12.5" at 565 yards and 10.3" at 200 yards results

[Eurodriver]

Yesterday I was unsuccessful at getting a good zero. Spotting scope troubles plagued me along with high winds and mirage.

I went back to the range today. I am VERY impressed with both of these rifles. The wind and mirage died down allowing me to actually get the rifle zerod effectively and these are the results...

For reference: Here are the two rifles I am shooting with.
A 12.5" BCM SS upper with a TA31 ACOG
and
A 10.3" (daniel defense 16" barrel cut to 10.3") with a Centurion 9" rail and Noveske receiver using an Aimpoint T1

http://img684.imageshack.us/img684/6206/riflesu.jpg

Here is my "rest". Not very effective but its all I had. I don't normally shoot from a rest but I wanted to eliminate as much of me as possible. Remember, the point of this is to prove that SBRs aren't "useless" at long range, not that I am a good shooter.

http://img846.imageshack.us/img846/7792/restf.jpg

This is 300 yards with the 12.5" using Hornady Superperformance 53gr.

http://img713.imageshack.us/img713/6733/300y125.jpg

This is 200 yards with the 10.3" using M855 62gr Green Tip .mil ammo I was blown away by this. I was looking through my spotting scope after each round questioning myself "Is that really a new hole in the bullseye?" repeatedly...

http://img7.imageshack.us/img7/5964/200y103.jpg

Then I moved the 12.5" to 565 yards. For a target I taped two targets backwards on top of one another and one black 8" circle. I then drew in a "body". I wanted the target at this distance to be as clean as possible so I was not distracted. The BDC in the ACOG covers up the 8" circle at that distance.

http://img221.imageshack.us/img221/372/poaf.jpg

This is the result with M855. This is not with match ammunition. I fired 10 rounds unsuppressed and then 10 rounds suppressed (unsuppressed are circled, suppressed are lined out. One round on each string of fire impacted the black) It appears that the group actually opened up a bit suppressed, but this was by no means scientific and that could have easily been user error. There was no real measurable shift in POI however.

http://img685.imageshack.us/img685/6797/2ndgroup565.jpg

[Eurodriver]

Now I have some questions:

First: Hornady Superperformance. At 300 yards I used the 300 yard aiming point on the BDC. As you can see, it was dead on. I was very limited with this ammo so I stopped at 7 rounds and then went to shoot at an 8" gong at 565.

However at 565 the POI was higher than M855. Thoughts? I know it should be higher than M855 as its faster, but why wasn't it higher at 300?

Also, the BDC on my ACOG is calculated for M855 out of a 14.5" barrel.

Why was it dead nuts on for my 12.5" then? Is that little bit of muzzle velocity lost not enough to affect drop? Does the SS barrel help a little? I'm really confused on this one because I have first hand experience using the 400 yard line aiming point effectively at 500 yards with an M16A4 and an RCOA4.

I was very surprised that the BDC was perfect despite the barrel length difference. I cannot ask for anything better than that.

[steve--oh]

Yup. Good shooting too. There was any earlier thread about some dirt shooters in AZ doing the same thing with their SBRs.

[Pappabear]

Now I have some questions:

First: Hornady Superperformance. At 300 yards I used the 300 yard aiming point on the BDC. As you can see, it was dead on. I was very limited with this ammo so I stopped at 7 rounds and then went to shoot at an 8" gong at 565.

However at 565 the POI was higher than M855. Thoughts? I know it should be higher than M855 as its faster, but why wasn't it higher at 300?

Also, the BDC on my ACOG is calculated for M855 out of a 14.5" barrel.

Why was it dead nuts on for my 12.5" then? Is that little bit of muzzle velocity lost not enough to affect drop? Does the SS barrel help a little? I'm really confused on this one because I have first hand experience using the 400 yard line aiming point effectively at 500 yards with an M16A4 and an RCOA4.

I was very surprised that the BDC was perfect despite the barrel length difference. I cannot ask for anything better than that.

The BC on Hornandy is better so maybe thats it?? My guess, its really hard to shoot precision at 500 yards with 3 to 4 power in 5.56 We were thumping steel at 500 today with my Colt 6940 and 18' White Oak. But I doubt I could call if one ammo was shooting a little different than another at 3 or 4 power ACOG. Its big fun but hard to get super precise, maybe you can? I doubt I could. We shot some test loads of Markm's in .223 today at 200 yards, with a 6mph wind on and off, that shifts POI 3 inches. When you get out 500 with 5.56 or .223 it can burn your ass ten ways to Tuesday.

Why is it hitting high. Like you said, all guns are different. The CAN could push it up? SS barrel ? Many things can cause it. But now you know your dope and your making hits, thats all good.:D

[ALCOAR]

Ive thoroughly evaluated the SF 53gr. Vmax and without question it's the flattest shooting .223 load Ive ever come across. Its a f**king laser beam...that simple:cool:

It doesn't group well at anything under 200yds though...much like MK262 mod1. I've taken it out to 750-800yds in my Recce.

http://i54.tinypic.com/534nsz.jpg

http://i52.tinypic.com/mjtjzp.jpg

[Eurodriver]

Trident, I only had 15 rds of the 53gr so I couldn't do too much work with them but I plan on getting more for sure. I was impressed.


The BC on Hornandy is better so maybe thats it?? My guess, its really hard to shoot precision at 500 yards with 3 to 4 power in 5.56 We were thumping steel at 500 today with my Colt 6940 and 18' White Oak. But I doubt I could call if one ammo was shooting a little different than another at 3 or 4 power ACOG. Its big fun but hard to get super precise, maybe you can? I doubt I could. We shot some test loads of Markm's in .223 today at 200 yards, with a 6mph wind on and off, that shifts POI 3 inches. When you get out 500 with 5.56 or .223 it can burn your ass ten ways to Tuesday.

Why is it hitting high. Like you said, all guns are different. The CAN could push it up? SS barrel ? Many things can cause it. But now you know your dope and your making hits, thats all good.:D

I'm trying my hardest to get as precise as I could. I know you guys shoot steel, but I wanted to see what I could do on paper. That 565 yard target was with M855, I'm really curious to see what I can do with some quality match grade 75 or 77gr offerings from Hornady/Federal.

As you said though, with a 4x optic its pretty difficult. The 5 tic on the BDC covers up the 8" circle at that distance. Hitting the "man" is easy, but shooting for precision is another story.

I'm just glad I can make hits at that distance. I'll pick up some match ammo and figure out my dopes for that range because my goal is to eventually put the BDC to the test on the ACOG and shoot a 24"x24" target at 800 yards. For that I'll need as much help as I can get, but I can't figure out if it would be best to go with a heavier match round or a lighter, faster round like the 53gr Hornady.