ammo.

[marinesg1012]

I have a 1-11.25 twist and a 1-12 and I know the handloads I shoot in the 1-12 with no swipes will show swipes in my 1-11.25....

[Jamesb74]

nm...............

[GSS]

I have a 1-11.25 twist and a 1-12 and I know the handloads I shoot in the 1-12 with no swipes will show swipes in my 1-11.25....

Which is likely a barrel-to-barrel difference, not the 0.75" difference in twist rate. And/or the recipe is on "hot plus" side.
Many times I have seen two identical factory rifles not handle or shoot the same load well, which is why when people ask " give me a good recipe for accuracy or speed"... nuances from one barrel to another likely prevent such succes. Reloading manuals would be mighty thin if load work was that easy.

Shooters run the 223 Rem in everything from 1:7 to 1:12, often using the same data. No doubt results may vary somewhat, but caveats of "don't run this load in that barrel, due to the twist" seldom if ever exist (unless it's about bullet stability).

Since the 6.8 crowd often cites a lack of "good" data from industry sources, thus relying on forums such as this, maybe some of the loads are a bit on the warm side? Warm as in well over 60k?

My 6.8 loads to date (in both a 1:10 and 1:11) have not experienced "swipes"...but nor have the bajillion 223 loads I made for my other AR's.
Am I doing somethin wrong? (sarcasm font not working)

[marinesg1012]

I guess that all the info we have that proves the slower twist helps reduce preassure is wrong then? I am not saying I am not loading hot, I am but I can take a load that doesnt show swipes in my 1-12 and put it into my 1-11 and it will have a swipe... maybe that is just my barrel but that info has been backed up by others using different barrels and loads...

If your loading your ammo to the specs listed in the loading manuals then thats fine, but why when you can load hotter with the same or equal preassure, if you have the better specs that werent out when the manuals were written?

[angsniper]

If you're not handloading or trying to shoot the hot loads I think the 10:1 would be fine. I've read reports from some with that twist that have good accuracy reports. I've even seen some good accuracy with a 9.5:1 barrel.

[GSS]

I guess that all the info we have that proves the slower twist helps reduce preassure is wrong then? I am not saying I am not loading hot, I am but I can take a load that doesnt show swipes in my 1-12 and put it into my 1-11 and it will have a swipe... maybe that is just my barrel but that info has been backed up by others using different barrels and loads...

If your loading your ammo to the specs listed in the loading manuals then thats fine, but why when you can load hotter with the same or equal preassure, if you have the better specs that werent out when the manuals were written?

Never said I was only using load manual recipes..but show me where many of the recipes listed here have known pressure ratings? If the pressures are "equal", why the swipes?

And as to "all the info we have that proves the slower twist helps reduce preassure"...often the slower twist was in conjunction with a chamber change and/or a reduced groove/lands number, so which change had the most effect?
Even a few ten-thousandths of bore diameter change can affect pressure (also documented).
Just lapping a bore has proven to allow warmer loads...lots of nuances in our different rifles.

I made the mistake of having a buddy bring his Hawkey borescope over...what a an eye-opener! It showed the differences between "identical" barrels, and why they preferred (demanded) different loads.

I love data development, as I shoot several wildcats where loading info is sparse. Twist rates seldom have been a factor, unless addressing bullet stability in flight. I certainly agree the 1:10 was a poor choice for the 6.8 from the beginning.