Glock G19 and G17 Aftermarket Match Grade Barrel Test Stock Feddersen Faxon ZEV and KKM Tested
For the vast majority of Glock shooters, practical accuracy is far more relevant than what a Glock can deliver when bolted onto a bench fixture, but we still all hope Glocks aftermarket barrels are a drop-in accuracy fix. Every buyer has the same question - “Will a match grade aftermarket barrel really deliver an accuracy improvement?” According to my testing, the answer is it depends.
Many times I have noted that aftermarket Glock barrels are questionable upgrades for buyers looking for a magic fix to improve 7-yard accuracy especially with budget blasting ammo. During a tour a few years ago inside Glock, I observed Glock’s own in-house pre-shipment testing which assures every Glock going out the door can deliver 1-inch 25-yard groups from a shooting fixture - factory Glock barrels have the potential to be plenty accurate.
In a previous article, I noted an example test where I fed my very accurate KKM barrel complete junk 9mm Maxx Tek 115gr ammo which netted a horrible giant group, but then to prove the point further I then proceeded to shoot a group a third the size with the stock factory Glock barrel with the same ammo. This previous test was just to showcase an extreme example that premium barrels really require premium ammo to outperform stock Glock barrels.
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Faxon Glock G19 G17 Barrels
featured 90-degree recessed match crowns |
This test confounds people, because after all, why would a premium barrel not always shoot better. The reasons are pretty simple. Most match grade Glock barrels such as Wilson, Storm Lake, KKM and others have historically feature a slower 1:14, 1:16, or 1:20 twist designed to stabilize heavier match grade rounds. In the case of KKM barrels they were specifically designed for 147gr Hornady Tap bullets, but they can shoot 115gr rounds pretty well also depending on the ammo. The 1:9.84 factory Glock barrel twist rate by comparison is fast compared to match barrels; in some cases almost twice as fast. The faster twist is usually more optimal for lighter and usually less expensive 115-124 grain rounds, while also tending to offer better bullet stabilization of less concentric bullets.
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| Feddersen Glock G19 G17 Barrels |
The other reason for improved accuracy with cheap ammo is that factory Glock hexagonal rifling by the design forces even crappy wobbly bullets to center up correctly, heavily distort/deform them to the point that pretty much any round shoots fairly well and usually shoot to about the same point of aim. The problem is that this hex rifling also heavily distort those perfectly concentric match grade rounds, so stock barrel you do not deliver the huge accuracy improvements from super accurate bullets. The less aggressive button rifled match barrels allow those premium match bullets to shine, but do not suffer fools who feed the match barrels cheap rounds.
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| Faxon Glock G19 G17 Barrels |
WHAT AMMO GRADE AND DISTANCE IS WORTH THE UPGRADE?
I was anxious to repeat my previous test with good quality mid-grade FMJ practice rounds. The test included the brand new Glock 17 and Glock 19 match grade barrels from Feddersen and Faxon along with my proven KKM, ZEV and factory barrels shot from a Gen 4 G19 with Apex Trigger and Gen 4 G17 Salient with Salient Trigger. My hope was to understand what ammo quality and shooting distance delivered a noticeable improvement after a barrel upgrade. A lot of other industry tests have focused on ransom rest testing at 25-50 yard ranges, but I wanted to go at this a bit differently because and I have always been focused on practical accuracy delivered as the gun is typically shot - I never shoot a pistol off a ransom rest in the field and want to know the results I can expect in the field.
After a little testing of a variety of ammo, I found that about 30 cents a round for factory FMJ range ammo was the point where there became a noticeable statistical accuracy advantage upgrading to a “match grade” barrel. Typically ammo of this grade is priced around $15-$25 per box of fifty. Using ammo under that tier of ammo quality, the factory barrel generally delivered similar or noticeably better accuracy than match barrels. As a good representation of “good quality” range ammo, the final testing ammo was 9mm Fiocchi 115gr FMJ, Sig Sauer 115gr FMJ, 124gr FMJ, and Winchester White Box 124gr FMJ. Notable 147gr rounds were not used because these are usually not “typical” range ammo most people shoot or that is widely available as range ammo unless you are a reloader.
Through a variety of test shoots and a lot of measuring, 15-yards seemed to deliver statistically significant and visually notable differences between factory and match barrels shooting mid-grade ammo. 15-yards is also the range at which most people can precisely still see the target with acuity. Sure most of us shoot well beyond that range and many NRA matches shoot at 25 and 50 yards, but 15-yards is a practical distance for most shooters to still see the inner bullseye crisply.
Of course there are Ransom Rests and all sorts of supports, but I had enough faith in my bullseye shooting abilities to go at this 15-yard test with dual sets of standing unsupported five round averaged groups. The worse flyer was thrown out of each group to remove a portion of my influence and allowed the two average groups to tell the accuracy story. A better shooter could certainly improved the groups, but this test is a group average good enough to give readers an idea of what each barrel can do. As you can see on some of these groups, these barrels were certainly capable of impressive accuracy.
TESTING - FEDDERSEN, FAXON, KKM, ZEV & FACTORY BARRELS
With the ammo selected and a 15-yard test based on dual averaged four-round groups, I was ready to test. An indoor range was used during off hours to assure I was not startled or unduly stressed from booming gunfire and I started working through testing. If I saw more than a 50% difference between the first and second group sets, I reshot the groups. Around 500 rounds later I felt I had a fair representation of what each of the barrels could deliver.
Though I am more of a steel banger with my Glocks, I will on occasion bulls-eye shoot to tighten up my groups. The results recorded some of my best Glock shooting ever which included several sub-1” groups, but most importantly I was able to show statistically how a match grade barrel Glock can start to improve accuracy.
Below are my accuracy results for the 15-yard four-round groups. With an air of caution, my suggestion is to look at this grid and the Average group size and Average % Improvement to understand the type of accuracy jump you can expect if you test through to find your Glock’s prefered practice round. This should not be used as a crib sheet of which ammo to feed each barrel. Every barrel, recoil spring variance, and trigger setup will shoot differently in every gun - in a few cases my setup was lucky. The net of this test was that the KKM, ZEV, Faxon and Feddersen barrels really started to shine at the 15-yard line with mid-grade practice ammo.
Though work was done to attempt to make sense from a trend perspective of which twist rate or barrel liked what bullet weight, the results captured seem to indicate that each barrel simply had preferences or disdain for particular rounds. For whatever reason the KKM really seemed to be all over the place on both the G19 and G17 depending on the ammo used. By contrast the Faxon has the smallest Standard Deviation and thus were more consistent across various ammunition.
(note my original post had some minor formula issues which have been corrected)
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Fiocchi 115g FMJ |
Sig 115gr FMJ |
Sig 124gr FMJ |
Winchester White Box 124gr FMJ |
AVG |
Min |
Max |
Standard Deviation |
Avg % Group Improvement over Stock G19 Barrel |
| Glock G17 Feddersen 1:9.84 |
1.756 |
1.461 |
0.804 |
1.118 |
1.285 |
0.804 |
1.756 |
0.413 |
48.8% |
| Glock G17 Faxon 1:10 |
1.778 |
1.301 |
1.178 |
0.859 |
1.279 |
0.859 |
1.778 |
0.381 |
49.0% |
| Glock G17 KKM 1:14 |
1.275 |
2.398 |
3.714 |
1.763 |
2.288 |
1.275 |
3.714 |
1.056 |
8.9% |
Glock G19 Stock 1:9.84
(Control) |
2.322 |
3.083 |
2.073 |
2.571 |
2.512 |
2.073 |
3.083 |
0.431 |
Stock |
Glock G19 Feddersen
1:9.84 |
1.517 |
0.523 |
2.525 |
1.866 |
1.608 |
0.523 |
2.525 |
0.835 |
35.9% |
Glock G19 Faxon
1:10 |
1.549 |
1.960 |
1.829 |
1.916 |
1.814 |
1.549 |
1.960 |
0.185 |
27.7% |
Glock G19 KKM
1:14 |
1.423 |
2.398 |
3.724 |
1.763 |
2.327 |
1.423 |
3.724 |
1.015 |
7.3% |
Glock G19 ZEV
1:10 |
1.581 |
2.145 |
2.989 |
1.694 |
2.102 |
1.581 |
2.989 |
0.639 |
16.2% |
ABOUT THE BARRELS
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| Faxon Glock G19 G17 Barrels |
Faxon - Faxon has come out of the gate hard with arguably some of the most accurate production priced AR15 barrels I have tested. In nearly every test we have completed, even the company’s ultra-light pencil profile barrels have far outperformed heavy typical mil-spec barrels delivers some shockingly small sub-MOA groups. Faxon has now introduced Glock Match Grade barrels. This was my first opportunity to test them and I am again impressed with the barrels. The Faxon G17 delivering the third best overall group and the second smallest group on the G17 platform and overall were the most consistent from round to round. Considering they are offering threaded options, custom fluting and color finishes at around $220 a barrel, I am positive they will become an instant hit.
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| Feddersen Glock G19 G17 Barrels |
Feddersen - Fred Feddersen is widely considered as the barrel genius in the gun industry and the inventor of dual patented SEPR (Single Edged Polygonal Rifling). Fred has received two patents on the SEPR rifling. Feddersen manufacturers match grade barrel blanks many companies use for their barrels and the company is now making Glock unthreaded and threaded and 1911 barrels with the SEPR technology. Noting that the Feddersen G19 and G17 delivered the top two shockingly small groups of this test… and yes folks those were dual 4-shot group averages with the ammo. These were test barrels and not for sale yet, but I hope that Feddersen is intending to get this on his site and into distribution right away based on my tests.
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| KKM Glock G19 G17 Barrels |
KKM - KKM has been long considered the top Glock match grade barrel for nearly ten years and still delivers some impressive groups. This test specifically was a little unfair to the 1:14 twist rate KKM because this barrel loves 147gr match rounds and really starts to strut its stuff at 25-yards and beyond. The KKM barrels can be a bit picky, but are amazing performing barrels when you find the rounds they like. KKM is still obviously delivering a dependable average 10% accuracy improvement with just range ammo. Feed this barrel the top tier ammo and groups drastically shrink.
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| ZEV Glock G19 G17 Barrels |
ZEV - ZEV initially noted that they use a proprietary rifling, but I have seen in more than one place a twist rate of 1:10 listed. ZEV is another fixture in the competitive Glock shooting circuit and has consistently been the barrel of choice for many pro shooters. ZEV was also the first company to offer “fancy” barrels with various finishes, threading, and even fluting for Glock barrels plus a huge line of Glock performance accessories. ZEV puts a lot of extra finishing into their barrels that you do not see elsewhere. They do deliver that wow factor and less picky than other faster twist barrels.
SHOULD I BUY A MATCH BARREL FOR MY GLOCK?
Aftermarket match grade barrels can improve accuracy with no impact on reliability. Through the course of planning, initial testing and final testing of eight different aftermarket barrels, I had zero functional issues with any barrel which is a great side note if you want to leave these barrels in your pistol for defense.
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| Faxon Glock G19 G17 Barrels |
The intent of this test was not to show which ammo shoots best in which barrel, or necessarily which barrel shots better, but to roughly prove that match grade barrel can deliver noticeable accuracy improvement at reasonable shooting ranges with reasonable priced ammo. Is it possible some other less expensive ammo would deliver similar result? Sure, but I was looking for a statistical rule of thumb for ammo quality to drive improvements with the match barrels.
Notably, these match grade barrels can statistically deliver accuracy improvements of 20%-100% over factory stock barrels, but at 15-yards that could only mean .5”-1” smaller group which could be a huge deal for buyers. The results proved that to me that these barrels do offer buyers an advantage at 15-yards and beyond. For the person intending on just shooting on the 7-yard line the difference would not be worth the investment.
Though I did not cover it in this test at 25-yards and 50-yards these match grade barrels can make a significant impact to hits on steel or scored bullseye groups. Feed these barrels the really great premium match ammo and I am positive this groups could improve further which could be another interesting test.
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