Post by MarkKw on Oct 22, 2004 7:12:36 GMT -5
Pretty much a reply to the coning thread below but with a twist. This came up on some other MB's a while ago and my mention of "non-traditional" rifles got some shall we say, offended. Hopefully since this MB has section for all rifles, no one here will be offended.
My experience with front stuffers is quite less than that of many people here but I do have a lot of rifle time and most of that time was spent making "cheap junk" functional again, mostly center fires but some ML's too. With this in mind, please bear with my references and examples.
First off, I see a lot of differing opions on crowns no matter what type of rifle is being discussed. Step, cone, bullnose, round, taper.... you get the idea. There are those who say a CF match rifle cannot possibly be worth anything without an X degree step crown recessed .XXX inches yet there have been many a match winning rifles with nothing more than a simple bull nose crown. Working with damaged bores is one way of learning OJT style. Many military rifles have considerable damage to the muzzle from excessive and improper cleaning. I've repaired these in two ways, one being to remove the damaged section and the other is to "cone" or "step" it when you don't want to loose barrel length such as those barrels with the front sight and bayonet lug being an integral part of the barrel.
A barrel can easily be cut and filed square with the bore taking your time and watching what you're doing. Putting a crown back on can be easier than the cutting, using a brass round head, strait slot machine screw in a hand drill works quite well. The slot holds grinding/lapping compound while the radious of the head gives a nice bullnose crown. If you prefer a tapered look, you can use a flat head screw whose shank fits the bore properly and drive as would normally be done using it as a screw. The key thing is to knock off the sharp edges of the rifling lands with a small file before trying to crown or cone but do not get beyond the finish depth.
Proper counter boring and crowning should be done on a lathe but many of us simply don't have that option, thus we make due with what we have or can justify spending. Pilot reamers make for excellent counter bores and can be had for around $15 each for decent quality ones. The basic design of the cutting surface of these produces a dandy modified step crown on the initial cut. Shaping a hardwood dowel (I prefer white oak or white ash) the same as the reamer only sized about .003" bigger makes for an excellent lapp to polish up the cut to a finished surface.
From my experience, keeping the muzzle square & symetrical is far more important than what type crown is used. Most of the ML's I've worked on that had patch cutting problems were caused by abrupt crowns as in too fast a transition to rifling lands while some were nothing more than rough/sharp cut rifling. I'm not fond of coning with sand paper / emory cloth simply because there is way too much variation in the thickness of the abrasive coating. It is perfectly fine for hogging or roughing the shape but should not be used for the final finish. All it takes is getting a gouge from an oversized grain of abrasive or a lump in the adheasive holding the abrasive to the paper/cloth and you have problems. The final finish should be achived by lapping with a good quality fine grained compound. The finer the grain, the better the surface. I use Clover brand compound, costs a little more but it has proven to be much higher quality than others.
Not to dicount coning, if done right, it is nothing more than an extended length crown. I would not be too quick to suggest it unless you have serious loading issues though. I would start with extending the taper of the crown first by using the "high tech" flat head screw. If you have patch cutting prblems, you need to first identify if the cutting is being done at the muzzle or in the bore. This is easy to check by starting a PRB with a short starter then using air/CO2 to pop it out into a bucket of rags or such so you don't add damage. If it's cut, it's happening at the muzzle, if not cut, it's being done down the bore somewhere.
Minor bore lapping can be done with simple scotch pad run in and out of the bore full length but I prefer to use leather lapp disks I make myself. Using disks helps eliminate getting a tight spot on one side of the bore which will cause un-even material removal. No matter what lapp you use, always be sure to completely clean the bore when you are done. I highly suggest a liberal solvent scrub and flush followed by a hot water detergent scrub and flush to ensure all abrasives are removed completely.
On a side note, if you're looking for a little easier loading for a hunting situation, try going with a little looser patch/ball combo and putting a wad between the ball and powder. I started using pre-lubed fiber wads from Circle Fly and what a difference they make. I can start my patch ball combo with the RR and slide it home in one smooth motion yet still print groups under 2" @ 100 off the bench and with my eyes seeing the sights clearly.
My experience with front stuffers is quite less than that of many people here but I do have a lot of rifle time and most of that time was spent making "cheap junk" functional again, mostly center fires but some ML's too. With this in mind, please bear with my references and examples.
First off, I see a lot of differing opions on crowns no matter what type of rifle is being discussed. Step, cone, bullnose, round, taper.... you get the idea. There are those who say a CF match rifle cannot possibly be worth anything without an X degree step crown recessed .XXX inches yet there have been many a match winning rifles with nothing more than a simple bull nose crown. Working with damaged bores is one way of learning OJT style. Many military rifles have considerable damage to the muzzle from excessive and improper cleaning. I've repaired these in two ways, one being to remove the damaged section and the other is to "cone" or "step" it when you don't want to loose barrel length such as those barrels with the front sight and bayonet lug being an integral part of the barrel.
A barrel can easily be cut and filed square with the bore taking your time and watching what you're doing. Putting a crown back on can be easier than the cutting, using a brass round head, strait slot machine screw in a hand drill works quite well. The slot holds grinding/lapping compound while the radious of the head gives a nice bullnose crown. If you prefer a tapered look, you can use a flat head screw whose shank fits the bore properly and drive as would normally be done using it as a screw. The key thing is to knock off the sharp edges of the rifling lands with a small file before trying to crown or cone but do not get beyond the finish depth.
Proper counter boring and crowning should be done on a lathe but many of us simply don't have that option, thus we make due with what we have or can justify spending. Pilot reamers make for excellent counter bores and can be had for around $15 each for decent quality ones. The basic design of the cutting surface of these produces a dandy modified step crown on the initial cut. Shaping a hardwood dowel (I prefer white oak or white ash) the same as the reamer only sized about .003" bigger makes for an excellent lapp to polish up the cut to a finished surface.
From my experience, keeping the muzzle square & symetrical is far more important than what type crown is used. Most of the ML's I've worked on that had patch cutting problems were caused by abrupt crowns as in too fast a transition to rifling lands while some were nothing more than rough/sharp cut rifling. I'm not fond of coning with sand paper / emory cloth simply because there is way too much variation in the thickness of the abrasive coating. It is perfectly fine for hogging or roughing the shape but should not be used for the final finish. All it takes is getting a gouge from an oversized grain of abrasive or a lump in the adheasive holding the abrasive to the paper/cloth and you have problems. The final finish should be achived by lapping with a good quality fine grained compound. The finer the grain, the better the surface. I use Clover brand compound, costs a little more but it has proven to be much higher quality than others.
Not to dicount coning, if done right, it is nothing more than an extended length crown. I would not be too quick to suggest it unless you have serious loading issues though. I would start with extending the taper of the crown first by using the "high tech" flat head screw. If you have patch cutting prblems, you need to first identify if the cutting is being done at the muzzle or in the bore. This is easy to check by starting a PRB with a short starter then using air/CO2 to pop it out into a bucket of rags or such so you don't add damage. If it's cut, it's happening at the muzzle, if not cut, it's being done down the bore somewhere.
Minor bore lapping can be done with simple scotch pad run in and out of the bore full length but I prefer to use leather lapp disks I make myself. Using disks helps eliminate getting a tight spot on one side of the bore which will cause un-even material removal. No matter what lapp you use, always be sure to completely clean the bore when you are done. I highly suggest a liberal solvent scrub and flush followed by a hot water detergent scrub and flush to ensure all abrasives are removed completely.
On a side note, if you're looking for a little easier loading for a hunting situation, try going with a little looser patch/ball combo and putting a wad between the ball and powder. I started using pre-lubed fiber wads from Circle Fly and what a difference they make. I can start my patch ball combo with the RR and slide it home in one smooth motion yet still print groups under 2" @ 100 off the bench and with my eyes seeing the sights clearly.
