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Consistent cold bore shot test

Discussion in 'Rifle Country' started by someguy2800, Oct 8, 2019.

  1. someguy2800

    someguy2800 Member

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    Here is an interesting test I like to do after you have your load worked out and scope zeroed they way you want it. Take your rifle of choice out and put up a paper target at whatever range you like. Shoot one cold bore shot and take the target down and take it home with you. Keep shooting other targets if you like but save that one with the cold bore shot for the next range trip. Do that every month or two till you have 6 or 8 shots on the same target in different weather conditions and seasons. Leave the scope caps on.

    You may just find that you have a rifle that shoots nice little .75 moa groups when they are all shot in the same session, but the cold bore shots combined make for a 2 or 3” group because poi is changing with temperatures or humidity or whatever.

    Likewise you may also suprize yourself and find that a rifle that shoots rather ho hum groups is very consistent on the cold bore shot. This can be an enlightening and frustrating exorcise!
     
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  2. jmorris

    jmorris Member

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    When I travel with a hunting rifle I almost always fire one shot to confirm zero.

    Some move around more than others as they warm up though.
     
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  3. Ks5shooter

    Ks5shooter Member

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    Interesting idea.
     
  4. BWS

    BWS Member

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    I'm pretty much 100% cast bullets,and reasonably high intensity,varmint blasting bolt rigs..... and a fondness for R700's with magnum profiled barrels. Stainless and fluted are like ice cream,love it.

    Cold bore shots,to be included into "rapid fire" 3 rd. groups off field position style rests have been a driving passion for a looong time. Got to get that bedding just right..... work on it to the point of being able to pull the stock,replace it.... shoot a 3 rd group.

    Next is optics..... pull the scope(quick release stuff just makes too much sense on hunting rigs),replace it.... shoot 3 rds.

    Balance has to be up there too.... this is from whatever rests the riv is going to see on a day to day basis. The check on balance,and overall "fit" is..... let a shooting bud try your rig. And vs/vs, shooting your friends rig after some discussion of how it's set up can help bring to light some minor handling issues one might have. And don't mix things up on balance,what works on a heavy bench rig ain't necessarily gonna "fly" off field rests.

    Triggers got be figured in here somewhere.... spend some $$$ but,don't assume lighter is better. Yeah,3# or so is getting on up there but with a dialed in rig/tune.... a clean breaking 3# trigger isn't,or shouldn't hold you back,that much. Good luck with your project.
     
  5. Slamfire

    Slamfire Member

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    That is very true. Most of my "long distance" shooting was at NRA Across the Course Highpower. Two hundred yards is not long range to those types who regularly shoot at animals at 800 to 1000 yards with a cold bore, but I sure saw the pattern move as the bore fouled. The higher the mileage barrel the more it walked until it fouled in. I also see this in Smallbore Prone. These matches start at 50 yards, and I can't remember a time when the first couple of shots out of a clean and oiled barrel were not out of the fouled group and tended to be erratic.

    That being said, I wanted to find out how greased bullets and and cases affected groups given a cold bore.

    HB9skFG.jpg

    jl5ItAK.jpg


    I bedded this rifle before taking it to the range. I created a Devcon pillar before routing out a massive amount of wood and pouring in even more Devcon


    NmLGS83.jpg
    SEKbk5j.jpg

    free floated the barrel, the original barrel channel was touching almost all the way up

    fR7tLND.jpg


    Using zero's established during a prior trip at CMP Talladega, perhaps this time

    LkbRc58.jpg

    and greasing up my bullets, similar to this:

    0kUSURg.jpg

    My first shot at 300 yards with a clean and oiled barrel:

    vz1IdKz.jpg

    The next nine shots

    17GGA58.jpg

    So the group was stable and the point of impact repeatable. This barrel may be non typical. It is from 1937 for one thing, and I believe it is a taper bore based on the fact that it feels tighter as a brush or patch is pushed down the tube. I do believe that being a tighter barrel is why this sporter rifle is exceptionally accurate.

    Ever since a two time Bullseye National Champ said Colt revolver barrels were more accurate than S&W barrels, because they were tighter, I have been looking for evidence that choke barrels (or tight barrels) are inherently more accurate. I have an exceptionally accurate Benchmark .22lr choke barrel on an Anschutz, so I think there is something to this.

    I am load testing when I go to CMP Talladega and so I don't start off with cold bore experiments at 300 yards, I will start at 200 and work my way out. And off the top of my head I don't remember what happened any other times I started off with the same load at distance.

    Regards of previous zero's, you have to look at range conditions, observe the range flag direction, height, and mirage, and make best guesses as to wind drift, in elevation and windage. Most of the long range hunting stuff I read totally ignores the effect of wind on point of impact. Well, it is real. I remember the year in the pitts at Camp Perry and I was complaining my 223 bullets drifted 36 inches in the wind and I thought conditions were bad. A gnarly ex USMC shooter stumped over to my target and told me that when he won the 1000 yard Match, with his M14, he was aiming three targets over and had full right windage!

    Based on the windage on a NM rear and the spacing between targets, his 308 bullets drifted 50 feet due to wind conditions! Horrible day to be out shooting!!


    nn9H4hg.jpg

    uqyuyzP.jpg

    I can say when I shot 1000 yards, the first shot to the target was always a mystery. Given the same rifle, same loads, established zero's, at the same range, if my first shot at 1000 yards was in the black, that is the eight ring, I was a happy camper. Due to my experiences at long range target shooting I think the practice of "long range game hunting" is extremely unethical because the first shot is unlikely to hit a vital area of the animal, and thus increase suffering of the animal as it runs off and dies an agonizing death.
     
    Last edited: Oct 9, 2019
  6. alfsauve

    alfsauve Member

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    I think I read this is how Carlos Hathcock sighted in and practiced. But he do it every day and clean the rifle every night as well.
     
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  7. z7

    z7 Member

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    My cold bore test is to shoot a 1” sticker with a single shot, i log all shots. 9 different cold bore shots tested like this with zero misses,

    I am the weak link
     
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  8. MCMXI
    • Contributing Member

    MCMXI Contributing Member

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    Shoot a bunch of 3 to 5-shot groups using a light rifle in the same session and you'll often see the group centers walk all over the place. It's fairly easy to be consistent within the same group, but much harder to come back to the same position between groups. Light rifles shooting common deer/elk hunting cartridges are so dependent on consistent contact points in order to shoot well within a group, and even more so from group to group.

    The test mentioned in your first post is a good one, but I add in clean bore as well.
     
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  9. Demi-human

    Demi-human Member

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    That sounds like an excellent plan and fun program, @someguy2800.
    Especially in humid, and then not, Michigan.

    It may take me a bit longer than a month, though.
    Because if I am going to take my rifle out and have it exorcised, I would like to have my pastor as my spotter...:)

    :rofl: Damp ewe auto-collate!
     
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  10. Edcnh

    Edcnh Member

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    I did something similar a few years ago and plan to do it again this year. I will start today and take my initial shot. I found in the past that my initial shot, with the exact ammo I will hunt with, was plenty good enough for hunting. I don’t remember the exact group size but was very confident my first shot would be a good one if I did my part. Unfortunately the few times I was able to hunt that year I never saw a deer with antlers in the woods.
     
  11. jeepnik

    jeepnik Member

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    Not surprised. I learned to "zero" a rifle with a cold barrel. Once you think you have a good zero let the rifle cool completely. Fire a round and adjust as needed. Allow barrel to cool and repeat. Think about it. Unless you are shooting varmits the first shot you take is the one that counts and if you do your part it's the only one you need.
     
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  12. rdnktrkr

    rdnktrkr Member

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    After deer season I'm planning on trying 9 shots on 9 different targets with cold bores, I've never thought about it causing a difference.
    During deer season after I sight in I wait till the end of the season to clean so I don't have a clean bore / fouled bore difference.
     
  13. JimKirk

    JimKirk Member

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    I have done the five shots on five different days using same target ... Cold bore

    That tells you the "true" hunting accuracy for .... in my case white tail deer hunting..... where the first(cold bore) shot is probably the only shot you get down here in the woods.....
     
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  14. Steve S.

    Steve S. Member

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    “This will work well in practice but not very well in theory.” (Warren Buffet)
     
  15. Shanghai McCoy

    Shanghai McCoy Member

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    Just came in from checking one of the rifles that I'm going to use for deer hunting. I'd zero'd it in July and shot it some so today took a cold shot and it went right where it needed to be.
    Over the years I have made the cold shot check with the rifles I'm planning to carry part of the pre-deer season routine.
     
  16. taliv

    taliv Moderator

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    I don’t really have a cold bore shift. I usually shoot my first round of the day on a 6”
    Head at 500-600 yards. Spend your time learning to get the wind right.
     
  17. Varminterror

    Varminterror Member

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    Maybe 2009/2010 one of these went around Predatormasters forum. My targets revealed two things more than any other influence - 1) lighting conditions influenced my POA hold significantly, and 2) my sleep condition, or lack thereof, influenced my ability to hold POA consistently from one day to the next.

    If I believe in anything, I believe in a “cold shooter,” but not in a “cold bore” influence. As I’ve shared in other threads here recently, if a rifle is walking because of barrel heat - notably - I won’t own it. I also believe a lot of guys will claim a rifle walks as it heats up far more often than it actually happens. Rather, they build a good position for the first shot, then “shoot themselves loose” over a few shots, without properly reestablishing the position. (Or worse, guys see their impacts and start shooting, subconsciously, at their bullet holes, and the subsequent shots keep walking progressively that direction). So if I buy a rifle which prints differently cold bore vs. warm, I fix it, or send it packing. My rifles can’t say the same about me - most days I’m ready for my first shot, somedays I’m not.
     
  18. someguy2800

    someguy2800 Member

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    Yes a properly bedded rifle with no stresses being put on it from the barrel shooting a load that does not vary significantly with temperature should not move poi much at all regardless of the conditions. The rifles in my stable that I really trust will shoot to the same place at 85 degrees in July as they did at -20 in January and I do test for that.

    Where I see the guns that don’t pass this test are wood stocked rifles where the forend is putting pressure up or sideways on the barrel or ones that change POI significantly with changes in velocity. I’ve seen this with several rifles, particulary older bolt rifles with pressure bedded forends or single shots. A guy needs to first be aware this is happening and then he can decide to fix either the bedding, the ammunition, or figure out a way to compensate.
     
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