why 1 in 8" over 1 in 7"?
Are they both dialed for 77gr SMK? if so what is gained with one over the other?
Thanks
Are they both dialed for 77gr SMK? if so what is gained with one over the other?
Thanks
-
Having trouble using the site?
Contact support
18" 5.56mm SPR barrel twist rate queston
- Thread starter hudsongunner
- Start date
Re: 18" 5.56mm SPR barrel twist rate queston
1:8 will stabilize anything you want to put through it, I've shot 52-75 through mine (20" bull) and they were all accurate. I have an spr upper in the works right now and the barrel is an 18" 1:8 sabre.
1:8 will stabilize anything you want to put through it, I've shot 52-75 through mine (20" bull) and they were all accurate. I have an spr upper in the works right now and the barrel is an 18" 1:8 sabre.
Re: 18" 5.56mm SPR barrel twist rate queston
and the converse, the 1:7 overstabilizes 55 grain bullets. I have found that for shooting these inexpensive easy to get 55 grain bullets the 1:7 is a poor choice.
Fast twist rates are for heavy bullets. The military uses 1:7. Therefore the common myth and trend is that 1:7 must be good. In fact, I would rather have a 1:8 or 1:9 any day of the week.
and the converse, the 1:7 overstabilizes 55 grain bullets. I have found that for shooting these inexpensive easy to get 55 grain bullets the 1:7 is a poor choice.
Fast twist rates are for heavy bullets. The military uses 1:7. Therefore the common myth and trend is that 1:7 must be good. In fact, I would rather have a 1:8 or 1:9 any day of the week.
Re: 18" 5.56mm SPR barrel twist rate queston
Thanks All...
My 16" barrels are 1 in 7 and 1 in 9. they seem to work just fine with the 55, 62 and 77 gr rounds I shoot through them. I just picked up a new upper here on the hide with an 18" Noveske 1 in 8 SPR barrel. The original owner had it built with the 1 in 8 and most SPR builds I have seen have a 1 in 7.
I am looking forward to shooting this upper. Everyone I know has nothing but good things to say about their Noveske SPR barrels, but they are all 1 in 7.
Specs:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">This one was built by MSTN. NOVESKE 18" SPR "MOD 2" CONTOUR WITH RIFLE LENGTH GAS SYSTEM AND SPECIAL ORDER 1X8" THREE GROOVE TWIST, IONBOND DIAMONDBLACK COATED. PINNED NOVESKE GAS BLOCK. BETTER BY FAR THAN THE ORIGINAL SPR BARREL IN BOTH CONTOUR DESIGN PLUS BARREL QUALITY. WEIGHS 1/2 OUNCE MORE.
LARUE STEALTH RECEIVER
KNIGHT'S LONG FREE FLOATING RAS SPR MK 12 MOD 1 FOREND WITH THREE HANDGUARD PANELS
OPS-INC 12TH MODEL BRAKE AND BARREL COLLAR
PRI GAS BUSTER, IONBOND DIAMONDBLACK COATED
YOUNG MFG STD CARRIER WITH LMT PROOF ROUND TESTED, MP-INSPECTED BOLT AND LMT INTERNALS, ALL IONBOND DIAMONDBLACK COATED. BOLT FITTED AT A TIGHT 1.4656".</div></div>
The only change I will make will be to replace the ops brake with a SureFire Brake or FH.
Thanks All...
My 16" barrels are 1 in 7 and 1 in 9. they seem to work just fine with the 55, 62 and 77 gr rounds I shoot through them. I just picked up a new upper here on the hide with an 18" Noveske 1 in 8 SPR barrel. The original owner had it built with the 1 in 8 and most SPR builds I have seen have a 1 in 7.
I am looking forward to shooting this upper. Everyone I know has nothing but good things to say about their Noveske SPR barrels, but they are all 1 in 7.
Specs:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">This one was built by MSTN. NOVESKE 18" SPR "MOD 2" CONTOUR WITH RIFLE LENGTH GAS SYSTEM AND SPECIAL ORDER 1X8" THREE GROOVE TWIST, IONBOND DIAMONDBLACK COATED. PINNED NOVESKE GAS BLOCK. BETTER BY FAR THAN THE ORIGINAL SPR BARREL IN BOTH CONTOUR DESIGN PLUS BARREL QUALITY. WEIGHS 1/2 OUNCE MORE.
LARUE STEALTH RECEIVER
KNIGHT'S LONG FREE FLOATING RAS SPR MK 12 MOD 1 FOREND WITH THREE HANDGUARD PANELS
OPS-INC 12TH MODEL BRAKE AND BARREL COLLAR
PRI GAS BUSTER, IONBOND DIAMONDBLACK COATED
YOUNG MFG STD CARRIER WITH LMT PROOF ROUND TESTED, MP-INSPECTED BOLT AND LMT INTERNALS, ALL IONBOND DIAMONDBLACK COATED. BOLT FITTED AT A TIGHT 1.4656".</div></div>
The only change I will make will be to replace the ops brake with a SureFire Brake or FH.
Re: 18" 5.56mm SPR barrel twist rate queston
I have 1/7 WOA 18" SPR wylde chaimber and use 75BTHP all the way down to 52gr Berger match,Accuracy wise It shoots 52gr as well as 75gr about 1/2MOA at distance.
YMMV all things the same do not always do the same..
I have 1/7 WOA 18" SPR wylde chaimber and use 75BTHP all the way down to 52gr Berger match,Accuracy wise It shoots 52gr as well as 75gr about 1/2MOA at distance.
YMMV all things the same do not always do the same..
Re: 18" 5.56mm SPR barrel twist rate queston
My MSTN upper is similar to yours.
mine has the DD lite 12" rail and Noveske Switchblock. Also I bought it with a Vortex FH but currently it has a JP brake.
you'll love it. It shoots better than I can shoot. Tried 55-77gr in it with great results.
My MSTN upper is similar to yours.
mine has the DD lite 12" rail and Noveske Switchblock. Also I bought it with a Vortex FH but currently it has a JP brake.
you'll love it. It shoots better than I can shoot. Tried 55-77gr in it with great results.
Re: 18" 5.56mm SPR barrel twist rate queston
thanks for the info...I am looking forward to shooting it.
thanks for the info...I am looking forward to shooting it.
Re: 18" 5.56mm SPR barrel twist rate queston
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">the 1:7 overstabilizes 55 grain bullets.</div></div>You can't 'overstabilize' a bullet; it's either stable, or it isn't. A 1 in 7 will shoot 55gr bullets quite well.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">the 1:7 overstabilizes 55 grain bullets.</div></div>You can't 'overstabilize' a bullet; it's either stable, or it isn't. A 1 in 7 will shoot 55gr bullets quite well.
Re: 18" 5.56mm SPR barrel twist rate queston
I concurr, my 1/7 WOA shoots the 55's as well as the 69 SMK out to 100yds. Gives me a cheaper option when practicing.
I concurr, my 1/7 WOA shoots the 55's as well as the 69 SMK out to 100yds. Gives me a cheaper option when practicing.
Re: 18" 5.56mm SPR barrel twist rate queston
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">the 1:7 overstabilizes 55 grain bullets.</div></div>You can't 'overstabilize' a bullet; it's either stable, or it isn't. A 1 in 7 will shoot 55gr bullets quite well. </div></div>
The theory is that the overstabilised bullet remains parallel to the line of the barrel rather than the parabola of flight, so at longer ranges the bullet's surfing, and keyholes.
I have no idea about the range at which this becomes a factor. Probably farther than 55s usually get shot at.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">the 1:7 overstabilizes 55 grain bullets.</div></div>You can't 'overstabilize' a bullet; it's either stable, or it isn't. A 1 in 7 will shoot 55gr bullets quite well. </div></div>
The theory is that the overstabilised bullet remains parallel to the line of the barrel rather than the parabola of flight, so at longer ranges the bullet's surfing, and keyholes.
I have no idea about the range at which this becomes a factor. Probably farther than 55s usually get shot at.
Re: 18" 5.56mm SPR barrel twist rate queston
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: frog5215</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">the 1:7 overstabilizes 55 grain bullets.</div></div>You can't 'overstabilize' a bullet; it's either stable, or it isn't. A 1 in 7 will shoot 55gr bullets quite well. </div></div>
The theory is that the overstabilised bullet remains parallel to the line of the barrel rather than the parabola of flight, so at longer ranges the bullet's surfing, and keyholes.
I have no idea about the range at which this becomes a factor. Probably farther than 55s usually get shot at. </div></div>
As interesting as it sounds it doesn't make sense!
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: frog5215</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tomcat</div><div class="ubbcode-body">the 1:7 overstabilizes 55 grain bullets.</div></div>You can't 'overstabilize' a bullet; it's either stable, or it isn't. A 1 in 7 will shoot 55gr bullets quite well. </div></div>
The theory is that the overstabilised bullet remains parallel to the line of the barrel rather than the parabola of flight, so at longer ranges the bullet's surfing, and keyholes.
I have no idea about the range at which this becomes a factor. Probably farther than 55s usually get shot at. </div></div>
As interesting as it sounds it doesn't make sense!
Re: 18" 5.56mm SPR barrel twist rate queston
Bullet weight has nothing to do with it. It's the length of the bullet that determines twist. The benchrest crowd has found that you can use faster twist barrels than previously thought. Hence, the trend for faster twist barrels. Remember, the 1 in 10 twist that is used in .308 barrels now, actually allows a greater range of bullets to be shot accurately. It's not uncommon for people shooting a 1 in 10 5R barrel state that they cannot really tell much accuracy difference between bullet weights.
The over stabilized myth comes from cheap bullets made with old technology that produced out of round bullets. Modern technology allows the manufacture of much more precisely round bullets that do not come apart at high twist rates.
http://anarchangel.blogspot.com/2007/01/stabilization-mythology.html
Bullet weight has nothing to do with it. It's the length of the bullet that determines twist. The benchrest crowd has found that you can use faster twist barrels than previously thought. Hence, the trend for faster twist barrels. Remember, the 1 in 10 twist that is used in .308 barrels now, actually allows a greater range of bullets to be shot accurately. It's not uncommon for people shooting a 1 in 10 5R barrel state that they cannot really tell much accuracy difference between bullet weights.
The over stabilized myth comes from cheap bullets made with old technology that produced out of round bullets. Modern technology allows the manufacture of much more precisely round bullets that do not come apart at high twist rates.
http://anarchangel.blogspot.com/2007/01/stabilization-mythology.html
Re: 18" 5.56mm SPR barrel twist rate queston
I also have a WOA 18in 1/7 it it shoots great across the board
I also have a WOA 18in 1/7 it it shoots great across the board
Re: 18" 5.56mm SPR barrel twist rate queston
I have not noticed any difference between 1 in 7 and 1 in 9 with my 14.5"-16" carbines within 300 yds.
I have not noticed any difference between 1 in 7 and 1 in 9 with my 14.5"-16" carbines within 300 yds.
Similar threads
