Molon
20 May 2015, 15:03
Accuracy Evaluation of a Noveske 18” SPR Barrel
https://app.box.com/shared/static/xo7ecsfy00l7r24032azve25v4q79als.jpg
Noveske’s 18” SPR barrel is a stainless-steel barrel that has a medium contour and a 0.750” diameter gas block journal. The gas block journal for this barrel is designed for Noveske’s low profile gas block and the journal is only one inch in length; standard length gas blocks will not work with this barrel. Fortunately, Noveske’s pinned and set-screwed low profile gas block is included with the barrel (as well as an intermediate length gas tube.)
https://app.box.com/shared/static/w6ryaniwlaxl65xdym2ud4e2jqpm5871.jpg
https://app.box.com/shared/static/ckdarziwj3e0ay7jipk4qf34tfbd8qcc.jpg
The Noveske SPR barrel employs an intermediate length gas system which eliminates the short-stroke issues that are sometimes encountered in cold weather with some 18” barrels that utilize a rifle length gas system. The barrel extension has “M4” feed-ramps. The barrel has a 1:7” twist rate and polygonal rifling (not a polygonal bore.)
https://app.box.com/shared/static/9me4uu47u5ke7q89kcpx3q5ris1trr7y.jpg
https://app.box.com/shared/static/2nr1zffw7j1uhlkqf6fgqlqpbnn3epuc.jpg
The chamber found in this barrel is Noveske’s proprietary Noveske Match mod 0 chamber that “was developed to fire MK262 Mod 1 on AUTO in hot environments." I installed the SPR barrel in a Colt M4 upper receiver and free-floated the barrel with a LaRue Tactical 12” handguard.
https://app.box.com/shared/static/6mjhqvzx7yrojh30a1zss4r4e7u0hhhg.jpg
I conducted an accuracy (technically, precision) evaluation of the Noveske 18” SPR barrel from my bench-rest set-up following my usual protocol. This accuracy evaluation used statistically significant shot-group sizes and every single shot in a fired group was included in the measurements. There was absolutely no use of any group reduction techniques (e.g. fliers, target movement, Butterfly Shots).
The shooting set-up will be described in detail below. As many of the significant variables as was practicable were controlled for. Pictures of shot-groups are posted for documentation.
All shooting was conducted from a concrete bench-rest from a distance of 100 yards (confirmed with a laser rangefinder.) The free-float hand-guard of the rifle rested in a Sinclair Windage Benchrest, while the stock of the rifle rested in a Protektor bunny-ear rear bag. Sighting was accomplished via a Leupold VARI-X III set at 25X magnification and adjusted to be parallax-free at 100 yards. A mirage shade was attached to the objective-bell of the scope. Wind conditions on the shooting range were continuously monitored using a Wind Probe. The set-up was very similar to that pictured below.
https://app.box.com/shared/static/xo4duzdgtp.jpg
https://app.box.com/shared/static/lkg47ptc04.jpg
For this evaluation, I used one of my standard match-grade hand-loads topped with Sierra 55 grain BlitzKings. When fired from my Krieger barreled AR-15s, this load has produced ˝ MOA 10-shot groups at 100 yards.
https://app.box.com/shared/static/n5uicctmu8ve7kxmht3zboy2inihdvzq.jpg
Three, 10-shot groups were fired in a row from the Noveske SPR barrel from a distance of 100 yards with the resulting extreme spreads:
0.812”
0.732”
0.873”
for an average 10-shot group extreme spread of 0.81”. The three, 10-shot groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group. The mean radius of the 30-shot composite group was 0.28”
The smallest 10-shot group . . .
https://app.box.com/shared/static/fs89f0e2sy9c48p6qb2japknx67i42nd.jpg
The 30-shot composite group . . .
https://app.box.com/shared/static/o9me2v3tg4g7gqubs09r3gyttmby30yf.jpg
….
https://app.box.com/shared/static/xo7ecsfy00l7r24032azve25v4q79als.jpg
Noveske’s 18” SPR barrel is a stainless-steel barrel that has a medium contour and a 0.750” diameter gas block journal. The gas block journal for this barrel is designed for Noveske’s low profile gas block and the journal is only one inch in length; standard length gas blocks will not work with this barrel. Fortunately, Noveske’s pinned and set-screwed low profile gas block is included with the barrel (as well as an intermediate length gas tube.)
https://app.box.com/shared/static/w6ryaniwlaxl65xdym2ud4e2jqpm5871.jpg
https://app.box.com/shared/static/ckdarziwj3e0ay7jipk4qf34tfbd8qcc.jpg
The Noveske SPR barrel employs an intermediate length gas system which eliminates the short-stroke issues that are sometimes encountered in cold weather with some 18” barrels that utilize a rifle length gas system. The barrel extension has “M4” feed-ramps. The barrel has a 1:7” twist rate and polygonal rifling (not a polygonal bore.)
https://app.box.com/shared/static/9me4uu47u5ke7q89kcpx3q5ris1trr7y.jpg
https://app.box.com/shared/static/2nr1zffw7j1uhlkqf6fgqlqpbnn3epuc.jpg
The chamber found in this barrel is Noveske’s proprietary Noveske Match mod 0 chamber that “was developed to fire MK262 Mod 1 on AUTO in hot environments." I installed the SPR barrel in a Colt M4 upper receiver and free-floated the barrel with a LaRue Tactical 12” handguard.
https://app.box.com/shared/static/6mjhqvzx7yrojh30a1zss4r4e7u0hhhg.jpg
I conducted an accuracy (technically, precision) evaluation of the Noveske 18” SPR barrel from my bench-rest set-up following my usual protocol. This accuracy evaluation used statistically significant shot-group sizes and every single shot in a fired group was included in the measurements. There was absolutely no use of any group reduction techniques (e.g. fliers, target movement, Butterfly Shots).
The shooting set-up will be described in detail below. As many of the significant variables as was practicable were controlled for. Pictures of shot-groups are posted for documentation.
All shooting was conducted from a concrete bench-rest from a distance of 100 yards (confirmed with a laser rangefinder.) The free-float hand-guard of the rifle rested in a Sinclair Windage Benchrest, while the stock of the rifle rested in a Protektor bunny-ear rear bag. Sighting was accomplished via a Leupold VARI-X III set at 25X magnification and adjusted to be parallax-free at 100 yards. A mirage shade was attached to the objective-bell of the scope. Wind conditions on the shooting range were continuously monitored using a Wind Probe. The set-up was very similar to that pictured below.
https://app.box.com/shared/static/xo4duzdgtp.jpg
https://app.box.com/shared/static/lkg47ptc04.jpg
For this evaluation, I used one of my standard match-grade hand-loads topped with Sierra 55 grain BlitzKings. When fired from my Krieger barreled AR-15s, this load has produced ˝ MOA 10-shot groups at 100 yards.
https://app.box.com/shared/static/n5uicctmu8ve7kxmht3zboy2inihdvzq.jpg
Three, 10-shot groups were fired in a row from the Noveske SPR barrel from a distance of 100 yards with the resulting extreme spreads:
0.812”
0.732”
0.873”
for an average 10-shot group extreme spread of 0.81”. The three, 10-shot groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group. The mean radius of the 30-shot composite group was 0.28”
The smallest 10-shot group . . .
https://app.box.com/shared/static/fs89f0e2sy9c48p6qb2japknx67i42nd.jpg
The 30-shot composite group . . .
https://app.box.com/shared/static/o9me2v3tg4g7gqubs09r3gyttmby30yf.jpg
….