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Can ya'll explain the function of a muzzle 'crown' to me?

robert38-55robert38-55 Senior MemberPosts: 3,621 Senior Member
OK, I know this subject has been posted here before, but I really didn't take an interest in it then. Anyway the thing is I would like some firearm education on what is main purpose of a muzzle/barrel crown, how is it determined, and/or deteremined for rifle and handgun. What happens to the gun be it rifle or handgun is the crown is altered, or modified or damaged? Bare with me fellows I am old and slow, not to mentioned somewhat ugly too at my old age...:silly::roll2::roll2::roll2::roll2: I have also read here that you gals and pals, are very careful when ya clean your guns,not to damage the crown....Thanks....

The other question I have while reading Snake's post on the brake, if you have a muzzle brake installed on your rifle,does the brake have the same crown at the end of it like the original rifle?
"It is what it is":usa:

Replies

  • LMLarsenLMLarsen Senior Member Posts: 8,337 Senior Member
    A trued muzzle crown ensures that the bullet exits the barrel consistently on all surfaces, and thus should fly straight. I'm sure that someone else can explain it better, but that's my take on it.
    “A gun is a tool, no better or no worse than any other tool: an axe, a shovel or anything. A gun is as good or as bad as the man using it. Remember that.”

    NRA Endowment Member
  • breamfisherbreamfisher Senior Member Posts: 13,490 Senior Member
    Properly speaking, the crown is the recessed or domed area around the muzzle that protects the muzzle from damage. Properly done, the muzzle of a rifled barrel will be on a plane perpendicular to the travel of the bullet, to allow for equal gas venting and stabilization of the bullet. The muzzle is the last point of contact between the barrel and the bullet, and your last chance of stabilizing the bullet. A damaged or poorly cut crown will stabilize one side of the bullet after it releases on the other, and could impart a wobble into the bullet. Likewise a damaged muzzle. Likewise, muzzles in bad condition will destabilize the bullet due to a burr, nick, or uneven area of wear causing uneven release.

    Properly done, a good muzzle will leave equal plumes of carbon on the crown.

    crown.png
    Overkill is underrated.
  • NNNN Senior Member Posts: 24,665 Senior Member
    The other question I have while reading Snake's post on the brake, if you have a muzzle brake installed on your rifle,does the brake have the same crown at the end of it like the original rifle?
    Some do some don't, with degrees of perfection in between.
    Shut up-----KAREN; OK Cynthia
  • woodsrunnerwoodsrunner Senior Member Posts: 2,725 Senior Member
    Just to complicate things a little, with muzzleloaders there is a practice called "coning" a muzzle. With this the muzzle is bored out slightly to allow a patched roundball to be initially pushed down into the muzzle with your fingers then set down the bore with the rod. This prevents wear and potential damage to the muzzle with ramrods or short starters. This has to be done very carefully and requires some fine tunning usually, but is worth the effort. Don't know if coning a muzzle would have any positive application with cartridge firearms, but doubt that it would.
  • TeachTeach Senior Member Posts: 18,428 Senior Member
    Since nothing is supposed to be inserted into the muzzle of a breechloader (not even a cleaning rod if the chamber is accessible) there would be no reason to relieve the rifling. The traditional muzzle crown was rounded, done by a specially-shaped lathe cutting tool, until fairly recently. Now it's popular to put an 11 degree taper from the edge of the barrel toward the rifling so the taper protects the place where the bullet exits from nicks or damage if the muzzle gets bumped accidentally. The idea is to vent the gases equally around the base of the bullet as it leaves the rifling.
    Jerry
  • snake284-1snake284-1 Senior Member Posts: 2,500 Senior Member
    OK, I know this subject has been posted here before, but I really didn't take an interest in it then. Anyway the thing is I would like some firearm education on what is main purpose of a muzzle/barrel crown, how is it determined, and/or deteremined for rifle and handgun. What happens to the gun be it rifle or handgun is the crown is altered, or modified or damaged? Bare with me fellows I am old and slow, not to mentioned somewhat ugly too at my old age...:silly::roll2::roll2::roll2::roll2: I have also read here that you gals and pals, are very careful when ya clean your guns,not to damage the crown....Thanks....

    The other question I have while reading Snake's post on the brake, if you have a muzzle brake installed on your rifle,does the brake have the same crown at the end of it like the original rifle?

    Robert, as was said, the crown is the last part of the barrel and it is critical in that if it is chipped or untrue in anyway, it can cause the bullet to fly off course. The purpose of crowning it as such is to protect the last bit of the lands from damage. That's why the crown extends past the rifling. Then if you dropped your rifle barrel downward there is metal out in front to hopefully guard the rifling from damage. That's why it's called the Crown. I hope this answeres your question. Keep plowing Robert, you've got the right idea. You gotta ask questions to learn and you ask some good questions.

    OK Never mind, see Teaches explanation above. I usually read above before posting but I got in a hurry.
    I'm Just a Radical Right Wing Nutt Job, Trying to Help Save My Country!
  • snake284-1snake284-1 Senior Member Posts: 2,500 Senior Member
    NN wrote: »
    Some do some don't, with degrees of perfection in between.

    Yeah Robert, the brake itself acts as the crown. Seeing that the brake is usually well over 1 inch long, it protects the last bit of rifling. Because the inside of the brake is slightly larger in diameter than the bore, there is no rifling in the brake. The brake allows the gas to disapate through the openings in the brake more or less perpendicular to the flight of the bullet. This dampens recoil because most felt recoil is actually the jet affect of the gas exiting the barrel when the bullet clears it. The gas actually creates thrust like a rocket which directs the rifle backward into your shoulder. This is felt recoil. If you expell the gases perpendicular to the barrel instead of straight out the front of the barrel, it eliminates most of the rearward thrust of the firearm into your shoulder.
    I'm Just a Radical Right Wing Nutt Job, Trying to Help Save My Country!
  • JayhawkerJayhawker Moderator Posts: 16,861 Senior Member
    The other question I have while reading Snake's post on the brake, if you have a muzzle brake installed on your rifle,does the brake have the same crown at the end of it like the original rifle?

    Here's a look at the business end of my FTE brake...

    thFTE003av.jpg

    the barrel still has a recessed crown...so actually (on my rifle at any rate) both the brake and the barrel are crowned...
    Sharps Model 1874 - "The rifle that made the west safe for Winchester"
  • snake284-1snake284-1 Senior Member Posts: 2,500 Senior Member
    Jayhawker wrote: »
    Here's a look at the business end of my FTE brake...

    thFTE003av.jpg

    the barrel still has a recessed crown...so actually (on my rifle at any rate) both the brake and the barrel are crowned...

    I always thought that the main function of a bevel or crown on a brake was mainly cosmetic, however an uneven surface at the end of the brake might cause inaccuracy too. So I guess a crown on the end is worth the trouble, even when the rifling is well back of the end.
    I'm Just a Radical Right Wing Nutt Job, Trying to Help Save My Country!
  • sarg1csarg1c Senior Member Posts: 1,707 Senior Member
    snake284-1 wrote: »
    Robert, as was said, the crown is the last part of the barrel and it is critical in that if it is chipped or untrue in anyway, it can cause the bullet to fly off course. The purpose of crowning it as such is to protect the last bit of the lands from damage. That's why the crown extends past the rifling. Then if you dropped your rifle barrel downward there is metal out in front to hopefully guard the rifling from damage. That's why it's called the Crown. I hope this answeres your question. Keep plowing Robert, you've got the right idea. You gotta ask questions to learn and you ask some good questions.

    OK Never mind, see Teaches explanation above. I usually read above before posting but I got in a hurry.



    Good post snake, you also teach... , you have described the real reason for a recessed crown, which many older rifles did not have. when I cut the barrel on my M/N, I had to make sure it was cut square and re crowned. I did not recess the cron but realy, it shoud have been. If you must clean from the muzzle a good guide should be used...
    Breamfisher, I liked your explanation... make sense.
    With these explanations, Robert should understand the importance of a crown and what it's for...
  • JasonMPDJasonMPD Senior Member Posts: 6,538 Senior Member
    The crown is nothing more than the terminus of the barrel at the business end. The vertical and horizontal planes of the crown must be completely, truly perpendicular to the lengthwise axis of the bore to facilitate the bullet leaving contact with the bore simultaneously around the bullet's entire circumference.

    Recessing the crown is done to protect the bore crown from contact with objects that may damage it.
    “There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves.” – Will Rogers
  • robert38-55robert38-55 Senior Member Posts: 3,621 Senior Member
    :tooth::tooth::applause: Ok instead of answering each individually a Great Big Thanks for all the information you folks offered here. Heck Ya'll just answered some question, that I though of on this subject after I logged off. Anyway sometimes when I read an article in a gun magazine, I don't always understand/get it the first time I read it. I have to go back and re-read it, sometimes seveal times... Anyway I ain't never seen that many article published on the importance of muzzle crowns and their importance to proper firearm perfomance... Again a Great big Thanks fellows.. It's usually a quicker to post and ask here as opposed to researching it...and it's a lot more fun!!!!

    After I read the replys here I actually went and looked a some of my rifles,guns and I could see exactly what you fellows were telling me!!!!!!! I did notice too, that my muzzle loading rifles, didn't actually have a crown on them,like woodsrunner stated..interesting,very interesting....but true! Heres what else I took note of while looking at the muzzles of some of my guns.. Shotguns ain't got no crown do they? Handguns have crown? And is the 11*degree pretty much standard for all calibers of rifles?

    Now don't anyone here take what I am about to write the wrong way.. So one just can't saw the barrel of a rifle,(and I don't know why anyone would),
    take the rifle with the shortened barrel to the range and expect it to do what it's supposed to do. If one did that,then they just ruined the gun I guess. You would have to have the business end of your rifle re-crowned, which is possible with the right tools and right gunsmith..
    "It is what it is":usa:
  • sarg1csarg1c Senior Member Posts: 1,707 Senior Member
    Sawing a barrel off is not a good pratice, shortening a barrel is ok if machine cut true and recrowned. Yes a muzzle loader is crowned, may not be recessed but will be crowned.Think of a barrel crown as a champher or counter sink at the barrel's end.
  • mkk41mkk41 Banned Posts: 1,932 Senior Member
    Also why a perfectly formed boattail , or square base on a bullet is so important to accuracy.
    Teach wrote: »
    Since nothing is supposed to be inserted into the muzzle of a breechloader (not even a cleaning rod if the chamber is accessible) there would be no reason to relieve the rifling. The traditional muzzle crown was rounded, done by a specially-shaped lathe cutting tool, until fairly recently.
    Jerry

    Which is why there is a MW or muzzle wear gage for M1 Garands. That sectioned hard steel parkerized(abrasive) GI cleaning rod probably does more damage to the barrels muzzle that any amount of shooting.
  • snake284-1snake284-1 Senior Member Posts: 2,500 Senior Member
    Robert, don't feel like the "Lone Ranger's aaah, Horse!" for lack of a better term. I don't care who you are or how long you been doing something, just about the time you start to think you may have written the book on the subject, some yeawho will come along and body slam your ego.

    How long I been loading, what! over 30 years now? And I had so much confidence in my knowledge level, because I have loaded many different cartridges with excellent results and one day about 3-4 years back on here we were discussing shooting 30-06 ammo in a 7.7 **** rifle that had the chamber reamed to fit 30-06 cartridges. We were talking about how to make it more accurate in that the 06 bore is .308 and the **** rifle's bore diameter is arould .311. Then Teach pops in and says just get bigger expander ball. Well "DUH!!!" LOL! I never woulda thunk it!!! Why didn't I think of that???

    Because I had never had reason to do it and never thought through that particular scenario.

    I have been blindsided on other very obvious problems. Like I say, if you've never crossed a certain bridge, you may not have a clue. Because I don't care how smart you are, you ain't never going to think of everything from every perspective. It's almost an impossibility because our brains are not usually programed to think around corners, LOL!!! The only thing you can do as a one cylinder human being is keep reading and asking questions and you should be alright. If anything I ever did has worked well for me, that's it.

    Enquiring minds need to know!

    :silly::roll2::rotflmao:
    I'm Just a Radical Right Wing Nutt Job, Trying to Help Save My Country!
  • TeachTeach Senior Member Posts: 18,428 Senior Member
    The guy I've been coaching through his learning curve for reloading likes short barrels for some reason- - - - -REALLY short ones! He wants me to shorten and re-crown a barrel on a rifle he just bought, down to 20" on a Tikka .308. No problem- - - -I'm glad to do it, and since he's shooting virtual one-holers with a .308 Savage Tactical set up that way, I'm not going to criticize his decision!
    Jerry
  • snake284-1snake284-1 Senior Member Posts: 2,500 Senior Member
    Teach, on most of my rifles I prefer the barrel on the long side. However, in my limited experience with .308s they seem to burn most of their powder inside 20 inches and extra barrel length doesn't seem to help much. Use of a faster burning powder such as IMR 4064 can net velocities as good as something like IMR or H- 4350. Actually, I think shorter barrels are more conducive to ultra accuracy. I've seen a coupe of .308s with 20 inch barrels shoot one hole groups all day. A short, fat accurate barrel on a well tuned action makes a .308 scary accurate.
    I'm Just a Radical Right Wing Nutt Job, Trying to Help Save My Country!
  • breamfisherbreamfisher Senior Member Posts: 13,490 Senior Member
    I hope Pegasus, with is 31? inch barrel doesn't read that, because it goes against most everything he's observed.
    Overkill is underrated.
  • robert38-55robert38-55 Senior Member Posts: 3,621 Senior Member
    snake284-1 wrote: »
    Robert, don't feel like the "Lone Ranger's aaah, Horse!" for lack of a better term. I don't care who you are or how long you been doing something, just about the time you start to think you may have written the book on the subject, some yeawho will come along and body slam your ego.

    How long I been loading, what! over 30 years now? And I had so much confidence in my knowledge level, because I have loaded many different cartridges with excellent results and one day about 3-4 years back on here we were discussing shooting 30-06 ammo in a 7.7 **** rifle that had the chamber reamed to fit 30-06 cartridges. We were talking about how to make it more accurate in that the 06 bore is .308 and the **** rifle's bore diameter is arould .311. Then Teach pops in and says just get bigger expander ball. Well "DUH!!!" LOL! I never woulda thunk it!!! Why didn't I think of that???

    Because I had never had reason to do it and never thought through that particular scenario.

    I have been blindsided on other very obvious problems. Like I say, if you've never crossed a certain bridge, you may not have a clue. Because I don't care how smart you are, you ain't never going to think of everything from every perspective. It's almost an impossibility because our brains are not usually programed to think around corners, LOL!!! The only thing you can do as a one cylinder human being is keep reading and asking questions and you should be alright. If anything I ever did has worked well for me, that's it.

    Enquiring minds need to know!

    :silly::roll2::rotflmao:

    Hey Snake that's some good advice Thanks. Allow me to tell everyone here a little something about Robert. One thing I learned very early in life is this: 'If ya don't know, then ya don't know, and it would be good insurance to ask someone that does. Now I will admit that I don't have near the gun experience,that you and others have here and granted some of my inquires may seem a little elementary and basic to a lot here, but heck that don't bother me... I will not under any circumstances, attempt to alter, modify, change, experiment with any of my guns or with reloading equipment unless I can fully understand and predict what the outcome will be, you know to a reasonable degree. It's just to dangerous for a non gunsmith person like me, and a non expirenced gun builder like me to do so... When I get proper guidance from gun folks, and proper training from formal gun smithing schools, then I might try to build some rifles, or tweet, a gun of mine. But for now I am just happy to post, and gather data, and information.. I ain't fussing at anyone here I am actually agreeing with ya snake.... Also currently I don't have the proper space, nor the proper tooling to do the things to my guns that you guys do.....And above my advice to myself and others is this, IF YA DON'T KNOW WHAT YOUR DOING, THEN YOU PROBABLY SHOULDN'T DO IT....especially to a gun or a handloaded cartridge..... in other words, ask first and live, as opposed to do first and maybe loose an eye or a hand or even get yourself and others killed,for no reason!!!!

    Anyway a Great Big Thanks to all that answer my gun and ammo questions.. This thread was really a good learning experience for me!!!!!!!!!!!!!
    "It is what it is":usa:
  • sarg1csarg1c Senior Member Posts: 1,707 Senior Member
    Teach, you probably read the same article in one of these gun rag about short barrels being just as accurate or maybe more so because the barrel will not viberate as much as a long sporting taperd barrel. Did you read this?....I would have to go back to tell you which Rag had this .I often pass my Magazine on to someone less fortunate or maybe the barber shop.
  • TeachTeach Senior Member Posts: 18,428 Senior Member
    About 40 years ago, the American Rifleman magazine ran a series of articles on the .243 where they started cutting one inch at a time off the barrel and doing a LOT of shooting with it, both factory ammo and reloads after each cut and recrown job. With the factory ammo and reloading powders available at that time, they got a steady decrease in muzzle velocity, but no big difference in accuracy. Today's guns, ammo and reloading components are a whole different kettle of fish. It's possible to fine-tune just about any length barrel to give outstanding accuracy, as Ernie has proved many times with those hand cannons of his!
    Jerry
  • RazorbackerRazorbacker Senior Member Posts: 4,646 Senior Member
    Teach wrote: »
    About 40 years ago, the American Rifleman magazine ran a series of articles on the .243 where they started cutting one inch at a time off the barrel and doing a LOT of shooting with it, both factory ammo and reloads after each cut and recrown job. With the factory ammo and reloading powders available at that time, they got a steady decrease in muzzle velocity, but no big difference in accuracy. Today's guns, ammo and reloading components are a whole different kettle of fish. It's possible to fine-tune just about any length barrel to give outstanding accuracy, as Ernie has proved many times with those hand cannons of his!
    Jerry
    I'm 51 yrs old so I can't say I remember that particular article from AR. At least if it was in fact 40 yrs ago. However I do remember an article like that. It was mostly velocity specific IIRC. Also if IRRC they used a hack saw to cut the barrel down. Taking no particular care. Then they trued up the barrel with a square and a file. Then re crowned it each time using a near field expedient method of an old fashioned hand cranked drill, rotating it with compound to slick it up.
    I think that famous advocate of the .270, (who's name is to sacred to be spoken), may even have referenced this in some of his writings. Again in the context of arguing barrel length and velocity.
    Teach your children to love guns, they'll never be able to afford drugs
  • PegasusPegasus Senior Member Posts: 2,749 Senior Member
    snake284-1 wrote: »
    Teach, on most of my rifles I prefer the barrel on the long side. However, in my limited experience with .308s they seem to burn most of their powder inside 20 inches and extra barrel length doesn't seem to help much. Use of a faster burning powder such as IMR 4064 can net velocities as good as something like IMR or H- 4350. Actually, I think shorter barrels are more conducive to ultra accuracy. I've seen a coupe of .308s with 20 inch barrels shoot one hole groups all day. A short, fat accurate barrel on a well tuned action makes a .308 scary accurate.

    Actually, in the .308 all the powder that's going to burn is consumed before the bullet has gone down the bore just a few inches. Extra barrel length helps a great deal, which is probably why you do not see short-barreled rifles at Palma of LR F-class competitions. The vast majority of the competitors will have barrels around 30 inches long. I have just finished building my new F-T/R match rifle (pictures soon,) and it sports a 32 inch barrel, just like my current rifle. With the extra 8 inches from 24, I get about 200FPS more velocity compared to load manual velocities, so much so that my 180gr bullets are traveling at the low end of .300 Win Mag velocities, from a .308.

    And I can do this without going over max on the loads. My philosophy is to let the barrel do its job.

    Also, it is easier to find accuracy nodes with a long barrel because the internal resonance has a lot more tube to travel so when the bullet exists the muzzle the resonance wave is more often away from the muzzle in a long barrel compared to a short one. Yes, you can get a great short fat barrel to be scary accurate, but I'm not really into grouping my shots into the ground a few hundred yards from the target because the bullets can't get to the target.

    Bottom line is, you get the barrel that will fit your needs. Unlike the vast majority here, I need long barrels to reach my target two zipcodes over.
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