Hi guys, so this morning I went to the range to see about accuracy regarding a cpl. types of duty/shtf ammo through my recent MRP CQB project. I like to use a honest evaluation method using 100yd. distances and 10rd. groups. I simply swapped the normal T-1 for this build w. a NXS compact 2.5-10x24 w. compact mil dot ret., and threw a bi-pod on it. All groups were fired prone with a bi-pod, with no support in the rear. The barrel is a Rock 10.5" CL 1/7 5.56 w. a standard A2 f/h.
After firing the three shtf loads I realized I wanted to let this dude off the lease with some more precision based loads, however unfortunately I had not planned on doing a true precision/accuracy evaluation and thereby left just about every accurate load I like to use at the house. Luckily I had 1bx. of Remington 55gr. Accu tip and always have Monarch brass 55gr. FMJBT for range use so I went ahead a shot a few groups with this stuff.
I unequivocally CHOKED my ass off on the far right group and I am absolutely sick over it. The furthest flyer was no shit the 8th rd. of the group…somehow managed to hit the mark w. the 9th even though I knew I had just ruined something unbelievable and finished up with a sloppy ass final shot that is the small flyer. For some who don’t chase the precision aspect of AR’s prob. cannot really understand, however some here will know just what it feels like when you have the first 5…6…7 rds of a group within or less than a half inch. It’s a complete mind f**k given how much likelihood that the last few rounds of a group always open up on a 10rd group at least a shade, and as always a flyer is just a jerk away.
After being floored today with this little 10.5" CL barrel’s accuracy, count on a follow up report involving 55gr. Vmax, TAP T2, BH’s 68gr. HPBT, and maybe even a 69gr. and 77gr. SMK load. I certainly expect this barrel to be well within sub moa territory with some precision type ammo and that is quite the surprise at least for myself.
eta…in case it’s non legible what the ammo types are…Hornady TAP 60gr. Barrier, Federal TRU, Remington Accutip 55gr., Monarch 55gr. FMJBT, and Barnes 55gr. TSX
Thanks for posting that. All BS aside, I think this post has some serious validity. Those groups are more than good enough for combat accuracy. Hopefully people reading this will realize that this was fired from a 10.5" barrel and according to some “internuts” we all know how “inaccurate” they are.
Would love to see some groups fired with BH 77gr. match, Hornady 75gr. TAP and some PPU 75gr. as well.
I like that report as well. I plan to do the same when I get my stamp. I have always wondered (and will find out) what my AR’s would shoot if I took off my scope from my LMT MWS 4.5-14 Luepold and shot groups.
I have shot 5 shot 1 inch groups with my Colt 6940 with 16 inch. Hornady 55g Vmax. With a 4X ACOG.
Just cant wait to see what 11.5 and 12.5 can do.
Great subject I look forward to learning more about. Its just most people have RDS or 4X power as max optic.
Thanks for the report and demonstration of capabilities. Pardon me if I was gone for the discussion, but I hadn’t heard a lot of grumbling about accuracy with that form factor. Isn’t the main issue with the 10.5" 5.56 barrel terminal effectiveness due to reduced muzzle velocity? If yes, can this reduced effectiveness be overcome with proper round selection?
Thanks for the kind words guys, glad to see the interest and I will certainly update this thread:)
Great question czy. That is what I hope to be learning exactly more on. I am trying to determine what length I can get away with in terms of a Rock SS. I am leaning towards 12" SS, and have a pal who started w. the 16" midlength CL barrel, chopped it down to 12", and Marvin IIrc dimpled it. He threw it in his CQB chassis and we nicknamed it CQB/SBR “Outdoor”. Reason being that the 12" would be the ideal length or the min. length needed really that one would need for lets say stepping outside a vehicle or dwelling and having to fire across 75-150yd’s of terrain to engage a target that is lightly concealed(high level of precision required), and still have enough punch to actual do the job when the rd. gets on target. I want to have a more methodical CQB/SBR “outdoor”, basically one with more emphasis on tack driving.
Buddy…I group everything at 10x unless I am having the rare mirage effect or similar environmental disturbance that requires a slight reduction in magnification. I think 10x for my eyes is the minimum power to do effective groups.
Sorry Quiet I did not check the thread before your question was answered correctly by the other gents.
LRB per your request:)
This is kinda random but nonetheless amazing from my experience…
The other day I borrowed the nxs that was perfectly zeroed affixed to my mrp recce…as shown here:
Pulled it off the recce…and replaced the T-1 above with it and the bipod.
Now zeroing adjustments… (note I was going from a completely different 16" rifle with an established zero to a new 10.5" rifle) and I swear the adjustments were as followed…elevation: 9clicks windage: 0 clicks All groups were fired w/o another adjustment.
I completely agree Trident. I feel 12in(in my case 12.5) is the barrel length that fits a “patrol” rifle just fine. Retains enough velocity out to 300 to be effective in stopping targets, and short enough for vehicle operations.
10.3/10.5 is IMO a 100yd and shorter gun. You can make hits just fine out to 300, but you lose to much velocity to be effective at that distance. 10.3/10.5 is a good length for a Close Order Security Detail(VIP, Base Security, “Gate” security, and Ship Based)
Im working on getting funding for a BCM 12.5in SS410 upper build to complete my need for what I call a “Patrol Rifle”, which will be topped by a 4x optic of some kind
Nice write up TRIDENT82. Thanks for verifying what many of us already knew, the a 10.5 can produce very good accuracy at 100 yards. I wonder how the groups would turn out using match grade and premium ammo in the heavier weight bullets.
Doing this kind of shooting makes me want to bash my head on the concrete until I am unconscious, hopefully waking up to find that someone else has done all of it for me.
I often forget that “patrol” would be what I am referring to as “outdoors”. I think the BCM 12.5" SS would make a damn fine choice. I agree with 4x just variable power…1-4x type. I really like the idea of sporting a baby nxs with this setup, but it always comes down to how badly you might miss the day light illumination.
Roger…within the next cpl. days I am gonna shoot 4-5 match type loads to include TAP T2, 55gr. Vmax, Fed GM 69gr smk, and most certainly some more of that Rem Accu tip 55gr. I think some will have interest if I also include Hornady Training brass 55gr. FMJBT so that will be included as well.
Rob…I have a bandaid on my forehead from shot number 8 on that far right group. As I’m typing and thinking about it I feel nauseous:suicide:
Magic…It’s indeed a CL. A suppressor is certainly in the plan but after doing my first stamp, I am no hurry to do my second.
eta…On the suppressor, I just learned that I am gonna be wanting a can for 300BLK really soon. Now I am torn in the decision for the particular model, The 762SDN for the 300blk setup…or the surefire 556-212(buddy’s rec) for the 10.5" setup as pic’d above. The 300blk setup will just be wicked though and the idea of having a MP5SD azzkicker is pretty nice.
update: I used somewhat of a control this time around by using my recce with TAP T2 since I can repeatedly make sub moa groups with that combo. (note: the one shot outside the group on the right hand target is from the sight in.)
MRP Recce/ Rock 16" SS VS. MRP CQB/ Rock 10.5" CL
ammo: Hornady TAP T2
Now just three additional groups with the MRP CQB 10.5"…L to R, Federal GM 69gr. SMK…Hornady 75gr. Match…Hornady Training Brass 55gr. FMJBT.
So far we have:
Hornady TAP 60gr. Barrier: 1.313
Federal 50gr. TRU: 1.374
Barnes 55gr. TSX: 1.574
Monarch 55gr. FMJBT: 1.872
Rem 55gr. Accu tip: 1.388
Hornady BT 55gr. FMJBT: 1.946
Hornady 75gr. Match: 1.423
Federal GM 69gr. SMK: 1.313
Hornady TAP 75gr. T2: 1.328
Still haven’t shot all but one of my favorite precision loads like BH’s 77gr. SMK, 68gr. match HPBT, Hornady 55gr. vmax, Hornady 52gr. match HP, etc. through the 10.5" so hopefully I can shave off a .25"-.5" with one or more of them
A variable power would be good, but a 3 or 4x ACOG would also be a good choice.
Im going to end up running a 4x ACOG on mine when I get it finished some point this year. Ive got a the Mk18 Mod one, so I think to save some money, Im just going to build a 12.5in SS410 upper for now, until I figure out if our new douche of a Sheriff will sign a Form 1 for me or not, definitely know his Chief Deputy wont…
With groups like you have with your 10.5, that T1 should have no problems on it from 150 and less. Id just prefer the extra barrel length and velocity for anything past that, plus a magnified optic.
