Long story short, I'm giving KAC small frame uppers another try after getting burned by them ~10yrs ago.
This thread will showcase my findings on how the current factory KAC SR-15 11.5" [with 3.2 BCG] upper stacks up against a few known good uppers to include a 11.5" FBI ODG "Fed" upper, a Centurion 11.5" upper, and a Colt 11.5" "Old HRT" upper for the comparison.
This study will span the next 2-3 months with updates at least every other week.
In this test, I'll be observing the following,
Reliability: This will be observed through the duration of the tests and across a number of ammunition types, paying close attention to ejection patterns with different buffer weights.
Accuracy: Groups will be shot out of the uppers with multiple types of match and non-match type ammunition, and will be documented.
Felt recoil: This will be measured using split times on drills. Presumably, split times will be faster on uppers that are gassed more efficiently [this will be tested suppressed and unsuppressed]. There will also be a subjective set of notes regarding this data point.
Balance: This will necessarily be subjective, but will be tested with the uppers slick, as well as with accessories on them. Overall weights with and without accessories will be noted.
Uppers to be tested:
-KAC SR-15 11.5" Mod 2 E3 with 3.2 BCG, with Aimpoint T2 on Unity 2.26" riser.
-FBI Fed near clone upper: FCD upper, BRT 11.5" barrel, Geissele "Fed" ODG HG, LMT E-BCG, and SF 4-prong FH, with Aimpint Comp M5 on Unity 2.26" riser.
-Centurion 11.5" flat top, A2 front sight, with FF extended C4 quad, and SF 4-prong FH, with Holosun RD on MI 1.93" riser.
-Colt heavy "Fed HRT" 11.5" flat top, A2 front sight, KAC RAS M4 HG, Bootleg Adjustable BCG, and SF Closed-tine FH, with Aimpoint Comp M5s.
Lower to be tested on:
LMT MARS factory lower [SBR] with SSA-E FCG and SOPMOD stock.
Known limitations of this casual study:
The primary control for the tests will be the home-built Fed upper with BRT barrel. Though it isn't a factory upper, it is the upper I have the most recent time behind. This should allow me to use it as a reliable benchmark for felt performance. In doing this, when I compare it against the Centurion and Colt upper, it will grant perspective on the overall standing it has in the group, thus providing a useful data set to compare against the KAC upper.
All of these uppers are samples of one. Each individual upper may not be representative of its brand or type. There may be defects in parts, or these examples may be exceptional when compared to the norm from these manufacturers.
A large portion of these tests could be construed as subjective. As a human I have my explicit, implicit, and unknown biases.
Final thoughts pre-study:
Pictures will come throughout the thread. [We all know that's what everyone wants.]
Please let me know if there's a data-point you want me to include or expand upon.
I hope this study puts into perspective the performance of decent upper options and helps someone make a decision on what to buy [or not buy].
I will be adding results to this first post as I they come.
Stay tuned!
Cheers!
Session 1
Actions Observed:
I took out the KAC and Gisele uppers.
100rds of PPU 55gr were fired through each.
I put a rough 50yd zero on each and played with targets from 20yds to 50yds.
I shot from the standing & kneeling testing my perceived ability to recover, get back on target, and take another shot.
Take Aways:
Failures: 0
The recoil impulse with both was smooth for a short barrel and carbine length gas system. They felt different, but at this point I couldn't quite explain why.
Learned: The KAC upper felt fine with the H buffer that was already in the lower, but ejection was weak; rounds were just falling out of the receiver at 4 o'clock. After switching to the provided KAC buffer, the upper was ejecting at normal strength to 3 o'clock.
The Geissele upper ejected roughly the same distance at 3 to 4 o'clock with both buffers. I believe this is due to the LMT E-BCG slowing the lockup and bleeding excess gas out of the extra hole in side of the carrier.
Session 2
Actions Observed:
I brought out all four 11.5" uppers, and a token 10.3" Crane spec suppressed rifle for flavor.
300rds of PPU 55gr and 60rds of Federal M855 were fired amongst all four of the 11.5" uppers.
The goal on this outing was to fire 3-6 round fast strings to gauge reliability, felt recoil impulse, how much the dot was jumping, and and how confident I felt in the follow-up-shots after each trigger pull.
I used the KAC buffer for all of these tests to keep it consistent. Ejection for all of the uppers was from 3-4 o'clock and they ejected at normal distance.
Take Aways:
Failures: There was one stoppage in the Centurion upper. One of the PPU cartridges didn't seat all the way in the chamber and the bolt was half way cammed into battery. The cartridge would not easily extract, so I collapsed the stock and mortared it without having to apply much force. I observed that the casing was dented below the shoulder. I don't know if it was loaded into the magazine that way or if it became dented upon ejecting it, but I put it back in the same upper and it fired/extracted/ejected just fine. Until I see more of a pattern, I'm going to chalk that one up as ammo related.
Dot Jump: The movement of the dot while firing quickly was similar amongst all of the rifles in the group. The Colt [old style] HRT upper was probably the worst, but not by much. The others were very comparable.
Felt Recoil Impulse and Confidence Getting Into the Gun: The felt recoil to my shoulder was similar between the KAC and BRT Geissele Fed upper, as was the Centurion similar to the Colt HRT upper. The interesting part was how the impulse displayed itself in each upper. The KAC seemed to have the most notable delayed impulse. It felt like it was punching my shoulder all the same as the Fed upper, but it was doing it in such a way that I felt more confident in driving the gun on target, getting into it, and shooting quickly. I'll have to repeat this test with a timer to determine if this is mostly perception or it I was faster on it.
The felt recoil impulse on the Centurion and the Colt were similar to each other, but the gross recoil was slightly more from the Colt. This was expected.
The Centurion and the Fed upper felt just as fast, but the recoil impulses were just different. The Centurion [by comparison with the Fed upper] had a more abrupt recoil impulse. With the dot jump being about the same, I found that I could knuckle down into the gun and shoot as fast wit the Centurion as I could with the Fed upper [just with more effort in thinking about controlling the gun through the string].
Suppressed: I couldn't help myself, so I fired 6rds through each upper with a Surefire SB2 [except I didn't shoot the KAC upper suppressed because I haven't changed out the muzzle device yet]. All of the uppers ran reliably without adjusting or changing anything. They all ejected to the 1 to 2 o'clock. The Fed upper felt the best so far as recoil impulse out of the bunch. There will be dedicated suppressor tests down the road.
Session 3
Actions Observed:
All four 11.5" uppers went out again, and 240rds of Patriot Sports 55gr FMJ was shot through them.
Patriot Sports ammo is Czech made and can be found for "cheaper" right now.
The goal was to shoot all of the uppers suppressed for this session, but time was tighter, so instead I ran reload drills and 3-10rds fast fire strings.
The KAC buffer stayed in the lower the entire time for all uppers.
Ejection with this ammo was at 3-3:30 [~5ft] for all of the uppers except the SR-15 which was at 4-5 o'clock and 7ft. This was interesting.
Take Aways:
Failures: 0
Felt Recoil & Dot Jump: I want to amend a previous observation. The more that I shoot these uppers, the more that I'm realizing the KAC upper is just different. The recoil in the SR-15 upper isn't less than the Fed upper with the BRT barrel. The recoil is certainly more, but the impulse is unique and inspires confidence in shooting quickly when getting into the gun. If you hold the gun [SR-15] loosely, almost like a novice would, then you definitely feel that it recoils more. The Fed upper recoils smoothly, and now I can confidently say has the least dot jump out of any of the uppers. The Colt upper and Centurion upper are still perceived as very similar to one another and both feel mil-spec in their performance.
I do have a SF muzzle device on the KAC now so hopefully we'll get some suppressed results soon!
Session 4
Actions Observed
All four of the 11.5" uppers went out to be suppressed.
The suppressor used was a Surefire SB2 5.56 can.
Roughly 300rds of the Czech made Patriot Sports 55gr ammo was used for this test divided equally between the uppers.
The KAC buffer remained in the lower receiver throughout the duration of this outing.
My goal was to test the uppers' ability to reliably shoot suppressed without changing anything.
During this session I observed ejection patterns as well as the felt recoil/dot jump in each upper.
Take Aways
Failures: 0
The Centurion and Colt upper were ejecting roughly 3' at 1-2 o'clock.
The Fed upper was ejection more confidently to 5' at 2 o'clock.
The KAC upper's ejection patterns surprised me. It was ejection 8' at 4 o'clock. This is very similar on paper to how it ejects unsuppressed.
So far as felt recoil, the KAC had noticeably increased recoil when shooting suppressed. Something to do with its bolts rate of unlocking while suppressed negated the nuances of the felt recoil I experienced unsuppressed. The recoil was now sharp and notable. It was still deferent than the Colt and Centurion uppers, but not in a good way. It was a different type of recoil made me less confident in getting fast rounds on target. The Colt and Centurion both felt similar and like many would expect for mil spec 11.5" uppers being suppressed. The Fed upper had the least felt recoil and dot jump out of the bunch when suppressed. This upper was the one which I was most confident in remaining fast and accurate with.
I suspect that [judging by the ejection patterns] the KAC upper would likely remain the most reliable while being suppressed over the long run and across different ammo types. This is assuming that ejection patterns are a tell for how well gassed a rifle is and how much room there is to play with factors affecting said gassing.
Session 5
Actions Observed
I brought out the Centurion and Colt uppers for accuracy testing.
I shot one 5-shot group with each of ammo type to get a feel for general accuracy potential from each upper.
The ammo types are the following. PMC 55rg FMJ, Black Hills 77gr SMK, FGMM 77gr SMK (.223), IMI 77rg SMK, & Frontier 75gr BTHP.
Scope that was used to test is a NF NXS 2.5-10 in a Giessele mount. Trigger in the lower used is a SSA-E.
Firearm was shot off of bags. All groups were shot at 100yds.
Take Aways
Failures: 0
Centurion accuracy results:
PMC 2.1"
Black Hills 1.1"
FGMM .5"
IMI 1.3"
Frontier 2.7"
Colt accuracy results:
PMC 3"
Black Hills 2"
FGMM 1.5"
IMI 1.1"
Frontier 1.6"
Thoughts:
I used five shot groups in an attempt to conserve my more expensive match grade ammo while still trying to showcase realistic performance of the cartridge/upper pairings.
The 5 shot group done with the Centurion upper using the FGMM was intersting. I'm curious if I can repeat those results.
The Colt upper was putting the IMI into a .5" pattern until I fired the last round. It's entirely likely that should have been a ~.5" group but then I got in the way of it.
In the Centurion, the PMC shot better than the Frontier "Match" ammo...
I was surprised by the results of both uppers. They both did very well in general for CHF CL mil-spec type barrels.
I'm excited to see what the Fed and KAC uppers will do.
Session 6
Actions Observed
I brought out the KAC and Fed uppers for accuracy testing.
I shot one 5-shot group with each of ammo type to get a feel for general accuracy potential from each upper.
The ammo types are the following. PMC 55rg FMJ, Black Hills 77gr SMK, FGMM 77gr SMK (.223), IMI 77rg SMK, & Frontier 75gr BTHP.
Scope that was used to test is a NF NXS 2.5-10 in a Giessele mount. Trigger in the lower used is a SSA-E.
Firearm was shot off of bags. All groups were shot at 100yds.
Take Aways
Failures: 0
KAC upper accuracy results:
PMC 1.9"
Black Hills 1.9"
FGMM .9"
IMI 1.1"
Frontier 2.2"
Fed Clone upper accuracy results:
PMC 2.1"
Black Hills 1.4"
FGMM 1.1"
IMI .9"
Frontier 3.6"
Thoughts: No real surprise, all four of these barrels shot at least "decent" with most of the match grade ammo. All but the Colt barrel had at least one sub minute 5-shot group and even it wasn't lagging too far behind the others. Frontier match ammo sucks. I should probably invest in more FGMM 77gr based on its performance in this test.
I found that I would feel confident in taking any of these uppers [with it's known good shooting ammo] to a DMR match, and probably do well with it under 500yds if needed.
I wish I could afford the time and ammo to shoot five 5-shot groups of each ammo type through each upper, but currently time and money are the resources I don't have. I hope the limited data provided here gives at least an idea of how each upper preforms accuracy wise.
Final Conclusions:
I must regrettably bring this review to a premature close. At least we got this far. I'm selling a house & buying a house, and need immediate funds to fix some things in the process. So I'm currently selling all but one of these uppers [as well as many other things] in order to take care of these rather important responsibilities.
None of the uppers performed poorly in any tests. They were all closer than I expected in the accuracy category.
Where they diverged the most in performance was with felt recoil while shooting them quickly. That's what I'll focus on for determining my winner.
So far as felt recoil, recoil impulse & shot recovery, balance, and maneuverability, the KAC and Fed clone upper stood out over the Centurion and Colt uppers. The Centurion and Colt uppers reminded me of what mil-spec M4's and MK18 Mod 0's felt like to get behind. I felt good behind them, but the KAC and Fed upper's made the rifle truly feel like next generation systems. They were simply more efficient feeling.
Now the elephant in the room: When separating these overall high performers, which one was better? The KAC SR-15 upper or Fed clone BRT barreled upper? Though they did feel different shooting wise, I still can't discern a clear winner. I found that both were easier to shoot faster [while maintaining baseline accuracy/precision] than the Colt & Centurion. They both also made it easier to maintain accuracy & precision while shooting faster. This is distinctly different. I would need much more time behind them both to refine my opinions further.
So is the KAC worth the squeeze? The SR-15 3.2 uppers are currently going for ~$2,000, while the Fed clone upper was put together for roughly 2/3's of the price. What's stopping you from combining a BRT barrel and LMT E-BCG on your quality upper and obtaining near [or even better] performance to the KAC 3.2 upper? Only availability. A few benefits of buying the KAC upper that immediately come to mind are having a manufacturer that will stand behind and warranty your product [though hopefully you'll never need that], and resale value.
So which one am I keeping?
Like in everything in life, there are many lenses which to view a situation through. I feel this necessary to state before giving my reasons for which one I would keep, and the answer would be different under different circumstances.
If I had plenty of money, I honestly would choose the KAC SR-15 as the keeper. It performed very well comparatively to the others, and is a factory upper which does bring a sort of "perceived" peace of mind.
If I wanted a bang-for-your-buck upper to maximize performance for the dollars, I'd keep the Fed upper. That BRT barrel is just gassed so well and I was surprised at how notably different it felt to the standard "crane spec" barrels. The downside to building your own is that there is no warranty, and if you ever need to sell it, you're either going to take a bath on it or it will at the very least be hard to sell whole or in parts.
Which one am I actually keeping?
I'm keeping the Centurion upper. I'm keeping it because it's possibly the least valuable and/or hardest to sell out of the bunch. As I said before, I'm trying to raise money right now, so this is probably the best decision from a financial standpoint. All of the uppers preformed great. Some were better, but being no stranger to Crane mil-spec quality, I can role with this upper just fine until I regain the capital to acquire another "high performance" upper.
I hope you enjoyed this as much as I have.
Feel free to ask me any questions, I'll be hanging around.
Cheers!
This thread will showcase my findings on how the current factory KAC SR-15 11.5" [with 3.2 BCG] upper stacks up against a few known good uppers to include a 11.5" FBI ODG "Fed" upper, a Centurion 11.5" upper, and a Colt 11.5" "Old HRT" upper for the comparison.
This study will span the next 2-3 months with updates at least every other week.
In this test, I'll be observing the following,
Reliability: This will be observed through the duration of the tests and across a number of ammunition types, paying close attention to ejection patterns with different buffer weights.
Accuracy: Groups will be shot out of the uppers with multiple types of match and non-match type ammunition, and will be documented.
Felt recoil: This will be measured using split times on drills. Presumably, split times will be faster on uppers that are gassed more efficiently [this will be tested suppressed and unsuppressed]. There will also be a subjective set of notes regarding this data point.
Balance: This will necessarily be subjective, but will be tested with the uppers slick, as well as with accessories on them. Overall weights with and without accessories will be noted.
Uppers to be tested:
-KAC SR-15 11.5" Mod 2 E3 with 3.2 BCG, with Aimpoint T2 on Unity 2.26" riser.
-FBI Fed near clone upper: FCD upper, BRT 11.5" barrel, Geissele "Fed" ODG HG, LMT E-BCG, and SF 4-prong FH, with Aimpint Comp M5 on Unity 2.26" riser.
-Centurion 11.5" flat top, A2 front sight, with FF extended C4 quad, and SF 4-prong FH, with Holosun RD on MI 1.93" riser.
-Colt heavy "Fed HRT" 11.5" flat top, A2 front sight, KAC RAS M4 HG, Bootleg Adjustable BCG, and SF Closed-tine FH, with Aimpoint Comp M5s.
Lower to be tested on:
LMT MARS factory lower [SBR] with SSA-E FCG and SOPMOD stock.
Known limitations of this casual study:
The primary control for the tests will be the home-built Fed upper with BRT barrel. Though it isn't a factory upper, it is the upper I have the most recent time behind. This should allow me to use it as a reliable benchmark for felt performance. In doing this, when I compare it against the Centurion and Colt upper, it will grant perspective on the overall standing it has in the group, thus providing a useful data set to compare against the KAC upper.
All of these uppers are samples of one. Each individual upper may not be representative of its brand or type. There may be defects in parts, or these examples may be exceptional when compared to the norm from these manufacturers.
A large portion of these tests could be construed as subjective. As a human I have my explicit, implicit, and unknown biases.
Final thoughts pre-study:
Pictures will come throughout the thread. [We all know that's what everyone wants.]
Please let me know if there's a data-point you want me to include or expand upon.
I hope this study puts into perspective the performance of decent upper options and helps someone make a decision on what to buy [or not buy].
I will be adding results to this first post as I they come.
Stay tuned!
Cheers!
Session 1
Actions Observed:
I took out the KAC and Gisele uppers.
100rds of PPU 55gr were fired through each.
I put a rough 50yd zero on each and played with targets from 20yds to 50yds.
I shot from the standing & kneeling testing my perceived ability to recover, get back on target, and take another shot.
Take Aways:
Failures: 0
The recoil impulse with both was smooth for a short barrel and carbine length gas system. They felt different, but at this point I couldn't quite explain why.
Learned: The KAC upper felt fine with the H buffer that was already in the lower, but ejection was weak; rounds were just falling out of the receiver at 4 o'clock. After switching to the provided KAC buffer, the upper was ejecting at normal strength to 3 o'clock.
The Geissele upper ejected roughly the same distance at 3 to 4 o'clock with both buffers. I believe this is due to the LMT E-BCG slowing the lockup and bleeding excess gas out of the extra hole in side of the carrier.
Session 2
Actions Observed:
I brought out all four 11.5" uppers, and a token 10.3" Crane spec suppressed rifle for flavor.
300rds of PPU 55gr and 60rds of Federal M855 were fired amongst all four of the 11.5" uppers.
The goal on this outing was to fire 3-6 round fast strings to gauge reliability, felt recoil impulse, how much the dot was jumping, and and how confident I felt in the follow-up-shots after each trigger pull.
I used the KAC buffer for all of these tests to keep it consistent. Ejection for all of the uppers was from 3-4 o'clock and they ejected at normal distance.
Take Aways:
Failures: There was one stoppage in the Centurion upper. One of the PPU cartridges didn't seat all the way in the chamber and the bolt was half way cammed into battery. The cartridge would not easily extract, so I collapsed the stock and mortared it without having to apply much force. I observed that the casing was dented below the shoulder. I don't know if it was loaded into the magazine that way or if it became dented upon ejecting it, but I put it back in the same upper and it fired/extracted/ejected just fine. Until I see more of a pattern, I'm going to chalk that one up as ammo related.
Dot Jump: The movement of the dot while firing quickly was similar amongst all of the rifles in the group. The Colt [old style] HRT upper was probably the worst, but not by much. The others were very comparable.
Felt Recoil Impulse and Confidence Getting Into the Gun: The felt recoil to my shoulder was similar between the KAC and BRT Geissele Fed upper, as was the Centurion similar to the Colt HRT upper. The interesting part was how the impulse displayed itself in each upper. The KAC seemed to have the most notable delayed impulse. It felt like it was punching my shoulder all the same as the Fed upper, but it was doing it in such a way that I felt more confident in driving the gun on target, getting into it, and shooting quickly. I'll have to repeat this test with a timer to determine if this is mostly perception or it I was faster on it.
The felt recoil impulse on the Centurion and the Colt were similar to each other, but the gross recoil was slightly more from the Colt. This was expected.
The Centurion and the Fed upper felt just as fast, but the recoil impulses were just different. The Centurion [by comparison with the Fed upper] had a more abrupt recoil impulse. With the dot jump being about the same, I found that I could knuckle down into the gun and shoot as fast wit the Centurion as I could with the Fed upper [just with more effort in thinking about controlling the gun through the string].
Suppressed: I couldn't help myself, so I fired 6rds through each upper with a Surefire SB2 [except I didn't shoot the KAC upper suppressed because I haven't changed out the muzzle device yet]. All of the uppers ran reliably without adjusting or changing anything. They all ejected to the 1 to 2 o'clock. The Fed upper felt the best so far as recoil impulse out of the bunch. There will be dedicated suppressor tests down the road.
Session 3
Actions Observed:
All four 11.5" uppers went out again, and 240rds of Patriot Sports 55gr FMJ was shot through them.
Patriot Sports ammo is Czech made and can be found for "cheaper" right now.
The goal was to shoot all of the uppers suppressed for this session, but time was tighter, so instead I ran reload drills and 3-10rds fast fire strings.
The KAC buffer stayed in the lower the entire time for all uppers.
Ejection with this ammo was at 3-3:30 [~5ft] for all of the uppers except the SR-15 which was at 4-5 o'clock and 7ft. This was interesting.
Take Aways:
Failures: 0
Felt Recoil & Dot Jump: I want to amend a previous observation. The more that I shoot these uppers, the more that I'm realizing the KAC upper is just different. The recoil in the SR-15 upper isn't less than the Fed upper with the BRT barrel. The recoil is certainly more, but the impulse is unique and inspires confidence in shooting quickly when getting into the gun. If you hold the gun [SR-15] loosely, almost like a novice would, then you definitely feel that it recoils more. The Fed upper recoils smoothly, and now I can confidently say has the least dot jump out of any of the uppers. The Colt upper and Centurion upper are still perceived as very similar to one another and both feel mil-spec in their performance.
I do have a SF muzzle device on the KAC now so hopefully we'll get some suppressed results soon!
Session 4
Actions Observed
All four of the 11.5" uppers went out to be suppressed.
The suppressor used was a Surefire SB2 5.56 can.
Roughly 300rds of the Czech made Patriot Sports 55gr ammo was used for this test divided equally between the uppers.
The KAC buffer remained in the lower receiver throughout the duration of this outing.
My goal was to test the uppers' ability to reliably shoot suppressed without changing anything.
During this session I observed ejection patterns as well as the felt recoil/dot jump in each upper.
Take Aways
Failures: 0
The Centurion and Colt upper were ejecting roughly 3' at 1-2 o'clock.
The Fed upper was ejection more confidently to 5' at 2 o'clock.
The KAC upper's ejection patterns surprised me. It was ejection 8' at 4 o'clock. This is very similar on paper to how it ejects unsuppressed.
So far as felt recoil, the KAC had noticeably increased recoil when shooting suppressed. Something to do with its bolts rate of unlocking while suppressed negated the nuances of the felt recoil I experienced unsuppressed. The recoil was now sharp and notable. It was still deferent than the Colt and Centurion uppers, but not in a good way. It was a different type of recoil made me less confident in getting fast rounds on target. The Colt and Centurion both felt similar and like many would expect for mil spec 11.5" uppers being suppressed. The Fed upper had the least felt recoil and dot jump out of the bunch when suppressed. This upper was the one which I was most confident in remaining fast and accurate with.
I suspect that [judging by the ejection patterns] the KAC upper would likely remain the most reliable while being suppressed over the long run and across different ammo types. This is assuming that ejection patterns are a tell for how well gassed a rifle is and how much room there is to play with factors affecting said gassing.
Session 5
Actions Observed
I brought out the Centurion and Colt uppers for accuracy testing.
I shot one 5-shot group with each of ammo type to get a feel for general accuracy potential from each upper.
The ammo types are the following. PMC 55rg FMJ, Black Hills 77gr SMK, FGMM 77gr SMK (.223), IMI 77rg SMK, & Frontier 75gr BTHP.
Scope that was used to test is a NF NXS 2.5-10 in a Giessele mount. Trigger in the lower used is a SSA-E.
Firearm was shot off of bags. All groups were shot at 100yds.
Take Aways
Failures: 0
Centurion accuracy results:
PMC 2.1"
Black Hills 1.1"
FGMM .5"
IMI 1.3"
Frontier 2.7"
Colt accuracy results:
PMC 3"
Black Hills 2"
FGMM 1.5"
IMI 1.1"
Frontier 1.6"
Thoughts:
I used five shot groups in an attempt to conserve my more expensive match grade ammo while still trying to showcase realistic performance of the cartridge/upper pairings.
The 5 shot group done with the Centurion upper using the FGMM was intersting. I'm curious if I can repeat those results.
The Colt upper was putting the IMI into a .5" pattern until I fired the last round. It's entirely likely that should have been a ~.5" group but then I got in the way of it.
In the Centurion, the PMC shot better than the Frontier "Match" ammo...
I was surprised by the results of both uppers. They both did very well in general for CHF CL mil-spec type barrels.
I'm excited to see what the Fed and KAC uppers will do.
Session 6
Actions Observed
I brought out the KAC and Fed uppers for accuracy testing.
I shot one 5-shot group with each of ammo type to get a feel for general accuracy potential from each upper.
The ammo types are the following. PMC 55rg FMJ, Black Hills 77gr SMK, FGMM 77gr SMK (.223), IMI 77rg SMK, & Frontier 75gr BTHP.
Scope that was used to test is a NF NXS 2.5-10 in a Giessele mount. Trigger in the lower used is a SSA-E.
Firearm was shot off of bags. All groups were shot at 100yds.
Take Aways
Failures: 0
KAC upper accuracy results:
PMC 1.9"
Black Hills 1.9"
FGMM .9"
IMI 1.1"
Frontier 2.2"
Fed Clone upper accuracy results:
PMC 2.1"
Black Hills 1.4"
FGMM 1.1"
IMI .9"
Frontier 3.6"
Thoughts: No real surprise, all four of these barrels shot at least "decent" with most of the match grade ammo. All but the Colt barrel had at least one sub minute 5-shot group and even it wasn't lagging too far behind the others. Frontier match ammo sucks. I should probably invest in more FGMM 77gr based on its performance in this test.
I found that I would feel confident in taking any of these uppers [with it's known good shooting ammo] to a DMR match, and probably do well with it under 500yds if needed.
I wish I could afford the time and ammo to shoot five 5-shot groups of each ammo type through each upper, but currently time and money are the resources I don't have. I hope the limited data provided here gives at least an idea of how each upper preforms accuracy wise.
Final Conclusions:
I must regrettably bring this review to a premature close. At least we got this far. I'm selling a house & buying a house, and need immediate funds to fix some things in the process. So I'm currently selling all but one of these uppers [as well as many other things] in order to take care of these rather important responsibilities.
None of the uppers performed poorly in any tests. They were all closer than I expected in the accuracy category.
Where they diverged the most in performance was with felt recoil while shooting them quickly. That's what I'll focus on for determining my winner.
So far as felt recoil, recoil impulse & shot recovery, balance, and maneuverability, the KAC and Fed clone upper stood out over the Centurion and Colt uppers. The Centurion and Colt uppers reminded me of what mil-spec M4's and MK18 Mod 0's felt like to get behind. I felt good behind them, but the KAC and Fed upper's made the rifle truly feel like next generation systems. They were simply more efficient feeling.
Now the elephant in the room: When separating these overall high performers, which one was better? The KAC SR-15 upper or Fed clone BRT barreled upper? Though they did feel different shooting wise, I still can't discern a clear winner. I found that both were easier to shoot faster [while maintaining baseline accuracy/precision] than the Colt & Centurion. They both also made it easier to maintain accuracy & precision while shooting faster. This is distinctly different. I would need much more time behind them both to refine my opinions further.
So is the KAC worth the squeeze? The SR-15 3.2 uppers are currently going for ~$2,000, while the Fed clone upper was put together for roughly 2/3's of the price. What's stopping you from combining a BRT barrel and LMT E-BCG on your quality upper and obtaining near [or even better] performance to the KAC 3.2 upper? Only availability. A few benefits of buying the KAC upper that immediately come to mind are having a manufacturer that will stand behind and warranty your product [though hopefully you'll never need that], and resale value.
So which one am I keeping?
Like in everything in life, there are many lenses which to view a situation through. I feel this necessary to state before giving my reasons for which one I would keep, and the answer would be different under different circumstances.
If I had plenty of money, I honestly would choose the KAC SR-15 as the keeper. It performed very well comparatively to the others, and is a factory upper which does bring a sort of "perceived" peace of mind.
If I wanted a bang-for-your-buck upper to maximize performance for the dollars, I'd keep the Fed upper. That BRT barrel is just gassed so well and I was surprised at how notably different it felt to the standard "crane spec" barrels. The downside to building your own is that there is no warranty, and if you ever need to sell it, you're either going to take a bath on it or it will at the very least be hard to sell whole or in parts.
Which one am I actually keeping?
I'm keeping the Centurion upper. I'm keeping it because it's possibly the least valuable and/or hardest to sell out of the bunch. As I said before, I'm trying to raise money right now, so this is probably the best decision from a financial standpoint. All of the uppers preformed great. Some were better, but being no stranger to Crane mil-spec quality, I can role with this upper just fine until I regain the capital to acquire another "high performance" upper.
I hope you enjoyed this as much as I have.
Feel free to ask me any questions, I'll be hanging around.
Cheers!
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