Range Report Spin drift?????

[bobo]

Was shootin at 800 yds tday. At sundown. Wind was zero. Dead calm muzzle to target. Shootin 308 w 168 gold metal match. Had to have 2.5 moa to left for center hit. Mine and a buddys gun. My app on phone is fte and seems to sho only .75 moa for spin. Was all this correction spin or was i missin a slight wind?

Mind you i was shootin with a couple of very expiernced shooters and they were both callin wind dead calm.

Opinions?

Oh yea i have rock 11.25 barrel and he has same bartlien if matters

 

[VTi]

Re: Spin drift?????

Your optic could be very slightly canted...

 

[Graham]

Re: Spin drift?????

2.5 MOA is a lot of spin drift at 800.
That ain't it.
Can you hold .75 MOA at 800?

 

[bobo]

Re: Spin drift?????

I thought that was a lot also but both of us had exact same issues if shootin to right like that, which way wuld b canted? How can tell for sure a fix it?

Wat do u mean by can i hold .75 moa at 800? Hold over or steady or smthn else?

 

[Jeff in TX]

Re: Spin drift?????

There is no question spin drift occurs and can be measured and calculated for in a closed environmentally controlled windless shooting range or vaccum. However once you take it outside any spin drift is lost in wind or shooters setups. My buddies and I have shot short to medium range distances on what we believed to be dead calm days. We lit candles at different intervals on our 300 yard range at the ranch. Guess what there we’re always slight winds and cross winds we could not really feel. The candles didn’t lie and sometimes blew out. Also just because it feels windless ground level really what’s happening 15 to 30 feet above us or across a canyon or divide we may be shooting across? Guess what I’m trying to say there is usually some kind of wind even if we can’t feel it.

If everything was perfect with your setup as well as absolute zero wind from point A to B including your 168’s would have just a tad over 6” +/- of spin drift at a grand. This would be dependent on the followings but you would be close
Bullet type
Barrel diameter
Twist rate
Velocity

A perfect set up includes a rifle that shoots
.15 moa or better @ 100 yds. It would be very difficult to measure spin drift on a .25 moa rifle and next to near impossible to accurately measure spin drift on a .5 moa rifle or worse
Zero degree of cant
A scope that tracks absolutely dead on
Perfect trigger control from shot to shot (more than likely the problem)
Shooter induced error

Sorry not trying to beat you down as you asked a good question and you're looking for answers and not to get beat up for asking.. However the answer to your question is not spin drift. Your problem lies somewhere else, more than likely with your trigger control if I was a betting man. Without knowing how well your rifle shoots and how well your scope tracks we're all just guessing.

 

[Killswitch Engage]

Re: Spin drift?????

there is no such thing as no wind unless you are in a vaccum. i guarandamntee there was wind.

get you some smoke grenades or smoke bombs and set it off on a day you think there is no wind. its even better if you can set one off every hundred yards the length of your range. tell me if the smoke goes straight up...

 

[Killswitch Engage]

Re: Spin drift?????

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bobo</div><div class="ubbcode-body">I thought that was a lot also but both of us had exact same issues if shootin to right like that, which way wuld b canted? How can tell for sure a fix it?

Wat do u mean by can i hold .75 moa at 800? Hold over or steady or smthn else? </div></div>

he means are you and your rifle capable of .75moa at 800yds.

 

[bobo]

Re: Spin drift?????

wind when we thought no wind makes the most sense. I will have to try the smoke bombs.

800 is farthest out Ive been with this rifle but at all ranges so far I have had no problem being at and below half moa (often well below) and always below .75 moa.

thx. learn something new everyday.

 

[9H_Cracka]

Re: Spin drift?????

Your barrel probably has deeper grooves in it than most, so the bullet has a deeper cut in it from the lands. That gives the bullet more traction against the wind, greatly increasing your spin drift effect.

You and your buddy should re-barrel. Or try a teflon spray like the one used in Ronin, where the guy tried to "stamp" Sam.

 

[Rthur]

Re: Spin drift?????

That is epic 9h, never thought of that.

 

[GrantB]

Re: Spin drift?????

Read the thread a little further down in this section called Shooting In the wind. I posted some comments in there that might be helpful. I have had your problem before and this took care of it

 

[wadebrown]

Re: Spin drift?????

There is always wind when shooting at 1,000 yards

 

[MitchAlsup]

Re: Spin drift?????

Bad wind call.

SD at 800 yards is on the order of 0.5 MoA and while it might contribute to your 2.5 MoA hold-off, it is small compared to the magnitude of the wind.

Trifflings of wind "get ya" out past 600 yards. In addition, you need to call the wind near, mid-ramge, and far inorder to get a reasonable guess at the real wind 'value'.

 

[bobo]

Re: Spin drift?????

9h, seriously or jokin on rebarrel thing. I no good at pickin up sarcasim on these boards. My barrel only has about 250-300 down it while the bartlien is at about 2500. Would that matter? Also, wuld gunzilla fit as teflon cleaner? I usually use sweats

 

[bobo]

Re: Spin drift?????

Gonna hav to check that grantb. Thx. But facts that both of us were same has me leanin twrd bad wind call.

 

[1Sg (ret)]

Re: Spin drift?????

what up bobo ? Dont think i will rebarrel just yet.We need some rebar stakes with some survey ribbon at diff.ranges to call the wind a little better.With both rifles shooting the same DOPE we must have missed the dead calm wind.

 

[bobo]

Re: Spin drift?????

yesir, i think that will be a good idear.

 

[Lowlight]

Re: Spin drift?????

You're probably right handed and most of the e tra drift was probably poor fundamentals, to include very bad trigger control which is causing angular deviation.

The further you shoot the bigger your deviation.

Trigger control is one of the hardest fundamentals to master and will cause the biggest errors down range. However saying you dialed 2.5 MOA of SD makes you sound smart and beats admitting you might have a fundamental shooting problem.

 

[1Sg (ret)]

Re: Spin drift?????

We didnt say we were smart. We were trying to figure out what the problem was. This is the first time we have been to 800.We probably do have some fundamental shooting problems.we both hit an 8 in target at 800 yds 5 times out of 10 was exciting to us.Using 2 diff. rifles with the same dope tells me we are not as bad on the trigger as u would would think.I was shooting a Gap Crusader and the other rifle was a custom Rem 700 with a Mike Rock 11.25 22in barrel.We dont have any formal training.We are just asking a question.

 

[Enough Said]

Re: Spin drift?????

Does your 700 dope show the same trend but less overall correction?

What do your focused snap-shots between live rounds reveal? Any movement indicates fundamental trigger-control error. I caught myself before my cold bore shot this afternoon and corrected it before the shot.

Happens to EVERYone.

Hope you get it worked out, though.

Hold and squeeeeeeeeeeze.

 

[1Sg (ret)]

Re: Spin drift?????

I didnt do any snap shots.We were in a time crunch.3 people shooting running out of time.Thanks for reminding me i usually do snap shots.

 

[bobo]

Re: Spin drift?????

Never said dialed 2.5 of SD. Certainly wasnt tryin to sound smart. Simply askin question.

 

[Lowlight]

Re: Spin drift?????

It's an inside joke,

Man up, and take it, you started the thread titled, "Spindrift" no us.

 

[Rob01]

Re: Spin drift?????

This is what you need!

<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/yvl_W-XVXD0"></param> <param name="wmode" value="transparent"></param> <embed src="http://www.youtube.com/v/yvl_W-XVXD0" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"> </embed></object>

 

[2Shots]

Re: Spin drift?????

Wow, you guys have way to much time on your hands!

 

[bobo]

Re: Spin drift?????

hahaha. I'll say. damn yall tough on beginners.

 

[Guest]

Re: Spin drift?????

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bobo</div><div class="ubbcode-body">hahaha. I'll say. damn yall tough on beginners. </div></div>

On a scale of 1-10 I rate this Spin Drift thread a 2.
Once upon a time, an long before spin drift was even a real number on this board, we had a thread that was a 10+.
David Tubbs made his comments to the reality of same, then Bryan Lutz commented as well. That said, your numbers are rather deep for 800yds. I'd suggest smoke an a look see at the bullet flight level for wind, an checking your systems, tracking an impact on a plum line.
Bullets don't know how to lie, but if you read mother wrong, or you/r system is off, it's much like a computer, shit in = shit out. Lastly never believe what you read/hear/see, what works for you is all that matters.

 

[Enough Said]

Re: Spin drift?????

That's hilarious. What a fukin' clown...

LOL

That's the Frank I remember! Try being trapped on a ship at close quarters with this guy for 6 or 7 months.

Taylor

 

[mateofeo85]

Re: Spin drift?????

http://www.snipershide.com/2012/01/trigger-school-trailer/

This was a great reminder of the basics of shooting. The final input between the shooter and the weapon is the trigger pull. My trigger pull was suffering tremendously, and I simply looked at blaming other factors for my decreased accuracy. This video took me back to the basics and put a mental post-it of how easy it is to throw off a shot with bad trigger control or grip.

Not saying this is specifically your problem, but a possibility. And a good refresher course at the very least!

 

[ejb]

Re: Spin drift?????

when i get into the spin drift thing i get real dizzy and have to reverse my magnetic direction polar wise