Bolt Action Grouping Questions

[wnchstrtnfldvlle]

I just have some questions for those more experienced than I when it come to grouping, zeroing, and factors that may affect those.

Context:
Sig Cross 6.5 Creedmoor, 18" barrel, with AAC muzzle brake attached.
Scope dialed to about 12-15x at 100 yards.
Shooting seated from a wooden bench using the bipods, and a sand sock for the stock. Unable to go prone at this particular lane.
Hornady Precision Hunter 143gr ELD-X ammunition. (Chrono'd at 2520-2570ish) Box said 2700 but I'm assuming that's based on a longer barrel.
5 round groups were averaging between 1-2", with moments of brilliance where there would be four rounds at about .5" with a flyer.

Questions:
1. Do you think a 50 fps variance between rounds at 100 yards is enough to open groups up like that? Any experience with other ammunition? I'm using a "hunting" rounds because I'm looking for take down capabilities at range.
2. Is there a more accurate hunting round out there you would recommend, or am I being unrealistic?
3. Would you recommend doing anything different with positioning? Should I do it prone? Should I throw a sandbag in front, or even go as far using a clamped vise set up of some sort?

Yes, I know that shooter error is involved as well. I'm just looking for advice regarding other factors or ideas the masses may have. I see on here where guys are shooting .3 moa using the 6.5cm, and I assume they're shooting like I am and just better. But maybe they're using a lead sled or something and didn't mention it. Any advice is welcomed.

 

[CAMSDADDY]

The only way to know if there is a more accurate round is to buy a few boxes and see what you get. For commercial rounds I think you are getting pretty good results.

 

[BHPSteel]

Specifically for point 1 - the fps variance (under 2%) - I wouldn't expect your POI to be affected by any measurable amount with that setup.

Out at 400? Maybe.

Point 3 - positioning - sure, anything that takes as much of the human element out of the equation. If you don't have a lead sled or something like that, a properly set up benchrest position with sandbags will still give you some idea on how much of the spread is you, and how much is the gun and ammo.

 

[ReservoirDawg10]

Lots going on with your questions. Most cannot be answered if there is shooter error involved, so I'll start with what can be answered. For most hunting, 1 - 2 moa will more than suffice. So, if the end goal is a dead deer, you should be fine.

At 100 yds, 50fps ES will not affect groups that much.

Are there more accurate/precise rounds for your set-up? More than likely. You may even find a different lot of the same ammo that works better.

If this is a hunting rifle, clamping it into a benchrest setup provides almost no benefits. Get a good position and work on fundamentals. If you shoot better prone, get your zero while prone.

Not all, but a lot of people that are shooting sub half-minute groups are loading their own ammo which is also tailored to their rifle. If they consistently shoot sub half minute, their fundamentals are solid. Anyone can get a quarter inch 3 shot group. You'll luck into that group at some point. Don't compare your 5 and 10 round groups to what some online nobody who shows his/her 1 random quarter-inch 3 shot "group." Work on you. Get directly behind the rifle. square your shoulders to the target. Keep your head on the rifle, both through the shot and while reloading and taking your next shots. Have good follow through. Load your bipod.

 

[CAMSDADDY]

I would rather have a 2" group where I want the bullets than a 3/8" group 4" from point of aim. I am a hunter and not a rifleman/marksman.

 

[Plinker66]

Hornady ballistics app says decrease from 2570 to 2520 fps will increase 143 eldx drop by .25” at 200 yards.

 

[Whatchagot87]

Lots going on with your questions. Most cannot be answered if there is shooter error involved, so I'll start with what can be answered. For most hunting, 1 - 2 moa will more than suffice. So, if the end goal is a dead deer, you should be fine.

At 100 yds, 50fps ES will not affect groups that much.

Are there more accurate/precise rounds for your set-up? More than likely. You may even find a different lot of the same ammo that works better.

If this is a hunting rifle, clamping it into a benchrest setup provides almost no benefits. Get a good position and work on fundamentals. If you shoot better prone, get your zero while prone.

Not all, but a lot of people that are shooting sub half-minute groups are loading their own ammo which is also tailored to their rifle. If they consistently shoot sub half minute, their fundamentals are solid. Anyone can get a quarter inch 3 shot group. You'll luck into that group at some point. Don't compare your 5 and 10 round groups to what some online nobody who shows his/her 1 random quarter-inch 3 shot "group." Work on you. Get directly behind the rifle. square your shoulders to the target. Keep your head on the rifle, both through the shot and while reloading and taking your next shots. Have good follow through. Load your bipod.

Pretty well summed up what I was going to say. Not many "truly" MOA rifles being used even less so .5MOA. Or at least shooters who can fully take advantage of them regardless of what the internet has taught us. Although I should add, all of my rifles are one-holers, that is, as long as I only shoot once!

 

[wnchstrtnfldvlle]

I appreciate the replies.

1. I believe my fundamentals are sound. Of course there's always room for improvement. I think it's a factor of just expecting too much from commercial ammo, and lazily not finding the best shooting setup I can.
2. I'll probably switch to the prone shooting platform on the next lane over. I try to avoid it because there is a lot of time wasted on waiting for guy shooting out further to run down to do target changes, etc.
3. I may try a box or two of target ammo to see if they tighten up at all.
4. I would like to get back into reloading again, so this could be a good excuse, lol. I used to reload 300 black and 9mm practice ammo and enjoyed the process and cost savings.

Again, I appreciate everyone's input, and if you have anything else to add by all means go ahead.

 

[wolfmanrogers]

How many rounds have you put through it?

 

[howl]

Did you every shoot a rifle grouping as well as you want this one to? If not, learn how with 22lr of the same style first.

Your current resting system takes English to get best results. If you want to buy something else, a bulls bag for the front and a rabbit ear rear bag with a stiff bottom makes most people look like better shots off the bench.