jerkface11
Member
If you have a chronograph you can see a rather significant difference in velocity from a clean barrel.
Myth or Fact?
- Thread starter cwmcgu2
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cracked butt
Member
Its 100% true unless you are zeroing the rifle by cleaning and oiling the barrel between each shot. This is especially significant if the barrel is oiled afetr cleaning.
After you clean and oil the barrel, the first shot will almost always be several inches away from the zero on the vertical plane.
Koos Custodiet
Member
22 rimfires definitely change POA for the first 10 or so shots. Even if you're just changing brands of ammo. Has to do with the wax lube they tell me.
But you're not hunting with a 22LR
But you're not hunting with a 22LR
Cannonball888
Member
When we talk about a cold bore, there are also different degrees of coldness such as hunting in freezing weather versus sighting in at the range in the fall.
Funderb
Member
That matters in my pellet rifle.
but really, for a firearm it factors to maybe a hundredth of an inch up on the target.
nothing to care about.
but really, for a firearm it factors to maybe a hundredth of an inch up on the target.
nothing to care about.
351 WINCHESTER
Member
Not a myth at all. Once your rifle is sighted in do not clean it until hunting season is over. It will change the poi.
Funderb
Member
Anyone see here that not cleaning, just like cleaning it, will change the point of impact. If you start out with a clean barrel, after sighting it in without shooting, then take 3-5 rounds to get it in tight, not cleaning will drop the bullet, cleaning will raise the bullet. Just bring the sights up a couple clicks to compensate. If you own the rifle, and are going hunting with it, you should be comfortable enough with the gun to know the discrepancy between clean and shot barrels.
cracked butt
Member
Thats all good if you are shooting an animal at the exact same range as you are sighting in. If you sight in at 100 yards, where do you compensate for a shot at 250 yards? Its likely that the poi will be outside of vitals at that distance. The only way to know would be to shoot with a cleaned bore at different ranges- most people simply don't have that much time on their hands.
Funderb
Member
It's pretty simple math though,
the equation comes right on the box for your scope.
if you're using one.
1 moa @ 100yds = 1 inch
If you know a clean barrel jumps up 1/2 of an inch at 100 yards, then you know it will jump up 1.25 at 250.
It's just that cleaning is imperative for those who hunt with milsurp rifles, and quite a few do, even with newpro ammo rust is an issue.
Just take a little time to chart out your rifle's err on a shot log.
you'd be like a real sniper.
the equation comes right on the box for your scope.
if you're using one.
1 moa @ 100yds = 1 inch
If you know a clean barrel jumps up 1/2 of an inch at 100 yards, then you know it will jump up 1.25 at 250.
It's just that cleaning is imperative for those who hunt with milsurp rifles, and quite a few do, even with newpro ammo rust is an issue.
Just take a little time to chart out your rifle's err on a shot log.
you'd be like a real sniper.
Leave it dirty. Then it'll literally be a case of hit or myth.
Seriously, for hunting level accuracy I don't see as it will make any difference since you're not required to hit with the accuracy of a police sniper in the "no twitch" shot. I think IMHO, it's far more likely that a trigger snatch or a flinch will cause a wild shot. A good scope on a good gun, properly zeroed won't be affected to any great extent.
Seriously, for hunting level accuracy I don't see as it will make any difference since you're not required to hit with the accuracy of a police sniper in the "no twitch" shot. I think IMHO, it's far more likely that a trigger snatch or a flinch will cause a wild shot. A good scope on a good gun, properly zeroed won't be affected to any great extent.
cracked butt
Member
The error is usually much more than 1/2" and isn't going to be consistant from one cleaning to the next. I've seen changes in poi over 2" before.
I've worked at deer rifle sight-in clinics for several years and have helped hundreds of hunters sight in their hundreds of rifles. The first shot in a sight-in group is discarded abotu 1/2 the time, reason being is that only about 1/2 of them cleaned the rifle since last year's deer season. The other 1/2 cleaned their rifle sometime after deer season and haven't shot it until now, 1 week before opening day. The best that you can hope for is to get their rifle sighted in and get them a bit more familiar with their rifle before they take to the woods. I have always advised them to not clean their rifle until the season is over unless it somehow gets wet or is exposed to some other corrosive environment. Having to tell them that need to correct for a first shot out of a clean barrel complicates matters too much for a person who only fires a dozen or so shots per year. Besides, after firing 7-10 shots to sight in a rifle, there isn't going to be enough fouling to diminish accuracy at all, and the firearm will not be harmed for not cleaning it for a few weeks unless they are shooting some sort of surplus garbage through it.
All of that being said, there is no advantage whatsoever to sighting in a rifle for hunting then immediately cleaning it. Its just plain sound common sense advice to not clean until the hunting season is over with barring the rifle being exposed to elements that can damage it.
Funderb
Member
Man, I'm totally going to the range this weekend and testing this.
cracked butt
Member
Keep me informed with your results, I'm very interested.
Funderb
Member
will do,
This can only really work if the gun is clamped and sandbagged though.
Gotta figure a way to do that.
This can only really work if the gun is clamped and sandbagged though.
Gotta figure a way to do that.
jpwilly
Member
The differance between clean or dirty bore will not impact your shot enough to matter. The decision you should make is whether you like your rifle clean or dirty. When I'm target shooting I always shoot a "fouler" before attempting to make little groups. When I'm done I clean my rifle and put away until next time.
sacp81170a
Member
No, they're the guys who post here who can hit a gnat in the eye at 1,000 yards with anything and go out with fashion models. Some of them duct tape trauma plates to their chest and back and work as mall security.
cracked butt
Member
The people that I'm usually helping are those that only get their rifle out once per year, the guys who shoot alot don't go to rifle sight-in clinics.
From my own circle of family and friends, I'm probably the only person who shoots more than 20 rds per year. In fact, some of them think I have a few screws loose because I have (many) 'nonhunting' rifles and shoot thousands of rounds per year. The only other person that I know on more than a casual basis who deer hunted and shoots alot was my father, but he no longer hunts deer. I do have friends who shoot alot but don't hunt.....
tnieto2004
Member
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- Jan 15, 2007
- Messages
- 1,389
Myth! I have never seen any evidence to say otherwise ..
jacobhh
Member
I believe the term "Fouling Shot" originated with black
powder muzzle loaders and is truly necessary with them.
I always shoot a fouling shot in practice and competition,
also wipe a BP gun one once damp and once dry between
each shot.
Shooting smokeless, it seems to me that barrel temp has
a greater effect but I shoot a fowler out of habit anyway,
which serves to mitigate both cold and clean.
I would never let a gun sit around dirty for any length of time
BP or smokeless.
powder muzzle loaders and is truly necessary with them.
I always shoot a fouling shot in practice and competition,
also wipe a BP gun one once damp and once dry between
each shot.
Shooting smokeless, it seems to me that barrel temp has
a greater effect but I shoot a fowler out of habit anyway,
which serves to mitigate both cold and clean.
I would never let a gun sit around dirty for any length of time
BP or smokeless.
StrikeEagle
Member
- Joined
- Jul 8, 2004
- Messages
- 709
How exactly does that work? If the shots are too close together to score on the target, how does it help to put something else behind the target? Just curious.
sacp81170a
Member
From http://www.nfa.ca/content/view/64/197/ :
"At the top levels, 5 round groups are usually a single ragged hole in the target. To ensure that the competitors fire 5 rounds into the target, a moving backer paper is installed behind the record target. This way it is easy for the match officials to see that all 5 rounds were fired.
"The world record for a 5 shot group at 100 yards is currently 0.052” for Heavy Varmint and 0.054” for Light Varmint."
"How is it possible to fire a group measuring only 0.1 inches across with a bullet that is 0.243 inches in diameter? Group sizes are measured from center to center of the two widest bullet holes. As a result bullet size is removed from the equation and groups from different calibre rifles can be compared on equal terms."
Yes, these guys are, ahem, accurate.
"At the top levels, 5 round groups are usually a single ragged hole in the target. To ensure that the competitors fire 5 rounds into the target, a moving backer paper is installed behind the record target. This way it is easy for the match officials to see that all 5 rounds were fired.
"The world record for a 5 shot group at 100 yards is currently 0.052” for Heavy Varmint and 0.054” for Light Varmint."
"How is it possible to fire a group measuring only 0.1 inches across with a bullet that is 0.243 inches in diameter? Group sizes are measured from center to center of the two widest bullet holes. As a result bullet size is removed from the equation and groups from different calibre rifles can be compared on equal terms."
Yes, these guys are, ahem, accurate.
R.W.Dale
Member
I've seen that first shot from an oily bore be as much as 200 fps SLOWER than the other shots afterward. Pressure = velocity and friction = more pressure. Adding oil gives - friction so therefore you have less velocity. To top it all off less velocity usually = a HIGHER point of impact.
So I always hunt with a dirty bore.
Another good myth is the one that says even with modern ammo you HAVE to clean your guns after each shooting session. I shoot em dirty till the accuracy drops off, usually about 500 rds later. Then I give the bore a good scrubbin and it's back to shooting like new.
So I always hunt with a dirty bore.
Another good myth is the one that says even with modern ammo you HAVE to clean your guns after each shooting session. I shoot em dirty till the accuracy drops off, usually about 500 rds later. Then I give the bore a good scrubbin and it's back to shooting like new.
Jenrick
Member
As I've a strong interest on getting on my departments tactical team and from there being a rifleman, I've done some research on the subject.
To echo what everyone else has said, a clean cold rifle shoots different then a clean warm rifle, which shots different then a dirty cold rifle, which shots different from a dirty warm rifle. The easiest way to do this of course is to shoot in all of these conditions, obviously this isn't an option for most people as they lack the time and money.
An easier and better option is to keep a rifle data book, it will allow you to track you rifles accuracy with different brands, loads, etc. As well as seeing what the weather does to you're shooting. An interesting side effect of this is that when you're making a shot at a decent range in poor weather, you can look in your book and see hard data on what's going to happen to the bullet to adjust your aim accordingly.
Anyway, if you keep a good rifle data book you'll have a good listing of cold clean, cold dirty, warm clean, and warm dirty shots. Look at the actual shots and see where the rounds land. My Rem 700P shoots about 1/8" high and 1" to the right of the rest of the group cold and clean. All following rounds group into .5" or less from there. Does this vary sometimes? Of course, as I'm not shooting from a machine rest, but I know that in almost all cases my first round shots POA, and the rest will impact just slightly low and right.
Is an inch or two an issue for deer hunting? In my personal opinion no. You shouldn't be taking a shot where that's the margin of error as a responsible hunter.
-Jenrick
To echo what everyone else has said, a clean cold rifle shoots different then a clean warm rifle, which shots different then a dirty cold rifle, which shots different from a dirty warm rifle. The easiest way to do this of course is to shoot in all of these conditions, obviously this isn't an option for most people as they lack the time and money.
An easier and better option is to keep a rifle data book, it will allow you to track you rifles accuracy with different brands, loads, etc. As well as seeing what the weather does to you're shooting. An interesting side effect of this is that when you're making a shot at a decent range in poor weather, you can look in your book and see hard data on what's going to happen to the bullet to adjust your aim accordingly.
Anyway, if you keep a good rifle data book you'll have a good listing of cold clean, cold dirty, warm clean, and warm dirty shots. Look at the actual shots and see where the rounds land. My Rem 700P shoots about 1/8" high and 1" to the right of the rest of the group cold and clean. All following rounds group into .5" or less from there. Does this vary sometimes? Of course, as I'm not shooting from a machine rest, but I know that in almost all cases my first round shots POA, and the rest will impact just slightly low and right.
Is an inch or two an issue for deer hunting? In my personal opinion no. You shouldn't be taking a shot where that's the margin of error as a responsible hunter.
-Jenrick
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