I purchased a Spikes Tactical complete lower, and was thinking of getting one of their complete uppers. However, I'm wanting a 1/8 or 1/9 twist rate, and it doesn't appear they sell any. I was also thinking of a BCM upper, and I don't think they sell any with those rates either. I plan to mostly shoot 55grn, and that's why I'm looking for a 1/8 or 1/9. I recently shot a RRA with a 1/7, and it did pretty well with heavier bullets, but the groups opened up more than I expected when I went to 55 grns. So, how much should I expect the groups to open up when shooting 55grns through a 1/7? Is it possible, the gun I shot, just doesn't shoot well with the lighter loads, or is this common? Again, I expect the groups to widen, but not nearly as much as they did. Thanks
- Thread starter FatboyStew
- Start date
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
1:12 will some some bullets, 1:9 will shoot a little heavier bullets, and 1:8 will go heavier.
But the 1:7 will shoot all the above and still go higher.
The Army uses a 1:7 barrel in the Mann Accuracy Device to test ammo.
They use 52 Grn SMS,s to test the Mann Accuracy device.
Here's an interesting chart from the Army Manual.
1:12 will some some bullets, 1:9 will shoot a little heavier bullets, and 1:8 will go heavier.
But the 1:7 will shoot all the above and still go higher.
The Army uses a 1:7 barrel in the Mann Accuracy Device to test ammo.
They use 52 Grn SMS,s to test the Mann Accuracy device.
Here's an interesting chart from the Army Manual.
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
Kraig,
Thanks for that info. I guess it was just the particular gun I was shooting. The owner, my uncle, said he didn't shoot it well, and thought it was his eyes. I'm thinking it's the gun. Now I won't mind ordering a Spikes or BCM upper.
Thanks again,
Brent
Kraig,
Thanks for that info. I guess it was just the particular gun I was shooting. The owner, my uncle, said he didn't shoot it well, and thought it was his eyes. I'm thinking it's the gun. Now I won't mind ordering a Spikes or BCM upper.
Thanks again,
Brent
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
I have 1/7, 1/7.7, 1/8. and 1/9. I love my 1/8 WYLDE chambered guns for precision, and they shoot lights out with 50's and 60 vmax's. 1/8 WYLDE w/ 60grVmax over 25 grains of H4895 and I've never saw one shoot worse than .5's. The good thing is use that same bullet over Varget, Benchmark, H335, and even BLC 2, has always got me under an inch. I love the .223's flexibility. Much like the 22-250. In that 1/8 config, they like about anything
I have 1/7, 1/7.7, 1/8. and 1/9. I love my 1/8 WYLDE chambered guns for precision, and they shoot lights out with 50's and 60 vmax's. 1/8 WYLDE w/ 60grVmax over 25 grains of H4895 and I've never saw one shoot worse than .5's. The good thing is use that same bullet over Varget, Benchmark, H335, and even BLC 2, has always got me under an inch. I love the .223's flexibility. Much like the 22-250. In that 1/8 config, they like about anything
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
I have a 1/8 in mine and it does not really like 55 gr bullets. It loves hornady's 75gr bthp.
I have a 1/8 in mine and it does not really like 55 gr bullets. It loves hornady's 75gr bthp.
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
My 2 cents is that if you're just blasting away I'd get a milspec type upper in 1:7 twist. Palmettostatearmory puts together some decent ones for not a lot of money, they are swamped though so if you order from them you may need to wait a week or two.
If you want to scope it look for a flattop, stainless, free floating, 1:8 twist upper and plan on handloading for it.
My 2 cents is that if you're just blasting away I'd get a milspec type upper in 1:7 twist. Palmettostatearmory puts together some decent ones for not a lot of money, they are swamped though so if you order from them you may need to wait a week or two.
If you want to scope it look for a flattop, stainless, free floating, 1:8 twist upper and plan on handloading for it.
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
Without knowing the specifics of the ammo, it may have simply been the case the the 55gr ammo was a less accurate ammo. The cheaper 55gr ammo out there is usually only a 2+ MOA ammo to start. In contrast, the heavier bullets are often capable of better accuracy (depends on the specifics of each round, but generally speaking . . .).
Without knowing the specifics of the ammo, it may have simply been the case the the 55gr ammo was a less accurate ammo. The cheaper 55gr ammo out there is usually only a 2+ MOA ammo to start. In contrast, the heavier bullets are often capable of better accuracy (depends on the specifics of each round, but generally speaking . . .).
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
Spin a shit bullet faster and its imbalances will reveal themselves more. Most 55gr FMJs are low quality high volume projectiles. Just a thought.
Personal opinion, for GP AR rifles/carbines I'd go 1:8 or 1:7, the 1:8 will stabilize anything that can be loaded to mag length, the 1:7 will stabilize bullets too long to load to mag length.
1:9 is not useless, just kinda limited, with the prevelance of other options of late, I'd only might get it for a dedicated varmint gun, even then I might go 1:12.
My first AR was 1:9, I still have it, shoot it allot and it does well, within its limits.
Spin a shit bullet faster and its imbalances will reveal themselves more. Most 55gr FMJs are low quality high volume projectiles. Just a thought.
Personal opinion, for GP AR rifles/carbines I'd go 1:8 or 1:7, the 1:8 will stabilize anything that can be loaded to mag length, the 1:7 will stabilize bullets too long to load to mag length.
1:9 is not useless, just kinda limited, with the prevelance of other options of late, I'd only might get it for a dedicated varmint gun, even then I might go 1:12.
My first AR was 1:9, I still have it, shoot it allot and it does well, within its limits.
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
Thanks to everyone for all of the input.
Thanks to everyone for all of the input.
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
I ran a test on my DPMS AR with a 1/9 barrel. I used 40gr bullets to see if throwing them out of a quicker twist (for the bullet weight) would hurt accuracy. I returned from the range with velocities in the 3400fps range and groups of about .375". It actually beat out 55gr bullets of the same type. While I have no urge to go to a faster twist as my bullets stay below 60gr (childrens' rifles are slower twisted and we all shoot the same loads), I would say the 1/7 was not what hurt you that day with your 55gr.
However, I caveat that with that if you are never going to use a 70gr bullet a 1/9 won't hurt you either. If your barrel is long enough to generate 3600-3800fps the 1/7 might tear apart any lighter bullets you try (40-45gr).
I ran a test on my DPMS AR with a 1/9 barrel. I used 40gr bullets to see if throwing them out of a quicker twist (for the bullet weight) would hurt accuracy. I returned from the range with velocities in the 3400fps range and groups of about .375". It actually beat out 55gr bullets of the same type. While I have no urge to go to a faster twist as my bullets stay below 60gr (childrens' rifles are slower twisted and we all shoot the same loads), I would say the 1/7 was not what hurt you that day with your 55gr.
However, I caveat that with that if you are never going to use a 70gr bullet a 1/9 won't hurt you either. If your barrel is long enough to generate 3600-3800fps the 1/7 might tear apart any lighter bullets you try (40-45gr).
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
I'm guessing the lack of accuracy with the lighter rounds may have been due to bullet quality. I have no idea what brand they were. The person that had the RRA gave them to me to sight in his weapon. I know he bought them in bulk, but that and the weight is all I know about them. I'll have to get with him to see what they were. I ordered a PSA mid length upper with a 1/7 twist.
I'm guessing the lack of accuracy with the lighter rounds may have been due to bullet quality. I have no idea what brand they were. The person that had the RRA gave them to me to sight in his weapon. I know he bought them in bulk, but that and the weight is all I know about them. I'll have to get with him to see what they were. I ordered a PSA mid length upper with a 1/7 twist.
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rhinomax</div><div class="ubbcode-body">1/8
Shoots everything well </div></div> over all this is the best 1/8 ...L/W barrel of this works out very well !
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rhinomax</div><div class="ubbcode-body">1/8
Shoots everything well </div></div> over all this is the best 1/8 ...L/W barrel of this works out very well !
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
My 18" Rainier Ultramatch barrel loves 1/8 77gr Federals bthp
My 18" Rainier Ultramatch barrel loves 1/8 77gr Federals bthp
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
1 in 8 shilen wylde 223 ratchet rifle SS 5R here and it shoots sub 1/2 inch all day long with good ammo and good glass. Its a 16 inch medium contour.
1 in 8 shilen wylde 223 ratchet rifle SS 5R here and it shoots sub 1/2 inch all day long with good ammo and good glass. Its a 16 inch medium contour.
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
You need to try more types of ammo. My Noveske (1:8 twist) shoots 40 grn Fiocchi .223 and 77 grn Black Hills 5.56 under .5 MOA, and shoots some other ammo about 1.5 MOA. You have to find what your own barrel likes best.
You need to try more types of ammo. My Noveske (1:8 twist) shoots 40 grn Fiocchi .223 and 77 grn Black Hills 5.56 under .5 MOA, and shoots some other ammo about 1.5 MOA. You have to find what your own barrel likes best.
Re: 1/7 vs 1/8 vs 1/9 for a 5.56
My 1:7 LMT shoots 77's great and sprays 55's. Every barrel will be somewhat different and I have seen 1:7 barrels shoot 55's fine.....mine does not.
My 1:7 LMT shoots 77's great and sprays 55's. Every barrel will be somewhat different and I have seen 1:7 barrels shoot 55's fine.....mine does not.
