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11/22/2017 10:05:29 PM
Posted: 8/24/2004 4:07:20 PM EST
I have never even thought of this before, but since I'm buying 2 uppers in the next few weeks, should I try to get 1in7 or 1in9 barrels? Does this matter if I go with a 14.5/phantom and a 11.5/5.5?

Thanks for any feedback!
Link Posted: 8/26/2004 12:43:35 PM EST
Depends. 1/7 will shoot any bullet weight that's currently available in the .223 caliber. 1/9 is about 50% chance of shooting the 75/77gr stuff acceptably. Some people say it works in their 1/9 and others (like me) find that it doesn't work in theirs.

You'll have to decide whether you need the extra effective range of the heavier bullets (check out the tacked threads in the Ammo forum) or if you can get away with using the 68/69gr or M193. Personally, I'd want 1/7, expecially in the 11.5" but they're harder to find so it may not be worth it for you.
Link Posted: 8/26/2004 12:57:00 PM EST
All questions will be answered by the Ammo Oracle
Link Posted: 8/26/2004 2:05:05 PM EST
1/7 because it's what our boys in green (actually desert tan right now) use.
Link Posted: 8/26/2004 2:06:01 PM EST
[Last Edit: 8/26/2004 2:06:16 PM EST by _DR]

Originally Posted By Mike_L:
Depends. 1/7 will shoot any bullet weight that's currently available in the .223 caliber. 1/9 is about 50% chance of shooting the 75/77gr stuff acceptably. Some people say it works in their 1/9 and others (like me) find that it doesn't work in theirs.

You'll have to decide whether you need the extra effective range of the heavier bullets (check out the tacked threads in the Ammo forum) or if you can get away with using the 68/69gr or M193. Personally, I'd want 1/7, expecially in the 11.5" but they're harder to find so it may not be worth it for you.



Cmmg has lots of 'em in 11.5" on up. They have everything in 1/7, and with M4 feed ramps no less.
Link Posted: 8/26/2004 2:15:11 PM EST
1/9
Link Posted: 8/26/2004 2:47:44 PM EST
[Last Edit: 8/26/2004 2:48:13 PM EST by Beyond_Visual_Range]
while trying to answer this question I did a lot of reading. simply using 1/7 because military uses is not a good reasoning. the military uses it because of the extra long nose tracers which requires faster twist rate to stablize. 1/7 is a compromise for the tracer and regular ball ammo. If you might shoot tracers or 77gr or above rounds, then by all means get 1/7 as it will give you a wider range of options. If you will stick to standard ball ammo, get the 1/9 unless it's 16" in which case 1/7 will give better stabilization.
Link Posted: 8/26/2004 3:08:14 PM EST
from what I understand, there is no reason not to get a 1:7 bbl if it is worth the trouble/time/expense to you. a 1:7 can shoot everything a 1:9 can, and anything above 55 gr should be better.
Link Posted: 8/26/2004 3:28:15 PM EST
1/7 is what I would prefer if I could get it and not have to pay anymore.
Link Posted: 8/26/2004 4:58:42 PM EST
1/7 or 1/8.
Link Posted: 8/26/2004 5:03:46 PM EST
1/9
Link Posted: 8/26/2004 7:17:40 PM EST
tagged in case i lern somfin'

Seriously this is exactly the discussion I was looking for tonight.

-YJ
Link Posted: 10/3/2004 3:10:36 PM EST

Originally Posted By Lon_Moer:
All questions will be answered by the Ammo Oracle



Man I was dead set on the 1-7 before I read that... Now I'm just not sure anymore

I'll most likely be sticking with like 62gr or so rounds in bulk but I've been seeing good prices on 55grs lately..

The dern search feature just confused me today with that link
Link Posted: 10/3/2004 4:03:49 PM EST
Here's a question:

What do you plan to use it for?
Link Posted: 10/3/2004 4:19:54 PM EST
Get 1/12 - use 55gr. Its over. Back to basics.
Link Posted: 10/3/2004 4:29:45 PM EST
The best source for this information is http://www.ammo-oracle.com/
From what I've read on this the 55gr is more than sufficient and provides
good fragmentation and yes "yaw" after hitting flesh.
The M193 out of 16" barrels will provide adequete fragmentation out to 150m
and it's less expensive than the heavier rounds. Heavier bullets
traveling a higher rate of rotation, will penetrate more and be more stable
flight and after hitting tissue.

This can sometimes lead to less wound channels at effective ranges.
Link Posted: 10/4/2004 8:35:11 AM EST

... Heavier bullets
traveling a higher rate of rotation, will penetrate more and be more stable
flight and after hitting tissue.

This can sometimes lead to less wound channels at effective ranges.



No bullet is stable after hitting tissue--it's much too dense. Expanding bullets like SP will mushroom and travel point forward. Pointed bullets like the FMJ and BTHP/OTM bullets will tend to yaw and turn base-first in tissue. Most of them will break up when they get to 90 degrees if they're moving fast enough. The only difference between them is how far they travel before they start to yaw, and how fast is fast enough to make them fragment. Within the "fragmentation range" they're all about the same for effectiveness, with the primary difference being how quickly they yaw. The main difference is in the fragmentation speed, which is generally lower for the heavier bullets, translating into longer "effective" range.

There's a tacked thread on one of the forums here with charts showing that range for the various loads and barrel lengths. In order of frag range they break down like this:
75/77gr
68/69gr
55gr (M193)
62gr (M855)
I think ".223" 55gr FMJ would fall between M193 and M855, but I haven't run the numbers. M855 out of 14.5" barrels is especially bad. There's a reason the military is buying 77gr now.

1/9 will shoot all but the 75/77gr well, and may or may not work with them. 1/7 (or 1/8) will shoot any of them. How much is the extra margin of the 75/77gr over the 68/69gr worth to you?
Link Posted: 10/4/2004 8:44:57 AM EST
If all you're planning to do is dump Wolf/Q3131/XM193/general surplus through it, then get a 1:9. Not too many people can afford to plink with Black Hills 77 Gr. Sierra MatchKing.
Link Posted: 10/4/2004 9:03:45 AM EST
If that's all you're ever going to shoot then 1/9 is all you need. But you can shoot all of that same stuff in a 1/7 too. So the question is whether or not you need the option of shooting 75/77gr some of the time.
Link Posted: 10/4/2004 9:14:43 AM EST
Get one of each. It is the only way to be sure.
Link Posted: 10/4/2004 9:28:14 AM EST
[Last Edit: 10/4/2004 9:34:07 AM EST by Jeepster]
Does BM make the 20" Govt Profile Barrel in the 1/7 twist?
Link Posted: 10/4/2004 10:16:30 AM EST
I think they do, but it's not a regular catalog item so you have to call and see if they have any in stock. It'll probably be "pre-ban" config only as well (in case you're in a state that didn't sunset).
Link Posted: 10/4/2004 2:09:00 PM EST
How about if you're planning on shooting 55 or 62gr bullets and that's pretty much it?

MOst likely I'll stick with those but I like to have the option if need be.

Suggestions?

BTW: Yes I can read a webstie but I just prefer personal opinions/experience.

Thanks
Link Posted: 10/4/2004 3:43:17 PM EST
[Last Edit: 10/4/2004 3:45:04 PM EST by DevL]

Originally Posted By Jeepster:
Does BM make the 20" Govt Profile Barrel in the 1/7 twist?



Yes they do and its not neutered but you can have a brake put on and the lug cut off if your not in a free state.
Link Posted: 10/4/2004 3:51:12 PM EST
1/7. It will shoot all 55gr ammo and up just fine.
Link Posted: 10/4/2004 3:57:31 PM EST
1/7 barrels will wear faster than the slower twist barrels also.
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