Orange Dust
Well-Known Member
Never heard of it before. Ill study up on it. Thanks for the tip. HBN is a pain, but it does work really well if you do it right.
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Clean cold MOI
- Thread starter James DeTorre
- Start date
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Ditto
Orange Dust
Well-Known Member
I think I'm going to give it a try, at least in my AR. I don't use HBN in those things. the one I have in .22 Nosler will be a perfect candidate. It is very accurate.
Please, someone, what is HBN?
Orange Dust
Well-Known Member
Hexigonal Boron Nitride. Best place to learn about what it is and does is David Tubb's website.
I have had pretty good success maintaining cold bore accuracy, quite critical for LRH and PRS competition. While I have a few rifles that could do this from a "clean' and cold bore, I will still prepare with a fouled bore, generally 2-6 shots fired from the rifle. It's also important to understand how many shots can be fired, holding cold bore accuracy, between cleanings. For my PRS rifles, this is a minimum of 200 shots, my hunters, a minimum of 40 shots....All this with group size and cold bore shot contained within .5MOA with velocity within an SD of 10. While this may sound like a tall order, or even BS, it's quite possible to achieve this. My basic approach:
-Start with a good barrel that has been properly broken in and demonstrated stabilized velocities. This can be 20-200 rounds fired. While I have achieved sufficiently good results with factory barrels, it can be hit or miss and my best results have come from quality custom barrels.
-Develop a load that that has been optimized with a maximum for a minimum of .5MOA at the maximum range of use with no more then a 6FPS change in velocity per .1gr change in charge weight over a .5gr range. Of course, other "best practices" practices with load development( runout, neck tension, etc) should be followed. All this may take some time and effort, but IMO, it's well worth it for LR Precision work. As with barrels, one can be lucky and find a factory load that can meet these requirements but it's hit or miss, and lot to lot differences can reek havoc.
-Consistency in the cleaning regiment is important, I will use a good solvent like Boretech Eliminator, visually removing carbon and copper using a bore scope. I then run a patch of a Montana Blend Bore Conditioner, wipe with a clen patch. Unless, the rifle will be stored or the bore subjected to the elements, I will only clean when I get close to the shot numbers previously mentioned.
-For fouling, I will simply fire the number of rounds required to bring the group on zero, and stabilize velocity. At this point I will test the number of shots before the accuracy and or bold bore falls out. With a good barrel/load, this can be surprisingly high,
but I will avoid overdoing it as to avoid excess copper build up or a carbon ring.
I do not use any of the coatings like Moly or HBN preferring to keep the process simple. There have been some cases where no matter what I do, I can't keep my cold bore in the central group. If it's a consistent cold bore placement, I may use the rifle and make the sighting adjustment, but will usually either continue working on the load, or scrap the barrel......I set there are lots of ways to skin this cat.....this works for me.
Shown:my PRS rifle. At 200 yards.
-Start with a good barrel that has been properly broken in and demonstrated stabilized velocities. This can be 20-200 rounds fired. While I have achieved sufficiently good results with factory barrels, it can be hit or miss and my best results have come from quality custom barrels.
-Develop a load that that has been optimized with a maximum for a minimum of .5MOA at the maximum range of use with no more then a 6FPS change in velocity per .1gr change in charge weight over a .5gr range. Of course, other "best practices" practices with load development( runout, neck tension, etc) should be followed. All this may take some time and effort, but IMO, it's well worth it for LR Precision work. As with barrels, one can be lucky and find a factory load that can meet these requirements but it's hit or miss, and lot to lot differences can reek havoc.
-Consistency in the cleaning regiment is important, I will use a good solvent like Boretech Eliminator, visually removing carbon and copper using a bore scope. I then run a patch of a Montana Blend Bore Conditioner, wipe with a clen patch. Unless, the rifle will be stored or the bore subjected to the elements, I will only clean when I get close to the shot numbers previously mentioned.
-For fouling, I will simply fire the number of rounds required to bring the group on zero, and stabilize velocity. At this point I will test the number of shots before the accuracy and or bold bore falls out. With a good barrel/load, this can be surprisingly high,
but I will avoid overdoing it as to avoid excess copper build up or a carbon ring.
I do not use any of the coatings like Moly or HBN preferring to keep the process simple. There have been some cases where no matter what I do, I can't keep my cold bore in the central group. If it's a consistent cold bore placement, I may use the rifle and make the sighting adjustment, but will usually either continue working on the load, or scrap the barrel......I set there are lots of ways to skin this cat.....this works for me.
Shown:my PRS rifle. At 200 yards.
snox801
Well-Known Member
Well that has nothing to do with your cleaning. I mean it is a creedmore btw.
Most will shoot that groups at 1000 without even trying.
snox801
Well-Known Member
I have had some hbn for a while now just haven't used it. Think I may try it with the 390gr atips in my .375 AM.
Orange Dust
Well-Known Member
Clean the bore to the bare metal, and I mean clean!! before you do. Also, treat the bore with it and then shoot at least 3 with a reduced load, a grain or two will do before going ahead. Then load to your previous velocity. May take a grain more. If groups are worse play with seating depth, not charge. Assuming it shot well before.
snox801
Well-Known Member
Kirby built it so of course it shot well. Lol
Much better than I could anyway.
Much better than I could anyway.
Orange Dust
Well-Known Member
I would love to have one of Kirby's guns. I know it will shoot well. Maybe I misspoke... Assuming you were happy with the previous load and don't want to develop a new one??? Better???
snox801
Well-Known Member
I know I got what you were saying.
He builds great rifles I only get to use mine once a year as Michigan is not known as a long range state. But I wanted my dream gun so I did it.
He builds great rifles I only get to use mine once a year as Michigan is not known as a long range state. But I wanted my dream gun so I did it.
Orange Dust
Well-Known Member
I would love to have a rifle built by one of the top builders in the country. I would already have one too, if I could just make up my mind what it would be? guess it will never happen until I come across something so cool I can't stand not to have it... Maybe a 30-06? High end shotguns are much easier to decide on...
