Barrel life Stainless vs Carbon steel

regulate34 said:
If stainless bbls are smoother with less drag. I guess you could assume less pressure. And possibly less velocity?
Click to expand...

I think it would be the opposite, more drag would mean more energy required to push the bullet down the barrel. Pressure I would assume is developed from the seal behind the bullet and the gases expanding from the combustion of the powder so my guess is that the ultimate goal is minimal drag and maximum pressure for max velocity.
 
Wouldn't their be less resistance. Therefor not allowing the pressure to biuld.

I think someone Needs to buy me identical rifles. One blued and one stainless.
Then I'll do some testing.
 
Pressure is an element of the seal around the bullet against the barrel and the time it takes for the combustion to push the bullet out the barrel. As long as the rifling interacts with the bullet properly, there should be a seal. Ideally, I am guessing that you want the total amount of powder to burn and fully expand right as the bullet reaches the crown of the barrel so I get what you're saying about wanting to extend the time it takes the bullet to travel the length of the barrel. I would really like to know just how much friction there is in a bullet and how much velocity the friction robs all things considered.

regulate34 said:
Wouldn't their be less resistance. Therefor not allowing the pressure to biuld.

I think someone Needs to buy me identical rifles. One blued and one stainless.
Then I'll do some testing.
Click to expand...
 
While stainless [416] may have a slight advantage regarding useful life, the difference is not as great as some assume.

A study that I read that examined this carefully, found the rate of erosion was very similar in 416 Stainless and 4140 CroMo.

I cannot put my finger on the article right at present, but it made a lot of sense, and was extensive.

Another factor was the small % of sulfur in the 416. This was being extracted from the stainless by the hot gases, and
leaving tiny cavities in the throat area, which showed under close examination.

Since the CroMO has noticeably less sulfur content, but is affected slightly more by the hot gases, the end result of comparing the two revealed
very little advantage to the 416 SS.

In any case, SS is great if one hunts in lousy, wet conditions, since it stands up better under such abuse. I personally am a Blued/Wood junkie,
and prefer it. That does not mean I do not have a couple of SS/Synthetic rifles for those really bad days in the field. Practical they are, but UGLY IMHO. lol.

Regards, Dave.
 
Last edited:
Eagleye said:
While stainless [416] may have a slight advantage regarding useful life, the difference is not as great as some assume.

A study that I read that examined this carefully, found the rate of erosion was very similar in 416 Stainless and 4140 CroMo.

I cannot put my finger on the article right at present, but it made a lot of sense, and was extensive.

Another factor was the small % of sulfur in the 416. This was being extracted from the stainless by the hot gases, and
leaving tiny cavities in the throat area, which showed under close examination.

Since the CroMO lacks the sulfur content, but is affected slightly more by the hot gases, the end result of comparing the two revealed
very little advantage to the 416 SS.

In any case, SS is great if one hunts in lousy, wet conditions, since it stands up better under such abuse. I personally am a Blued/Wood junkie,
and prefer it. That does not mean I do not have a couple of SS/Synthetic rifles for those really bad days in the field. Practical they are, but UGLY IMHO. lol.

Regards, Dave.
Click to expand...

Makes sense good post thanks
 
The more polished surfaces creates less drag, less deposit which means less friction. What drives the bullet is the rifling. Reducing friction is also achieved by using lubricants, were they dry (Molybdenum) or wet (oïl).
Click to expand...
I imagine you're right ... I don't know .. possibly correct.... but at some point the increased contact (surface area) between bullet and barrel will increase the friction.. which is one of the reasons 1/4mile drag strip cars use slicks and not snow tires. And of course discussing the barrel in isolation of the other surface acting against it is only half the story. Are the lands of a barrel acting like ice skate blades on an ice rink ? is the jacket (or lead) momentarily converting to a state that increases lubricity ?? I know there are folks who have spent decades studying this stuff .. and probably have the answers ... not me .. I just have a lot of questions....
 
The bullet jacket material acts like a friction modifier. Same goes for lead bullets. That's also why they leave deposits in the barrel. A big part of the pressure is related to the force needed to push the bullet to imprint the grooves, past that, the bullet starts getting velocity, so the least resistance means more velocity. Moly coated bullets usually run at higher velocity but at a reduced pressure.
If you take two pieces of polished glass and rub them together, you will fill very little drag. Add a thin film of oïl or even graphite powder, it will slide even more easily.

BTW, not all SS barrels are finished to mirror like surface.

Dave, ChroMoly steel also contains sulphur, but to a lesser extent.
 
BTW, not all SS barrels are finished to mirror like surface.
Click to expand...
I'd wager that NONE of them are

If you take two pieces of polished glass and rub them together
Click to expand...
.. moving us into the area of stiction.. no?
 
Last edited:
Baribal said:
Dave, ChroMoly steel also contains sulphur, but to a lesser extent.
Click to expand...

Yes, the writer of the article pointed that out, but I worded my statement rather poorly, didn't I? :) [PS, I reworded it now]
Should have stated that the sulfur in the Cro/mo was there, but in smaller amounts.

Regards, Dave.
 
Dave, it sounds like the article I mentioned earlier (Barker).

AP,
It's all about kinematics... When you have less friction, the acceleration takes less time to act hence a higher final velocity.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom