Why does this happen? (Not a lever)

[geobru]

A friend of mine has a newer bolt gun that is giving him fits trying to develop a load for it. He tried several different loads last weekend and for some reason, the 3rd or 4th shot was ALWAYS a flyer. He showed me his targets, and there were be 4 shots that are sub moa and then a flyer that was consistently one inch left and 1.5 to 2" low. He has tried three different powders and run through the range of loads for each and the results are similar.

Have any of you run into this before? Any ideas?

[CEMENTHEAD]

Yup. Barrel heat. Stick to 3 shot groups. This really only pertains to sporter weight barrels, although I've had heavy barrels do it too.

Tom

[geobru]

Yup. Barrel heat. Stick to 3 shot groups. This really only pertains to sporter weight barrels, although I've had heavy barrels do it too.

Tom

That is what he thought too, so he waited between each shot to let it cool down, with the same results. He is about ready to toss the gun, but I keep reminding him that it IS a hunting rifle and the first two shots are dead on...

[86er]

ditto

[Alan Wood]

How long is he waiting for it to cool down between shots? It takes rather a while for a hot barrel to cool down.

[TedH]

Three shot groups on sporter weight hunting rifles is all you need.

[BigSky56]

Float the barrel, stock is touching somewhere, if he's got a floated barrel then try a barrel resonator made by limbsaver about 10-12$ that will dampen the barrel. danny

[piller]

What brand of bolt gun is it? Remington makes their model 700 series to have the fore end press upward on the barrel. If the 700 is wood stocked and has been in the rain, it can do just what you are describing. Bedding the barrel is another option instead of free floating it. It may not be the solution for your friends rifle, but it did work for me. Still, the first 3 shots should be all that he needs if he is able to hit his aiming point under field conditions. Remember the old saying, 1 shot-1 deer, 2 shots-maybe 1 deer, 3 shots-no deer. Unless he is using something like a .223 which is kind of small for most deer, he should be able to get his deer with one shot. I have even known of people using a .223 on deer and doing fine because they are accurate.

[Buffboy]

I agree with the other posters, it is not likely the load but the rifle that is causing the problem but there's nothing "wrong" with the rifle. If you understand that resonance is such a part of accuracy in all rifles and that any changes in the heat structure of a barrel can affect that resonance, it's easy to see where the problem is. It takes an surprising amount of time for the barrel to cool in sporter weight barrels. So it is likely still barrel heat, unless he's taking the first three shots at the same interval as he's waiting before the 4th. If he's getting great 3 shot groups without waiting 15-20 minutes between shots (because that's how long it takes to get the heat out, after each and every shot, in heavier calibers), he's got a great rifle.

Even free floating won't completely cure heat problems. Heck, it shows up all the time on benchrest rifles with over an hour between strings. The heat is still there in the steel of those heavy barrels, affecting accuracy. Even if the outside feels cool, there is residual heat between the bore and the outside still to dissipate.

[FWiedner]

Apparently the gun in question is entirely predictable and that's just not good enough.

Not to go on a tangent but a note on the .223 being "kind of small" thing, I had an uncle who kept his family of 11 children fed on Texas whitetails with a .22WMR for over 20 years (He might have been a first-class poacher, but he never wanted or needed welfare).

It's the man, not the gun.

[Mich Hunter]

Like others have said, it probably is the barrel heat. You can run heavy barrels, fluted barrels or light weight barrels but once they warm up, things change. I work with quite a few M24's, M107's Barretts etc on a daily basis. We get flyer's on these even though they are made specifically for precision shooting. This is why it is important to document your shots and know where your cold bore round is going to strike. Keep in mind that if it is a sporter weight barrel, don't expect bench rest accuracy from it.

[geobru]

What brand of bolt gun is it?

Browning A bolt 2, plain barrel.

Remember the old saying, 1 shot-1 deer, 2 shots-maybe 1 deer, 3 shots-no deer. Unless he is using something like a .223 which is kind of small for most deer, he should be able to get his deer with one shot. I have even known of people using a .223 on deer and doing fine because they are accurate.

+1

[Nath]

Did you mention what bullet weight and twist?? (223rem yes?)

Too slow a powder, wrong primer.

Nath.

[geobru]

Did you mention what bullet weight and twist?? (223rem yes?)

Too slow a powder, wrong primer.

Nath.

Sorry. It is a 30-06.
I'll ask him what powders he has tried.

[Sixgun]

Could be a tiny nick or deformation on the crown. Sometimes you get 5 straight perfect ones and then one will be thrown several inches, even a foot. I've had that experience many times with the antique leverguns.-------------Sixgun

[Chuck 100 yd]

My Rem. 700 ADL .243 did that until I floated the barrel.
She settled down and keeps them together after that.

[Noah Zark]

Tell him to make sure the triggerguard screws are tight. Tighten the front one first. Loose guard screws will cause accuracy issues.


If that's not it, then he should try shimming under the chamber area of the barrel, using brass or wood veneer shim stock to provide a little more support under the chamber and prevent the triggerguard boss from bottoming on the front receiver boss due to a compressed stock.

HTH,

Noah

[geobru]

Thanks for the input guys. I'll give him the tips you have given and let you know how it turns out.

The barrel is already floated, I'll have him check the crown, and the trigger guard screws. (I never would have thought of that.)

[Nate Kiowa Jones]

Thanks for the input guys. I'll give him the tips you have given and let you know how it turns out.

The barrel is already floated, I'll have him check the crown, and the trigger guard screws. (I never would have thought of that.)

If he has checked all the obvious and you say this is a new gun, how about the bore. Is he starting with a clean bore? Clean and new, it may need to be seasoned some or even firelapped. If he puts 50 or so rounds through it and it still does it look to float it and possible dampen it.

[Steelyonfly]

Gentlemen (and ladies if you are out there),

I just joined to reply here. I'm the one that geobru is talking to you about.

I did read somewhere about tightening the trigger guard screws in that order. I've since done that. I will check it again though. I think that I might try to see if I can shim the receiver and see what happens there, too. Thanks for the suggestions. You are all probably right in that it's just a sporter barrell and I'll just have to let it cool a long time. Btw, geobru has shot it, as well, and had the same thing happen.

Just to be clear, this last time out (resulting in the targets that geobru mentions), I was shooting 2 rounds, cooling, 2 rounds, cooling, 1 round ... then I let it cool and went to he next charge. I think the barrel had at least 10 minutes to cool each time and it was a cold day in the 30s. Maybe that's not long enough.

FYI, my loads were with Reloader 19, 5 rounds each of charges from 57.5 gr to 59 gr, and 165 gr Nosler Accubonds. I think the 57.5 gr charge looked the most promising if I disregard the 4 shot flyer.

Thanks again for your suggestions. If there's a gremlin to be found, I'll let you know.

[Buffboy]

Gentlemen (and ladies if you are out there),

I just joined to reply here. I'm the one that geobru is talking to you about.

I did read somewhere about tightening the trigger guard screws in that order. I've since done that. I will check it again though. I think that I might try to see if I can shim the receiver and see what happens there, too. Thanks for the suggestions. You are all probably right in that it's just a sporter barrell and I'll just have to let it cool a long time. Btw, geobru has shot it, as well, and had the same thing happen.

Just to be clear, this last time out (resulting in the targets that geobru mentions), I was shooting 2 rounds, cooling, 2 rounds, cooling, 1 round ... then I let it cool and went to he next charge. I think the barrel had at least 10 minutes to cool each time and it was a cold day in the 30s. Maybe that's not long enough.

FYI, my loads were with Reloader 19, 5 rounds each of charges from 57.5 gr to 59 gr, and 165 gr Nosler Accubonds. I think the 57.5 gr charge looked the most promising if I disregard the 4 shot flyer.

Thanks again for your suggestions. If there's a gremlin to be found, I'll let you know.

Barrels wiggle like a snake when you fire them, accuracy depends on the barrel always wiggling the same at each shot, harmonics. Once upon a time I had a video of a 30-06 rifle being fired filmed at a very high frame rate. It's long gone and I haven't been able to find it again, but that barrel moved a tremendous amount as that bullet went down it. I'm still amazed that anything moving that much is putting a bullet in near the same place as the previous one but it happens all the time. IMO hand loading is the search for that sweet spot where the harmonics work the same each time. Heat changes harmonics, with heavier barrels just pushing it farther down the line but eventually getting to the same point. Barrels heat up from the inside out and cool (mostly) from the outside in, even if you are leaving the bolt open to allow air that way too. IMO you weren't letting it cool long enough and by the 4th shot of your string you got heat induced fliers. Cooling before shot 5 had the heat back down to where it should have been for shot 4. 30-06 class cartridges put a lot of heat into barrels, less than the magnums but still a lot of heat. You can speed cooling using the chimney effect by placing the rifle in an upright position with the bolt open. IMO you didn't cool long enough to rid the heat in the interior (between bore & outside) and messed up the harmonics.

You weren't by chance leaving a cartridge in the barrel, as that can heat soak your ammo to change pressures and cause the same effect but for slightly different reasons?

Have you seen the old trick with the ceramic shuttle tiles? Where they take one out of an oven at 1500 degrees put it on a table, then pick it up bare hand a few moments later, still glowing, but the outside cool enough to do that. The same thing happens with a barrel to a lesser extent.

[AJMD429]

I just joined to reply here. I'm the one that geobru is talking to you about.

WELCOME to the forum, and we look forward to hearing how things go with your 'flyers'.

I'll bet that even on a cold day, with just air-cooling the barrel temperature probably doesn't get back down to truly 'cold-bore' conditions for a half-hour.

I've had situations where I fire say one shot per minute and on the fifth shot the barrel is 'warped' enough to give me a flyer, yet the other four shots showed no signs of movement. I can take the same gun, and maybe just shoot two shots through it, let it sit for three minutes, and the 'third' shot will be the same place as the 'fifth' would have been if I'd kept shooting. So in that case, it makes me think that the heat, even from that first shot is somehow travelling through the steel, and eventually making something expand that changes impact.

It would be interesting to tape a thermometer-probe to a barrel and do some shooting, just to see what the temperature does. I suppose with some good 'contact' paste, and then wrapping with foam tape or styrofoam under duct tape, you could get reasonable data*.

*Anyone's kid need a SCIENCE FAIR project...

[Steelyonfly]

Buffboy and others ... I think you're right about the barrel needing to cool more. Geobru and I were talking about this as to whether the metal in the barrel when cool but not cool enough is maybe structurally different (the metal is "softer" than normal, etc) when it's not had time to cool long enough. I do put the gun on the rack to let it cool and I don't leave it loaded. I also let the bolt down. I do this all the time unless I'm all alone on the range. It's just what I do as a lot of people always leave their guns on the bench even when retreiving targets. It's a safety thing to me. The last time out I was not alone. If I shoot some tomorrow, I'll only shoot 5 rounds with 20 minutes between each shot. I'll let you know what happened. Thanks again.

[Buffboy]

Welcome, I forgot that part in my earlier post, enjoy, sit a spell. You should take care if you are too dedicated to bolt rifles as these guys can be corrupting influence towards the name of this forum

It's maddening sometimes finding that sweet spot but it's there in almost all rifles and it sounds like you are well on your way to finding yours. There are so many things that can change it up. I had the same problem, still do, as a matter of fact, every time I get the urge to shoot my 90gr Sierra varmint load in my 270. My rifle will do the same thing as yours is doing if I shoot too fast with it. Actually, it does it with any load, but I've just run into it more with that load. It gave me fits 30+ years ago when I first started reloading for it but fortunately I had a mentor that had been loading for 30+ years before me to help sort it out. Back then, the sporter that would get to MOA was a rare commodity and usually hideously expensive. Now everybody expects that from the cheapest bolt rifle out there and they usually get that or better.

You can wait for the full cool down if you want but I think you were on the right track with your previous method of shoot 2, then wait, before shooting the next 2. Just wait a little longer because it's good to know if your rifle will make that second shot right there with the first for hunting situations.

My 270, mentioned before, will do 3 in fairly quick succession but fling the 4th if not allowed to cool all the way down after the 3rd with every load I've put through it. Been like that with the original stock(pressure point), bedded & free floated original stock, then the Bell & Carlson it is currently wearing. It is hardly unique, it was just the first and every rifle since has had its own issues.

[Steelyonfly]

Geobru reminded me that 2 of the targets with the flyers were in my trash at work. I fished them out and attached is what they show. The 57.5 grain charge is 5 rounds with the 4th round being the flyer. I also ran a bore snake through after each shot. The 58.0 grain charge is only 4 rounds with the 3rd one being the flyer.

I didn't get to shoot this weekend, but I probably will next weekend. If I do, I'll post the results.

targets_Page_1.jpg

targets_Page_2.jpg

[CEMENTHEAD]

57.5 grains is your winner. No need to pull a bore snake through after each shot either. If the barrel is broken in you should shoot until the rifle tells you it needs cleaning. I have noticed that a rifle will shoot more accurately fouled. The bore will "settle down" after it has fouled to it's liking. Some in as few as 2 shots, one heavy barrel Savage I own takes 10 shots before settling in. Then it shoots consistently lights out. I think you're on the right track load wise.

Thanks, Tom