The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Rifles Medium Bore Rifles 7mm remington magnum keyholingGo | New | Find | Notify | Tools | Reply | |
| 7mm remington magnum keyholing | Login/Join |
One of Us |
aw come on turnips can be useful meat is murder..... tasty,tasty murder | |||
|
| one of us |
Incorrect. I fired 295gr .338 competition bullets from a 1:10" twist 338 Win Mag. The target showed perfect lengthwise profiles at 10m. The same bullet from a 1:7" 338Lapua Magnum has won the Lapua Sniper Competition numerous times. A customer sent me email two days ago to say that our 70gr .243 SP bullet keyholes perfectly from a 1:14" twist, as I said it would, but he wanted to see for himself. The same bullet produces perfect, accurate results from a 1:9" barrel out to silly distances. A 7X61 S&H with a 1:11" twist keyholes everything from 175gr to 140gr to a lesser degree and shoots under a minute of angle with Sierra 120gr bullets. The list is endless. | |||
|
| one of us |
I really like topics on barrel wear because it shows me who the inexperienced shooters are.You guys are the type who read the newspaper and go by what it says. | |||
|
Moderator |
 You kill me, shootaway. You get 70 rounds per barrel, and you've only shot out 3 barrels on your 7mm RM and you are calling the rest of us inexperienced???? You are one of the funniest people alive.  Doing simple math, I am betting many of us get more shooting experience every week than you have ever gotten with your 7mm.But keep it up, please, I haven't laughed this much in a long time.  Cheers, Canuck | |||
|
| One of Us |
I think that he when returns the rifle for a new barrel. His gunsith gives a speech about shootaway being his favorite customer, cleans the barrel then gives it back to him the next day, whilst charging him for a new one! | |||
|
One of Us |
The brass that was fired in that rifle may have some stories to tell. Anything on it look odd? In addition to what others have suggested, it may be advisable to get the headspace checked. | |||
|
| One of Us |
Well the laughs keep on coming . Knuckle heads Turnips , Blunder Dummy's . I have no Idea where anyone would get the " Silly Ass Idea " that if a projectile comes out the end of the muzzle unstable from the very beginning that some twist rate is going to Straighten it up !. Where does that magic happen ?. 250 or 7 light years form the muzzle !. Think about that for a hot second !, Unstable is unstable PERIOD !. In my entire life I've never seen a totally worn bore or wrong projectile ever shoot any weight of bullet and Straighten up DOWN RANGE !. Granted twist rate is useful , in helping to stabilize projectiles of various weights too twist ratio , but they don't jump out the end of the bore wrapped around the bullet and lift or push the dam thing down range !. I can clarify this whole B S in a Nut shell !. The New Guy says he's slugged the bore , he also says he's shooting " Factory Ammo " !. Factory , Guys OK !. Who manufactures unstable out of round wrong size projectiles in 7 MM ?. They must be doing a whopping business HUH !. Yes sure Ammo some is far better than others , but I've never seen any " KEY HOLE " . Even the shit surplus corrosive WW1 or 2 or prior !. It Shoots shitty groups granted , but it doesn't even Key Hole . UNLESS something is wrong with the weapon to begin with !. Gerard ; I've shot near 40 years 3-5K rounds a year in various ( Rifles alone ) of mine . Not one time have I ever Key Holed a round under 100 Yd. ( With the exception of an Arisaka ) It missed a 4 Ft. target at 100 yd. !. When I was finally able to put it on the board the projectiles were 18 " off center and 6 " high and a perfectly horizontal profile of the bullet was left as an impression !!!!. I don't think TWIST had a DAM thing to do with that !. Now what do you think ???. Shoot Straight know your target . ...  | |||
|
One of Us |
Don't be too high and mighty! I think with the exception of a few, almost everyone on this board has had a long chunk of experience with rifles, just as you have. We all know that factory ammo is high quality and shoots very well, and again, because we are experienced riflemen, we have seen numerous factory recalls due to ammo mishaps. As for the twist rate BS, I think that Gerard is trying to say that he feels the problem may be the barrel has insufficient twist rate to properly (maybe just barely) stabize the bullet. Having dabbled in a few physics classes and having a bit of experience with bows and arrows, I have no trouble believing that a projectile launched from a stand still will oscillate as it accellerates. As the projectile stops accelerating, it will stabilize. What I am unsure of is if a 150 gr 7mm bullet would oscillate enough for it to appear to keyhole. There just isn't enough data to make an educated opinion; therefore, all anyone can do is to offer an hypothesis. And my summation of scientific theory, all hypothesis are equally wrong until proven otherwise. John | |||
|
| One of Us |
I am curious, and have oft been told how dangerous curiousity can be, but I gots to know... How did you discover the barrel life of a 7mm Rem Mag? John | |||
|
| one of us |
I would get good groups in the begining at long distances and clean when the groups would open up.The groups would return to normal,usually under an inch.When the group size would not decrease after cleaning,sometimes opening up to over a foot,I looked at my barrel and rifle closely to see what changed.When I removed the bolt and looked down the action,I saw the rifleing in FRONT of the chamber missing for a few inches.I DISCOVERED the cause of the problem after spending long hours of thinking.Since then some calibers would stop grouping sooner than others.With max loads the big 7 would last about 70 rds,compared to 3000 rds of min loads with my 308.The 308 would go over a thousand rds before seeing any rifleing missing.Now, if anyone here has still not discovered this and laugh at people who have,then what can I say? When I kept shooting the big 7 after the erosion and it would not strike the target anywhere,I tried shooting at a closer distance of 50 yds to see if it would group there.To my surprise the bullets struck sideways on the target paper and the rifle started to hangfire. | |||
|
| One of Us |
That explains why you are losing the rifling after 70 shots. The column of air ahead of the rifle at more than 50 yards is longer and this holds the cartridge tight up against the bolt face and it prevents the rifle from having a hangfire. At 50 yards the pressure ahead of the rifle is much less and the cartridge moves forwards when the firing pin drops on the primer. Ignition of the powder is erratic and pressure in the case is much higher due to the shorter distance to the target. This erodes the rifling and causes the hangfires at 50 yards. When you shoot at short distances you should use one of those electric radiator fans to blow at the muzzle of the rifle. This will raise the air pressure enough to stop the hangfires and the rifling will last much longer. An added bonus is that it also cools the barrel and you can increase your rate of fire from one every two seconds to one every second. I had the same problem with an air rifle when I was ten years old and that is how I solved it. You must also remember that you must crank the the pressure down to no more than 30psi when you clean the barrel with a sandblasting machine. I know that cleaning at 100psi is faster but I found that spending the extra two minutes blasting at 30psi doubled the barrel life. | |||
|
| one of us |
RAT ,like I said,it's the topic on barrel wear that identifies all the inexperienced shooters. | |||
|
One of Us |
I like Rat Motor's explanation.   Makes about as much sense as what you are saying shootaway. Of course he was trying to be absurd, you are just a natural at it. BTW, in exactly 221 shots out of a new Hart barrel 280AI the OAL has moved from 3.330" to 3.353" as measured exactly by 2 different methods. This is shooting a 160 gr bullet at 3000 fps which IMO should be considered a hot load. But I hate to throw facts into this, it might show shootaway how stupid his assertion is and he might stop entertaining us with his absurdities.  ____________________________________ There are those who would misteach us that to stick in a rut is consistency - and a virtue, and that to climb out of the rut is inconsistency - and a vice. - Mark Twain | Chinese Proverb: When someone shares something of value with you and you benefit from it, you have a moral obligation to share it with others. ___________________________________ | |||
|
| One of Us |
I am glad to see you are truly educated on the subject; however, my experiences are not the same. My military issued 308 bolt had over 10K rounds on the barrel when I got it. It would still hold 3" at 500m. Having owned 7mm mags, I can say the barrels were in excellent shape after shooting considerably more than 70 rds. Most folks I know shooting the 30-378 Weatherby have it tough, their barrels start wearing around 5000 rds. It is possible to erode the front rifling with 70 rds though, so I can't call you a complete numbskull. If you fail to let the barrel cool between shots, it will expand during the heat to the point that the rifling will erode like you have described. But other than firing 70 rds in a 2 minute period, I think you may be off base. John | |||
|
One of Us |
Canuck, your rifle has a CHAMBER in the barrel? My God! Can you hear chamber music? Or is it an ante-chamber? This is a really good mystery! Now I note that sot-away's rifle had 3-4 inches of the chamber missing! For that to happen, I suspect there would have to be a void of some size where the front of the chamber had been. This void would have to be larger than the chamber component it replaced. Now, it is entirey possible that this void explains the hang-fires, but I doubt it since the 7Mag headspaces on the belt. But the cartridges had to fire-form to fill the void, thus releasing their bullets in a haphazard manner, which explains the poor grouping. Hangfires only add to the lack of uniformity here. "Bitte, trinks du nicht das Wasser. Dahin haben die Kuhen gesheissen." | |||
|
| One of Us |
And here I thought all the looneys were South of the Canadian border!!!! "Bitte, trinks du nicht das Wasser. Dahin haben die Kuhen gesheissen." | |||
|
| One of Us |
Shootaway (should be "shot-away" or maybe "thataway"!!) I think it's your shooting ability that has suffered from "erosion". The one and only 7mm Magnum I've ever owned is a Ruger No. 1B with 26" barrel. I got it new in about 1969 or 1970. From the very beginning, this rifle has been able to shoot 1" groups at 200 yards, and one-holers at 100. It has been fired over 1000 times with hot handloads over the years, and STILL shoots as well as the first day I put that Leupold 2X-7X on it. It now wears a Kahles Helia fixed power 6X, and is my mountain elk rifle to this day. There is no visible wear in the throat at all, per the local borescope! "Bitte, trinks du nicht das Wasser. Dahin haben die Kuhen gesheissen." | |||
|
| One of Us |
Now, this is a very technical explanation that I've never considered. Sounds like a quote from Hatcher's Notebook..... See, shot-away, boars don't wear, they are slowly cut/blown/eroded away by high temperature gas. The action is something like an acetylene cutting torch. High temperature gas melts a tiny bit of the steel of the bore at each shot, and then that molten steel is vaporized and carried away, actually shot-away, just like your name. Now, if you place your boar in a freezer and let it get down to -40 F before each shot, this can't happen. So your bore will remain in place. But be careful not to get the barrel too cold, because a brittle, cold bore might shatter (in 70 or so shots....). But I can't guarantee that yur groups won't swell up. "Bitte, trinks du nicht das Wasser. Dahin haben die Kuhen gesheissen." | |||
|
| one of us |
Deguello,if you bought the rifle in 69 then your eyesight is questionable and those thousand rds may not really be a real thousand.Here is a quote from Randolph Constatines book-MODERN HIGHPOWER COMPETITION."I think if you are having accuracy problems with a Palma gun and the barrel has less than 2000 rds through it,and is free floating and clean,it is more likely that any problem is with your ammunition and not with the rifle......Change that 2000 figure to 400 for a magnum" I suppose he should stick his muzzle in the ground and pull the trigger also. | |||
|
| One of Us |
Makes our point for us, if the problem is with the ammo and not the rifle then he is saying the rifle is fine after that many rounds.  ____________________________________ There are those who would misteach us that to stick in a rut is consistency - and a virtue, and that to climb out of the rut is inconsistency - and a vice. - Mark Twain | Chinese Proverb: When someone shares something of value with you and you benefit from it, you have a moral obligation to share it with others. ___________________________________ | |||
|
| one of us |
 | |||
|
| One of Us |
Big Bore Boar Hunter ( High & Mighty ? ). You obviously have me confused with some one else !. High I'm not nor mighty . I just know certain things to be impossible . Like a projectile leaving a bore unstable then some how re gain it's composure and fly straight !. Don't happen no way shape or form !. Twist rates in a bore are for spin rotational stabilization correction of projectiles,YES . Leaving a bore at the incorrect spin for weight of projectile will lend it's self to the inevitable failure of long range stability !. I agree !!. How ever it will NOT STABILIZE a unstable projectile . Unstable is Yaw , Pitch balance , spin is what it is !. The point is for the final time . 7 MM mags or just about any other Med., Heavy caliber ( with in reason now ) will shoot a hand load or factory Ammo projectile between the weight of 100 - 180 grains well enough to mark 300 Yd. with out key holing !. If the twist rate is between 1:7 - 1:10 . The weapon in question has got other issues besides twist rate or projectile weight !. I never implied others didn't have experience shooting . I've been at it a fair amount of time was the only point I was referencing !. How ever I'm not a Smith and have never given advice nor will I, on metal working for any weapon . I'm the finish man !. Epoxy, wood, Metal coating treatments is where my expertise lyes . Shoot straight Know your target !. ... | |||
|
| One of Us |
One last note which I forgot some how to mention in the beginning . CHECK the CROWN of the Muzzle . It could also explain poor groupings . Shoot straight Know Your Target . ... | |||
|
| One of Us |
I didn't read all the responses, so I don't know if anyone got the right answer, but here it is. When bullets are fired out of a rifle with a scope, the bullet is going up at an angle. The bullet will then fly it's entire trajectory with the same attitude. The tip or point of the bullet is always pointing up. It's not like a rocket that goes point up and halfway points down. The bullet is always following the same attitude throughout its flight. At really close range sometimes you get what is called overstabilization. I doubt that's what happening here, but it's the same principle. The tip is pointed up... It has nothing to do with loads or twists or anything of the matter, end of story. 500grains is on my ignore list for being who he is, which is not the type of person I like, want to be around, hear from or read anything he has to say, period. | |||
|
| One of Us |
What ever gave you the Idea that bullets or projectiles leave a rifle or any other firearm with the " Tip " UP ??. Stick with this ; Projectiles leave the bore of any weapon parallel to the bore !!. whether or not the weapon is tilted canted or tipped up or down !. ( THEY HAVE NO CHOICE ). A firing pin strikes a Primer ignites powder contained with in a cartridge or case to me more precise . Hot gases expanding ( Modern powder near 5K FPS ) Creates a measurable amount of pressure , which forces the projectile down the bore . The rifling in the bore does two things . Starts the projectile spinning and is an avenue which allows hot gases to escape or vent . Exploding Gases and several forms of debris ( copper, lead , carbon, nitrate traces along with several others ) exit the bore before the projectile does . A damaged or incorrect crown on a muzzle can deflect projectiles by allowing those gases an uneven path in which to escape !. Thus can contribute to tipping a bullet in any direction . Enough damage to the crown can make a projectile key hole normally out beyond 50 Yd. . With in 10 Yd. of the muzzle would mean half the crown would be missing or another problem !. Bullets drop they don't rise or fly tip up !. Aim points are lobbing the projectiles into a target for all practical purposes !. That happens with or with out a scope !!. Shoot Straight Know Your Target . ... | |||
|
| One of Us |
Bullets fly in the direction they are pointed, tip up, tip down, tip left or tip right. All projectiles fall to earth at 9.8 m/s/s, the trajecory is determined by the speed and drag of the projectile. All projectiles with center of gravity forward of the center of pressure at a ratio of 1.6 with regards to the total length of the projectile will self stabilize irregardless of the rate of spin (ever see a rocket spin? Every wonder why multi staged rockets where used instead of using one with a big tank). Truthfully Modern bullets don't have the length required to self stabilize, so they are spun to stabilize. It is possible for a bullet with a forward biased mass to self stabilize if the initial spin rate is not enough to stabilize the round (think of a badmitton birdie). Arrows in flight exhibit this behavior, and so do artillery rounds. Not voodoo, just physics. John PS, if a bullet spind perfectly about its axis, consider yourself lucky. | |||
|
| one of us |
Without reading 3 pages of whys and what fors and so fourth, if my gun keyholed at "10 yards" then I would be ordering a new barrel from Lothar Walther...the rest is just town talk! BTW, thousands of factory 7 mags out there with 1x10 or other twists handle the 175 gr. bullets at least to acceptable hunting accuracy of say 3" at 100.. For heavy bullets a 1x9 or 9.5 is certainly preferable but hey you got major problems IMO... Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
|
| One of Us |
The reason a bullet leaves the barrel tip up is because the bullet must cross the line of sight for the scope. Therefore, the barrel is pointed up, not parallel to the ground. I'm not aware of anyone who'd ever try and shoot with a barrel parallel to the ground. Sorry I didn't realize people didn't get that one. Think about it long enough you'll get it. The barrel is pointed up, the point goes up. The bullet stays in that orientation during the flight. 500grains is on my ignore list for being who he is, which is not the type of person I like, want to be around, hear from or read anything he has to say, period. | |||
|
| One of Us |
Cs273 ; What planet did you hatch from ?. First of all projectiles don't fly !. They're pushed . They have no wings or stabilizing fins to create lift !. Bullet or projectiles as I prefer are captured confined to a bore , there for they have NO choice but to follow that bore . They then begin to drop once they have left a bore . MANY MANY factors determine how far . Weight of projectile , powder charge ,Temp. , Wind , Humidity ,air pressure , Gravity to name a few ( hence flatter shooting calibers as well as projectile designs ). Projectiles don't care if a weapon has a " Scope or not " !. What kind of nonsense are you on ?. Think about this for a sec !. If projectiles were pushed tip up as you suggest , EVERYONE would key hole !!!!!!!!!!!!. they wouldn't need to design them , to be aerodynamic !. They could just shove a chunk of brick in there !. Flying Brick !. Projectiles are pushed parallel to the bore !. JUST as I said earlier . Tipping a bore up or down does nothing to change the dynamics of physics !. If you can't figure that out plain and simple . I would suggest you turn over all your weapons to the nearest authority's ASAP. Go back to school . Shoot Straight Know Your target . ... | |||
|
| One of Us |
From websters: ballistics One entry found for ballistics. Main Entry: bal·lis·tics Pronunciation: b&-'lis-tiks Function: noun plural but singular or plural in construction 1 a : the science of the motion of projectiles in flight b : the flight characteristics of a projectile ****** ****** When you look through a rifle scope, you are looking at a straight line from your eye to the target. The barrel will be inclined to the point where the bullet will leave the barrel and cross the line of sight of the scope, then proceed higher in elevation(height) and then begin to drop along it's trajectory, parabolic in nature, and then re-cross the line of sight. The second and final time it crosses the line of sight is where the rifle is sighted in for..... Now when the bullet leaves the barrel, the barrel is pointing up, so that the bullet can cross the line of sight, during it's flight. The bullet stays in that same orientation during it's flight. 500grains is on my ignore list for being who he is, which is not the type of person I like, want to be around, hear from or read anything he has to say, period. | |||
|
| One of Us |
i'd love to be his gunsmith. "dang, this barrel is shot out looks like were gonna have to replace it again.' "what? yeah it looks like the same barrel buts it different" cha-ching! | |||
|
| One of Us |
cs273 ; How does it feel to be related to Forrest Gump ?.Stupid is as Stupid Does ! I've seen a few mental midgets in my days but your just plain STUPID !. Oh bright one what happens if you should happen to shoot down hill ?. I keep trying to explain BULLETS DON"T FLY !. They're PUSHED GOT THAT , just PUSHED !. Weapons DON'T give a RATS ASS if there is a SCOPE or not !. Anyone who has ever really shot a weapon knows this FACT !. Understand the BASIC principles before adorning the fire arm !. Better Yet tell the rest of us you haven't reproduced off spring !. You have turned all your weapons over too the local authority's hopefully !. You said they fly tip up ! YOUR DEAD WRONG !. They follow the bore PERIOD !. Once leaving the bore they start to drop PERIOD !. I don't care if the weapon is pointed UP DOWN SIDE WAYS it's ALL the SAME !. The Aiming point and projectile ARC in which your now referring to is Correct !. Because the barrel is tipped NOT the Projectile it's self !. Shoot Straight Know Your Target . ... | |||
|
| One of Us |
maybe the reticle has shifted? buy another scope and see it that helps. | |||
|
| one of us |
cha-ching! cha-ching! Shall surely shine shoes soon! She sure is keyholing! | |||
|
| One of Us |
All radar tracks and photographs of bullets in flight show that bullet fly in the same orientation as when they leave the barrel. If the barrel is elevated relative to the ground the bullet will come out in the orientation. It's not possible for it to come out facing left, right, backwards or sideways. It stays in the orientation through out it's flight, unless acted up by some other force. Why would you even think that as soon as it leaves the barrel it switches directions or orientation? 500grains is on my ignore list for being who he is, which is not the type of person I like, want to be around, hear from or read anything he has to say, period. | |||
|
| One of Us |
Ever hear of " GRAVITY "!. If the barrel is pointed left or right or up or down that's the direction the bullet travels IN relation to the bore . I see why 500 grains wrote your dumb ass off !. A moron for sure !!!.  | |||
|
| One of Us |
Gravity affects the whole bullet. It doesn't make it change the tip different than the base or vice versa Why would you think the force acts differently on one part differently than the other.Here's some information for you to read up on.\ http://www.nennstiel-ruprecht.de/bullfly/index.htm#Contents http://www.exteriorballistics.com/ebexplained/index.cfm An object in motion will remain in motion unless acted upon by a net force. http://www.ammo-oracle.com/ At ammo oracle look at picture referencing overstability. The picture there will give you an idea of the orientation of bullets throughout it's flight. 500grains is on my ignore list for being who he is, which is not the type of person I like, want to be around, hear from or read anything he has to say, period. | |||
|
| One of Us |
cs273 You are absolutey correct, a bullet does not fly point on. aslo if you are north of the equator the point of the bullet will fly point up and to the right of the center of axis and point up and to the left of center axis if you are south of the equator. Doesn't matter very much for hunting but if you are lobing a artillery 15 miles you better figure it into the equasion. Rich | |||
|
| One of Us |
If it keyholes at 100yds I would be concerned. A bullet has to cover some distance before it stabilizes and 25yds for that bullet isnt far enough. | |||
|
| One of Us |
SOT-away, you simple turkey! I just had my eyes examined by an opthalmologist ("eye doctor" to you), and my five-year old glasses are still correcting to 20/20 (they had been 20/15 five years ago). Palma match sdhooting requires rifles to be fired at a rate of one shot per minute or faster. That kind of shooting WILL cause the bore to deteriorate quicker! And the magnums being discussed are things made for 1,000 yard shooting, like the .30/378 Weatherby. And 400 is still a hell of a lot more than 70, in case you forgot!! "Bitte, trinks du nicht das Wasser. Dahin haben die Kuhen gesheissen." | |||
|
| Powered by Social Strata | Page 1 2 3 4 |
 | Please Wait. Your request is being processed... |
|
The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Rifles Medium Bore Rifles 7mm remington magnum keyholing
Visit our on-line store for AR Memorabilia
