vertical stringing

[AceRoth]

I am having big vertical stringing problems with my encore.  The problem is fairly consistent across multiple barrels so I think it's either me or it's the receiver.  I am trying to close it consistently but I am not sure how to measure whether I really am.  I went to the T/C expanding hinge pin with no improvement whatsoever.  Anything is possible but I don't think it's a hot barrel on forearm problem because it is a problem even between cold bore and second shot, when a heavy target barrel is still stone cold.
This is driving me nuts because the gun is shooting great laterally (quarter minute five shot groups) but more like 3 minutes vertically.
Anyone have similar problems and figure out a solution? 

[stubshaft]

I don't mean to insult your abilities but you might have someone else shoot a couple of groups and that would eliminate you as the source of the problem.  You could also try to shoot with the barrel directly on the bags to check to see if the forearm is the problem.

[JustaShooter]

Are you using factory rounds or reloads?  If reloads, how are you resizing?  Do you know your barrel to frame gap, and what headspace are you allowing?

Just a Shooter

[okie44]

Encores are prone to vertical stringing, make sure your buttstock placement and forearm rest is consistant, if possible use some sort of rest like a leadsled.

[Grumulkin]

1.  If he has 1/2 MOA horizontal spread and 3 MOA vertical spread, the problem is NOT with his shooting ability.


2.  Whether he using reloads, how he is resizing, barrel to frame gap  and headspace are ALL entirely irrelevant to the problem of vertical stringing.


3.  I shoot a lot of Encores and Contenders and have never found them prone to vertical stringing and certainly not to the degree AceRoth speaks of.


The things I would consider are:


1.  If you are resting the forearm directly on a hard object when you shoot which I doubt, try resting it on something soft like a sand bag.


2.  Consistent buttstock and forearm placement are important but even with inattention to this I don't think a 3 MOA vertical string would result.


3.  It could be some kind of barrel or forearm issue though I would think it much more likely that those issues would cause general enlargement of group size rather than marked vertical stringing.


4.  Strongly consider your scope as the culprit.  The windage adjustment may be working fine and the elevation adjustment loose.  Also make sure the base is firmly attached to the barrel though a loose base would probably cause general enlargement of the groups rather than a vertical string.

[Grumulkin]

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[AceRoth]

Thanks for all the replies.  Some answers and further musings:
1.  I'm shooting reloads, different sizing methods in different barrels, ranging from fire-formed and minimally neck-sized in the 6 ppc (where the problem is most pronounced) to full-length sized in the 243 where the stringing is less noticeable, likely partly because the groups aren't so tight laterally.
2.  How does one measure barrel-frame gap?  I have not checked headspace.  What's the best way to do that on an encore?  a series of go/no gauges for each thou?  Precision mic?
3.  I'm shooting off a caldwell rock rest jr so not super hard or super soft.
4.  I wondered about the scope, especially because I use cheap optics but since I'm having the problem with three barrels, each with different scopes I kind of don't think that's it.
5.  I keep wondnering about the forearm.  I am running a cheap plastic forearm and have never heard definitive instructions on how much to torque down the screws.  Is shooting it with no forearm the way to rule that out as a cause or is that just going to make it worse?  In other words, are encores designed to be able to shoot right without a forearm?
Thanks again and looking forward to further comments.

[Curtis]

I think shooting it without the forearm is a good way to confirm or rule out whether it is related.
Curtis

[Rol Page]

I have an Encore 260 Rem. rifle and have some vertical stringing which I suspect is due to inconsistent cheek weld to the stock shot to shot.  I am attempting to built the comb up to give me a consistent weld to my cheek bone to see if that helps reduce the groups.  Have taken some dense foam and placed it over the top of the stock to give me a good anchor, it can be taped in place for a few trial shots.  If this proves an improvement I will either buy an add on comb raiser from Brownell's or buy a wooden stock and modify it by slicing off the top, adding the appropriate piece and then replacing the original top to give me a solid anchor.  Due to weather and other commitments I have not had a chance to go to the range to test this temporary arrangement. 
 
I checked the space between the breech block and end of the barrel, with the action closed, on my Encore with a feeler gauge, came up with .003.
 
Keep us posted on your findings as it may help others, (me).  Good Luck,  Rol

[JustaShooter]

2.  Whether he using reloads, how he is resizing, barrel to frame gap  and headspace are ALL entirely irrelevant to the problem of vertical stringing.

Actually, it is entirely relevant.  If he is reloading for the Encore, especially when neck sizing, and doesn't know barrel to frame gap he probably doesn't know how to allow for proper headspacing, and if not allowing for proper headspacing it is all too easy to get vertical stringing due to inconsistent pressure of the cartridge head against the frame.  Unlike bolt guns, as the cartridge grows when fired and is only neck sized, the inconsistent pressure of the cartridge head against the frame will lead to vertical stringing.  I had it in my .243 until I started resizing the brass so that I got a consistent .001" gap between the case head and frame face (actually the firing pin bushing or whatever it is called).  I've also helped a few friends with similar vertical problems resolve it the same way, and I've read a number of forum posts where a vertical problem that defied all other attempts to correct was solved this way.

Think about it - no matter how good your bench technique is, no matter where you place the rest, no matter how consistently you place the rest, or hold the rifle, if the cartridge is putting inconsistent pressure on the frame face in a break action rifle, you can't help but introduce vertical.

Detecting whether this is part of the problem is easy.  Take a feeler gauge (to really get precise you need a set of gauges starting with .001 and going up in at most .0005 increments at the smaller end of the scale) and a handful of your fired but not resized brass (you could use reloads, but I prefer not to) and chamber them one at a time and measure the gap between the case head and frame face.  Just close the action trapping the thinnest feeler gauge between the cartridge head and frame face and then remove the feeler.  If it comes out easily, go to the next largest, etc, until you find the one that you can remove but that resists removal.  Repeat with each piece of brass and note what the gap is for each one.  If it is pretty consistent, especially if it is right around .001-.002 with no noticeable variation, then this isn't your problem.  If, however, the measured gap varies noticeably and/or is much larger than .002 or if it is so tight none of the feelers are easily removable then this could easily be your problem.

Solving it is easy too - instead of neck sizing, use a full length die and bump the shoulder back till you get the desired gap.  This technique relies on the brass already being a bit long (measures less than .001 cartridge head to frame face), but if you've been neck sizing and have fired the brass a few times, it is probably there.  If not, keep firing it until it is - too much of a gap can still cause vertical since the pressure isn't consistent, but I don't know of an easy way to stretch the brass other than firing it... 

You'll need a good .001 feeler gauge and a bit of patience, though a .0015 or .002 gauge would work for anything but the most particular of reloaders (like me). Start with the die far enough out that you are barely or not even touching the neck.  Turn the die in slightly (and I do mean slightly - remember, reloading dies are 14 pitch, which means 1/16 of a turn is still .004") and lock it in, resize the brass, then check the gap.  Keep repeating this until you get the measured gap down to .001 (or whatever gauge you are using).  Then resize another piece or two of brass with that same setting and make sure you are producing a consistent gap of .001 (or whatever) between the cartridge head and frame face.

And there you are.  Nice, consistent reloads with minimal gap.

I'm not saying that you shouldn't eliminate other possibilities if you are getting vertical, and certainly some are easier to eliminate than this.  But especially if you have already explored other possibilities, this can certainly be the problem.  I know, I've been there and done that.

Just a Shooter

[Jay, Tx]

 If not, keep firing it until it is - too much of a gap can still cause vertical since the pressure isn't consistent, but I don't know of an easy way to stretch the brass other than firing it... 

Just a Shooter

 If the barrel to frame gap is adequate, one can shim the firing pin bushing out to create a headpsace dimension almost of their choosing (within reason). Just establish a workable length for the round, then shim the bushing out to re-establish headspace (again, within reason).

[Curtis]

.......but I don't know of an easy way to stretch the brass other than firing
it...

That is true but care is needed to properly fireform brass that has too much headspace.  The proper way to fire form any bottleneck case is to seat the bullet out to the lands and use a reduce load.  This way, the case is held in place and the shoulder is moved forward instead of stretching the brass near the head.  Merely firing it won't result in the best fireformed brass and may result in case head separation, since the stretching will occur in that area.
 
I speak from experience.  I have a 7-30 Waters barrel rechambered from 7TCU that someone cut the chamber 0.020" too deep (I got it cheap at a gun show).  As long as I properly form my brass and resize to my chamber dimention instead of SAAMI I'm good to go.  Of course, my ammo won't fit in anyone else's chamber.
 
Curtis

[Dezynco]

I agree with Justatshooter.  Measuring the gap and keeping it consistent can make all the difference in the world.  Also, check and make sure that your barrel and frame are not actually bumping up against each other when they're closed.  If the barrels are actually against the face of the frame this will DEFINATELY cause vertical stringing - don't ask me how I know.  If this is the case, then your barrel to frame gap is too tight, and the only thing you can do is try another frame or have every one of your barrels faced off a bit on a lathe, which would be expensive and time consuming.
 
I'm betting with Justashooter, you'll just need to adjust your dies a bit to fine tune the cartridges to your rifle.