PF Neptune VIII Hates SST

[Sticks]

Took her back out for another range session. I needed to verify zero, then hit the 1k range to see how I could do.

I am 250 +/- shots down the tube, including recommended break in, and I still can not get SST to group...and I have a lot of it.


Center group was first round with SST, and the upper most hole (behind group details) was cold bore shot. Top group was second round of SST. Bottom group was Amax. The top shot in that group I rushed, but I always cont my flyers and f' ups.

From a previous outing I know she likes American Eagle 120gr OTM (had to be the expensive one) and now Amax - Discontinued . I've tried the new Black ELD, but it was not one of my better days, and have not measured it out yet. IIRC it was slightly under 1". I had some with me on this outing, but forgot to run some through.

This is the 8th target that I have tried to get SST to group and I can not get it consistently under 1.25. This was in fact the best result that I have achieved with it.

I also did a quick turret tracking test while I was on the 100. I had pre hung the target, but the stand would not sit straight in the range mounts when I walked to place it. During the run, vertical and horizontal pattern matched the reticle.

Vortex Viper PST FFP Gen I, 5-24 x 50 MRAD


Shooting steel at the 1k range, I was able to place hits out to 700, but the wind (variable 3-10 @ 0400) took the sound past 600 so all I could do was watch movement, and past 700 the mirage made it a PITA to verify. 800 - 1k was may or may not have hit, the mirage all but blocked out the plates, and forget about bullet trace or verifying movement/spotting misses...At least for me at this stage in my abilities.

Next range session, I will make a run at 200, and flavor test again. I am shooting the Sporting Rifle Match in Raton NM in 2 weeks. I gotta get some more American Eagle and ELD in. I've got enough brass now to start loading up, but want to get to that 500 mark.

[Kilco]

Both my 20" Shilen and my 16" Odin Works preferred the 123 eld and 120 BT more than the SST. I can get the eld and BT to group at .75 without much fuss. SST Runs around 1 to 1.25 moa regardless of seating depth, powder or charge weight.

Good enough for hunting out to 300 yards.. but I would prefer tighter. Seems to be a trend with a lot of rifles and posts lately.

[StoneHendge]

What magnification are you shooting LR at? I have the same scope with EBR 2C MOA on my 308 RPR. I generally have mine around 15x for shooting steel to minimize mirage, keep the target in the sight picture and give me enough reticle for holdovers. But then again, I imagine it's pretty damn hot down there....

[Sticks]

Stonehenge -

I was at 24x. Did not even occur to me to back off the magnification. I know my Sig Kilo 2000 could not even range past 800 with the mirage. By the time I got over to the 1k side, temps were climbing into the upper 80's/low 90's when I packed up.

[GaCop]

Sighted in my friend's AR Grendel this morning using the Hornady 123 gr. SST ammo he bought at Academy Sports (4 boxes). It's the most inaccurate stuff I've ever seen! I would have been happy to see the groups you got but the best I saw at 200 yards was over three inches. I was hoping once the barrel was broken in it would shoot the Hornady ammo a bit better but now I'm not too sure! Total rounds through the barrel are 20. I was using a 6-24X50 side focus scope set on 24X to shoot the groups. Day was over cast but somewhat bright, calm and no mirage.

[VASCAR2]

What barrel does yor Friend's 6.5 Grendel have now, make, length/twist?

[GaCop]

I believe it's a Bear Creek, 20" with 1 in 8" twist, chrome molly fluted HBar, taking a .750" gas block.

[Sticks]

I finally managed to get a group under an inch...barely


Then on my second round of ELD...



All I could see was the two holes. I am thinking that there is no way I shanked 3 shots off paper. I start checking scope mounts muzzle, everything.

I walk on down to the target, and sure as hell, 4 shots in one hole. .13MOA until I count the "flyer" bumps it out to .74MOA.

What I would give to be able to know exactly how I was holding the rifle, tension, position....damn.

I loaded up another 10 rounds before I walked down there and the results were typical of me. .5 to 1" with the ELD.

Can anybody diagnose the stringing of shots up and right at the 45*. It's a pattern with me.

[rabiddawg]

Would you by chance be shooting off a lead sled?

If so, ditch that thing. I get similar results when using my dads lead sled. For bolt guns it's fine but my ar's don't fit it properly.

[grayfox]

I had (still probably have it a little to be honest!!) similar, a stringing assist says the palm of right hand is pushing the stock down and left at/after the trigger pull.
Plus for me either a) leaning into the rifle a bit too much can cause the muzzle to tip up at the shot,
b) not being square (in this case your body being a bit left and leaning right into the rifle) behind the rifle. I was setting up with body just a bit left and unconsciously leaned to the right - webtalk says the way you're leaning makes the shot go that way as well. Makes some sense to me b/c there's a sharp force and break at the shot which could cause a slightly-off-balance body to re-position slightly... 1/1000's of an inch at the shot multiplies into 1/10's or bigger at the target.
o, and disclaimer... I'm not an expert, there are several on here who are. I'm just sharing what seems to help for me.

[Sticks]

rabiddawg - No, shooting prone in the dirt off a bipod (mounted forward, not at the receiver this time), and a bag under the buttstock

grayfox - Thank you. I will pay more attention to my final shooting position to make sure I am squared up with the rifle, and watch my grip.