What is the advantage of 410 stainless steel to 416? I know that 410 is harder and more resistant to the elements but how about function? Be gentle, I just ordered a 416 stainless barrel with melonite coating. I noticed the price of 410 was substantially more but all other features seemed to be the same.
I’m glad you posted this. I’ll delve into it as well as pass anything I find interesting on to Mike Rock of Rock Creek Barrels. There are MANY ways to make what appears to be an identical alloy. So one 416 is not necessarily the same as another. I’ll check my Metallurgy and Alloys Handbooks to see what I find. (I doubt they will tell me much other than the alloy content percentage ranges, though).
I bought this…
http://www.spikestactical.com/z/index.php?main_page=product_info&cPath=63_67&products_id=328.
Along with this purchase I bought a Daniel Defense 16 inch Cold Hammer Forged Mid length barrel. I spoke to Tom (from Spike’s) about the stainless barrel before purchasing it and he could have easily talked me into something better but he was adamant that this was a good barrel. I didn’t want to spend a ton of cash on this particular build because this carbine is for work and will be getting beat around going in and out of my vehicles. I still can’t get a solid answer as to why most SS barrels I see on the market are 1/8 twist not 1/7. The duty ammo is 55 gr. Federal so the twist rate is a non-issue with this particular rifle. I will however, be shooting the s%*t out of this gun so it’s gotta hold up somewhat.
Duty Rifle: This SS barrel with a Mega upper, Spike’s BCG, Gunfighter CH, Troy TRX 13" rail, Eotech 553, S&W M&P lower with a LPK from Grant, RRA 2 stage FCG and Magpul KoolAid.
IIRC, the main difference between 410 and 416 is that 416 has a higher sulfur content, which makes the 416 easier (cheaper) to work than the 410. The 410 is a bit tougher, and I believe also retains a bit more of its strength in extreme cold. That said, 416 is still pretty tough, and quite a few people underestimate it.
A word of caution on your Melonited barrel: applying Melonite to stainless makes it tougher, but also less rust resistant. Keep it oiled decently.
The 1/7 vs. 1/8 argument is pretty complicated. Basically, the longer a bullet is, the faster it has to be spinning to be stabilised. Also, the faster the twist rate, the longer the bullet will remain stable as the velocity drops off at long range. Both 1/7 and 1/8 will stabilise anything that will fit in an AR mag. At longer ranges (like 600+ yards) the 1/7 will continue to stabilise rounds that would have since become unstable from a 1/8. However, at that point, you’re essentially past the reliably effective range of the round, anyway. The other factor to consider is that faster twist rates wear the leading edge of the lands and grooves faster than the slower rates.
I prefer 1/8. Unless you’re shooting tracers, super heavy/long rounds out of bolt guns, or want to punch paper at extended ranges, I think the 1/8 is better all-around.
I’ve been looking into this and came upon this thread. What follows is just what I’ve read and attempted to put together on my own. If there are some metallurgists out there, please chime in!
From what I can tell, there are only a few steel companies in the world. Barrel makers seem to rely on what they hear from steal companies. So it kind of depends on which company they use.
Crucible says in their data sheet for 416R, that it was developed for gun barrels. It also seems to be a proprietary product, unique to Crucible. I can’t find any reference to 416R on Carpenter’s site, despite a document put out by a barrel maker saying they use 416R from Carpenter.
http://www.crucible.com/PDFs/DataSheets2010/ds416Rv12010.pdf
http://www.crucible.com/PDFs/DataSheets2010/Data%20Sheet%20410.pdf
There is some swag out there that stainless steel can’t be used in the cold safely. Crucible says 416R is safe to -40F.
I think the cold thing may have come partially from Kreiger, who states that stainless shouldn’t be used below 0F. I suspect this may be related to a specific incident, or some lawyer crap.
BCM says that 410 is harder than 416. That may be true, but 416 is not 416R, these are two different products from Crucible. 416R seems desirable (to machine) due to the added sulfur. Either way, different levels of hardness can be obtained with either.
Crucible says this about 416R;
Crucible 416R is a pre-hardened chromium stainless steel
which is suitable for use in precision match-grade rifle barrels.
It can be supplied in various hardness ranges according to
your specific requirements ( HRC 24/28, 28/32, or 32/36)
From what I’ve managed to read, the problem with adding sulfur is if the sulfur bands together in the steel, then you get a weak spot. I guess at some point you have to trust that steel companies know what they are doing and check this kind of thing. You could say the same for parts in your engine. If someone fell asleep on the production line of the steel factory that made the blank for the connecting rod, you could have a problem.
Lothar-Walther uses LW50 stainless barrels, which Larue Tactical uses. LW50 is a proprietary product unique to Lothar-Walther.
Bottom line, from what I’ve lost days of my life reading about, is while the material going into barrel production is important, what the maker does with the blank, how the barrel maker produces the barrel and the processes they employ, is much more important.
Pretty much sums it up. 416R is a very specific make up of 416 SS and is easier to machine which saves wear and tear on tooling. I think too much is made of barrel material for what we do with them 410 vs 416 vs 4140 vs 4150 you’re probably not going to be able to tell an appreciable difference.
Very well put. +1
The difference between the two steels would be fairly apparent in military uses.
Not to mention that melonite is an inferior treatment on a barrel that is soft. It fucks up the heat treat.
The best barrel material remains 11595-E.
Best for what?
I assume you realize that the mil-spec you listed is only the requirement for 4140/CMV blanks, more specifically their content?
This is no way relates to a discussion for stainless barrels.