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Montana Pete
Guest
I was just reading through this thread and I thought alinwa's comments were unnecessarily sharp and ill-tempered.
Am I the only one?
Am I the only one?
Barrel Steels?
- Thread starter varminter22
- Start date
Butch Lambert
Active member
Montana Pete, I didn't read it that way. Knowing Al, I would definitely say that wasn't his intention. He was asking for more info.
Butch
Butch
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haze10
Guest
Jackie,
I thought the PH stainless would have a Rockwell number in the low 50's. Wouldn't this be too hard to machine or ream? Or do you think they are only hardening to high 30's. Is PH hardened SS hardened all the way through or only on the surface?
I thought the PH stainless would have a Rockwell number in the low 50's. Wouldn't this be too hard to machine or ream? Or do you think they are only hardening to high 30's. Is PH hardened SS hardened all the way through or only on the surface?
jackie schmidt
New member
Haze
The Precipitation Hardenning Stainless Steels are age hardenned. In other words, you do a single step heat treat at a specific temperature for a specific time. I will use 17-4 as an example.
The way it comes out of the foundry is called condition "A". The best way to explain condition "A" would be to compare it to most carbon steels in the normalized and annealed condition.
Three common heat treat grades are H-1150, H-1050, AND H-900. The number represents the heat treating temperature. At H-1150, you get a RC number in the high 20's, and a tensil strength at about 125,000. In H-1050, you get a RC number at about 33, with a tensil strength in the 135,000 range, and in the H-900 grade, the RC number is up in the low to mid 40's, with the tensil strength in the 180,000 range.
As hardness and strength go up, ductility, (impact strength), go down, as well as machinability.
The H900 grade is a real bear to machine. I believe that Stiller uses the H1050 grade in the production of his Diamond Back Actions. 1050 and 1150 are not that bad, but all of these steels have a certain "toughness" that is hard on tooling.
One advantage that these steels poccess is that you can perform the heat treat after much of the finished machine work, as there is a minimum amount of warpage and "creep" during the proccess.
We use a lot of it in H-1150 grade for the manufacture of solid stainless propellar shafts for tug boats. Ductility is a big factor here. The big draw back is initial cost. 17-4 Aquamet Boat Shafting at H1150 can cost as much as $5 a pound. For a shaft weighing 5,000 pounds, that is a $24,000 cost before you ever touch a tool to it.......jackie
The Precipitation Hardenning Stainless Steels are age hardenned. In other words, you do a single step heat treat at a specific temperature for a specific time. I will use 17-4 as an example.
The way it comes out of the foundry is called condition "A". The best way to explain condition "A" would be to compare it to most carbon steels in the normalized and annealed condition.
Three common heat treat grades are H-1150, H-1050, AND H-900. The number represents the heat treating temperature. At H-1150, you get a RC number in the high 20's, and a tensil strength at about 125,000. In H-1050, you get a RC number at about 33, with a tensil strength in the 135,000 range, and in the H-900 grade, the RC number is up in the low to mid 40's, with the tensil strength in the 180,000 range.
As hardness and strength go up, ductility, (impact strength), go down, as well as machinability.
The H900 grade is a real bear to machine. I believe that Stiller uses the H1050 grade in the production of his Diamond Back Actions. 1050 and 1150 are not that bad, but all of these steels have a certain "toughness" that is hard on tooling.
One advantage that these steels poccess is that you can perform the heat treat after much of the finished machine work, as there is a minimum amount of warpage and "creep" during the proccess.
We use a lot of it in H-1150 grade for the manufacture of solid stainless propellar shafts for tug boats. Ductility is a big factor here. The big draw back is initial cost. 17-4 Aquamet Boat Shafting at H1150 can cost as much as $5 a pound. For a shaft weighing 5,000 pounds, that is a $24,000 cost before you ever touch a tool to it.......jackie
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Different Stainless steels
I have chamber a few barrels over the years. Before changing over to a flush system I worried about work hardening in stainless. I now use a flush system with a semi synthetic coolant/lubricant. My barrels and reamers never even get warm. Running high speed gives a better finish and reamers today are made to cut not grind. I don't encounter the reamer chatter that I once did at slow speeds I now encounter bushing squeel. If one runs the coolant pressure up and floats the bushing and the squeel goes away. My normal flush preasure is about 30 psi but on small claibers I have run the coolant up to 125 psi.
I have reamed the Krieger 410s in the past with no machining or reamer problems. The swarf teneds to be sticky and stringy when machining. The reamer knew no difference, even though I would withdraw the reamer and check the shoulder area for sticking chips more frequently. Some reamers that have been sent to me by customers have improper rake angle and tend to hold chips.
I have found a difference in the quality of steel different barrel makers use. Some seem solf, some seem hard, some seem to have hard spots in them.
It may just be my opinion that barrels that are stress releived multiple times during their machining are easier to machine and chamber. It cost more money for the barrel maker to do the stress relieving. Again you get what you pay for. As for cut versus button rifling. The higher end barrel makers may just buy better quality steel.
Why anyone would go out of America to get their barrels when we have some of the best barrel makers in the world right here.
Rustystud
I have chamber a few barrels over the years. Before changing over to a flush system I worried about work hardening in stainless. I now use a flush system with a semi synthetic coolant/lubricant. My barrels and reamers never even get warm. Running high speed gives a better finish and reamers today are made to cut not grind. I don't encounter the reamer chatter that I once did at slow speeds I now encounter bushing squeel. If one runs the coolant pressure up and floats the bushing and the squeel goes away. My normal flush preasure is about 30 psi but on small claibers I have run the coolant up to 125 psi.
I have reamed the Krieger 410s in the past with no machining or reamer problems. The swarf teneds to be sticky and stringy when machining. The reamer knew no difference, even though I would withdraw the reamer and check the shoulder area for sticking chips more frequently. Some reamers that have been sent to me by customers have improper rake angle and tend to hold chips.
I have found a difference in the quality of steel different barrel makers use. Some seem solf, some seem hard, some seem to have hard spots in them.
It may just be my opinion that barrels that are stress releived multiple times during their machining are easier to machine and chamber. It cost more money for the barrel maker to do the stress relieving. Again you get what you pay for. As for cut versus button rifling. The higher end barrel makers may just buy better quality steel.
Why anyone would go out of America to get their barrels when we have some of the best barrel makers in the world right here.
Rustystud
Kreiger website, scroll to bottom of page.
There has been more written on the subject and there may be more on the website but this is the caveat at the bottom of the barrel page.
http://www.kriegerbarrels.com/Rapid...ommon/viewPage.cfm&PageId=3390&CompanyId=1246
al
J
JeffVN
Guest
Are there any barrel makers/sellers willing to make a rifle barrel in 17-4? I am trying to find one to test barrel life on a head-to-head basis against a 416R barrel?
JeffVN
JeffVN
jackie schmidt
New member
Jeff
Regardless of what they say about it being a big secret, Lothar's L-50 Alloy is quite similiar to 17-4. Why not contact them.
I doubt you would get a barrelmaker that does not currenty us 17-4 to build you one. It's more to it than simply putting that material in as a substitute. Deep Hole Drilling 17-4 in the age hardenned state, (I suppose you would use H1050), is not an easy task unless you specifically use tooling for that purpose.
Perhaps if you were willing to pay for the drills, reamer, button, (or hook tool in Kriegers case), and set-up time, they might........jackie
Regardless of what they say about it being a big secret, Lothar's L-50 Alloy is quite similiar to 17-4. Why not contact them.
I doubt you would get a barrelmaker that does not currenty us 17-4 to build you one. It's more to it than simply putting that material in as a substitute. Deep Hole Drilling 17-4 in the age hardenned state, (I suppose you would use H1050), is not an easy task unless you specifically use tooling for that purpose.
Perhaps if you were willing to pay for the drills, reamer, button, (or hook tool in Kriegers case), and set-up time, they might........jackie
S
slugger
Guest
I don't know if they do anymore, but I have a Krieger SS barrel in 30 cal 1-12 twist in a #2 contour. I called him and he had it on the shelf. Asked me where I lived and where I intended to use the rifle. I told him Arizona and he said he would send it right out! This was a few years ago!
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Rad Mrdal
Guest
Pal, you're so correct. Crucible has developed a special improved grade of 17-4 PH especially designed for barrels, but it looks like no one wants to use it. Why?... because the brainless apes smiths can't get over the hurdle of changing their chambering speed/feed/cooling methods to accomodate for the PH steel requirements.Rad