400-series SS barrels

[SRMohawk69]

Do any of you gents have any experience with the new 400-series stainless steel barrels Bartlein is making? I only got wind of the fact that they were even using a new steel yesterday on watching a year-old interview Eric Cortina did with Frank Green. And what Frank had to say about the U.S. Army's findings on experimenting with them was enough that I just called and ordered one this morning in .284-calibre. It was $665 though, not $465. I hope I won't be disappointed.

 

[msalm]

I’ve chambered a couple, they have shot as well as any and will hopefully last a bit longer in the more intense cartridges. One was for a 22 Creed, another in 6.5 PRC. Have a blank sitting here now for a 338 Lapua.

 

[DaveTooley]

I've done some. No problems. I tested a 300 WM for throat erosion. I don't have my notes but the throat moved slowly compared to similar rounds.

 

[LVLAaron]

I've done 10 of them. No real data but they do seem to last longer. They are harder, you can feel/hear it when you cut them. It's subtle but noticeable.

 

[DaveTooley]

Probably tougher, not harder.

 

[jackieschmidt]

Probably tougher, not harder.

From a machinist standpoint, I think this is what the reality is, although I have never had a Rockwell C test performed on one to see the actual hardness as compared to 416R or Chrome Moly.

I have written about it before, but for the OP, I was sent a 30 caliber 1-18 twist Mod400 barrel to put on my 30BR to test the accuracy. It shoots as well as any Bartlien 30 I have ever had.

Of course, the longevity factor in a 30BR is kind of a non factor, as the round is probably one of the most barrel friendly used in competition shooting.

 

[Kracken McGraw]

Probably a silly question, but did the harder steel give the bullet any additional speed?

 

[SRMohawk69]

It had a 416R Krieger barrel, but 23 years ago I had my local riflesmith build a .300 WSM for me and I immediately started loading as hot as I reasonably could for it, sub-half MOA accuracy withstanding, of course. Granted, I was loading with those Vihtavouri N500-series propellants, but I saw throat erosion of 0.088" in the first 200 rounds down the barrel of that rifle. Then, at around 800 rounds, the gun stopped shooting even 'Minute of Barn Door'. That same smith later built a .300 WinMag for me, the 416R Bartlein barrel of which lasted not 1,300 rounds before it stopped shooting. But on hearing about this new steel Bartlein is using, I thought I'd wade back into precision bolt rifle.

 

[jackieschmidt]

Probably a silly question, but did the harder steel give the bullet any additional speed?

I never chrongraphed it. I can’t imagine why it would.
I have the drop off of that barrel. If I get a minute this week, I will take it and a drop off of a 416R barrel and have them RC tested.

 

[SRMohawk69]

I just received the invoice for the subject barrel blank from Bartlein Barrels and it reads 'Bartlein Barrels proprietary 400 MOD BB'. I assume 'ole Frank and the boys there in Jackson, WI have been burning the midnight oil with a brilliant metalurgist and/or the rep from the mill they use.

 

[Willow]

Probably a silly question, but did the harder steel give the bullet any additional speed?

No, at least not on mine. Throat wear is noticeably slower which is the main benefit.

 

[okie]

Dave, Aaron or Jackie : do reamers seem to dull quicker???

 

[DaveTooley]

Probably. For the home smith don't worry about it. For us working guys an extra $2 cost per chamber is the cost of doing business.

 

[LVLAaron]

I did two barrels for one guy with his reamer... I did notice the cutting edge get a little fuzzy. It cut fine, but I did notice it. Sample size of one there. Take it with a grain of salt.

 

[okie]

So not significantly harder...??

 

[LVLAaron]

Nothing that gives me any amount of concern.

 

[jackieschmidt]

There is also a machinability factor that many overlook.
416R is deliberately produced with a free machining quality. The main alloying element that accounts for this is the addition of sulphur, which is used in many steels to improved machinability.
The limits of how much is predicated on the ductility of the steel, or in some cases, the weld ability of a certain steel.

More sulphur does tend to lessen ductility and weld ability.

 

[DaveTooley]

Doing a BB steel barrel now.
Hardness about Rc 28 near as I can tell.

 

[nwmnbowhunter]

Doing a BB steel barrel now.
Hardness about Rc 28 near as I can tell.

What's normal barrel rc

 

[DaveTooley]

28-32
Just roughed in the chamber with a core drill. Spindle load was basically the same as 416R