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Posted: 9/7/2010 6:15:59 AM EDT
[Last Edit: 9/7/2010 6:21:34 AM EDT by DavidC]
We were doing some reloading data chrongraphing over the holiday weekend, but since we had a lot of different guns available and a broad selection of factory ammo, we also ran a lot of standard ammo over the Chrony. One set of results really stood out; the performance of a 11.5" upper vs. a 10.3" upper.

The 11.5 inch is a CMMG, the 10.3" is a factory Colt (pictures follow).

We ran four types of ammo through both guns (and a 14.5" LMT with permanently attached FH as a form of "control").

PMC Bronze 55gr 223
Radway Green 5.56 (1991 HS)
M855 (not XM)
XM193

We also ran Black Hills 75gr, but those results aren't included here.

All barrels are 1/7

Temperature was in the low 70's

Altitude was 925 feet.

We fired a lot more ammo than the strings shown in the figure below. They were very consistent as were the results across the board.

As expected, the 14.5" barrel had the highest velocities. What was unexpected was that, on average, the 11.5" barrel was only 70 FPS slower (92 FPS widest mean difference, 29 FPS narrowest).

What was really unexpected was the abysmal performance of the 10.3" barrel, which averaged over 300 FPS slower than the 11.5" (511 FPS widest, 210 FPS narrowest).

THE SBRs were tested suppressed in the posted numbers, but tests with and without suppressor were in the same velocity range.

For the record, the owner of the Colt is obsessive about taking care of his guns and the barrel was not shot out or any other obvious reason for the velocity difference.

Obviously, these results are not definitive, but are interesting nonetheless. We may have to duplicate the testing at the campout I'm hosting at the end of the month and add in additional barrel lengths and ammo types.

The data:



The guns:

Link Posted: 9/7/2010 6:43:20 AM EDT
[Last Edit: 9/7/2010 6:43:41 AM EDT by Overton-AR]
WOW.....I knew the 11.5" was superior, but I had no idea that it was THAT MUCH. I have SBR's in both sizes, and I am absolutely shocked by that data.
Link Posted: 9/7/2010 6:49:49 AM EDT
So what WERE the results with the heavier bullets?

There's a reason why it's usually recommended to run heavy bullets in the short barrels and rely on expansion instead of fragmentation...
Link Posted: 9/7/2010 7:04:52 AM EDT
MK 262 VELOCITY DATA
__________________________________


7.5" 2053 FPS ... 10.5" 2363 FPS
DIFFERENCE 310 FPS
DIFFERENCE/INCH 103 FPS

10.5" 2363 FPS ... 14.5" 2576 FPS
DIFFERENCE 213 FPS
DIFFERENCE/INCH 53 FPS

14.5" 2576 FPS ... 16" 2669 FPS
DIFFERENCE 93 FPS
DIFFERENCE/INCH 62 FPS




M855 VELOCITY DATA
__________________________

7.5" 2244 FPS ... 10.5" 2639 FPS
DIFFERENCE 395 FPS
DIFFERENCE/INCH 132 FPS

10.5" 2639 FPS ... 14.5" 2861 FPS
DIFFERENCE 222 FPS
DIFFERENCE/INCH 56 FPS

14.5" 2861 FPS ... 16" 2938 FPS
DIFFERENCE 77 FPS
DIFFERENCE/INCH 51 FPS




XM193 VELOCITY DATA
_________________________________


7.5" 2364 FPS ... 10.5" 2755 FPS
DIFFERENCE 391 FPS
DIFFERENCE/INCH 130 FPS PER INCH

10.5" 2755 FPS ... 14.5" 2984 FPS
DIFFERENCE 229 FPS
DIFFERENCE/INCH 57 FPS PER INCH

14.5" 2984 FPS ... 16" 3075 FPS
DIFFERENCE 91 FPS
DIFFERENCE/INCH 61 FPS

Link Posted: 9/7/2010 7:09:10 AM EDT
Interesting. Guess I'll stick to my 11.5" colt.
Link Posted: 9/7/2010 7:14:11 AM EDT
This is good poop, thanks for your input.
Link Posted: 9/7/2010 7:16:35 AM EDT
also just wondering did you do your testing with the suppressor? cause the suppressor would also add some velocity
Link Posted: 9/7/2010 7:22:59 AM EDT
Interesting, but.........

This data would translate into milliseconds at distances of 50 yards or less. I built my 10.5" as an entry gun for work. In an urban setting, I don't see needing to take a shot more than about 50 yards. I don't think this data proves that one barrel length is superior to the other as far as practical application goes. If you are in a 20x20 room, I don't think one rifle would advantageous over the other for that application.

I do think it is interesting data for long range shooting, but that is why I have a 16" for that application.
Link Posted: 9/7/2010 7:23:05 AM EDT

Originally Posted By Raizo_Sekai:
also just wondering did you do your testing with the suppressor? cause the suppressor would also add some velocity

Originally Posted By DavidC:
...
THE SBRs were tested suppressed in the posted numbers, but tests with and without suppressor were in the same velocity range.
...


Link Posted: 9/7/2010 7:27:32 AM EDT
[Last Edit: 9/7/2010 7:29:54 AM EDT by RDTCU]

Originally Posted By 15x:
Interesting, but.........

This data would translate into milliseconds at distances of 50 yards or less. I built my 10.5" as an entry gun for work. In an urban setting, I don't see needing to take a shot more than about 50 yards. I don't think this data proves that one barrel length is superior to the other as far as practical application goes. If you are in a 20x20 room, I don't think one rifle would advantageous over the other for that application.

I do think it is interesting data for long range shooting, but that is why I have a 16" for that application.
Except for that whole pesky "terminal ballistics" thing..
Also your blast and flash will be greater the shorter you go unless you're running suppressed, so keep that in mind...

ETA: something like this is more of a flamethrower than a firearm:


Link Posted: 9/7/2010 7:31:09 AM EDT
[Last Edit: 9/7/2010 7:31:57 AM EDT by Overton-AR]
Originally Posted By 15x:
Interesting, but.........

This data would translate into milliseconds at distances of 50 yards or less. I built my 10.5" as an entry gun for work. In an urban setting, I don't see needing to take a shot more than about 50 yards. I don't think this data proves that one barrel length is superior to the other as far as practical application goes. If you are in a 20x20 room, I don't think one rifle would advantageous over the other for that application.

I do think it is interesting data for long range shooting, but that is why I have a 16" for that application.


The fact that XM193 needs to be above 2700 fps to fragment, this is HUGE information.
The 10.5" barely, if at all gets the necessary velocity to frag at all. I would say that even
in a 20x20 room that bullet frag is very important.
Link Posted: 9/7/2010 7:41:00 AM EDT
Wonder how the 5.56 TAP would fair in these applications...

This has me second guessing my 10.5" build...

Link Posted: 9/7/2010 7:47:33 AM EDT
[Last Edit: 9/7/2010 7:52:47 AM EDT by DavidC]
Originally Posted By RDTCU:
So what WERE the results with the heavier bullets?

There's a reason why it's usually recommended to run heavy bullets in the short barrels and rely on expansion instead of fragmentation...


We didn't do a full run with the Black Hills in all the guns. But it averaged ~2550 FPS in one 5 shot string in the 11.5" and ~2350 in the 10.3". In my 18" SPR it averaged ~ 2750 (and shoots well under a 1/2 MOA at 100 yards; that's the gun I usually shoot it in)
Link Posted: 9/7/2010 7:50:52 AM EDT

Originally Posted By DavidC:
We didn't do a full run with the Black Hills in all the guns. But it averaged ~2550 FPS in one 5 shot string in the 11.5" and ~2350 in the 10.3". In my 18" SPR it averaged ~ 2750 (and shoots well under a 1/5 MOA at 100 yards; that's the gun I usually shoot it in)

You mean well under a 0.200" group, or a 1MOA 5shot group?

Because I'd be willing to believe the latter...
Link Posted: 9/7/2010 7:52:19 AM EDT
Interesting, dont suppose you have pics of the guns without the suppressors, or at least the one with the vltor handguard?
Link Posted: 9/7/2010 7:53:06 AM EDT
Originally Posted By DavidC:
Originally Posted By RDTCU:
So what WERE the results with the heavier bullets?

There's a reason why it's usually recommended to run heavy bullets in the short barrels and rely on expansion instead of fragmentation...


We didn't do a full run with the Black Hills in all the guns. But it averaged ~2550 FPS in one 5 shot string in the 11.5" and ~2350 in the 10.3". In my 18" SPR it averaged ~ 2750 (and shoots well under a 1/5 MOA at 100 yards; that's the gun I usually shoot it in)



What does a 1/5 MOA hole look like??? Isn't a .224 caliber bullet BIGGER than 1/5 MOA??? Not, slamming you....just hoping that it was a TYPE-O. If not, you are a SHOOTING GOD!!!
Link Posted: 9/7/2010 7:54:09 AM EDT
Originally Posted By RDTCU:

Originally Posted By DavidC:
We didn't do a full run with the Black Hills in all the guns. But it averaged ~2550 FPS in one 5 shot string in the 11.5" and ~2350 in the 10.3". In my 18" SPR it averaged ~ 2750 (and shoots well under a 1/5 MOA at 100 yards; that's the gun I usually shoot it in)

You mean well under a 0.200" group, or a 1MOA 5shot group?

Because I'd be willing to believe the latter...


Typo; meant to type 1/2 MOA. The BH 75 gr is good stuff.
Link Posted: 9/7/2010 7:56:11 AM EDT
[Last Edit: 9/7/2010 7:56:58 AM EDT by Overton-AR]
That is still incredible shooting.....good on ya man. I put 3 shots in the same hole.....ONCE. I went straight home and demanded a BJ from the wifey.
Link Posted: 9/7/2010 7:57:15 AM EDT
[Last Edit: 9/7/2010 8:00:47 AM EDT by DavidC]
Originally Posted By Overton-AR:
That is still incredible shooting.....good on ya man. I put 3 shots in the same hole.....ONCE. I went home and demanded a BJ from the wifey.


Good rifle, bipod, from a rest

ETA:

Link Posted: 9/7/2010 8:03:20 AM EDT
Originally Posted By Szurgot:
Interesting, dont suppose you have pics of the guns without the suppressors, or at least the one with the vltor handguard?


That one is mine, so you are in luck



Picture was taken to show the mount, which is the reason for the DOF efffect.
Link Posted: 9/7/2010 8:04:36 AM EDT

Originally Posted By DavidC:
Typo; meant to type 1/2 MOA. The BH 75 gr is good stuff.

Ok, that i might buy
Link Posted: 9/7/2010 8:24:07 AM EDT
Wow, I never knew 1" could make that big of a difference.(that's what she said)
Link Posted: 9/7/2010 8:46:42 AM EDT

Originally Posted By Rokchukrslave:
Wow, I never knew 1" could make that big of a difference.(that's what she said)

From the snake thread, the rare and deadly Chode Viper:



Link Posted: 9/7/2010 9:00:02 AM EDT
I would like to see the results including a 12.5" barrel. Based on your study, I may revisit my getting a SBR .....
Thank you
Link Posted: 9/7/2010 9:01:00 AM EDT
I wonder what the terminal velocity of M855 penetrator is? It should fall in the tolerances that create fragmentation. I am sure the Navy did their homework for the MK18. You tested a 10.3, so I wonder what the increase in ft-second is to a 10.5". It seems the ft/second increases quite a bit with not much increase in length of barrel, so the numbers could change significantly for a 10.5".
Link Posted: 9/7/2010 9:08:01 AM EDT
Originally Posted By 15x:
I wonder what the terminal velocity of M855 penetrator is? It should fall in the tolerances that create fragmentation. I am sure the Navy did their homework for the MK18. You tested a 10.3, so I wonder what the increase in ft-second is to a 10.5". It seems the ft/second increases quite a bit with not much increase in length of barrel, so the numbers could change significantly for a 10.5".


+1
was thinking the same thing
Link Posted: 9/7/2010 9:28:47 AM EDT
Originally Posted By Raizo_Sekai:
MK 262 VELOCITY DATA
__________________________________


7.5" 2053 FPS ... 10.5" 2363 FPS
DIFFERENCE 310 FPS
DIFFERENCE/INCH 103 FPS

10.5" 2363 FPS ... 14.5" 2576 FPS
DIFFERENCE 213 FPS
DIFFERENCE/INCH 53 FPS

14.5" 2576 FPS ... 16" 2669 FPS
DIFFERENCE 93 FPS
DIFFERENCE/INCH 62 FPS




M855 VELOCITY DATA
__________________________

7.5" 2244 FPS ... 10.5" 2639 FPS
DIFFERENCE 395 FPS
DIFFERENCE/INCH 132 FPS

10.5" 2639 FPS ... 14.5" 2861 FPS
DIFFERENCE 222 FPS
DIFFERENCE/INCH 56 FPS

14.5" 2861 FPS ... 16" 2938 FPS
DIFFERENCE 77 FPS
DIFFERENCE/INCH 51 FPS




XM193 VELOCITY DATA
_________________________________


7.5" 2364 FPS ... 10.5" 2755 FPS
DIFFERENCE 391 FPS
DIFFERENCE/INCH 130 FPS PER INCH

10.5" 2755 FPS ... 14.5" 2984 FPS
DIFFERENCE 229 FPS
DIFFERENCE/INCH 57 FPS PER INCH

14.5" 2984 FPS ... 16" 3075 FPS
DIFFERENCE 91 FPS
DIFFERENCE/INCH 61 FPS



I'll just bump this post to make sure it wasn't completely ignored. You'll notice the 10.5 has PLENTY of V to get your frag on.
Link Posted: 9/7/2010 9:32:09 AM EDT
Originally Posted By 15x:
I wonder what the terminal velocity of M855 penetrator is? It should fall in the tolerances that create fragmentation. I am sure the Navy did their homework for the MK18. You tested a 10.3, so I wonder what the increase in ft-second is to a 10.5". It seems the ft/second increases quite a bit with not much increase in length of barrel, so the numbers could change significantly for a 10.5".


The gun used was, in fact, a Mk 18 Mod 0. According to the owner, it's a 10.3" barrel.

Link Posted: 9/7/2010 9:32:18 AM EDT
Originally Posted By Frens:
Originally Posted By 15x:
I wonder what the terminal velocity of M855 penetrator is? It should fall in the tolerances that create fragmentation. I am sure the Navy did their homework for the MK18. You tested a 10.3, so I wonder what the increase in ft-second is to a 10.5". It seems the ft/second increases quite a bit with not much increase in length of barrel, so the numbers could change significantly for a 10.5".


+1
was thinking the same thing


+2
Also, I am stuck between the 10.5 Noveske Light Shorty barrel chrome lined vs. the Noveske stainless polygonal rifled 10.5 barrels. It's a fact that polygonal rifling will result in slightly more velocity vs std rifling. Question is, how much, in this case...
Link Posted: 9/7/2010 9:32:31 AM EDT
bitis gaboonica gabooinca

Is that yours? If so, nice charge. Longest fangs of any snake in the world - can get 2 1/2" long. They are spectacular and beautiful!

Now, back on topic
Link Posted: 9/7/2010 9:32:59 AM EDT
[Last Edit: 9/7/2010 9:33:22 AM EDT by DavidC]
Originally Posted By Brahmzy:
Originally Posted By Frens:
Originally Posted By 15x:
I wonder what the terminal velocity of M855 penetrator is? It should fall in the tolerances that create fragmentation. I am sure the Navy did their homework for the MK18. You tested a 10.3, so I wonder what the increase in ft-second is to a 10.5". It seems the ft/second increases quite a bit with not much increase in length of barrel, so the numbers could change significantly for a 10.5".


+1
was thinking the same thing


+2
Also, I am stuck between the 10.5 Noveske Light Shorty barrel chrome lined vs. the Noveske stainless polygonal rifled 10.5 barrels. It's a fact that polygonal rifling will result in slightly more velocity vs std rifling. Question is, how much, in this case...


Unfortunately, I recently sold my Noveske 10.5" (polygonal) so I can't check on this.
Link Posted: 9/7/2010 9:34:22 AM EDT
Originally Posted By RDTCU:

Originally Posted By Rokchukrslave:
Wow, I never knew 1" could make that big of a difference.(that's what she said)

From the snake thread, the rare and deadly Chode Viper:

http://img.photobucket.com/albums/v39/canadianbacon/misc%20snakes/2004_0907_170620.jpg



bitis gaboonica gabooinca

Is that yours? If so, nice charge. Longest fangs of any snake in the world - can get 2 1/2" long. They are spectacular and beautiful!

Now, back on topic
Link Posted: 9/7/2010 9:34:23 AM EDT

Originally Posted By 15x:
bitis gaboonica gabooinca

Is that yours? If so, nice charge. Longest fangs of any snake in the world - can get 2 1/2" long. They are spectacular and beautiful!

Now, back on topic
Not mine

http://www.ar15.com/forums/topic.html?b=1&f=5&t=1087663

Link Posted: 9/7/2010 9:47:04 AM EDT
Originally Posted By Brahmzy:
Originally Posted By Frens:
Originally Posted By 15x:
I wonder what the terminal velocity of M855 penetrator is? It should fall in the tolerances that create fragmentation. I am sure the Navy did their homework for the MK18. You tested a 10.3, so I wonder what the increase in ft-second is to a 10.5". It seems the ft/second increases quite a bit with not much increase in length of barrel, so the numbers could change significantly for a 10.5".


+1
was thinking the same thing


+2
Also, I am stuck between the 10.5 Noveske Light Shorty barrel chrome lined vs. the Noveske stainless polygonal rifled 10.5 barrels. It's a fact that polygonal rifling will result in slightly more velocity vs std rifling. Question is, how much, in this case...


poly cut barrels do not produce more velocity. SS barrels on the other hand do produce more velocity compared to non SS barrels
Link Posted: 9/7/2010 9:47:37 AM EDT
Originally Posted By WindRiver78:
Originally Posted By Raizo_Sekai:
MK 262 VELOCITY DATA
__________________________________


7.5" 2053 FPS ... 10.5" 2363 FPS
DIFFERENCE 310 FPS
DIFFERENCE/INCH 103 FPS

10.5" 2363 FPS ... 14.5" 2576 FPS
DIFFERENCE 213 FPS
DIFFERENCE/INCH 53 FPS

14.5" 2576 FPS ... 16" 2669 FPS
DIFFERENCE 93 FPS
DIFFERENCE/INCH 62 FPS




M855 VELOCITY DATA
__________________________

7.5" 2244 FPS ... 10.5" 2639 FPS
DIFFERENCE 395 FPS
DIFFERENCE/INCH 132 FPS

10.5" 2639 FPS ... 14.5" 2861 FPS
DIFFERENCE 222 FPS
DIFFERENCE/INCH 56 FPS

14.5" 2861 FPS ... 16" 2938 FPS
DIFFERENCE 77 FPS
DIFFERENCE/INCH 51 FPS




XM193 VELOCITY DATA
_________________________________


7.5" 2364 FPS ... 10.5" 2755 FPS
DIFFERENCE 391 FPS
DIFFERENCE/INCH 130 FPS PER INCH

10.5" 2755 FPS ... 14.5" 2984 FPS
DIFFERENCE 229 FPS
DIFFERENCE/INCH 57 FPS PER INCH

14.5" 2984 FPS ... 16" 3075 FPS
DIFFERENCE 91 FPS
DIFFERENCE/INCH 61 FPS



I'll just bump this post to make sure it wasn't completely ignored. You'll notice the 10.5 has PLENTY of V to get your frag on.



exactly i posted and apparently no one read it...
Link Posted: 9/7/2010 10:05:01 AM EDT
[Last Edit: 9/7/2010 10:05:43 AM EDT by shadowcop]
I've got to say the 7.5" did better than I thought it would. Some act like it's marginally better than a sling shot
Link Posted: 9/7/2010 10:12:25 AM EDT
Where's the ballistic gel testing? LOL
Link Posted: 9/7/2010 10:15:33 AM EDT
[Last Edit: 9/7/2010 10:24:43 AM EDT by DavidC]
Originally Posted By Raizo_Sekai:

exactly i posted and apparently no one read it...



or they read it and noted it. Those weren't the results we saw.
Link Posted: 9/7/2010 10:19:41 AM EDT
[Last Edit: 9/7/2010 10:20:04 AM EDT by Overton-AR]
I don't think that BARELY cracking the 2700 fps threshold with the 10.5" gives "plenty" of frag capabilities.
To me, that is way to close for comfort. Don't get me wrong, I own a very nice 10.5" SBR and I love it.
However, after seeing this info, I would like to get a "do over" and build another 11.5" upper.
Link Posted: 9/7/2010 10:23:51 AM EDT
[Last Edit: 9/7/2010 10:28:42 AM EDT by DavidC]
Originally Posted By shadowcop:
I've got to say the 7.5" did better than I thought it would. Some act like it's marginally better than a sling shot


We ran M193 and M855 through my 7.5" as well. .

5-shot string XM193 in 7.5"

2303
2304
2335
2340
2335

mean is 2323 FPS

5 shot M855 in 7.5"

2257
2271
2208
2200
2229

mean is 2233


So roughly the same results posted by Raizo_Sekai

However, I stand behind the numbers posted for the 10.3" Colt barrel. They are significantly lower than expected and consitent with all ammo tested in terms of relative velocity. It's not like we went into ths atempting to trash people who use a 10.5" barrel in their builds; the results were prttey much unexpected along with the significantly superior performanc3e of the 11.5". We went in expecting maybe a 50 FPS difference.

Additional uppers would be required for more definitve results.
Link Posted: 9/7/2010 10:35:06 AM EDT
Good thread. thank you. I am glad I bought a 11.5 instead of a 10.3.
Link Posted: 9/7/2010 10:35:13 AM EDT
[Last Edit: 9/7/2010 10:38:08 AM EDT by 87GN]
How many rounds through the 10.3"?

Your results mirror those of the 10.3" CQBR with M855 at 10,000 rounds.

http://www.dtic.mil/ndia/2003smallarms/john.ppt
Link Posted: 9/7/2010 10:52:01 AM EDT
Originally Posted By 87GN:
How many rounds through the 10.3"?

Your results mirror those of the 10.3" CQBR with M855 at 10,000 rounds.

http://www.dtic.mil/ndia/2003smallarms/john.ppt


I'll check with the owner, but I'm sure it's nowhere near that.
Link Posted: 9/7/2010 11:26:26 AM EDT

Originally Posted By DavidC:
Originally Posted By 15x:
I wonder what the terminal velocity of M855 penetrator is? It should fall in the tolerances that create fragmentation. I am sure the Navy did their homework for the MK18. You tested a 10.3, so I wonder what the increase in ft-second is to a 10.5". It seems the ft/second increases quite a bit with not much increase in length of barrel, so the numbers could change significantly for a 10.5".


The gun used was, in fact, a Mk 18 Mod 0. According to the owner, it's a 10.3" barrel.


Mk18 Mod 0 barrels are 10.3" not 10.5", how many times do I have to repeat myself?
Link Posted: 9/7/2010 11:29:37 AM EDT
Originally Posted By DavidC:
Originally Posted By Raizo_Sekai:

exactly i posted and apparently no one read it...



or they read it and noted it. Those weren't the results we saw.


its cause people were asking about 10.5 instead of 10.3 after i had posted about 10.5
Link Posted: 9/7/2010 11:31:39 AM EDT
Sounds like we need a thread devoted to 10.5" chrono testing. Various barrels, various ammuntion...
Link Posted: 9/7/2010 12:14:30 PM EDT
Originally Posted By Overton-AR:
Originally Posted By DavidC:
Originally Posted By RDTCU:
So what WERE the results with the heavier bullets?

There's a reason why it's usually recommended to run heavy bullets in the short barrels and rely on expansion instead of fragmentation...


We didn't do a full run with the Black Hills in all the guns. But it averaged ~2550 FPS in one 5 shot string in the 11.5" and ~2350 in the 10.3". In my 18" SPR it averaged ~ 2750 (and shoots well under a 1/5 MOA at 100 yards; that's the gun I usually shoot it in)



What does a 1/5 MOA hole look like??? Isn't a .224 caliber bullet BIGGER than 1/5 MOA??? Not, slamming you....just hoping that it was a TYPE-O. If not, you are a SHOOTING GOD!!!


if you measure the outside, then subtract .224, it gives you the true deviation of the shots. True deviation is measured center to center so 1 shot is 0moa, not .224 moa.
Link Posted: 9/7/2010 12:16:05 PM EDT

Originally Posted By Fields_Overseer:
Originally Posted By Overton-AR:
Originally Posted By DavidC:
Originally Posted By RDTCU:
So what WERE the results with the heavier bullets?

There's a reason why it's usually recommended to run heavy bullets in the short barrels and rely on expansion instead of fragmentation...


We didn't do a full run with the Black Hills in all the guns. But it averaged ~2550 FPS in one 5 shot string in the 11.5" and ~2350 in the 10.3". In my 18" SPR it averaged ~ 2750 (and shoots well under a 1/5 MOA at 100 yards; that's the gun I usually shoot it in)



What does a 1/5 MOA hole look like??? Isn't a .224 caliber bullet BIGGER than 1/5 MOA??? Not, slamming you....just hoping that it was a TYPE-O. If not, you are a SHOOTING GOD!!!


if you measure the outside, then subtract .224, it gives you the true deviation of the shots. True deviation is measured center to center so 1 shot is 0moa, not .224 moa.

It was a typo anyway, he meant to say 1/2moa as he corrected it earlier...
Link Posted: 9/7/2010 12:18:40 PM EDT
[Last Edit: 9/7/2010 12:23:28 PM EDT by Fields_Overseer]
Originally Posted By WindRiver78:


I'll just bump this post to make sure it wasn't completely ignored. You'll notice the 10.5 has PLENTY of V to get your frag on.


yea, all 55 feet per second

It was a typo anyway, he meant to say 1/2moa as he corrected it earlier...
I know, just saying it since he was like "isnt .224 > .220"
Link Posted: 9/7/2010 12:53:16 PM EDT
I guess I didn't word my question right. I am fully aware that the barrel of an MK18 is 10.3". That stated, I was wondering what the difference in ft/second would be between a 10.3" and a 10.5" in relation to the first chart. I think it would be significant due to the fact that 1" of barrel length made 500+ ft/second difference.
Link Posted: 9/7/2010 12:54:14 PM EDT

Originally Posted By 15x:
I guess I didn't word my question right. I am fully aware that the barrel of an MK18 is 10.3". That stated, I was wondering what the difference in ft/second would be between a 10.3" and a 10.5" in relation to the first chart. I think it would be significant due to the fact that 1" of barrel length made 500+ ft/second difference.

so a very rough estimation would be ~100fps gain?
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