Cold Barrel Shots

Teri Anne

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I consistently read about the miracle of a cold barrel shot and understand the psychological aspects of being able to place your bullet exactly where you want it out of a cold barrel. As a hunter I want my first shot (Cold barrel) to go exactly where I have the reticle cross hairs placed when the round breaks. As a target shooter I want every shot to hit the exact same spot that I'm aiming from the first shot of 20 slow fire in 20 minutes as well as rapid fire with 10 shots in either 60 or 70 seconds. I want my Rifle zeroed for that first shot out of the cold barrel, to the same spot 10 or 20 shots fired rapidly within a given short time period of 60 (50) or 70 (60) seconds out of a sizzling hot barrel. For my competitive friends holding a 1 MOA or less group from anything from 100 to 600 yards or more is absolutely required not just a nice thing to happen. In the competitive world bullet drift from barrel heat needs to be minimized or eliminated. These days this is a lot easier to accomplish simply because of the massive strides in barrel technology from the factory as well as most rifles now come from the factory with free floating barrels and bedded actions, The big question is, "Does your barrel warp with heat?" In years past this syndrome was handled by using, "Bull Barrels," where the physical mass of the barrel caused them to heat up slower, reduce flex and maintain accuracy shot after shot. This did not come without a downside, the first issue being weight. In competitive shooting carrying around a 12 to 16 pound rifle was not an issue on the range, but who wants to carry that same rifle out in the woods? I tried it, I didn't much like it." My solution, for whatever that matters was to get another rifle in the same action with a lightweight barrel. Both were post 64 Winchester Model 70's, the match rifle had a 26 inch stainless steel Obermeyer super match barrel chambered for the 7.62 x 51 NATO cartridge and an additional .025 inches of freebore. Some warned me that the 7.62 x 51 chambering and extra freebore would compromise accuracy. In reality the first 3 shot group out of the new barrel formed a cloverleaf at 100 yards and things just got better from there. My other Model 70 has a 20 inch factory sporter barrel and out of the box was only able to do a 1 1/4 inch group. It didn't matter if I was using factory or handloaded 165 gr ammunition approximating Lake City Match. Both rifles have wood stocks however the match rifle had a floated barrel. The hunting rifle did not. So what did this mean for accuracy? Since the match rifle was somewhat custom from this point on it's simply something to keep in mind and I will talk about the changes made to the factory Model 70 Sporter (Sitting in my gun safe about 8 feet to my left) Back in the early 70's Winchester was simply making rifles that out of the box would keep your shots in a Deer's breadbasket at 100 or 200 yards. The barrels were button rifled and not made to shoot thousands of rounds before being fired out. (I have mentioned this before in another post relating to my now match rifle) So how do we take a sporting rifle shooting 1 ¼ inch groups down to less than 1 MOA? Keep in mind that this rifle has a beautiful wood stock. Back then synthetics were not in common or even uncommon usage. From the factory the Winchester did not have a glass bedded actions and the barrels were not even close to free floated most having a lot of upward pressure on the barrel at the muzzle end of the stock. The action was, at that time simply bedded with only the recoil lug epoxy bedded. I took the rifle out of the stock, did some Prussian blue impressions, and found out exactly where the barrel and action met the stock. From that point I, well let's call it what it was, "Gouged," out the barrel channel to keep the barrel from hitting the stock. Then with a Dremel Tool opened up the recoil lug and action area in the stock. Now it was bedding time, and at the time pillar bedding was not common, or in my case even known. Using the epoxy barrel bedding kit from Brownells, release compound in the action area and layered Mylar tape on the barrel proceed to do a bedding job to tighten the action into the stock as well as free up the barrel to stock contact. At the time it was customary to bed the first inch or two of the barrel along with the action. I chose not to and free floated the entire barrel. When all was said and done in order to break the action and barrel from the bedding compound I had to freeze the rifle and stock in my freezer along with beef, venison and whatever else was in it at the time. 24 hours at zero degrees and the action popped out of the stock with a simple thump from the palm of my hand. I now simply removed the tape and release compound and after waiting for temperatures to stabilize at room temperature worked the action back into the stock as well as checked the barrel as being completely free floated all along its length. The action now firmly bedded into the stock and the barrel completely free floated it was the time to see how the rifle would shoot. I used hand loaded ammo approximating Lake City Match ammo with Nosler Partition 165 grain bullets. Out at the range, of course with the rifle as bedded and at that time a Bushnell 3 x 9 x 40 scope bore sighted, the first shot out of the barrel at 25 yards was high and left. Scope adjusted to be dead on at 25 yards. Moved out to 50 yards and the point of impact was, as I remember about ¼ inch high. Moved out to 100 yards and the point of impact was a bit over ¾ inch and off to the left. Adjusted the scope to zero the hits at 2 inches high at 100 yards. Then to confirm all of what I had done I fired 10 shots, starting from a cold barrel in about 5 minutes to see how the barrel heat would affect the flight of the bullet at 100 yards. Amazingly the 10 shot group bench rested within ¾ inch from cold to hot out of a sporter barrel. There was a ½ inch improvement in the group size shooting from cold to hot. OK so there you have it. Doesn't matter if you shoot out of a cold barrel to one blazing hot, the rounds should impact virtually at the same point of aim which is what it's all about. ACCURACY no matter what the conditions, well maybe not but that is yet another story for yet another day. FOOD FOR THOUGHT: How does temperature affect accuracy and what can we do about it?
 

Teri Anne

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Wisconsin
It's not the cold bore. It's the time of day you fire the shot in relation to the angle of the sun. Fire one shot every hour for 12 hours at the same spot on the same target and see what happens.
Well experience over some 60+ years says that no matter what the angle of the sun, the brightness of the day or angle of the shot there is little difference in where the bullet will land if the person shooting the rifle is experienced. An experienced shooter will automatically make up for all of these differences and adjust accordingly.
 

Mikecr

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I would attest to lighting changes to POI Barrelnut. It's a real phenomenon.
But Teri is not actually talking about cold bore ACCURACY.
She's describing PRECISION from 1st shot through the last in long shot strings.

On precision,,
There are probably factory guns without contact bedding and barrel clearance, but nobody would compete with that.
Obermeyer barrels are cut rifled, and I'm sure this low stress condition is vital to reduce bore wonderings and dimensional changes.
So where I choose, I choose cut rifled barrels. Some button rifled barrels available go through a cryogenic stress relieving before final lapping. Should do well.
If I were a competitor with a focus on grouping I would use LabRadar and carefully define MV from each shot in needed strings.
With this, I would compensate my loads in order, and not just in MV but to bring each back into mark.
The assumption here being that maybe the bore is changing in dimension and friction, the barrel's elasticity is less than linear, and the powder burn rate is changing with temperature of it's confinement. I would probably experiment with custom fluting to pull barrel droop favorably with increasing temps.
I don't know of anything else that could be done other than dry pre-fouling to keep the first few with the rest.

For cold bore accuracy,,
The gun still needs to be built well, but I haven't seen barrel attributes causing significant difference.
This is because accuracy is defined with EACH single shot.
So I've had bad grouping potential from very accurate guns, and bad accuracy potential from great grouping guns.
My focus has always been on cold-clean bore accuracy, so the guns providing this are the guns I keep.
That has always taken cold bore load development to reach though (a lot of work).
 

Teri Anne

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It's not the cold bore. It's the time of day you fire the shot in relation to the angle of the sun. Fire one shot every hour for 12 hours at the same spot on the same target and see what happens.
Hmmm...I do believe that if you do your job that the bullet will hit the exact same spot from shooting light in the morning until shooting dusk before it gets dark out. After dark you probably wouldn't be able to even see the target unless you were jack lighting. Then the chances of finding out that even jack lighting a target at night is probably illegal and your firearm and all associated equipment including your purely innocent truck would be confiscated and you would never be able to make such a comparison again. It's kind of like never date when horny. Never shoot after dark.
 

Frank in the Laurels

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Everything and anything affects the point of impact...even with minutes !! My son and I shoot the VBR Matches at 850-1000 yards and it's amazing how even within 2 minutes after your sight in period the impact could change a foot or between your first and second set of 5 targets at the same distance...even clouds and all of a sudden bright sunlight...the gentleman above is correct, same gun and load fired at 1 hour intervals off a bench at the same target will leave you scratching your head and talking to yourself...
 

Hard rock

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Hmmm...I do believe that if you do your job that the bullet will hit the exact same spot from shooting light in the morning until shooting dusk before it gets dark out. After dark you probably wouldn't be able to even see the target unless you were jack lighting. Then the chances of finding out that even jack lighting a target at night is probably illegal and your firearm and all associated equipment including your purely innocent truck would be confiscated and you would never be able to make such a comparison again. It's kind of like never date when horny. Never shoot after dark.
Hmmm...I do believe that if you do your job that the bullet will hit the exact same spot from shooting light in the morning until shooting dusk before it gets dark out. After dark you probably wouldn't be able to even see the target unless you were jack lighting. Then the chances of finding out that even jack lighting a target at night is probably illegal and your firearm and all associated equipment including your purely innocent truck would be confiscated and you would never be able to make such a comparison again. It's kind of like never date when horny. Never shoot after dark.
That last sentence is a new one on me again maybe so maybe not
 

baldhunter

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Texas
Does barrel break in make a difference?There is no way to tell,but I have to say,rifles I have done recommended barrel break in rarely require a fouling shot to stay in the group.I remember one rifle I had years ago that required two fouling shots.I thought it was just me,but I found the first shot from a ckean,cold barrel,it was consistently 4" off.I did not break this barrel in,I just shot it.I always liked to keep my barrel clean and I missed a few times using this rifle until I figured out I needed fouling shots to make it group.After that I could get it to shoot half inch groups.
 

Prairie

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May 24, 2012
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Kingman, Arizona
Does barrel break in make a difference?There is no way to tell,but I have to say,rifles I have done recommended barrel break in rarely require a fouling shot to stay in the group.I remember one rifle I had years ago that required two fouling shots.I thought it was just me,but I found the first shot from a ckean,cold barrel,it was consistently 4" off.I did not break this barrel in,I just shot it.I always liked to keep my barrel clean and I missed a few times using this rifle until I figured out I needed fouling shots to make it group.After that I could get it to shoot half inch groups.
Just curious. If a rifle does indeed need a fouling shot to resume accuracy, what would stop a person from not cleaning the bore after a session at the range and then when hunting, use the rifle without being cleaned. Taking into count of course that the rifle hadn't reached the degree of fouling as to have excess copper fouling. Kind of makes sense to me to not clean a bore until copper fouling dictated that you clean. I'd like to see what others think about that!
 

Greyfox

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I would separate any lighting, wind, mirage, etc effects from a rifles basic cold bore accuracy.
I will test for cold bore accuracy at 100-200 yards. I will measure cold bore and follow-up shot precision as well as velocity/SD. I look for a maximum variation of .5MOA and SD 7. With a new rifle/load I will test this for day to day(or week to week) as well as same day with cooling time gaps. I generally look to get a minimum of 60 shots and will not clean the barrel for the hunting season, unless subjected to the elements or I did excessive shooting.
From a clean barrel I will always foul the barrel with 5-10 shots. I use a similar standard/regimen for my competition rifles with the exception of number of shots needed for a match(100-120/PRS), and clean after every match.
Rifles meeting this standard generally have heavy steel(minimum Light Palma size), Cleaned with BoreTech, and lubed with Montana Blend Bore Conditioner. Wiped dry before fouling. Load parameters, selection of components, barrel bedding, the particular barrel, and scope/mounts can all effect cold bore accuracy. IMO.

Last years cold bore, sighting check before my Wyoming hunt.
7253CB5B-1FF7-48C2-BDC2-2DCB751F7D08.jpeg
 

baldhunter

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Just curious. If a rifle does indeed need a fouling shot to resume accuracy, what would stop a person from not cleaning the bore after a session at the range and then when hunting, use the rifle without being cleaned. Taking into count of course that the rifle hadn't reached the degree of fouling as to have excess copper fouling. Kind of makes sense to me to not clean a bore until copper fouling dictated that you clean. I'd like to see what others think about that!
I always leave my bore dirty after varifing it's on target before hunting.Eliminates any question for the need of a fouler.During hunting season the only time I clean is if my rifle has been in the rain or very wet conditions.
 

Teri Anne

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In reality I have found that fouling shots are indeed necessary, at least when competitively shooting. Why? Well our reasoning and it seems to have borne itself out over the year and many different competitions, courses of fire as well as different rifles seems to be that the first shot out of a clean bore will always go a bit wacko. In the Army the rule was, "You shoot it, you clean it before putting it away." This always meant that there was a light coat of oil in the rifle bore. As we all know oil is a liquid and as such is susceptible to gravitational puddling. This puddling, it is thought causes different friction withing the barrel for the first couple of shots which in turn causes the fliers. The fouling shots would burn and blow out the oil leaving a uniform surface inside the barrel for the bullet to travel through. A partial solution to this issue was to run several dry patches through the bore before heading out to the range. While this helped it did not completely eliminate the fliers, only made them fly a lot less from the rifle's zero. In competition we usually had two sighting shots prior to each stage, which were used to fire fouling shots prior the the first shot for record. In case some of you have not noticed I am a stickler for sub moa accuracy out of my rifles. I have also learned that it doesn't matter if its a Winchester, Tikka, Remington or Browning, each and every one of them will shoot a flier or two out of a squeaky clean barrel and then settle down to it's natural zero. To answer the second part of the question, "Is it OK to not clean the barrel until the end of the season?" There are varied thoughts on this and I'm sure some will disagree with me. First of all it depends upon your rifle. If you have a stainless steel barrel they are more impervious to corrosion than are steel barrels. The next consideration is what ammo you are shooting? The more modern ammunition these days is not as corrosive as those of years ago. After shooting, take out the bolt and take a good look down the barrel using a bright light. If there is no evidence of crud in the barrel then there won't be any concentration points for corrosion to start. If there is crud left in the barrel, clean it and then look for some better ammunition. It has been my experience that inexpensive ammunition is usually made of somewhat inferior components and will not burn as cleanly as the premium ammunition. When I buy factory ammo for the .270, .308, 30-06 and 300 Win Mag it's going to cost between $45 and $70 for a box of 20. You will also find that the premium ammunition not only burns cleaner, but it is inherently more accurate. So without visible crud in the barrel and a rifle not exposed to moisture it is generally safe to not clean the barrel during a normal deer season which is most states ranges from 7 to 14 days. Another thing one might consider if you are a hand loader is to load up a few cartridges with only primers. Just like when hunting with muzzle loaders and you fire a couple of primers to check to make sure the nipple or breech plug is clear it also burns out any residual oil in the bore. I have tried it and it seems to work, magnum primers work best for this and still may not burn out all of the oil residual, but it will help. So now that I have said my peace, let's hear from others and how they solve the clean bore flier issues.
 
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