Melonite barrel treatment

[elkaholic]

I don't know about smoothing the bore with a couple dozen copper bullets, that seems like wishful thinking to me.

Now the sharp edges and some burrs from the chamber reamer makes sense. I suspect those are mostly removed by the heat, like a thermal deburring process, not the bullet.

Looks to me like freshly cut throats would be a perfect application for abrasive flow machining. Anyone ever tried that? Then you could send them straight to nitriding.

I suspect it may well be a combination of heat and bullet abrasion, but for whatever reason, it does smooth things out. Iosso is also a VERY good polish for fine tuning. Explain the abrasive flow process if you would.....Rich

 

[Edd]

If there was a gentler and cost effective method that didn't risk damage to the bore, I suspect that method would already be in common use.

Are you a descendant of Charles Duell?

 

[Pdvdh]

I don't know about smoothing the bore with a couple dozen copper bullets, that seems like wishful thinking to me.

Now the sharp edges and some burrs from the chamber reamer makes sense. I suspect those are mostly removed by the heat, like a thermal deburring process, not the bullet.

Looks to me like freshly cut throats would be a perfect application for abrasive flow machining. Anyone ever tried that? Then you could send them straight to nitriding.

I will add this. When I break in my new barrels, I visually see copper laid down the full length of the bore, visible at the muzzle with the initial shots. And on a custom barrel, that quantity of copper is visually reduce with each following shot. So I personally believe the entire bore is being lapped in the direction of bullet travel. Such that the result is the entire length of the bore is improved to the point that very little copper stripping occurs, after bullet lapping break in of the new bore. There may be larger imperfections caused by the chamber reamer or the crowning tools, but to my eyes, the entire bore surface is markedly improved with as few as 6 bullets being fired against a spanking clean bore. Lesser quality barrels may require 12 or 20 shots to yield the same improvement. Some bores won't condition and clean up no matter how many bullets fired, in my experience. I give up after about 25 shots.

 

[Edd]

I will add this. When I break in my new barrels, I visually see copper laid down the full length of the bore, visible at the muzzle with the initial shots. And on a custom barrel, that quantity of copper is visually reduce with each following shot. So I personally believe the entire bore is being lapped in the direction of bullet travel. Such that the result is the entire length of the bore is improved to the point that very little copper stripping occurs, after bullet lapping break in of the new bore. There may be larger imperfections caused by the chamber reamer or the crowning tools, but to my eyes, the entire bore surface is markedly improved with as few as 6 bullets being fired against a spanking clean bore. Lesser quality barrels may require 12 or 20 shots to yield the same improvement. Some bores won't condition and clean up no matter how many bullets fired, in my experience. I give up after about 25 shots.

From the Krieger website...............Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is removed from the jacket material and released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this plasma and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat. If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it, copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat "polished" without allowing copper to build up in the bore. This is the reasoning for the "fire-one-shot-and-clean" procedure.

 

[Pdvdh]

Are you a descendant of Charles Duell?

Ouch. That hurt. Actually it was the time it took to Google 'Charles Duell' that hurt.

If you're prepared to share a breakthrough process that is both cost effective and works as well or better than what's currently practiced and recommended by virtually every custom barrel manufacturer in the U.S., and used by bench rest competitors and hunters alike, please lead the way...

Many things can be accomplished is enough money is invested into the effort. But if the cost required to achieve the end result exceeds the cost the retail market will profitably support, the invention will typically receive little use. Maybe that's what Charles Duell meant to say.

 

[elkaholic]

From the Krieger website...............Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is removed from the jacket material and released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this plasma and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat. If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it, copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat "polished" without allowing copper to build up in the bore. This is the reasoning for the "fire-one-shot-and-clean" pro
edure.

Ya, I've read this too. Again, could you explain the abrasive flow process? ...Rich

 

[elkaholic]

Ouch. That hurt. Actually it was the time it took to Google 'Charles Duell' that hurt.

If you're prepared to share a breakthrough process that is both cost effective and works as well or better than what's currently practiced and recommended by virtually every custom barrel manufacturer in the U.S., and used by bench rest competitors and hunters alike, please lead the way...

Many things can be accomplished is enough money is invested into the effort. But if the cost required to achieve the end result exceeds the cost the retail market will profitably support, the invention will typically receive little use. Maybe that's what Charles Duell meant to say.

I guess I'm just a "Red neck bullet slinger" but who the !!!!!! is Charles Duell?

 

[Pdvdh]

From the Krieger website...............Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is removed from the jacket material and released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this plasma and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat. If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it, copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat "polished" without allowing copper to build up in the bore. This is the reasoning for the "fire-one-shot-and-clean" procedure.

I'm sorry. I should have stated I've read Krieger's web site, Lilja's web site, and additional barrel manufacturer's web sites. Does Krieger's web site state if their commentary applies to all brands and quality of barrels? And more importantly, do they provide barrel break-in advice prior to melonite treatment that differs from the bullet firing break-in method being described in this Thread?

 

[Edd]

Explain the abrasive flow process if you would.....Rich

It's a process where an abrasive media could be pushed thru the barrel to deburr and polish the throat. Google Abrasive Flow Machining and you can read until you get tired of reading.

 

[Edd]

I'm sorry. I should have stated I've read Krieger's web site, Lilja's web site, and additional barrel manufacturer's web sites. Does Krieger's web site state if their commentary applies to all brands and quality of barrels? And more importantly, do they provide barrel break-in advice prior to melonite treatment that differs from the bullet firing break-in method being described in this Thread?

Unless Krieger has changed their mind in the last 90 days, they won't give their blessing to nitriding.

 

[Pdvdh]

It's a process where an abrasive media could be pushed thru the barrel to deburr and polish the throat. Google Abrasive Flow Machining and you can read until you get tired of reading.

Does Krieger bless the abrasive flow machine method for polishing the throats in their barrels?

 

[Edd]

Does Krieger bless the abrasive flow machine method for polishing the throats in their barrels?

I've never asked them. I've not heard of anyone using AFM on rifle barrels.

 

[elkaholic]

I've never asked them. I've not heard of anyone using AFM on rifle barrels.

I beg to differ but I spoke with Mike at Krieger about a week ago and I think it depends on "what is is?" Here is what Mike told me: "We don't endorse it at Kreiger because we don't want to be liable for other peoples work, but if done properly, I think it is a very worthwhile process"! He said the problem is, if done by someone who is not a professional, the heat necessary for the process to work is very close to the point where the barrel will lose its temper. He also said that Joel Kendrick is the best and he trusts his work.....Rich

 

[Edd]

I beg to differ

Who is using the AFM process?

but I spoke with Mike at Krieger about a week ago and I think it depends on "what is is?" Here is what Mike told me: "We don't endorse it at Kreiger because we don't want to be liable for other peoples work, but if done properly, I think it is a very worthwhile process"! He said the problem is, if done by someone who is not a professional, the heat necessary for the process to work is very close to the point where the barrel will lose its temper. He also said that Joel Kendrick is the best and he trusts his work.....Rich

That's pretty much what they told me about 90 days ago. I don't know who I was talking to. Whoever it was also said he had been considering getting some barrels done for testing.