Range Report New shooter to focus on 100 yard groups?

Srikaleak

Gunny Sergeant
Full Member
Minuteman
May 11, 2018
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So this weekend was my second trip out with my two rifles. I was truly successful getting the 100 yard zero this go around. Started at 25 yards, then moved to 50 and finally 100 yards. At 100 yards though, all I could muster was 1.5 inch groups at best. Should my next few range trips focus on trying to get that grouping down before heading out to longer distances? Should I also ignore windage adjustments to get the zero because of the weather conditions?

More info about last range trip:
  • Weather was 45 - 50 deg F
  • Gusts of up to 20 mph, wind seemed steady at 5 mph. (Weather.com information)
  • Sighted in a 12in 6.5 Grendel DIY AR15 and a 22in 6.5CM JP LRP-07
  • Started with mechanical zero on both scopes
  • 6.5 Grendel scope (NF NX8) 100 yard zero ended up being 5.8 mil lower and 0.4 mil to the left than mechanical zero
  • 6.5 Grendel rifle shot off of Atlas CAL bipod
  • 6.5 CM scope (NF ATACR 4-16x50) 100 yard zero ended up being 5 mil lower and 5.6 mil to the left than mechanical zero
  • 6.5 CM rifle shot off range supplied rifle rest
Next steps will be setting the zero-stop of the scopes and validating 100 yard zeroes.
 
Get a feel for the longer stuff too while you're out there! 100 yards is BB gun range :)

Video yourself and see what silly ass shit you do.

Then watch a video of someone that we all agree is awesome. You will be able to see some of your faults... A JP should do better than that easy.
 
I would say yes you want to work on getting that group about an inch at 100 yards especially for your 6.5. Once you know you have the MOA or less group then start to reach out.
Should I also ignore windage adjustments to get the zero because of the weather conditions?
You should not be making any adjustments for the effects of wind when zeroing. At 100 yards the effect of wind is minimal to nonexistent so you should be using the windage to get your rounds on target and then zero the turret. With that being said I don't zero my guns in 20 mph winds, even though you can, I just don't like to. Also you shouldn't have to walk your guns out like that, if you need to when first setting up a rifle, pull the bolt out and look down the barrel and once it's on the target walk the scope on, that will get you close enough to hit paper from 100 yards.
 
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One thing that helps is when you are zeroing, get the most definitive aim point as possible. If you are shooting at a circle it is difficult to center your crosshairs on the circle in the exact same spot each time, because of a lack of a reference point. I zero on 1 inch squares, and I hold the crosshairs on one of the corners, so that you can get them back to the exact same spot each time, and then you know if the group is within the size of the square then your'e good. This will tighten up you group, along with setting proper parallax. One last bit is make sure you squeeze off 2-3 rounds at least before making any adjustments or else you will be chasing your zero.
 
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I would say yes you want to work on getting that group about an inch at 100 yards especially for your 6.5. Once you know you have the MOA or less group then start to reach out.

You should not be making any adjustments for the effects of wind when zeroing. At 100 yards the effect of wind is minimal to nonexistent so you should be using the windage to get your rounds on target and then zero the turret. With that being said I don't zero my guns in 20 mph winds, even though you can, I just don't like to. Also you shouldn't have to walk your guns out like that, if you need to when first setting up a rifle, pull the bolt out and look down the barrel and once it's on the target walk the scope on, that will get you close enough to hit paper from 100 yards.

That was kind of what I was thinking in regards to winds effect at 100 yards.
My first time zeroing my rifles ended up in tragedy and despair. I decided to go the guaranteed route this time so as to not waste any more ammo than I already had.
 
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You may have already done this, if so please ignore:
If these are new rifles it may take a few different types of ammo before you find one that your rifles enjoy the most. Now your using 2 cartridges that are factory ammo friendly. While initially it can be expensive, I will always splurge for match grade ammo ( I handload now and still do this to get a feel for the new rifle and get a reference zero) and go from there. You have some great glass and I am assuming well mounted/secure/level. As mentioned above get a good repeatable sight picture to use. I find the 2 inch orange sticker dot targets have a thick enough center target line to align to at 100 and easy to hold. Get into a routine when setting up and do the exact same thing ( breathe count, eye scratch or whatever) and never rush when setting up a new rifle/zero.
Have fun!!
 
^^^This^^^, plus, the bore may benefit from a few boxes of ammo before going for minimum group sizes. I know there's a bit of dissent about barrel break-in, but I do see some grouping improvements after 100yd vs the first few shots on a new factory barrel. A good part of that is my own familiarity with a new rifle.

Generally, my primary goal with the first 100 rounds is to get 100 pieces of brass fireformed, even though I still shoot with serious care just the same as any other times.

...Also, winds gusting to 20MPG definitely opened up your groups, so save the above attempts for calmer days.

I like a dot with an X in the center, rather than a plus (conventional crosshair). It helps me refine my aiming point somewhat better.

Greg
 
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Did you say 5.6 mils of windage adjustment from zero? Check your mount. If the windage zero is really center of mechanical adjustability that is not right. I've only seen it with crooked rails or mount screw holes drilled off center.
 
If you shot 1-1/2” groups with a 12” Grendel, that is about as good as it gets normally. The Creedmoor should definitely be capable of less than 1” at 100, but follow the advice above and use match ammunition, get a hundred rounds down the tube and try again when the wind isn’t so gusty.
 
@bfglowkey @lash @Greg Langelius * I've yet to hit 100 rds through both rifles. They're both around 60rds through the barrel. I'm using Hornday Black ELDMs for 6.5G and Prime ammo for 6.5CM. Haven't tried with anything else yet but those two should perform.

@flyright I don't remember if I messed with the turret caps or what but I'm 90% positive I reset to mechanical zero and adjusted windage to get the bore zero. I thought that much windage adjustment to bore zero was odd too, especially when the NX8 was only 0.2 mil off from mechanical zero to bore zero.
 
I own 3 Grendels (2 AR, 1 Howa), and the GF another 3 (Howas). Hornady Black is match ammo for Grendel of any length. Past that you are getting Alaxander Arms or Precision Firearms ammo. Shoots .5 MOA out of all 6 with Black.

What barrel is the Grendel? If it's BCA, you are lucky is shoots that good. If you are using SST ammo, again, lucky it's that good.

Try several types of ammo in both rifles. Hornady Black, American Gunner, American Eagle 120 OTM, Federal Fusion for the Grendel, not familiar with the top CM lines.

I agree on the windage adjustment on the CM. I had a Howa that required .8mil of windage to zero, and was horrid past 400 for compensating for the rail. New rail, and problem solved. Took me a while and 200 rounds to put that puzzle together (GF Rifle). Now I know better. Check your rings, nothing you can do with a machined rail on the LRP-07 .

Did you lap the rings?

More importantly, is this a factory new scope on the CM or a take off, used buy?
 
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Around 1 mil or so of windage adjustment would not concern me but 5.6 mils would. The machined rail of the JP should not be the problem unless the barrel is not in line with the receiver. Otherwise, it's the mount/base, rings, or scope. Are you using rings directly on the receiver rail or a mount with rings?
 
@Sticks @flyright The 6.5 Grendel barrel is a Green Mountain barrel that my smith guarantees 1 MOA. It's all I really need for hunting. I'll definitely try different ammo with the Grendel. Thanks for the ammo suggestions.

As for the 6.5 CM scope (NF Atacr 4-16x50): it is a used scope I bought from a member here on the Hide. He said it was very lightly used (he wanted to compare with NF 4-16x42 and he liked the x42 better). It is mounted using a brand new Nightforce Unimount. I've got it torqued down to specs using a Borka torque wrench. It should be mounted properly but I can go back and remount it.
 
@Sticks @flyright The 6.5 Grendel barrel is a Green Mountain barrel that my smith guarantees 1 MOA. It's all I really need for hunting. I'll definitely try different ammo with the Grendel. Thanks for the ammo suggestions.

As for the 6.5 CM scope (NF Atacr 4-16x50): it is a used scope I bought from a member here on the Hide. He said it was very lightly used (he wanted to compare with NF 4-16x42 and he liked the x42 better). It is mounted using a brand new Nightforce Unimount. I've got it torqued down to specs using a Borka torque wrench. It should be mounted properly but I can go back and remount it.

Was it a group buy barrel Monster Barrel on the Grendel? Bedding the barrel / propper assembly and getting used to it should reveal MOA or better with good ammo...not Wolf steel or Hornady SST.

With your CM - Verify mechanical zero. Either look up the specs on it and go full rotation one way then 1/2 back, or flat out count clicks and go to the middle and see if that is still 5.6 off your zero. If so, I'd be looking real hard at your scope mounting. Possible it's the JP, but unlikely.
 
@Sticks the 6.5G barrel was sourced and cut by my local smith. He personally guarantees MOA from any of the barrels he makes.

I'll explore the mounting and mechanical zero again.
 
Well went back to the range and validated that yes, the NF ATACR windage is zeroed to the bore. It was a perfect, sunny 38 deg F day with 5 mph winds but it shot well, considering my setup. And yes, I was shooting off of a steel ammo can with my jacket on top. I'm waiting to see what Shot Show 2019 brings about in bipod innovation.
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I think with a lot more practice I can get it to be consistently similar to my 3rd group or even better. Some things I learnt from this range outing:
  • You cannot load a magazine with the bolt closed on an AR10. It just doesn't lock in place.
  • I shoot better with my thumb on the same side as my wrist and not when it is wrapped around the pistol grip.
  • Really driving the stock back into the shoulder allows a much more stable platform. I had to consciously make sure I was doing this otherwise I'd loosen up and the groups would open up.
  • I need to make a better effort of flipping the safety to safe when I stop shooting. The muzzle was always pointed down range and it was never in a dangerous situation, it's just holding myself to higher standard of safety.
  • Brass straight out of the chamber can melt a tarp
  • I'm really enjoying the pursuit of precision!
 
As has been stated: Large frame AR’s are NOT the same as bolt guns. As such, they are MUCH s’more difficult to shoot accurately. Not that it can’t be done, it just requires more work. Some will be easier than others.
The AR has a horribly long lock time. Also, there is a ton of things going on AFTER you pull the trigger. We measure lock time on bolt guns in nano seconds. AR’s, no where near as fast. The tiniest, most insignificant change in a gasser will open your groups.
I will even say this: guys that can shoot AR’s well, will shoot bolt guns well, the reverse is not necessarily true.
Also, the gun matters. I have a GAP-10 in 6.5 that has always made me feel like a rockstar. It’s a 22” barrel, heavy, and shoots super nice. My KAC ACC is an awesome rifle as well, but it’s shorter, lighter, and, being .308, it has more “jump” than my GAP. It is more difficult for me to shoot my ACC consistently well than it is my GAP.
They both shoot, one just requires a lot more work from me.
1.5 from a gasser, and a newer shooter, you’re doing great. Don’t sweat it in the least. Practice a bit, maybe take a lesson or two from someone who you know shoots AR’s well, and you’ll be doing even better!