9MM AFTERMARKET BARREL
COMPARISON
By
Will Wingfield (wwingfield@fire -4-effect.com)
Matt Haidu ([email protected])
Matt Wingfield ([email protected])
Tests performed at
FIRE 4 EFFECT PROVING GROUNDS & TEST FACILITY
El Paso, Texas
Full Disclosure / Motivation
Fire 4 Effect Weapon Systems, LLC has an arguable financial interest or affiliation with
the following products and services used in this comparison of barrel performance as
performed and evaluated by Fire 4 Effect Weapon Systems, LLC.
o Blacklist barrels are retailed on the Fire 4 Effect company website.
o The test fixtures designed by Fire 4 Effect Weapon Systems, LLC and used during
this evaluation will be offered in the near future for retail sale on their company
website.
o The stated motivation for performing this test is to demonstrate Fire 4 Effect’s
testing facility and techniques, to be offered in the future as a retail professional
service available to the general public.
While we feel we must disclose these facts, we believe once the following report is
reviewed, the reader will agree these potential conflicts of interest have no bearing
on the data and information presented in the following study.
Abstract
The purpose of this study was to evaluate barrel performance; specifically the isolated
barrel accuracy as demonstrated by consistency in point of impact (POI), using a
selection of aftermarket 9mm pistol barrels commonly available to the public. To do
this each barrel was secured in a custom-built stabilizing fixture and strings of shots
were fired using standardized ammunition at a known distance target, allowing
measurement of POI group sizes. The results yielded some very interesting data as
well as some less intuitive. While some barrels performed markedly better or worse
than others in the test sample, it was noted that all of the barrels tested were capable
of holding a string of ten rounds, in a group with a vertical, horizontal and extreme
spread of less than 2.75” at 20 yards, regardless of ammunition tested. Several were
capable of holding groups under 0.75” at 20 yards with one or more specific
ammunition selections.
Introduction
In this study fifteen barrels were evaluated from eight different identifying brands. A
custom fabricated, precision barrel-mounting fixture was utilized to isolate the
barrel’s performance from the rest of the firearm or any human physical or behavioral
input. The tests were performed at the Fire 4 Effect Proving Grounds and Test Facility
with complete environmental control, again isolating barrel performance from outside
variables such as wind and temperature, as much as possible. The testing apparatus
captured chronograph speeds from all ammunition fired as well as shot string point of
impact (POI) group measurements. From these POI groups, measurements of
horizontal spread, vertical spread and extreme spread were obtained. The data
collected is consistent with theorized performance in most respects however some
data behavior was counter-intuitive to common ballistic theory employed in precision
shooting barrel designs.
Materials & Methods
Barrels
To create a pertinent barrel comparison, all barrels compared were required to be of
the same ‘nature’. Test barrels selected met the following criteria. All barrels
evaluated are manufactured and advertised to be “Glock 17 drop-in barrels”. All
barrels selected for evaluation are threaded for suppressor, compensator or brake
attachment in a ½”-28 thread pattern, none are ported. (No suppressors,
compensators or brakes were used at any time during the evaluation). It is recognized
that many of the barrels evaluated are not actually manufactured by the same
company that is selling the barrel with their company ‘brand’ on it. As such we will
refer to the companies selling the barrel as the ‘brand provider’. It is also suspected
that some of these ‘brand providers’ utilize the same manufacturer to machine the
actual barrel for branding. The brand providers do not volunteer their
supplier/manufacturer information publicly that we could find.
Ideally a comparison test such as this would optimally evaluate as many samples of the
test barrels as possible. Performing the exact same evaluation test on 1000 barrels
from a brand provider would carry more “statistical weight” than testing a single
barrel from the brand provider. However testing large quantities of barrels as
described thus far is cost prohibitive and time consuming. Testing a single barrel from
each brand provider is also wrought with concerns. Was the single barrel tested a
perfect specimen? Did we just happen to purchase the one barrel they produced that
manufacturing cycle that was perfect? Alternatively, was the single barrel tested a
lemon? Did we just happen to buy the one barrel shipped to that vendor that had
some defect unrecognized at the manufacturer? Testing one barrel is very easily
disregarded as a ‘fluke’ should the results not be as anticipated or desired by the
reader. For this evaluation the decision was to purchase two barrels from each brand
provider. It is assumed the chances of a perfect specimen or lemon is less likely to
occur in pairs, which also happened to arrive at the same vendor at the same time. In
some cases, vendor stock required us to purchase identical barrel models, branded the
same, from different vendor sources, again suggesting that the barrel sample was
random and theoretically more representative of the brand provider’s overall barrel
inventory available to the public in general.
To research the various barrels in an unbiased fashion, all barrels were purchased from
a third-party vendor. None were purchased direct from the brand provider, none were
donated or on loan by the brand provider for study. No brand provider was aware of
the study prior to barrel acquisition. This strategy should eliminate any chance of
‘cherry picking’ by a vendor or brand provider. Since all barrels were purchased at
retail price, no bias should be present related to financial favoritism from a brand
provider.
As stated above, two barrels were purchased from each brand, however there was one
exception. The Glock 17 OEM threaded barrel was very difficult to locate.
Unfortunately, only one test barrel was available. Because only a single Glock OEM
threaded barrel was tested, the data associated with that barrel must be scrutinized
closer. Does that barrel fit into the ‘perfect specimen’ or ‘lemon’ category? This
must be considered more so than with the other barrels evaluated. The barrel
specifications are provided below for your review. While all the barrels procured for
the evaluation are stated to be Glock 17 drop-in threaded barrels, there are notable
differences in dimensioning between brand providers. See Table 1.
Table1(listedinordertested)
RIFLING
IDENTIFIER
LENGTH*
TWIST
MATERIAL
FINISH
MSRP
TECHNIQUE
BLACKLIST 1
5.190”
1:10
BROACH
416R STAINLESS STEEL
STAINLESS
$214.99
BLACKLIST 2
5.110”
GLOCK OEM
5.315”
1:9.8
UNKNOWN
UNKNOWN
UNKNOWN
NA
KKM 1
5.106”
“PROPRIETARY
“416 GUN BARREL
1:10
STAINLESS
$230.00
BUTTON”
QUALITY STAINLESS”
KKM 2
5.106”
ALPHA WOLF 1**
5.030”
SALT BATH NITRIDE
1:16
BUTTON
416R STAINLESS STEEL
$159.95
(SBN)
ALPHA WOLF 2**
5.030”
S3F 1
5.005”
PULLED
1:10
416R STAINLESS STEEL
BLACK NITRIDE
$190.00
BROACH
S3F 2
5.005”
SILENCER CO 1
5.001”
1:10
UNKNOWN
416R STAINLESS STEEL
BLACK NITRIDE
$226.00
SILENCER CO 2
5.002”
STORM LAKE 1
5.194”
1:16
BROACH
416R STAINLESS STEEL
STAINLESS
$260.00
STORM LAKE 2
5.195”
ZEV 1
4.995”
“PROPRIETARY”
“CUT RIFLED”
416R STAINLESS STEEL
DLC
$250.00
ZEV 2
4.995”
*-Lengthwasmeasuredfromtherearmostpartofthechamberhoodtothemuzzle,doesnotrepresentlengthofrifledbarrel.
Measurementerrortolerance+/-0.002”
**-AlphaWolfisthemodeldesignationgivenbyLoneWolftotheirnewmadeintheUSAlineofbarrels
-Alldataobtainedfrombrandprovider’swebsitesordirectemailquestioning
-MSRPobtainedfrombrandprovider’swebsite
-BLACKLISTbarrelswereobtainedseveralmonthsapart,BLACKLIST1obtainedinJanuary,2015,BLACKLIST2obtainedin
June,2015.Brandproviderreportschangingdesignspecsbetweenthetwotestbarrel’smanufacturingperiods.
Ammunition
The ammunition type and source was examined carefully for use in this barrel
comparison. Our study goal was to identify which barrel might perform best for the
consumers that are purchasing the barrels on the open market. It was determined
that commonly accessible, economical ‘target ammunition’ should be compared. It
was also determined that comparing a commonly accessible, ‘defensive ammunition’
would be appropriate. Lastly it was determined there should be a ‘control
ammunition’. The purpose of the control ammunition would be to identify problems
with the barrel test fixture setup. It was proposed that if evaluation was only using
two commercially available ammunitions and a barrel grouped poorly, how would the
evaluator know if the barrel fixture had a problem with the setup, or did they witness
poor ammunition consistency, or was it actual poor barrel performance? It was
determined that we needed to identify an ammunition source that had proven
performance and consistency. Using this ammunition, it would be relatively
identifiable by the first grouping using the control ammunition, whether the barrel had
shifted or moved in the fixture between string shots, an apparent fixture setup
problem. The control ammunition would theoretically eliminate the variable of
inconsistent ammunition as well. The test barrel sample, firing the control
ammunition, should demonstrate relatively good grouping if the fixture to barrel
interface was of good quality and constant. With these two variables relatively
eliminated by verification with the control ammunition, the only factor left to cause
poor grouping of the defensive and/or target ammunitions would be actual barrel
performance.
It is important that the reader recognize while this may appear to be an evaluation of
control ammunition vs. defensive ammunition vs. target ammunition, that is not the
study’s design or intent, nor is it a reasonable comparison to make. The three
ammunitions are far too different in their overall manufacturing process and design to
be compared in such a manner. It is important that the reader understand the control
ammunition is used simply to identify a problem with the test platform setup.
Control Ammunition
Atlanta Arms based in Atlanta, Georgia began developing ammunition several years
ago, specifically with the cooperation and guidance of the United States Army’s
Marksmanship Unit or AMU. The AMU’s ammunition testing platforms were used to
evaluate Atlanta Arms ammunition until they met the strictest requirements set by the
AMU to be used in their world class competition team guns. Atlanta Arms reached this
quality benchmark and has sustained it as the AMU continues to test their ammunition
quality with every bulk purchase for their team. Atlanta Arms markets this very same
ammunition on their company website under the name “9MM 115GR FMJ Match
AMU”. Members of this barrel evaluation team visited the AMU at Ft. Benning,
Georgia in September 2016, just prior to testing, to confirm the ammunition details
and quality control. Once verified, the AMU ammunition was chosen to be the ‘control
ammunition’ for our testing platform. Lot number of the control ammunition used is
629165; this number was verified on every box of control ammunition used.
Defensive Ammunition
Federal 147gr jacketed hollow-point (JHP) with the manufacturer SKU of 9MS was
selected as the ‘defensive round’ used in the evaluation. It was determined that this
round was commonly available to the general public and possessed the necessary traits
to be considered a reasonable defensive round choice. The round is reported to
possess a 147gr jacketed hollow-point bullet with a reported muzzle velocity of
1000fps. All of the ammunition tested was purchased at the same time and is believed
to be from the same lot due to the bulk packaging style, however lot number was not
identified on the packaging and this cannot be confirmed at this time.
Target/Practice Ammunition
Remington UMC 115gr full metal jacket ball-nose ammunition was selected for use as
the ‘commonly accessible, economical target ammunition’. This ammunition appears
to be commonly available through a number of sources and is economically priced.
The round is reported to possess a metal case 115gr bullet, ball nose in style, with a
reported muzzle velocity of 1145fps. It is assumed the entire supply of ammunition
used was manufactured from the same lot however no lot ID could be found and this
assumption is based on the bulk packaging style only. Lot number identification
cannot be confirmed at this time.
Test Platform
The test platform designed and constructed at Fire 4 Effect Weapon Systems is based
upon previous designs employed at the AMU. The platform consists of a solid base,
mounted into the ground with a receiver at the top. This test platform is constructed
to tolerate and minimize vibration and/or movements of any kind from the
surrounding environment. The receiver then has the barrel fixture attached using
appropriate fasteners to assure a solid, movement free interface. Finally, the barrel
fixture is designed to clamp the test barrel into a solid steel housing that traps the
barrel and arrests any position change during firing. The muzzle end of the fixture has
an adjustable support that mimics the interface between the slide and the barrel,
thereby simulating the support provided by the slide and any barrel harmonic damping
properties as well. Simply put, each barrel is mounted and locked down, in a manner
identical to every other barrel in the test series. Any influences from the fixture itself
on the barrel’s performance, are constant and without change through the barrel test
sequence. The test fixture is designed with a breech, which can be opened between
shots for reloading without any manipulation of the barrel. The test platform is
located at the Fire 4 Effect Proving Grounds & Test Facility, a fully enclosed shoot
house/range with climate control and secured access. The facility creates an ideal
environment to test projectile motion with minimal environmental influence.
Target & Target Distance
Heavy grade, white construction paper of the same quality and type used in
international competition paper targets was used. This paper is used because of its
tendency to create clean well-defined holes when penetrated by projectiles,
specifically hollow-point style. Since point of aim (POA) was not evaluated in this
test, no markings on the target paper were required.
Target distance was considered thoroughly. The AMU tests their barrels at 25 and 50
yards. They do this because their competitors shoot these distances in many of their
competitions. The FBI uses a 25-yard target distance in their tests. There is no
documentation that we could find explaining their rationale for the 25-yard distance.
It was stated by professionals involved in the industry at the AMU, that the FBI elected
to use the 25-yard distance simply because that was the first distance the AMU had
begun testing at. We have no evidence to confirm or deny this claim.
Fire 4 Effect elected to use a 20-yard range. Data reported in the Law Enforcement
Officers Killed & Assaulted report, which can be found at the FBI website tracks the
distance between an LEO officer killed and the offender. There is no other source for
credible ‘gunfight distances’ that could be located. Table 36 of that report only
reports distances where LEO officers were killed in a gunfight. Per that table, from
2003 to 2012, 493 officers were killed in a gunfight. Of those 493, 423 (85.8%) were
killed from a distance of 50 feet (16.7yards) or less. It can be surmised that any barrel
performing as intended at 20 yards, will perform as intended for over 85.8% of
probable lethal self-defense scenarios, statistically speaking. It is worth noting that
the farther the target is placed from any test barrel, the larger the group size is likely
to become. Our testing indicated that 20 yards demonstrated adequate distance to
demonstrate measurable group size changes from barrel to barrel, ammunition to
ammunition.
Test Procedure
The testing protocol is an internal document created by the testing team at Fire 4
Effect. It can be examined at the Fire 4 Effect website (www.fire-4-effect.com) in
the Proving Grounds Section. To summarize, each barrel was tested with the following
steps. The barrel is placed in the test fixture and secured per protocol. Once secured
and the range condition is safe for live fire, a single “spotter round” is fired using the
UMC 115gr ammunition at the designated paper target backer, fixed 20 yards
downrange from the barrel. With the spotter indicating the general area anticipated
for POI, a clean target is mounted with the spotter round hole roughly centered
behind it. Next a string of ten rounds is fired from the test barrel using the control
ammunition. Each round is chronographed and recorded. When the ten round string is
complete, the target is retrieved and inspected for grouping. If grouping is consistent
with the known grouping capabilities of the control ammunition (approximately 0.91.5” extreme spread), the barrel is considered properly mounted and secured in the
fixture. If the grouping is too large or contains characteristics of barrel movement in
the fixture between string shots (obvious flyers, linear ‘climbing’ patterns, etc.), the
barrel is removed from the fixture, re-mounted per protocol and the control ammo
sequence is repeated on a new clean target. Once the barrel passes the control ammo
phase it is considered properly mounted for testing. The barrel is then tested using
the same string shot sequence on two new targets using the two test ammunitions,
Federal 147gr and UMC 115gr. Once the three targets are acquired (control, Federal
147gr and UMC 115gr), all chronograph speeds are logged into the test databank and
the target penetrations are measured for horizontal spread, vertical spread and
extreme spread using a Mitutoyo dial caliper.
Results
The results of the barrel tests were recorded in an excel spreadsheet on a computer as
the test was conducted. Various analyses were performed on the data to identify
patterns or calculations that would help understand the information gleamed.
Chronograph
Because each round fired was chronographed, data sets were acquired for each barrel
and ammunition combination. Evaluation of the low, high and average speeds of each
10-shot string as well as the variability was completed. The low, high and average
speeds are fairly self-explanatory. It was discovered that the advertised velocity and
measured velocities while similar were not the same. Across the board, the
ammunition didn’t average the advertised velocity; they were routinely lower. The
variability, in layman’s terms, suggests how consistent the ammunitions velocity was
in a specific barrel. Variations in the ammunition’s assembly can certainly contribute
to this velocity variability and when hand loading, it is attributed solely to the
ammunition assembly because it’s being tested in a single firearm. However, while
reviewing our data it was peculiar that ammunition from the same lot, the same box
of 50, would have such large variability for 10 rounds, then immediately change to
much lower variability the next 10 rounds when a different barrel was employed, only
to again jump back up with the next barrel change. This pattern suggests that the
barrels are culpable for the velocity variability, not the ammunition assembly. It is
theorized that the chamber sizes, throat depths and overall barrel internal finish are
the likely causes. A large or loose fitting chamber, while easier to chamber and
arguably more reliable in a semi-automatic platform, allows for more pressure leak
and round shifting (if irregularly shaped). This would alter combustion pressures and
resultant velocities. Longer throats can allow the bullet to begin traveling down the
barrel sooner in the powder ignition phase, thereby altering case pressures, chamber
seating and ultimately velocities achieved. Differing barrel finishes can allow the
round to move down the barrel easier or with more friction depending on the finish.
Both of these alter velocity by altering the pressure buildup behind the bullet as the
powder combusts as well as bullet residue or transfer as it moves down the barrel. It
is notable that the average variability for the three ammunitions demonstrated that
the Federal 147gr ammunition varied the least in the test samples, with the Atlanta
Arms following and the UMC ammunition a more distant third in rank. One might
interpret this to mean that the barrel’s overall, ‘fit’ a Federal 147gr bullet better than
the other 115gr rounds used. Because only a single 147gr ammunition was used in the
evaluation, this is speculative. One might also assume that the barrels demonstrating
the lowest variability have the best chambers, throat depths and finish, this would
theoretically translate to better performance. However, when comparing the best
chronograph variability barrels to the best average group sizes, the data doesn’t
reinforce the theory at all.
For example, it was noted that the majority of barrels grouped best using the Atlanta
Arms control ammunition. This was the anticipated result as it was certain that the
Atlanta Arms performance consistency would be superior, as already proven through
years of testing at the AMU. To demonstrate the lack of relationship between
chronograph variability and group size, refer to the table below. This table list from
left to right, the barrel identification, the ten shot string variability of the control
ammunition and lastly, the average of the measured horizontal, vertical and extreme
spreads from the same shot string. (The barrels are listed in the order tested nothing
else is implied.)
IDENTIFICATION
BLACKLIST 1
BLACKLIST 2
GLOCK 17
KKM 1
KKM 2
ALPHA WOLF 1
ALPHA WOLF 2
S3F 1
S3F 2
SILENCER CO 1
SILENCER CO 2
STORM LAKE 1
STORM LAKE 2
ZEV 1
ZEV 2
VARIABILITY
671.51
174.54
179.51
356.54
256.06
410.40
305.88
158.46
168.01
298.32
333.79
264.54
384.68
670.84
806.68
GRP AVG
1.05
0.87
0.68
0.73
0.99
1.13
1.49
0.72
0.96
0.85
0.68
0.92
0.82
1.21
1.38
The table above demonstrates that the barrel identified as S3F 1 demonstrated the
lowest variability, 158.46 (underlined) for the control ammunition. However the
average shot string group in barrel S3F 1 was 0.72”. Meanwhile the tightest average
grouping to two significant figures, 0.68” (underlined) was a tie between barrels
identified as GLOCK 17 (OEM) and SILENCER CO 1. Interestingly, the variability for
those two barrels was 179.51 and 333.79 respectively. Overall one might argue the
variability approximates ultimate performance. In some instances, such as ZEV 2 with
the highest variability and the largest grouping this appears to confirm the theory but
is significantly off as in the case of SILENCER CO 2 with the seventh highest variability
of fifteen, but tied for first in smallest grouping average.
While the chronograph data is intriguing and a bit counter-intuitive, it is somewhat
distracting from the more relevant data, shot string grouping. Ultimately that’s where
the real performance is demonstrated. Does the barrel place the round in the same
spot when fired at the exact same location every time?
Shot Grouping
Shot grouping is arguably the best indicator of a barrels performance regarding
accuracy. For a barrel to be “accurate” it needs to place the round at the desired
point of aim (POA) every time. Typically, to achieve this, the barrel is fired over and
over while the sights are adjusted to align the POA with the point of impact (POI). For
this strategy to work, the barrel must consistently place the bullet in the same
location at the same distance as long as the barrel is not moved. This grouping
consistency therefore defines the barrel’s “accuracy”.
Each ten shot string’s horizontal spread, vertical spread and extreme spread were
measured using a Mitutoyo dial caliper. Measurements were made from penetration
centers as best as could be determined with the unassisted eye. As such, some room
for error in measurement must be assumed. A tolerance measurement is not
provided, as there’s simply no way to give an accurate measured value here. For
purposes of this evaluation, the evaluation team is confident of an error rate of no
more than twenty-five to fifty thousandths (0.025-0.050”) of an inch exists. In the
table below, we list the following data from left to right. Barrel identification,
Atlanta Arms control ammunition group measurements, Federal 147gr group
measurements and finally Remington UMC 115gr group measurements. Barrels are
listed in the order tested nothing else is implied. Group sizes are in inch units.
BLACKLIST 1
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.785
0.600
1.490
HORIZ SPREAD
1.175
1.080
2.050
EXTREME SPREAD
1.175
1.080
2.050
CUMULATIVE AVG
1.045
0.920
1.863
BLACKLIST 2
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.930
0.978
1.565
HORIZ SPREAD
0.740
0.740
2.751
EXTREME SPREAD
0.930
1.170
2.751
CUMULATIVE AVG
0.867
0.963
2.356
GLOCK 17
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.662
1.105
1.050
HORIZ SPREAD
0.680
1.483
0.775
EXTREME SPREAD
0.695
1.780
1.110
CUMULATIVE AVG
0.679
1.456
0.978
KKM 1
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.715
0.770
1.510
HORIZ SPREAD
0.580
0.870
1.375
EXTREME SPREAD
0.908
0.900
1.790
CUMULATIVE AVG
0.734
0.847
1.558
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.910
1.080
1.920
HORIZ SPREAD
0.950
1.585
1.110
EXTREME SPREAD
1.103
1.763
2.203
CUMULATIVE AVG
0.988
1.476
1.744
ALPHA WOLF 1
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.690
0.665
1.630
HORIZ SPREAD
1.260
0.740
1.680
EXTREME SPREAD
1.430
0.740
1.975
CUMULATIVE AVG
1.127
0.715
1.762
ALPHA WOLF 2
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
1.610
0.750
1.455
HORIZ SPREAD
1.214
0.745
1.890
EXTREME SPREAD
1.650
0.810
2.020
CUMULATIVE AVG
1.491
0.768
1.788
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.675
0.860
1.260
HORIZ SPREAD
0.680
0.790
1.030
EXTREME SPREAD
0.790
0.860
1.465
CUMULATIVE AVG
0.715
0.837
1.252
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.625
1.230
1.062
HORIZ SPREAD
1.120
0.815
1.092
EXTREME SPREAD
1.120
1.420
1.270
CUMULATIVE AVG
0.955
1.155
1.141
SILENCER CO 1
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.670
1.130
0.130
HORIZ SPREAD
0.890
0.608
1.080
EXTREME SPREAD
0.983
1.151
1.250
CUMULATIVE AVG
0.848
0.963
0.820
SILENCER CO 2
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.580
0.515
1.470
HORIZ SPREAD
0.630
0.760
0.688
EXTREME SPREAD
0.840
0.765
1.470
CUMULATIVE AVG
0.683
0.680
1.209
KKM 2
S3F 1
S3F 2
STORM LAKE 1
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.780
0.580
0.750
HORIZ SPREAD
0.930
0.826
1.021
EXTREME SPREAD
1.060
0.919
1.081
CUMULATIVE AVG
0.923
0.775
0.951
STORM LAKE 2
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
0.885
0.650
1.693
HORIZ SPREAD
0.570
0.920
1.820
EXTREME SPREAD
0.990
0.935
2.180
CUMULATIVE AVG
0.815
0.835
1.898
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
1.335
1.135
1.640
HORIZ SPREAD
0.866
0.960
1.760
EXTREME SPREAD
1.420
1.408
2.220
CUMULATIVE AVG
1.207
1.168
1.873
ATLANTA ARMS
FEDERAL
UMC
VERT SPREAD
1.040
0.740
1.370
HORIZ SPREAD
1.490
0.850
1.963
EXTREME SPREAD
1.610
1.020
2.070
CUMULATIVE AVG
1.380
0.870
1.801
ZEV 1
ZEV 2
Discussion
The data in the table above was organized in the order the barrels were tested. No
other factors were involved in the table’s design. This is intentional. It is left to the
reader to identify the data they deem most useful. Ranking of barrels based on a
specific performance measurement is premature, as other measurements will almost
invariably disqualify the ranking assigned. Some very interesting points can be taken
away from this comparison however.
Please note that the single Glock OEM barrel performed remarkably well with the
control ammunition however its performance with the test 147gr ammunition was
much less impressive. While we must consider this is a single barrel, basically an
‘unacceptable’ sample size, it’s performance is remarkable none the less. When one
considers the barrel twist in an OEM barrel is 1:9.8, the tightest twist of all the barrels
compared, it makes this performance even more puzzling. Traditionally tighter twists
were utilized with heavier bullets to allow the bullet to reach stabilization during
trajectory better. The opposite appears to have been demonstrated here. The
tightest twist fired the lighter projectile best. This is further demonstrated or
reinforced by the Alpha Wolf barrels. They provided the smallest and third smallest
groups using the 147gr ammunition, but their barrel twist is a remarkable 1:16, the
slowest twist of the barrels compared. These findings are completely opposite of
traditional theory. Another interesting finding was noted regarding barrel length. A
top performer in the group size was the Glock OEM barrel. It is also the longest barrel
evaluated. This is consistent with commonly accepted ballistic theory and firearm
design, the longer the barrel, typically the more accurate the firearm. However, the
Silencer Co barrels were arguably the best overall performers but are also the shortest
barrels in the group. While reviewing the data in the tables above, the reader will
undoubtedly reach many assumptions regarding various barrel’s performances. We
caution the reader and ask they consider the following.
The Glock OEM barrel was the only one tested. The sample size is therefore one. This
would disqualify it from any serious statistical analysis and as such its data should be
considered curious or provocative at best. All of the other brand provider’s barrels
tested were again, an exceedingly small sample size, two. While designed in an
attempt to eliminate the likelihood of a ‘lemon’ being tested or a ‘perfect specimen’
being tested, it still may have happened. The number of rounds fired from each
ammunition source was only ten rounds, again, a very small sample size. From a
statistical perspective alone, this comparison is exceptionally weak and has no
significant statistical power.
From a performance results perspective it should be noted that the absolute worst
spread measured from any barrel using any ammunition was 2.751 inches. In other
words, every single barrel tested could hold a ten shot group of 2.751” or better, at 20
yards. We challenge the reader to shoot a better group with any Glock 17 pistol barrel
at that distance. If you can, then, and only then, might you consider looking for a
better barrel. Using the best performing ammunition overall, the control ammunition,
the worst grouping from any barrel was 1.65”. Again, if the reader can shoot a ten
shot group 1.65” or tighter using Atlanta Arms ammunition, there are some paid
competitive teams looking for you. All of the barrels performed well, especially
considering the intended application for their use and the distance tested.
This report invites further testing with larger sample sizes, both in number of barrels
tested per brand provider and number of rounds fired for group measurements. It
would also invite further investigation into barrel twist rates correlated to bullet
weight, specifically in pistol length barrels.