Preventing Vertical Flyers from a Rest

[kohler]

My Greenlaw rest limits much windage variation but i still produce vertical flyers 4-5” above hoped for aim point. It’s been more than a year since last outing so I’m always rusty.

Wondering if there is a technique to tame the verticals? How much forearm should extend beyond the front rest, etc.?

The offender is 22” barrel sporter barrel .270 win. The trigger doesn’t help, it’s heavy, but the last shot today felt good, but was a flyer.

Thanks

[Dave Hoback]

Flyers are almost always a product of the shooter. So to answer your question, a technique to take them? Sure... practice. Unfortunately there is no easy "fix".

As for the forearm extending beyond the rest...it shouldn't. The closer to the muzzle the support, the more control the shooter has. Think of it like a lever. You ever see rifles with an extended spigot in the front for bipod attachment? Same principal here.

[JulioB22]

Barrel tuners can work well for vertical stringing issues. Search YouTube for "barrel tuner" videos.

[yobuck]

Especially for those of us who dont shoot very often, you might find that using the rear bag as little as possible works better.
Do most of the fine tuning between shots with the front rest adjustment, not the rear bag and see if it helps.
But get the trigger adjusted first.
Or be like me and be satisfied with hitting objects, and not worry about shooting small groups.

[Dave Hoback]

Hey! I resemble that remark!:surprise: I remember shooting... think I did it once or twice back in 19-Aught-Eleventy-12, LOL!

Yes, I forgot the trigger. Flyers are much more prone without a decent trigger. What model is it? Newer or older? You should have either an Accutrigger or Three-Screw trigger; either can be adjusted nicely. A bit of work & they will behave like the more expensive target triggers.

[kohler]

Thanks for the input.

The 270 uses an Accutrigger, Bartlein copying Savage sporter contour barrel, and SSS Monte Carlo sporter. Yes, this trigger is heavy. My 260 Rem has an Accutrigger set too light which makes it easy to shoot, tu I don’t trust it.

Along with the Greenlaw rest I did buy a rear bag which I used Sunday. I will try without the bag. The Greenlaw rest has a forearm stop. I’ll employ it to limit forward creep.

Off topic, I also took out my 26 Nosler (Savage action) which had been re-headspace earlier in 2021. First time out since that change. I never bought more than two boxes, both from Nosler, same day same lot number. The gun has only about 30 rounds through it. Bolt wouldn’t close on one box, cycled a little tight on the other. The gs changed headspace and threw out the box with fewest rounds left.

Since buying from Nosler will be a 50/50 bolt closing proposition, I’ll have to look for a local hand loader. I’m guessing the problem is case length tolerance.

[Dave Hoback]

Have you tried adjusting either of your Accutriggers? They are adjustable. https://m.youtube.com/watch?v=IXNKD9A-vXo

[kohler]

Thanks for video. Will give me a winter project. Couple years ago I bought a beam torque driver to set action screws. Now I just need a trigger pull gauge to get to ~3 lbs.

[Full Chisel]

It sounds suspiciously like shooter and trigger from what you've said. But, if you don't mind, I'd like to ask if you're sure it isn't the load or the stock torque putting your rifle at a harmonically unstable point?

Okay, the long-winded reason I asked this .... the reason is just due to the time of year and temp fluctuations, and that you mentioned the flyer shot "feeling good". I have seen numerous times where certain loads put shots in a respectable group followed by a flyer that "felt good", generally vertical. Most people would say "shooter". But I was able to confirm in many of my cases that it is the load/rifle combo, and not the shooter, as it would repeat at/near that same load every time - or pellet model/weight in the case of an airgun - or ammo in the case of 22LR. I have seen it on .50 Hawken style muzzleloader, 22LR, Marlin 30-30, and even spring piston airguns. Most of these are generally sporter barrels and/or the actions tend to be torque sensitive. I have also seen hints of it on heavy barrel rifles, just not as extreme or as noticeable. When it appears, it seems to correlate generally with a charge that has a fairly large velocity deviation and the charge is just next to a known accuracy node. I have also noticed that it can be induced by temperature swings, which could be related to powder, stock torque, or both.

Similar thing happened to a friend and his 112 22-250 recently on a cool day at 300 yards with one of his new loads that he had made up this past summer. Drove him crazy. As a test, we got him to warm the bullets up in his pocket for a while to mimick summer conditions, and presto, the flyers disappeared and the groups were as expected. It was a load thing. His load was probably on the bottom edge of an accuracy window and the temp drop, along with big variations in his shot tempo, was enough to put it out of the node at that distance. His rifle was a light polymer stock, not bedded, and not torqued properly, which I believe also contributed in his case.

Anyway, just another possibility for you. If I could figure out how to get pics up here and resized, I'd post some images from targets where I've seen it. I can absolutely guarantee it was not shooter in these instances.

[kohler]

Thanks Full Chisel for the experienced explanation. Today a Wheeler pull gauge arrived which I can pair with my beam wrench for a winter project.

Winter was on the other side of last night’s 50 mph gusts. It will be April or May before I get back out.

I won’t be going to West TN after Christmas for deer sadly. This week I committed to a furnace, central air, plus a new catalytic converter. Nothing left for the TN out of state license.

[Full Chisel]

Thanks Full Chisel for the experienced explanation. Today a Wheeler pull gauge arrived which I can pair with my beam wrench for a winter project.

Winter was on the other side of last night’s 50 mph gusts. It will be April or May before I get back out.

I won’t be going to West TN after Christmas for deer sadly. This week I committed to a furnace, central air, plus a new catalytic converter. Nothing left for the TN out of state license.

Ouch! The check engines light came on in van last cold spell. Catalytic converter. Does it every winter and goes off in the spring. Lol.

[Dave Hoback]

Ouch! The check engines light came on in van last cold spell. Catalytic converter. Does it every winter and goes off in the spring. Lol.

Yep... good ol’ P0420 (Catalyst system efficiency below threshold.) The death sentence for the Cat... and bank accounts! I always ran a cat delete pipes. My Mustangs didn’t care because they were ‘89s, pre-OBD2. Oh yeah, and I was an Inspection/Emissions tech here in Pa during those years. Then with my Turbo DSM, I knew how to tune the car via fuel & ignition mapping so the CEL wouldn’t come on. MAN, I loved being an Auto Tech. I truly enjoyed what I did.

[kohler]

WI temps last week cycled from 20’s to 60’s then back down and I wondered if that could cause the engine light cat code to come on. Now I know!

Normally I would not put $2k into a car with rust showing but I figured cars on the lots are overpriced by more than that. The oxygen sensors were reused so that helped put some jingle back in the stocking. My son in law (they’re honeymoon today, thanks Marriott points!) works as an analyst for one of the big auto auction houses, he explained old cars are appreciating as we drive them so no reason to spend if it can be avoided.

[Robinhood]

4"-5" isn't much at 1000. Are we talking 100 yards? That kind of vertical could be witnessed by recording your trigger hand with your phone camera. Replaying the vid would tell you a lot. I used video to reduce my group size along with dry firing. After you prove yourself on video then you can move to the rifle.

[kohler]

200 yards.

Interesting idea on selfie video. I need to go to a buddy’s range where I can get a few unhurried hours. The range behind my house allots time in 1 hour segments which is enough for a handful of rounds with set up and tear down.

Last year with bench plans from this site I built three complimentary mobile benches for my friend’s range. There is a sign next to the benches that says Sponsored by Krieger which flattering because I hadn’t turned on a table saw in a few years. I think Krieger deserves better!

[Full Chisel]

Kohler, funny you brought this topic up when you did. I have a Marlin 30 AW 30-30. I've going through a load re-tweak because my new lot of LVR powder appears to be quite a bit hotter than the last. I have two possible loads that I've come up with from my load workups - 34.0 grains, and 37.0 grains. When I was working up loads, I found windows from 33.2-33.7 grains, and 36.3-37.3 grains which BTW is super stable in that window. FYI, I have consulted on those high loads, including Hornady, and with my "generous" chamber, and a complete lack of pressure signs, we have all concluded everything looks clear. All loads were worked up at 300 yards.

Now I chose 34.0 and not 33.7 grains because I was taking a chance it was still in the accuracy window with the 33.2-33.7, but I really wasn't sure. I know at 34.2, the velocity and vertical jump up sharply to another very narrow window. So, I have one load at 34.0 that may be right on the edge of a node, and another load at 37.0 grains that is well within its node.

So, went to 300 yards and put 10 of each down the pipe at each charge at 70* F a couple of days ago, then 3 down at each charge at 45* F today. At 70* F, The 34.0 was putting most of them them in a 4" vertical band, BUT I also got 4 flyers out of 10 shots, some going stupid vertical, like 6-18" high - one almost went over the board. The 37.0 gr loads all stayed within a neat little 3" vertical band - no flyers. Today, at 45* F, the 34.0 grain load put 2 almost touching, and one 8" above them. The 37.0 gr load put all 3 in a 1" vertical band.

Anyway, so goes my point about loads behaving badly when your right on the edge of a good load window. So far the 37.0 gr load has put 13 shots in a 3.5" vertical band at 300 yards from 45-70* F. I am dropping the lower charge down to 33.7 gr because I know that is within the window, and I'm going go repeat with it. I don't mind running the high charge, and it's accurate as all get out, but at 2350 fps, it throws my stupid BDC circles off. The lower load running 2200 fps has always matched up perfectly with the Nikon BDC circles so that is worth a lot in itself.

[South Prairie jim]

Thomas (speedy) Gonzales’ Benchrest hall of fame shooter and rifle builder has published articles on vertical stringing and one thing to keep in mind is the fill ratio and type of sand your front bag, heavy sand will kill you with bounce. Use med grit sand at 90ish % then adjust a tea spoon at a time judging better or worse. Also be aware of recoil management and shoulder contact with your rifle.
when tuning for loads at a set distance such as mid or long range we tune for barrel timing/exit timing or sometimes referred to as positive compensation, when ladder testing loads with incremental charge weights these loads climb vertically until barrel timing is optimized the loads typically overlap meaning despite the increase in charge they impact at the same vertical plane, this is the node.. any increase from that charge will began an erratic pattern or (break out) in any direction not just vertically.
hope this explanation helps the OP.