1-10, 1-11, or 1-12 twist on M1A barrel?

[Sven]

Krieger offers 1-10, 1-11 or 1-12 twists in their M1A/M14 barrels.

Which twist rate would you choose for your rifle, and why?

 

[Powderman]

Get the 1-10. It is the most versatile, and will stabilize any bullet weight up to and including the 175 grainers.

Sounds like it will be a fine rifle.

BTW, if you get the Peerless package from Fulton Armory, not only will you get the Kreiger barrel, but the bedding, new stock, new barrel, fitments, and 1 inch guarantee.

 

[Steve Smith]

Sven, I'm getting an answer for you. I suspect that the 1:10 is correct.


Fulton....Ha! Man, that guy's PR IS good!

 

[Powderman]

Uh oh...

Did I detect perhaps just a little bit of sarcasm?

Is there something I don't know about Fulton Armory? Enquiring minds are curious.........Let me know!! Or, perhaps some unpleasantness in the past? I need to know....I'm trying to save up for some of their services.

 

[uglymofo]

Dunno about FA, but even the "lowly" Springfield National Match is guaranteed 1.5MOA and you can generally find them NIB for about $1650-1700 on the open market. A Super Match with the Douglases are also guaranteed "sub-MOA"; I've not seen a Super Match shoot over .5 MOA with reloads, and at maximum, .75MOA with FGM or BH. You can find those NIB in the $1800 range with some searching. (I've seen both models new, for hundreds less.) The FA Peerless price seems all of that, and they're much harder to find from another source.

As to twist, I'd recommend 1/10. That'll handle lighter bullets adequately, and at longer ranges (>600yd) the stability it will provide the 175/178's will far outweigh the slightly larger groups you'll get with lighter bullets at short range. If you go to sell your M1A, most of the LR crowd will prefer the 1/10.

By the way, the way to chose is thus: 1/12 (slower twist) is good for lighter bullets (168SMK's are the favorite here, with 155's for Palma shooters). 1/10 is a faster twist which is required to stabilize the heavier bullets. Generally, it is recommended that the bullet be under 180gr. (thus my reference to 175SMK's or 178AMAX's above). The M1A is supposedly not built to stand the port pressures generated by heavier bullets (however, with some trick venting, it is said that 190's can be used). As an aside, I have a vented gas cylinder plug from Accuracy Speaks (Derrick Martin) and it works fabulously in my experience. I'm driving 178AMAX's at 2650fps, without bending the op rod nor any signs of peening the action. (I just completely stripped the rifle for its' 1500 round (seasonal) cleaning. I clean after every shoot, but I don't strip the rifle apart except every 1500 rounds. It would loosen the bedding to disassemble it too often, and I haven't found a reason to strip it except guilt. The gas cylinder was pretty clean, but it gets cleaned every 750 rounds.)

Lastly, the 1/11 twist is a compromise for the shooter who's gonna shoot both 168's for short range and 175's for long range. I've never seen a 1/11 barrel shoot. I can't imagine its' accuracy is so much better with 168's than it would be out of a 1/12 barrel, that it would be worth the LR loss with the 175's.