Crome moly barrels vr's stainless steel

[ltam1198]

What the different between Crome moly and stainless steel barrels, witch one last longer and has better accuracy. Is the steel different hardness.

 

[Robert]

What the different between Crome moly and stainless steel barrels, witch one last longer and has better accuracy. Is the steel different hardness.

The datas hereunder are ISO, can be converted to imperial, but show the différences.

Except one manufacturer, for corrosion-resistant steel (the term Stainless is inadequate here), all uses the same steel, and it is the416+S (Euronorm X12CrS13 or Wk Nr 1.4005). This alloy is sulphur-added for better machinability.

---The 416, supplied in annealed condition, is about:
-Brinell Hardness : 170-175HB.
-Rm: 630-650MPa.
-Modulus of Elasticity: 200Gpa.
-Thermal conductivity: 25W/m-k.
-- -While the 420 as used by Lothar Walther is:
-Brinell Hardness 205HB.
-Rm: 725Mpa.
-Modulus of Elasticity: 200GPa.
-Thermal conductivity: 25W/m-k.

---A typical CrMo alloy used in barrelmaking is:
-Brinnell hardness: 225 to 241HB.
-Rm: 1000MPa.
-Modulus of elasticity: 205GPa.
-Thermal conductivity: 43W/m-k .
Barrels made from CrMo alloys are perhaps not better shooters than 416 and 420, but, from material considerations, they have the potential to be such, with no doubt increased accuracy life.
Better thermal conductivity might also be of consideration?
R.G.C

 

[Ggmac]

Both can be accurate . Stainless , nowadays is usually better finished inside , and it breaks in faster . Shilens barrels only has select match in stainless it's not available in CM (according to an old mans memory ), not sure if it's because ease of manufacturing or customer request .

 

[butchlambert]

Both can be accurate . Stainless , nowadays is usually better finished inside , and it breaks in faster . Shilens barrels only has select match in stainless , not sure if it's because ease of manufacturing or customer request .

Shilen makes Match and Select Match in stainless. I've used a lot of CM barrels in the past and seen no difference in accuracy or longevity.

 

[Dusty Stevens]

I think stainless caught on for its lack of a need to be finished and you can be more lax on your cleaning. So in the end its cheaper and easier to maintain. A chrmo barrel i feel will shoot just as well maybe better.

 

[DuaneinND]

SS is slightly easier to machine, resulting in less work to obtain a really smooth interior barrel surface. My experience is that most CM barrels show the value of "breaking in a barrel". Barrel life is more dependent rate of fire than SS or CM.

 

[butchlambert]

SS is slightly easier to machine, resulting in less work to obtain a really smooth interior barrel surface. My experience is that most CM barrels show the value of "breaking in a barrel". Barrel life is more dependent rate of fire than SS or CM.

What are you breaking in? I mean if the barrel is lapped, what needs breaking in?

 

[Ggmac]

Butch it was my understanding that Shilen doesn't make select match in CM . That is what I was trying to say , correct me if I'm wrong .
As far a barrel break in ,I'm referencing Dave Kiffs book of reamer prints where he addresses the barrel break in procedure for stainless 5 cycles of shoot and clean vs 25 for CM . Numbers may be off but I remember it being a factor of 5x for CM.
When you chamber , the throat needs to be broken in , even if the barrel has been lapped .

 

[butchlambert]

Butch it was my understanding that Shilen doesn't make select match in CM . That is what I was trying to say , correct me if I'm wrong .
As far a barrel break in ,I'm referencing Dave Kiffs book of reamer prints where he addresses the barrel break in procedure for stainless 5 cycles of shoot and clean vs 25 for CM . Numbers may be off but I remember it being a factor of 5x for CM.
When you chamber , the throat needs to be broken in , even if the barrel has been lapped .

Shilen does not advertise a match or select match CM barrel, but they have them of that quality. Most folks want SS automatically for their comp rifles. I didn't get that page in my Kiff's book, but none the less I would probably differ with him on that. As you mentioned the throat is the only thing that needs attention.

 

[JohnKielly]

Was told to me by one British shooter experienced in extended life of .308 target barrels that the significant difference between the two is that CM accuracy degrades by small increments throughout its shooting life while stainless shoots fine until it suddenly goes belly up.

 

[DuaneinND]

Butch, I do a 1 & clean 2& clean, 3 & clean, 4& clean, 5& clean on every rifle I build. Some people say a barrel doesn't need the effort, some barrel makers recommend, some don't. I also use the shooting time to evaluate the accuracy so the process serves a dual purpose.

 

[AckleymanII]

High volume, shooting so fast that you could not see through the scope taught me to shoot Stainless barrels only for long life. We would dump out a box of 50 and fire as fast as we could work the bolt, again, and again. CM got pitted faster. SS seemed to just wash out. We were shooting 1000-1200 rounds of center fire a day back then.

 

[butchlambert]

Butch, I do a 1 & clean 2& clean, 3 & clean, 4& clean, 5& clean on every rifle I build. Some people say a barrel doesn't need the effort, some barrel makers recommend, some don't. I also use the shooting time to evaluate the accuracy so the process serves a dual purpose.

I understand what you are doing. The reamer fluff in the throat is what you are dealing with, not the lapped lands and grooves.

 

[DaveTooley]

As far a which one last longer, they are for all practical purposes the same. Two ammunition manufactures. One uses SS pressure barrels and the other use CM. Comparing the same caliber they both replace the barrels at almost identical round counts when pressure and velocity readings start to vary.

 

[butchlambert]

Butch it was my understanding that Shilen doesn't make select match in CM . That is what I was trying to say , correct me if I'm wrong .
As far a barrel break in ,I'm referencing Dave Kiffs book of reamer prints where he addresses the barrel break in procedure for stainless 5 cycles of shoot and clean vs 25 for CM . Numbers may be off but I remember it being a factor of 5x for CM.
When you chamber , the throat needs to be broken in , even if the barrel has been lapped .

Gary, a couple years ago you mentioned Shilen CM barrels. They offer match grade only and all of their barrels are lapped.

 

[Alex Wheeler]

I happen to think softer barrels shoot better. I may be getting some soft ones for testing.... I dont think most guys would mind replacing a barrel 500 rounds sooner if it shot better.

 

[DaveTooley]

I happen to think softer barrels shoot better. I may be getting some soft ones for testing.... I dont think most guys would mind replacing a barrel 500 rounds sooner if it shot better.

Just curious, and I fully understand what I would describe as intuition, any data to support that?

 

[Alex Wheeler]

No. Just a handful of record setters and the owners, myself included agree they all burned out faster than normal. Throat movement. Its not the easiest thing to get guys like Krieger to let you try things. I am trying to get some at 25 Rockwell to test. Could be totally wrong...

 

[Shawnba67]

I think stainless caught on for its lack of a need to be finished and you can be more lax on your cleaning. So in the end its cheaper and easier to maintain. A chrmo barrel i feel will shoot just as well maybe better.

The lack of finish is a huge deal to the budget, CM add $75-100 for a xyz-coat of your choice now try and quantify that a CM shoots $75-100 better.

 

[butchlambert]

The lack of finish is a huge deal to the budget, CM add $75-100 for a xyz-coat of your choice now try and quantify that a CM shoots $75-100 better.

You need somebody else to coat or treat your CM barrels.