I am sure this has been discussed before but I can't get any useful results from the search feature so here goes again.

I have a 264 Win Mag with a fairly new barrel. The first round from a cold barrel always goes an inch or more above the rest of the group. It is aggravating for a new barrel to behave this way. Is there any wisdom out there on why a rifle does this? Is it related to the throat? Type of powder? Primers? Weight of barrel? My current load is a 120 TTSX over Magnum with a Federal 215.

Is that a clean barrel with maybe some oil in it or is it a cold barrel that has had some use or fouling shots previously? Many rifles do this.
First thing I do at the range, is take two fouling shots into the berm before I set up. The rifle has cooled down by the time I am set up and begin to shoot.Then I do not clean until after hunting season has ended

Bedding?

Does this occur with a clean, cold barrel or the first cold shot from the barrel clean or fouled? My 338 Win Mag puts the first 2 shots 2" high and left from a clean barrel but it's fine after that. My 7x57 won't group worth a damn until it's been fouled by at least 10 shots. These are the 2 most extreme examples in my gun collection. My M70 classic 300 wby mag shoots perfectly from a clean barrel with no shift in POI or degradation in accuracy.

What have you tried to eliminate the problem?

Yeah the first lesson here is to never clean a bore. It's not needed and counterproductive.

If you're getting POI shift between the 1st and 2nd round on a rifle where no unnecessary cleaning has been done, then the culprit is likely the effect of temperature on the action to barrel interface, because one or more surfaces are not trued. So as the rifle heats, it bends. Such a rifle will also have POI shifts with the weather, and should generally be fixed (by truing the action), relegated to short range use, or sent down the road.

It is also possible the bedding is at fault or the action screws are loose, but those are less common causes. It's worth checking the screws with a torque driver though and inspecting the stock to see what the rifle is sitting on. A "sprung" action that is sitting on a high spot between the action screws can exhibit temperature instability. Similarly a rifle that is shifting in the stock may be inconsistent.

Got a 25.06 that when the barrel is cold and clean first shot goes 1” low and left, 2nd and following shots are on the money. It’s repeatable and predictable. Cold and fouled it never happens. Never found a cure so I just don’t clean it until I am done for the year.

If the barrel is already fouled, I'd be thinking it's a bedding issue where something is under stress or not secured correctly.

A properly constructed and bedded rifle will not have significant changes in zero between a cold shot, and it’s 2nd round. “Fouling shots” are important for benchrest or smallbore competitors, but the concept, adopted many outside of those accuracy demands, hides what is usually a bedding problem.

Some rifles will shoot better (smaller groups) with some degree of a dirty bore, but they will shoot to the same zero (if properly bedded).

If bore is fouled, try changing your action screw tension - perhaps 10-15in/lbs tighter if not already over 65in/lbs. If this changes the nature of your result, it's likely in your bedding as others have mentioned.

The rifle is bedded in a synthetic stock. The stock looks like a Brown. It behaves the same in the old wood stock. Also tried different scopes. This is from a cold dirty bore but it does it from a clean bore too. I don't clean barrels unless they need it.

The rifle has been a safe queen for several years because of this problem. I just got it out the other day to see if I could solve this problem. I don't remember what all I tried when I was working with it before.

The original barrel shot good. The first three would go into .75" or so. Then they would start climbing and five would go into 1-1/4" or 1-1/2". The throat went and it quit shooting. This use to be my deer rifle. Killed a lot of deer with the old barrel.

The barrel receiver interface sounds logical. Worth a look.

It's more than just bedding. Most factory rifles, especially older ones that predate CNC, are not true. When the action & barrel heat, the non-true action pushes on one side of the barrel shank more than the other, and the rifle literally bends.

If you really think you’re going to see the effects of that in a hunting rifle with a factory chamber, fired off of anything less than a machine rest, with “run of the mill” ammunition . . . You are truly an optimist

Interesting that is does the same when in two different stocks.

I don't think it, I know it.

Because as already stated the issue is most likely a non-true action/barrel rather than the bedding. Bedding is a possible culprit, but if it happens in two stocks that's unlikely.

I had a RU77V in 25-06 that did that. First shot through a clean barrel went 4" or so, 45 degrees high and left. Anything after the first fouling round was MOA, where intended. The rifle was factory standard, completely unmodified. Factory loads (Rem) went about 5 MOA, my reloads via a $19.95 Lee Loader were MOA after the first fouling shot.

I just never hunted with a clean bore. If I did not swab out the bore between trips, it was fine. And no, there wasn't oil in the bore on that first clean-bore shot. 70 above to 20 below made no difference as to that first clean-bore shot placement in relation to following shots.

It was what it was. Never should have sold that rifle. The stock was fiddleback end to end. You don't find many factory stocks like that.

I’ve seen the same thing from rifles that are fouled but haven’t been fired in a while. Almost as a if the fouling “cures” or hardens and causes a rifle to toss a shot.
I’ve found with some that running a patch with Kroil on it through the bore after cleaning works if I follow that with several dry patches to essentially dry it. Try different things to see what works.

I tested this on several of my hunting rifles and found that none of them shot the first shot out of a cold , clean barrel to a different point of impact at 100 yds to succeeding shots. However, each first shot had a lower velocity than succeeding shots. This lower velocity was not enough to cause a difference in point of impact at 100 yds on my rifles. My conclusion was the high shot or flyer sometimes experienced was often the result of not holding the rifle in exactly the same way as on succeeding shots and the first shot resulting in more of a "shock" to the brain, resulting in not holding through the shot the same. Now this might not apply to all rifles and hunters, and probably not the reason your .264 Mag does this, but I believe it is the cause at least some of the time.

This is a strong contributor as well.

Repeatability on the bench, even with higher end rests is MUCH more difficult than most people appreciate. Ask any IBS competitor.

You shooting 3 shot groups? Your load may not be fine tuned yet... It could also be pressure on the barrel. Is it properly glass bedded? How and what are you shooting off of? Good front rest and rear bag? No lead sleds I hope.. Good scope without parallax issues?

I agree. There are some instances where the barrel has residual stresses from the machining process and that results in first shots being out of the group. Those barrels generally react better to a pressure point on the barrel, or a full length bedding process. Op can experiment with pressure on the forend tip to barrel and see if anything changes..

Just damn. Where they all come from.

Ex IBS and NBRSA shooter.

Shoot once.

Among the other causes already listed, have encountered more than one rifle which had a slightly loose thread-connection between the barrel and action--one reason I suspect the reason a "tip-hump" pressure-point became popular with some rifle manufacturers.

I gave my bench setup a lot of attention in the last couple weeks. My 30-06 started stringing horizontally so I suspected my bench setup first. That has been refined and the 30-06 stringing turned out to be caused by the scope. I use a heavy cast iron front rest inherited from an old benchrest shooter and a rear bag.

The most plausible culprit looks to be the barrels connection to the action. I will try shimming the barrel at the forend tip since that is easy to do.

If the front of the action is not square to the centerline of the action, would that also indicate that the threads are probably not concentric? That would seem to be a potential problem too?

One thing to note, upon firing the rifle starts moving before the bullet leaves the barrel
If the butt is dropping down your shoulder due to barrel lift and a not properly compacted rear bag this can result in a high shot.

After this first shot the bag is better settled and POI stabilizes

I'm still wondering about a clean bbl. The three rifles I shoot TSX's/TTSX's all shoot high with a clean bbl. A new SS 308 is the most dramatic--initially I refused to believe it was only a clean bbl thing, but have now repeated it 3 times. A clean bbl (not a 100% clean, but fairly clean) will shoot 4"+ above my normal POI where I'm sighted in at, and takes two or even three rounds to "walk" down to where it should be.

There was a time when the 264 shooters were a pretty exclusive club. The wisdom was passed around. Much was written about cleaning barrels . Barrel life was a hot topic, and clean barrels lasted longer. So with the short life of 264 barrels keeping them clean is very important.The first barrel on my 264 walked. I could take the targets with numbered holes, lay them on top of each other and they would line perfectly when using a good consistent powder. Besides that problem, it was high pressure and slow. .I had it changed.

Your barrel is no where near as bad. But it too suffers from stress. Group size is very important in Farky Class, but is totally meaningless in a hunting rifle.(It just makes load development and sighting in easier ) To get a three shot group, it takes three days to be realistic . Dead cold between each shot . So I would take the first shot as the true one and the rest as fliers. A single shot hunting rifle is not much of a handicap. The second shot is for putting the game out of it's misery.

Yes - forward pressure is specifically designed to cover up for machining flaws, less than true actions and barrels, and failure to lap the barrel into the action. It's the last resort of manufacturers with machining problems.

The first round from a cold barrel always goes an inch or MORE above the rest of the group. It is aggravating for a new barrel to behave this way.

How much MORE than an inch does it shoot high?

This is so untrue. I have SEVERAL barrels that will put the first shot into the group from a clean cold barrel every time. These are barrels that have been verified clean with a bore scope. The OP is not talking about a rifle that shoots in the 1’s here. If the bore is dry and this rifle is doing this there is an internal barrel issue.

I had a rifle that would do this. Not only would it throw the first shot high, but pressure would be higher. That bore had a tight spot in it. That was corrected and the problem went away.

So to get a zero, you fired one shot then completely cleaned the bore, or was your final zero out of a bore that had multiple shots fired through it?

In all four of the rifles that I tested, the first shot did NOT shoot to a different point of impact to the other succeeding shots at 100 yards. It only shot slower. The second shot was also slower, but not as slow as the first shot. These were hunting rifles that typically would group 5 shots in 0.4" to 1" at 100 yards.

I’m not sure what you are talking about

Dang.
To get your zero did you fire 1 shot and completely clean it and cool down, fire another shot and completely clean it and cool, then make scope correction fire 1 shot completely clean and cool. Repeating until you had final zero.
Or did you fire 2-3 shots, make scope adjustments and fire 2-3 more shots to get your final zero.
If you did condition one I would say you have a clean cold bore zero, if condition 2 then you don’t. Not hard.

Have a Winchester Classic synthetic ( early 90's) that I placed a piece of plastic under each action screw and it solved this very issue I had. Now it will shoot first shot in in a half inch group any time I try it. I like to shoot on a windless day....only one shot and then next day fire that one shot and the two targets will be within half inch. What this did was allow me to run a dollar bill all way to the action....and before the bill would go only go about half way. There is a guy with a video on You Tube shows how to do this....remember my rifle when new came with some kind of plastic cement under the front screw and over time it had gone bad so I removed it and replace with a plastic shim cut out of a detergent bottle.....simple solution to my problem.

Don’t believe in windless days, been shooting over flags of some sort for 30 years. I’ve got videos of flag tails going straight up at the 50 while the vane stayed stationary, flags at 25 and 75 never moved. Also have a video that has the 50 and 75 flags moving 180 apart. Windless nope.

Did you clean the rifle each day? Otherwise it’s not a clean cold bore shot. You did prove though that under non exact conditions your rifle moved from its previous POA to POI.

I think the best way to tell if it's a barrel heat vs barrel fouling cause is to shoot a fast group of 3, let the barrel cool for 10 minutes, then shoot a slow group of 3 with 10 minutes between each shot.

None of the above. I’m shooting to the some POI whether the barrel is fouled or clean. Zero was established long ago and has absolutely nothing to do with it. This isn’t a zeroing exercise. This is a can I hit where I’m aiming exercise.

If somebody has to let their barrel cool for 10 minutes or more between shots and/or groups to get decent accuracy, there's something wrong with the bedding and/or stress-relief of the barrel. Both are pretty common in factory rifles--and don't necessarily have anything to do with the "weight" of the barrel. Have had it happen with heavy varmint barrels on inexpensive factory rifles, that were free-floated.

Hunters should not have to put up with that sort of BS.

Prolly time for a reality check here, this question hasn’t been answered

On some rifles, I spend the $100 bucks and few weeks wait to send the rifle to "300 Below" and have it Cryogenically treated. I don't do it to smooth the bore molecules, necessarily (some say it reduces fouling), but to relieve stress. Its cheaper than having a rifle Blueprinted. Just saying.

No it’s been answered bedding or machining problem. If in his situation it does it on the first shot clean or fouled I myself wouldn’t put up with it. Now like my 25.06 it’s been pillared and properly bedded. Still a cold clean barrel will put the first shot low left about an inch every time. Fouled and cold no problem so in my case there is just that one little quirk. Is it worth rebarreling? Some might but not to me. It’s a hunting rifle that’s taken 17 deer and an antelope in the fifteen years I’ve had it. Never in 40 years have I taken a clean unfired weapon hunting so it’s a quirk I can work around. Rabbit hole I don’t need.

Speaking of rabbit holes, I went down one for 4 years with a No.1V. That thing just wouldn’t quit throwing shots. Had my gunsmith put a Hicks device on it, bedded the hanger and Hicks plus the radius of the forearm where it met up with the action. Still would chuck shots for no real reason so that thing languished till I was ready to rebarrel it. Decided I needed aggravation so I went out and shot it, man for some reason it started grouping like a 22.250 should, reason was I took the forearm stop off my rest. Put the stop back on it would chuck shots, take it back off and it wouldn’t. Why, don’t know and don’t care as it’s a quirk I can live with.

Exactly. That's the beauty of this simple test. If the rifle groups well waiting 10 minutes between shots but otherwise won't it's a barrel heat related change.

If waiting 10 minutes between shots produces fliers then it's a different cause such as barrel fouling, optics, or other inconsistency.

I have been gone elk hunting. Took a day off today. Old men need their rest! I dug out the notes I have on the 264. It has been 10 years since I got disgusted with it and put it in the back of the safe so I don't remember much. Based on my notes the biggest problem is it is very inconsistent. It occasionally shot some good groups but I it shot to many lousy groups. I am going to start over with it and check everything; scope, mounts, bedding etc. I have 100 and 120 TTSX's, 140 Hornady's, 120 Sierra Match and a few Sierra 140's. Powders on hand are IMR7828, H4831, H870, RL-22 and 25, and Magnum. Primers are Federal 215's and WLRM's.