re-crown a barrel?
- Thread starter mattri
- Start date
jonbearman
I live in new york state,how unfortunate !
You have a smith decide how much if any needs to be cut off then a nice sharp crown and you're done.
Here is what I know about it. Some believe a reverse taper of 11 deg. (target crown) is the best. However, others doubt there is any evidence to support this magic angle. The simplest crown is a recess to protect the critical edge of the bore, but a flat profile. Savage factory barrels have this type of crown.
If a crown is cut on a lathe you have to be careful on how it is done. It is fairly normal to not have the bore concentric with the barrel OD. In general lathes have three jaw and 4 jaw chucks. The three jaw self center on the OD of the barrel. If you cut a flat profile then it really does not matter which type is used. However, if you go for the magic 11 deg. target crown, you must ensure the barrel is centered on the bore, not the OD of the barrel. If you don't then you could cut a crown that is not concentric with the bore. So in that case you have to use a 4 jaw chuck and adjust the chuck so it is centered on the bore.
The typical DIY method is to use a pilot in the bore and a hand turned cutter. Pacific Tool and Gauge sells this type of cutter. This can do a good job if you can avoid chatter. The pilot ensures the profile is concentric with the bore. The chatter probably does not affect accuracy, but does look ugly.
If you are only doing one re-crown, it is probably cheaper to have a gunsmith do it.
If a crown is cut on a lathe you have to be careful on how it is done. It is fairly normal to not have the bore concentric with the barrel OD. In general lathes have three jaw and 4 jaw chucks. The three jaw self center on the OD of the barrel. If you cut a flat profile then it really does not matter which type is used. However, if you go for the magic 11 deg. target crown, you must ensure the barrel is centered on the bore, not the OD of the barrel. If you don't then you could cut a crown that is not concentric with the bore. So in that case you have to use a 4 jaw chuck and adjust the chuck so it is centered on the bore.
The typical DIY method is to use a pilot in the bore and a hand turned cutter. Pacific Tool and Gauge sells this type of cutter. This can do a good job if you can avoid chatter. The pilot ensures the profile is concentric with the bore. The chatter probably does not affect accuracy, but does look ugly.
If you are only doing one re-crown, it is probably cheaper to have a gunsmith do it.
If you reload your own ammo and use the Lee Case trimmer tool to trim your brass then you should read my post that is a sticky on another gun forum on one way to recrown a muzzle. Works quite well for me.
http://www.surplusrifleforum.com/viewtopic.php?f=79&t=63966
http://www.surplusrifleforum.com/viewtopic.php?f=79&t=63966
watercam
Silver $$ Contributor
Of the fifteen rifles and one .44 Mag. revolver I own I have recrowned all but two at one point or another. I, like you, started with a project rifle - Mauser 98, short-chambered barrel from Brownell's, hand-turned crowning tool (Brownell's but I would buy the PTG if I were buying another as I think theirs has less chatter - use a drill and some pressure to obtain a smoother cut but save it for the final 'litte bit' at the end), glass and pillar bedding, trigger work, etc.. It all worked out well for me. Referenced several different gunsmithing books (Gunsmith's Kinks from Brownell's are educational as well as humorous).
Several of my match rifles have been recrowned at home and shoot great for my Long Range (800-1000 yds.) competitions ( the guns anyway, I myself still need work!).
Go for it!
Several of my match rifles have been recrowned at home and shoot great for my Long Range (800-1000 yds.) competitions ( the guns anyway, I myself still need work!).
Go for it!
What you are looking for in a crown is a very sharp edge that is the same all around the bore. It may not matter that it is 0 deg. or 11 deg. but it will be quite flat and perfectly uniform.
I would suggest that reamer you posted a link to is like using a meat cleaver to do heart surgery. The only proper way is cut a crown is a lathe with a four jaw chuck, or using a piloted reamer. Yes, there are home grown methods out there like using brass acorn nuts, and marbles, with grinding compound and all sorts of things. But, you are back to the meat cleaver...
If you are going to do it without a lathe, then this is what you need:
I would suggest that reamer you posted a link to is like using a meat cleaver to do heart surgery. The only proper way is cut a crown is a lathe with a four jaw chuck, or using a piloted reamer. Yes, there are home grown methods out there like using brass acorn nuts, and marbles, with grinding compound and all sorts of things. But, you are back to the meat cleaver...
If you are going to do it without a lathe, then this is what you need:
shortgrass
Silver $$ Contributor
A+++ to what Ron said, any other way will just be 'playing'.RonAKA said:What you are looking for in a crown is a very sharp edge that is the same all around the bore. It may not matter that it is 0 deg. or 11 deg. but it will be quite flat and perfectly uniform.
I would suggest that reamer you posted a link to is like using a meat cleaver to do heart surgery. The only proper way is cut a crown is a lathe with a four jaw chuck, or using a piloted reamer. Yes, there are home grown methods out there like using brass acorn nuts, and marbles, with grinding compound and all sorts of things. But, you are back to the meat cleaver...
If you are going to do it without a lathe, then this is what you need:
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