MOA at 400 but can't get on target at 650?

[Bruce Treloar]

What I am about to suggest I do with great hesitation due to the company I am in and there are so many that disagree with me on this. I had this happen to me while I was shooting 1,000 competitions in California. My rifle was a 1:10" and I started out with 200 and 210 grain slugs with somewhat the same results as you are having but at a bit different ranges. between 600 and 700 yards my groups started opening up with 210 grain slugs, between 800 and 900 yards the 200 grain slugs opened up their groups. this phenomenon is called marginal stabilization. as the slug slows down so does the rotation, when you see a dramatic opening of your groups from one yardage to another your slug is going through a decay of stabilization. normally a 1:10" barrel should stabilize a 180 grain slug out to 1,400 to 1,700 depending on the AOL of the slug. Berger VLD's ruined all that very quickly. the longer the slug the faster the twist needs to be. where the cutoff is for a 1:10" twist ends its stabilizing of a particular slug and the need for a 1:8" twist barrel has changed over the years. from what you are saying your slugs are not stabilizing at or near 600 yards. this can be two reasons. rotational velocity is not fast enough keep the slug stable, or your FPS and your rotation are too slow to ever keep it stable out past 500 yards. I would try a 175 grain Nosler Accu-Bond and run the same 400 and 650 yard shooting. if your gun shoots true at 650 then your gun needs a lighter slug or a faster twist barrel.

 

[jeff1965]

Cabela's set it up? No need to check on their work.

You need to do your own work on your gun! I won't even talk to anybody in the gun department at Cabela's because of there lack of knowledge. Sad but true.

 

[Bruce Treloar]

Freddie is pretty close to solving your problem. When shooting long distances it's not uncommon for a projectile to become unstable at a slower velocity hence the larger groups at a distance. That is why most shoot boatails with around a 10% advantage over flat base at longer distances. It appears your projectiles are stable but not at the longer distance. You can quicken the twist, use shorter projectiles or increase the velocity. Any one of these changes make the difference. I did have a mathematical equation to use when working out the above three but can't find it just now.
Do a bit more experimenting by placing a cardboard target every 100 yards right out to 1000 yards, check the holes for roundness. If elongated that will show the distance projectiles are becoming unstable. A big rock doesn't tell the whole story , invest in good quality targets which should help solve your problem.

 

[aushunter1]

I would see bullet stabilization being a problem if its to heavy/long for the twist rate or when entering the transonic/subsonic stage but if a bullet is stable at 400 then I cant see how it would be less or unstable at 650 unless it is entering transonic/subsonic speeds.

Just my 2c.

 

[DSheetz]

The carbon wrap on a barrel acts as insulation and holds the heat in . You said that you were in a strip mine was there ground cover or was it bare ground . Bare ground causes air to boil up and make turbulence that is hard to detect and shifting in all directions . I like to level my action on the bench after I set up a piece of butchers paper out at 50 - 80 yards then use a 4 foot level to put a black line down the paper . with the action leveled you can then true your scope if your rifle is stable so that it doesn't move while you true your scope . I no longer trust some one else to mount my scope for me after loosing a 4x12 wide field scope to a person that ruined it trying to mount it then went bankrupt after he sent it in to be repaired .

 

[Triple BB]

Do you have the twist rate the hammer bullets are calling for? You just don't hear of anyone disappointed with them on here.

I have 1-9 which is their recommendation...

 

[Dell]

Hey guys, so I have browning stainless stalker in 300 WSM topped with a Leupold VX-5hd and shooting 180 grain trophy grade accubonds. I have a 100 yard zero and chornographed the speed im shooting. Im also using a gunwerks br2500 to get my elevation dials, and it worked perfect out to 400 or so yards where it was still holding MOA.

The issue is when I tried to take it out to 650, I spray painted a large rock about 3 feet by 3 feet orange and set up on it, made my dial and took aim slowly squeezing the trigger, each time I shot id raise my head to see a puff of smoke drifting in the wind near the rock thinking I made a hit..

Well after about 10 rounds I drove to my target to see I didn't make contact a single time! I hit ALL around it tho but could not even touch a 3ft by 3 ft target..

I also had another shooter with me who was also making Moa size hits at 400 yards with the rifle and they too had the same results as me at the 650 range..

Does this sound like a shooter issue or is it possible for the rifle to open it groups up that big over an extra 250 yards?

Thanks for any input.

Tommy

You need to put up a 4' X 4' piece of cardboard at 650 and see where your rounds are impacting. I'm not sure how you got your dope at 650 but I can tell you that even if using the best ballistic charts, they really fall off after 500. You truly need to shoot your dope in on paper at 50 yard intervals unless you happen to get extremely lucky. Using Berger, Hornady and a host of other ballistic programs, then figuring in all the atmospheric conditions known to man, you can still be off one to two or more MOA when you move past 600. Try it. Paper doesn't lie. All rifles are different. I'm only relaying my experience and what's worked very well for me.

 

[CVCOBRA1]

If you are pulling a plow with a trace team all day long put the mule in the middle because they can stand the heat.

 

[ilc]

You have received a lot of well meaning responses, however because none of us were with you they are all just speculation.

My advice is to get an experienced long range shooter to go with you and shoot some paper to find out what the issue actually is.

I'm not suggesting this is your problem, but bullets can become unstable at long range due to dynamic stability issues, typically at transonic velocities. The 168 grain Matchking is a classic example of this. As a general rule gyroscopic stability increases downrange as velocity decays faster than spin rate. Dynamic stability is dependant upon bullet design factors and much more difficult to predict.

 

[LazzInc]

I probably should not throw my 2 cents worth in here, but if the rifle/load wont shoot MOA 3 shots groups at 650, I would question whether or not it can do the same at 400 yards ,,, that has been my experience ,,,, generally I like to see 1/2 MOA or better at 300 yards, before I will take a particular rifle to 1000Y ,,,,

 

[milo-2]

Ok back to the range this evening. I didn't have time to stretch it out but I did validate that I was still on at 100 yards.

Also shot 3 different type of ammo, ballistic silver tip shot 2 moa, Barnes ttsx shot 2 moa however the accubond shot 0.5 moa, I'll attach a pic below of one of my 3 shot groups with the accubond.

Next trip will be going back out to long range and trying to figure out what the heck is going wrong.

Ignore the group up high, that was Barnes.

This post is epic really. I am surprised no one has told you to change underwear between shots. I could walk Stevie Wonder on to a 10" plate at 1K just by twisting his dreads while he was on the rifle.
Do post what happens on the re-test.
I have to say this though, from an accuracy standpoint, almost all you have done is failure. Let me explain, I would never even test a different powder in a barrel w/o cleaning, let alone a different bullet. Using different powders just upsets fouling patterns. Throwing in different bullets in pencil thin barrels just doesn't work, think of barrel whip, every different box of ammo you shoot is different, from the powder to the bullet. Your Barnes Titty yx may not strip copper till the end of the barrel but the Nos LRAB may start stripping 4" in, but yet you are going to fire all these in a barrel and expect results.

About me, I am a nobody really, I do not compete, I do not hunt, I just shoot a lot, minimum of 4K centerfire LR rounds a year. I have a high school education is all, but I pay attn to detail. I've been shooting LR for 10 yrs, many cases, 6's, 6.5's 7mm's, and a 338 snipetac, so 30 cal has never been in my wheelhouse. But I have also spotted for enough guys to know the Nosler long range accubond has a distinct cutoff point of viability. Not saying it is no longer accurate, but it's no longer viable predictability wise in a cacl app.

Over this coarse, I have shot heavy to lighter barrels, and let me say, heavy barrels are more forgiving. From heat, to fouling, which is compounded in rate of fire. Let's not start the cleaning debate here.
If you are going to shoot your rifle today, you need to clean the barrel before hand, and not with Hoppes #16 benchrest, get a carbon dissolving solution like Boretech C4, then a copper remover like Montana Extreme copper killer. If either of these are not available, try Gunslick bore foam and a bronze brush, 3 passes in and out will reveal a disgusting residue on your cleaning rod that tells a story.

Right now, you have a goal to achieve, shooting a paper setup at any distance serves no purpose unless you can run down or drive down after every 2-3 shots. Dust signature behind an obscured target is irrelevant, unless you have glass to pinpoint impact, a high right impact may look centered up from your vantage point with wind direction.

What this boils down to, you need at some point turn the odds in your favor, from finding someone who is knowledgeable to accompany you, to just using common sense and not firing a thin barrel 20 times in 30 minutes and expect to hit.

It does not matter at this point whether some turd at cabela's mounted your scope canted to the left at 4 degrees, you said yourself that your impacts at 650 boxed the rock, from 6" off to 1 foot, in all directions. So basically you were shooting 8 moa at 650, you need to decipher if the rifle is capable of this distance, or if the ammo used is capable, or unfortunately, if you are. Basically at this point, you need some luck, which in turn into a self directed success.
Play your cards right, do not overthink think this, it is a simple obstacle in a meaningless faction of your overall life.
Good luck !! !!

 

[JimmyCP]

What I am about to suggest I do with great hesitation due to the company I am in and there are so many that disagree with me on this. I had this happen to me while I was shooting 1,000 competitions in California. My rifle was a 1:10" and I started out with 200 and 210 grain slugs with somewhat the same results as you are having but at a bit different ranges. between 600 and 700 yards my groups started opening up with 210 grain slugs, between 800 and 900 yards the 200 grain slugs opened up their groups. this phenomenon is called marginal stabilization. as the slug slows down so does the rotation, when you see a dramatic opening of your groups from one yardage to another your slug is going through a decay of stabilization. normally a 1:10" barrel should stabilize a 180 grain slug out to 1,400 to 1,700 depending on the AOL of the slug. Berger VLD's ruined all that very quickly. the longer the slug the faster the twist needs to be. where the cutoff is for a 1:10" twist ends its stabilizing of a particular slug and the need for a 1:8" twist barrel has changed over the years. from what you are saying your slugs are not stabilizing at or near 600 yards. this can be two reasons. rotational velocity is not fast enough keep the slug stable, or your FPS and your rotation are too slow to ever keep it stable out past 500 yards. I would try a 175 grain Nosler Accu-Bond and run the same 400 and 650 yard shooting. if your gun shoots true at 650 then your gun needs a lighter slug or a faster twist barrel.

My dad called these whirly birds.lol

 

[eric v.]

Hey guys, so I have browning stainless stalker in 300 WSM topped with a Leupold VX-5hd and shooting 180 grain trophy grade accubonds. I have a 100 yard zero and chornographed the speed im shooting. Im also using a gunwerks br2500 to get my elevation dials, and it worked perfect out to 400 or so yards where it was still holding MOA.

The issue is when I tried to take it out to 650, I spray painted a large rock about 3 feet by 3 feet orange and set up on it, made my dial and took aim slowly squeezing the trigger, each time I shot id raise my head to see a puff of smoke drifting in the wind near the rock thinking I made a hit..

Well after about 10 rounds I drove to my target to see I didn't make contact a single time! I hit ALL around it tho but could not even touch a 3ft by 3 ft target..

I also had another shooter with me who was also making Moa size hits at 400 yards with the rifle and they too had the same results as me at the 650 range..

Does this sound like a shooter issue or is it possible for the rifle to open it groups up that big over an extra 250 yards?

Thanks for any input.

Tommy

i have an xbolt that was shooting lights out,but now it's doing the same thing yours is. give me a call when you have a minute to chat. 276 701 2682 if i don't answer text me.

 

[John Klingenberg]

I started to hear swaami music and a sitar playing in the back of my head as i read that.