I RECENTLY PURCHASE AN M4 BARREL FROM BUSHMASTER THAT TO MY SURPRISE CAME IN 1/9" TWIST RATE.  I CURRENTLY HAVE A 16" COLT PENCIL THAT IS A 1/7" TWIST.  I UNDERSTAND THIS TO BE THE BEST. I WANTED THE 14.5" M4 TO COMPLETE MY M4GERY.  

I HAD BUSHMASTER SEND IT TO GEMTECH FOR THE PERMANENT AFFIXING OF M4-96D BI-LOCK SO I WOULD HAVE THE SHORT BARREL AND THE OPTION OF A SUPPRESSOR.  

THEY TOLD ME AFTER ORDERING THAT THIS BARREL IS A 1/9 AND I REALLY LIKE MY 1/7.

MY QUESTION IS WILL I BE HAPPY WITH THE 1/9", WILL I EVEN NOTICE, IS THE 1/9 COMPARABLE TO THE 1/7"?

I have 3 1x9 barrels and think they are more versatile.

If you wanted a 1/7 you should talk to Bushmaster and see if they can help sort this out.

I disagree with innocent_bystander. I believe the 1/7 is more versatile than the 1/9 twist, especially for an M4 style carbine.  If you're wanting a rifle for benchrest and super accuracy then you may want a 1/8 or 1/9.  If you want a SHTF carbine for fighting than I would go with a 1/7 twist.

The 1/7 twist will still let you shoot the cheap lighter stuff but it will also let you step up the heavier good stuff like the 77gr Mk262.  The 1/9 twist hasn't proven to be good with ammo heavier than 75gr and even the 75 gr will not always work well in all 1/9 barrels.

Yes you will loose "some" accuracy with the lighter loads but it will not be noticable unless, as I mentioned earlier, you setting up a super accurate bench rest rifle.  Hell, new_arguy was getting sub MOA groups at 300 yards with his 14.5", 1/7 barrel using 45gr varmint rounds!

Just my 2 cents![;)]

Keep us posted on the outcome.

My 1x9s group 55gr ammo better than my 1x7s. Most of what I shoot in my ARs is XM193.

I shoot Wolf .55 grain but am considering switching to .62 grain instead.  Probably not the best ammo but fits my budget so I can afford the gear that the speed boys use.  I know that a rifle is only as good as the ammo you shoot in it but I have to train first, plinking, practicing.

Unfortunately for me it is too late.  I really wanted the 1/7 but I did not know and assumed that the M4 barrel would be 1/7 by default.  Before I could correct this error on my part, the barrel was half way to Gemtech in Idaho.  Bushmaster told me it would 8 to 10 weeks before the 14.5" barrels would come in and it only took 2.  I am sure that I will be happy with it since I never really take long shots or vary in my ammo selections.

Man I thought new-arguy was using 1/9!

(edited to add)

Well who cares, just shoot Black Hills 68gr OTM for SHTF! It might not be good as 75gr OTM but it is still better than standard stuff.

I have both; BM 14.5" 1/7 M4, and BM 16" 1/9 M4. The 1/7's are a limited run and you can't order it off the website, you needed to call them to order it. That said, they both are sweet, but the 1/9 is the gun that I let everyone shoot, because it has the most "normal" reliability and accuracy. (does that sound right? [>:/])

234747

How often do you shoot bullets that are above 77 grain?  How often do you shoot them beyond 100 yards?  If you don't, then it isn't a concern.

The 1/9 is a great GP barrel, especially if you shoot 55-62 commercial or mil surplus.

PLEASE STOP TYPING IN CAPS..........YOU ARE MAKING MY BRAIN HURT.......IT ALSO MEANS YOU ARE YELLING AT US.......WHICH ISN"T POLITE

That is the 'standard' response from Bushmaster.

However I've shot bullets up to 77gr from my 1:9 twist barrels 14.5", 16", and 20".  Note all the barrels were chrome lined Bushmaster barrels, produced about 2 years apart from each other.

I get acceptable accuracy (for defensive purposes) with the heavy rounds.

Note the Black Hills 75gr I picked up indicated right on the box that it needed 1:9 as a minimum.  Certainly 1:7 or 1:8 is better from an accuracy point of view - but you can get by with 1:9 in most cases.

For the ammo you are using (55gr & 62gr) the 1:9 is a better choice for accuraccy and a slight improvement in barrel life.  

What will 1 in 7-twist barrels do to 55 grain Ammo? Anyone shoot this? I think 1 in 9 is the great compromise. I know this, I shoot ONE HELL OF A LOT more 55-grain stuff than I ever do 62 grain and in the M-4 it never gets higher than that. Hell In My SPR the MOST I go is 77 Grain Black Hills stuff and that is it. Usually I shoot the 68 and 69-grain stuff. For an M-4 go with the 1 in 9 and never look back,

IPSC_GUY sends

Oops!  new_arguy corrected and he does indeed have a 1/9!  My fault for posting faster than I can think...[;)]

IPSC_GUY,

Using XM193 from my 1/7 16" M4 profile barrel I can get 1-2 MOA depending on how good or bad my shooting is. I'm sure my 1/7 barrel is more accurate than me but that's plenty good enough for a fighting carbine.

I gotta add, I only own one AR so when I upgraded it I wanted a barrel that can handle everything. You're situation may be different so YMMV...

BTW, I do have an A2 carbine upper with a 1/9 barrel so I'm covered either way.[:D]

I regularly shoot the SA surplus without any problems.  Good groups at 100 yards.

Man I am torn.

I really don't think I will notice any difference in using 55 grain and 62 grain bullets.  I never take shots beyond 100 yds., the 1/9 will probably fulfill all of my self defensive and plinking needs.  I can't even buy .75 grain bullets around here.  

My set up in the end will be a 14.5" 1/9 Bushy Barrel with Gemtech M4-96D Suppressor and Bilock permanently fixed, Aimpoint ML2 on GG&G Cantilever, ARMS #40 BUIS, Vltor MOD Stock (Carbine Config.), Knight's Armament RIS, Royal Arms Bungee Sling.  

This will be more of a phillips head screw driver gun for me, a tool, a patrol carbine.  I will never need to take the long shots, and when I do, I can just switch to my 16" SP1 1/7 Pencil barreled upper.  I just put a 3-9X42 Scope on this upper, so when I want to take the long shot I'm good to go.

Thanks everyone for your information.  You guys really know your stuff.