Why I hate 1:7 twists

[CarlosDJackal]

Could it be the ammo that's problem? Have you tried some 55-grain match ammo to see if it really is a bullet-weight vs. rifle-twist issue?

[TY44934]

Whats this have to do with his FUBAR'D SIG 1/7 barrel?

Is his 556 barrel FUBAR'D ?

Consider this: the barrel for the 556 is supposed to be identical to the barrel for the Swiss-made 55_ series rifles.

Only problem here: the 55_ rifles are on the 1989 ban list. Since the rifles are banned from import into the US, the barrels are also banned from import - as is the upper reciever (since 2003).

So - your 556's barrel is not Swiss "made." By law it must be made in the US if its for civilian sale.

No one is saying just how Sig is pulling this one off (to our benefit - I am glad they offer the 556 to us).

But, they are probably importing Swiss forged blanks and doing the finish work here. I would suspect Sig-USA's finish work is to blame.

[WS6]

Call SIG, when my SIG 226 ST Elite broke they fixed it within a week, AND payed shipping both ways.

[Shihan]

Is his 556 barrel FUBAR'D ?

But, they are probably importing Swiss forged blanks and doing the finish work here. I would suspect Sig-USA's finish work is to blame.

Isnt that what I said? i didnt say all of the Sig's barels are FUBAR but the one in his possesion.

[Alaskapopo]

I just prefer 1:9 twists as being more versatile. If only the SIG had a 1:9 twist. I know that heavy bullets are in vogue now but my lighter bullets just don't perform up to my standards in a 1:7 twist. I hunt a lot of varmints and need a precise machine. The SIG has been my first experience with 1:7. I shot DCM on a shortened range with reduced diameter targets so I never loaded anything over 63 grains.

1/7 will work with 55 grain bullets and higher with easy while the 1/9 abomination doesn't work well with the heavier bullets I prefer. 1/7 is the way to go.
Pat

[HolyRoller]

1/7 will work with 55 grain bullets and higher with easy while the 1/9 abomination doesn't work well with the heavier bullets I prefer. 1/7 is the way to go.
Pat

Have you tried different twist rates in otherwise identical barrels? Do the heavier bullets make bigger groups, or start to keyhole, with the slower rate? That's the only way I'd agree that 1:9 is an abominable snowman. 77s and overlength 75s stabilize perfectly well in my 1:9 bean.

[ckay]

Interesting...that's the first I've heard of anyone being fed up with a 1:7. My only AR is 1:9. My stash consists of 55 and 62gr. However, I am jonesing for a 1:7 upper.

[Alaskapopo]

Have you tried different twist rates in otherwise identical barrels? Do the heavier bullets make bigger groups, or start to keyhole, with the slower rate? That's the only way I'd agree that 1:9 is an abominable snowman. 77s and overlength 75s stabilize perfectly well in my 1:9 bean.

Yes I have tried 1/9 uppers with heavier bullets. While they don't tumble the groups are much larger. 1/9 sucks in my opinion. I don't use it anymore.
Pat