Horizontal Stringing

[GT27]

What usually causes this in your experience,taking out human error of course?

[geargnasher]

In general, numerous things. If the gun is know to be mechanically sound because it doesn't string with a different load, then you can suspect barrel harmonics. Back off the powder charge about 2-3% and see if it changes.

Gear

[Larry Gibson]

Undue pressure on barrel at forend along with shooing to fast cause barrel to heat up and "walk" vertically. If the shots "walk" up or down in pretty much consecutively fired order then this is usually the cause.

However, if the vertical string shot order is random then it is most often caused, with cast bullet loads, by poor ignition due to a wide variation in the shot to shot velocity. This is most often because the powders burning rate is too fast or too slow for efficient ignition and burning with the cartridge and load used. Solution is a heavier charge (if psi limits, case capacity and velocity level permit it), a change to a faster burning powder that will give better ignition and burning, a change to a heavier bullet to increase psi (if psi limit allows it) or a filler to reduce case capacity which increases the ignition and efficient burning.

I find a dacron filler to be most helpfull in eliminating the erratic and poor ignition with many loads. With some combinations of components a filler does not work well or can cause problems. You might want to read the sticky "filler" if you want to try using a filler.

Larry Gibson

DOH!!!!

That was definately a "maggies drawer's" on my part! I'm always easy to admit a mistake, sure nailed vertical stringing though:mrgreen:

[GabbyM]

In a Ruger M77 it can be the way you tighten up that three screw bottom plate.

[GT27]

I'm thinking erratic ignition also,along with the other stated causes,but in my case I suspect EI! Larry,you know my ongoing project! I used a starting load of 16 grains of 4198 and 16 of 4895 and got the same results PB/NGC Saeco 223,no leading,horizontal stringing.I loaded 10 @17,10@18,10@19,haven't got to the range yet to test them? GT27

[paul h]

Handgun or rifle?

For a bolt action rifle it's usually an action/stock bedding issue or a stress issue in the barreled action. Sometimes increasing or decreasing the powder charge will tighten up the group.

With a handgun it's generally an issue of how you are supporting the gun and followthrough after the shot.

[beagle]

With a properly bedded rifle and proper sighting, it's usually shooter position error or in the case of sandbags, an improperly positioned rear bag or inconsistent positioning./beagle

[Marlin Junky]

What usually causes this in your experience,taking out human error of course?

Assuming you don't have bedding issues and your boolit fit is correct, (I'm assuming you're not experiencing fouling issues) if you are observing this situation and your chronograph stats are normal, then your alloy could be too hard for the pressure developed. You could also have a situation where your lube is too slick or just too thin. I experience stringing all the time when I'm experimenting with lube while trying to hold all other variables constant. Granted, boolit hardness sometimes gets away from me because I can't possibly do a BHN check on every boolit I shoot and BHN does vary with time; however, If you give a hoot about rifle accuracy and you're not running all your development loads through a chronograph, then you're well... shooting handicapped.

MJ

[429421Cowboy]

I would say Larry is spot on as usual! If you are crony'ing loads, you should be able to see a large SD spread between shots that will tell all.

[geargnasher]

I would say Larry is spot on as usual! If you are crony'ing loads, you should be able to see a large SD spread between shots that will tell all.

Actually, Larry missed by a mile. The original question was about HORIZONTAL stringing, not vertical.

Gear

[429421Cowboy]

Gear... I'll slap myself in the back of the head for that one, i missed it too...

[44man]

Now we don't know what he is shooting. He has HORIZONTAL stringing Larry, not vertical. That will NOT be a difference in velocity.
Hold and gun torque would be my guess. Canting a rifle or handgun from shot to shot?
A rifle with forearm bounce or a handgun with trigger finger push to the side instead of straight back, we don't know.
I will not answer until we see what he is shooting.
Then wind when shooting, nothing to sneer at.

[GT27]

Its a Stag 3...shoots sub MOA with green tips all day!

[swheeler]

What usually causes this in your experience,taking out human error of course?

Usually a bedding problem.

[oneokie]

AR clone? The upper is loose in the lower, the pins are undersize, or you need one of the polymer wedges for the rear of the reciever.

[geargnasher]

Agreed, 44man, lots of things can cause it, gun 'control' being probably near the top of the list. I was throwing out one common cause of that phenomenon with sporter-weight rifles, assuming the fore end isn't "grounding" on one side of the barrel and the action/optics are tight. The effect of barrel harmonics on group size and stringing is very much overlooked by the average shooter.

Larry's right in a way about some of the causes of vertical stringing, but the real root of ignition-related stringing is ignition consistency itself, the most critical part being the very start of the ignition cycle that establishes the barrel harmonic. Peak pressures can have a wide variance and still achieve excellent accuracy. The initial rise is tough to measure well with a strain gauge. I believe, based on a small amount of experience, that his is also one of the reasons that slow powders improve accuracy so much when a finely-tuned duplex "kicker" charge is used.

Gear

[felix]

Typically, when using accurate guns (read: BR) vertical stringing is followed by horizontal, and then by round circles as one goes up in powder volume. A simple primer change can and will change where in this sequence the new load is situated. A primer sets up its own wave which is added to that of the powder. A kicker powder is nothing more than a primer extension. ... felix

Also, barrels of 21.75 inches are perhaps the best to use when appropriate for type of gun. It has been shown that this is true with every cartridge tried in the warehouse experiments, including hunting guns and calibers. And, it appears if the velocity is divisible by 3 evenly, that is just about where the accuracy peaks using our standard primers, powder, bullets. ... felix

[geargnasher]

Typically, when using accurate guns (read: BR) vertical stringing is followed by horizontal, and then by round circles as one goes up in powder volume. A simple primer change can and will change where in this sequence the new load is situated. A primer sets up its own wave which is added to that of the powder. ... felix

A graduate course in component selection and barrel harmonics condensed into three sentences for those paying attention. Superb, Felix!

Gear

[runfiverun]

simply rolling the rifle from side to side wil make the groups appear the be stringing horizontally.
if using the open sights or a low powered scope it's pretty easy to get some horizontal dispersion simply through aiming error, your hand on the scope or the front rest is hitting the forearm inconsistently.
the sun will also cause groups to walk across a target throughout the day.
or an open sighted rifle to shoot to the sun side of the front sight.

[felix]

Aiming error is reason enough to employ some experienced rifleman to validate your gun is doing its best. If the gun cannot shoot better than the high ONEs, it is not worth making it do better; so say the experts in THE warehouse (now defunct, naturally because of being in the middle of Houston). ... felix

[725]

horizontal string - check your seating depth

vertical string - more or less powder

[felix]

Yep, that's the most obvious two steps to be performed first. ... felix

[Moondawg]

I was never specificed how much horizontal, a couple tens of an inch, a half inch, or one to several inches?

1. Not watching wing flags close enough, not enought wind flags for the range (three flags are about minimum for 100 yards), or no wind flags at all. The wind/breeze can cause a lot of hortizonal on bullets.

2. Bench error or poor bench techinque on the part of the shooter.

3. mechanical problems with rifle.

4. Poor load development.

[GT27]

AR clone? The upper is loose in the lower, the pins are undersize, or you need one of the polymer wedges for the rear of the reciever.

Upper and lower are as tight as Obama's butt right now! I went up in charge as I also suspect poor ignition,and burn,thanks for all the great idea's,if this don't work I'll be back for more great advice! GT27

[felix]

Vibes will naturally rotate the grouping between different loads. Horizontal and vertical must be recognized as such. They could be at right angles to each other for the most part, but not guaranteed, which depends on how close the load is to being perfect for the current ambients. Bigger the circle, the vibes are at fault. One hole, say in the ZEROES, the vibes are not infringing on the target's intent, meaning the projectiles are leaving the muzzle when the muzzle is moving the least, or not at all for all practical purposes. ... felix

[tomme boy]

AR rifles you have to make sure that you follow through with the trigger. There is a lot of things going on when the trigger is pulled. You have recoil in two directions. Going back then the recoil from the carrier going forward. Make sure that you feel the reset of the trigger after the shot has been taken an deliberately let it reset. This helps with follow through. I think it is more head position on the stock that is going on. Most people have the wrong mounts on an AR an they are either stretching their neck from too high to smashing their face on the stock from too low. We need more details.

[44man]

Can't add much.
But SUN---- AAAARRRRGHH! [smilie=l:
I mounted a scope solid in the early morning on a bench, sighted it center at 200 yards. I checked every 15 minutes without touching a thing. The cross hairs moved way left, then up, then right, then down as they followed the sun until in the evening they worked back to center again. It showed the target is not where you see it.
I am not talking an inch or so but a HUGE movement.
Now add in mirage and wind.
If the target is in shade for a shot and the next shot has sun on the target, never expect to shoot a group.
It is why IHMSA is so tough. No sighter shots when the targets are not where you see them.

[montana_charlie]

Considering how high above the bore the sights are on a "Stag 3", I would say that runfiverun has the right answer in his post #19.
Of course, rifle cant is a form of human error, and we were told to disregard such.

CM

[popper]

Its a Stag 3...shoots sub MOA with green tips all day! I would suspect the shooter. Big difference between shooting cast and jacketed.

[GT27]

Its a Stag 3...shoots sub MOA with green tips all day! I would suspect the shooter. Big difference between shooting cast and jacketed.

Please elaborate the differences,I'm 51 and never too old to learn something new! I understand the loading differences! Shooting differences???

[felix]

Don't know how to answer that. Pointers can be given if you can have a movie made of your shooting from at least three different angles. We need to see ALL points of your gun interaction. If at all possible, see if you can employ an expert shooter to do the same with YOUR gun. That alone might tell you something to investigate (with before and after effects) which we can see here should you decide to show the movie(s). ... felix

[Boyscout]

USMC training told us to check these three first: horizontal-jerking the triggger, vertical-breath control, circular-chasing the bullseye (focusing on the bullseye and not the front sight post). When I first start shooting cast lead, the store I purchased powder at recommended Accurate 5744 because of its bulk, positional ignition would not be as big a problem.

[popper]

Even in an AR, there is a difference. 1) fps - 1800 vs 2700 bbl movement, my 308 skips sideways left on bipod. 2) recoil, trigger followthrough, post #32. I can get small groups with jacketed (1") but string left with cast.

[GT27]

I just came back from my range and the lead in this AR is good for making noise, prints nice neat little holes @ 25 yards that will cover a poster board, with Jwords its a
MOA shooter! I think I'm going to sell the Saeco 221,and the bator and buy jwords!I'm frustrated as Haides! UNCLE! GT27

[popper]

Your last post doesn't exactly jive with your first. Other than a 65 gr. 223, no alloy, load, lube, fps or sizing info. We can't help much without that info. Mine will do moa w/jacketed, started with 6" @ 25, now got it down to 2-3". Just takes some thinking and work.

[GT27]

Your last post doesn't exactly jive with your first. Other than a 65 gr. 223, no alloy, load, lube, fps or sizing info. We can't help much without that info. Mine will do moa w/jacketed, started with 6" @ 25, now got it down to 2-3". Just takes some thinking and work.

IMR 4198 15 grains-19 grains/IMR 4895 16-19 grains/BLC2 15-19 grains have been tried with this mold,no joy! You can use a 55 grain Jword,Hornady,Winchester,IMI, so far with 19 grains of 4198/25 grains 4895/25 grains of BLC2 and it will shoot MOA.Saeco is 62x225 wheelweights.Sized 225(Lee sizer),Lube is LLA,pan lube 50/50 beezwax-LLA.I've tried both lubes.I've tried Sage's GC's,and without GC's,same results!No joy with the groups at all!! I can throw a rock from 25 yards and be more accurate,no joke!All loads were worked up for function first,now trying to get reasonable accuracy.If the function isn't there,the accuracy is worthless to me,thats what they make bolt guns for. I dont know what else to look for??????:veryconfu

[popper]

I don't believe any of the powders you list are recommended for 'light' loads. Use some dacron filler? I haven't had any luck not using GC on any rifle, so far. I use 50/50 Pb/#2 and heat treat, if you are using AC COWW, it's a little lower than my BHN. I use cooking oil for lube. Make sure the GC is in the neck completely. The issue I see is that your load data suggests you are running those poor ol boolits > 2200 fps. You need all the ducks in a row to get there.

[303Guy]

Can't add much.
But SUN---- AAAARRRRGHH! [smilie=l:
I mounted a scope solid in the early morning on a bench, sighted it center at 200 yards. I checked every 15 minutes without touching a thing. The cross hairs moved way left, then up, then right, then down as they followed the sun until in the evening they worked back to center again. It showed the target is not where you see it.
I am not talking an inch or so but a HUGE movement.
Now add in mirage and wind.
If the target is in shade for a shot and the next shot has sun on the target, never expect to shoot a group.
It is why IHMSA is so tough. No sighter shots when the targets are not where you see them.

Very interesting indeed!

[Baryngyl]

Can't add much.
But SUN---- AAAARRRRGHH! [smilie=l:
I mounted a scope solid in the early morning on a bench, sighted it center at 200 yards. I checked every 15 minutes without touching a thing. The cross hairs moved way left, then up, then right, then down as they followed the sun until in the evening they worked back to center again. It showed the target is not where you see it.
I am not talking an inch or so but a HUGE movement.


That was just the sun heating up and expanding different parts of the bench as the sun moved causing the scope to point in slightly different directions. :kidding:


Michael Grace