Longer life barrel steel from Bartlein?

[PeteFox]

In my FB feed this morning from Bartlein Barrels official page. It’s not on the website so i hope it’s correct.


“ Bartlein Barrels is pleased to announce the release of a new barrel material. Working with the mill and testing different types of material and tweaking the material over the last few years and with testing having been performed by ammunition makers we now have a different grade of material that we have had made and is proprietary to us.

The material has been proven in lab testing and in outside real world testing to provide a barrel life that is 1.5 to 2 times longer than the standard 416 grade of material.

We are calling the material 400MODBB. Pricing for this barrel material in standard diameters/contours etc...will be $555.

As always there are a list of things that effect barrel life and we cannot guarantee everything a 100% but for an example as I know it will be asked....in 6.5CM ammunition pressure test barrels are normally pulled from service at around 1700 rounds. The new material doing the same type of ammunition test work the barrel was pulled from service after it had 3500 rounds on it. We've had several 6mm's in calibers that the barrel normally is pulled around 1500 rounds go 3000 rounds.

We and or the customers that have done the threading and chamber work have had no issues with machining. I will say your reamers will not last as long but nothing that would really concern me. It does machine a little different but it's not horrible to work with.

So you will have a choice of the standard 416 material from us and the 400MODBB material.

Any questions it would be a lot easier if you emailed us at info@bartleinbarrels.com or called in directly at 262-677-1717 but I can only imagine the amount of questions we will be getting and with everything going on in the world currently I'll ask you to be patient for the replies.”

[willow]

Well this is interesting, those prices will likely translate to an AUD price similar to what you would pay for a carbon wrapped barrel, except without the carbon. So who is first in line to put this new steel to the test?

[Matt P]

Don't be surprised if your gunsmith charges a little more to fit, extra wear on tooling (in particular reamers) could be a problem. Especially at the moment, getting items out of other countries due to Covid 19 is becoming a real issue. Some items that took around a week to get from the US to Australia are now taking many months.
Matt P

[Frank Green]

Well being as we got a couple of phone calls today from Down Under and a email as well I figured I’d better pop in here and see what is going on.

I will say the material does machine a little differently and as my gut would tell me the chamber reamers might not last as long but we are not seeing anything horrible at all. Everything is totally manageable. We’ve cut chambers with standard HS tooling as well as with carbide reamers.

Any questions let me know and I’ll check in from time to time like I normally do and will answer any questions the best I can for you all.

Later, Frank

[bruce moulds]

frank,
what is it about these barrels and their steel that makes them last longer?
bruce.

[PeteFox]

This could be a real game changer in terms of running costs - cost per round fired and less load development time/expense per round fired.

My instinct tells me that as soon as you change something, another (un)foreseen issue will pop up.
I’d be interested to know how much more (or less) these barrels are likely to foul.
I’m thinking the coefficient of friction between copper and steel will be different, leading to ? Picking up copper (or not), velocity changes?
What about barrel harmonics?
Pete

[willow]

You would be spewing if you dropped $1200 plus and the barrel isn't a hummer...

[williada]

Pete got a feeling the grain structure will be finer in these barrels so less inclined to foul unless they polish too much. Getting that co-efficient of friction just right is important. Also think Hbn or moly would iron out any issues. Been through a lot of changes in barrel steel over the years from chrome moly, chrome plated and stainless. I think Black Star barrel way back were harder and used an EDM method to produce them. They all shot well. The query about the harmonics should not be a problem. The barrels may be stiffer and have lower amplitude and effectively give a longer tune range and be less finicky across varying distances if ES and SD's are better with a lower tendency to foul and longer barrel life.

The total running costs should be lower and that would be a trade off with the higher fixed cost. People already paying nearly $1100 to have a top smith fit and supply now. Postage costs are also through the roof. Agree with Matt that reamers are harder to get and may wear faster. Reamer wear maybe marginal if combined with a suitable lubricant. Time will tell. Always a minor hiccup, but I am sure the top boys won't worry about money in FOpen.

We will wait and see.

[Frank Green]

frank,
what is it about these barrels and their steel that makes them last longer?
bruce.

Bruce, We modified/changed some of the levels of the chemical composition of the standard 416 material. That's why we call it 400MOD. Still a 400 series stainless and the MOD of course stands for modified. We had to come up with a name for the steel mill when we went for the mill run. We concentrated on the things that is suppose to take the heat better and help with wear.

Later, Frank

[Frank Green]

This could be a real game changer in terms of running costs - cost per round fired and less load development time/expense per round fired.

My instinct tells me that as soon as you change something, another (un)foreseen issue will pop up.
I’d be interested to know how much more (or less) these barrels are likely to foul.
I’m thinking the coefficient of friction between copper and steel will be different, leading to ? Picking up copper (or not), velocity changes?
What about barrel harmonics?
Pete

Pete, Haven't seen anything effect velocity at all. The ammunition pressure test barrels and accuracy barrels have performed with no issues. The first barrel pressure test barrel we shipped was in 6.5CM. Normally the pressure test barrels in that caliber get pulled from service at around 1700 rounds. The barrel we made got pulled from service at 3500+. That barrel got on average between 150 to 300 rounds a week put on it (depending on the testing schedule and other things going on at the ammo/bullet maker). After every X amount of rounds the barrel got a pressure correction test done. It's a standard operating procedure to make sure the barrel isn't doing anything out of the ordinary etc....They don't want to see a pressure change of no more than 2k psi and I think a velocity change of 50fps (might be wrong on the velocity but I know I'm close they told me but don't remember exactly). Anyways when they ran a pressure correction test at 3300+ the barrel lost 40fps and pressure jumped 1800psi. So they did fire another couple hundred rounds thru it but pulled it from service then. Up until that time every pressure correction test they performed the barrel didn't deviate more than about 10fps and pressure never changed over 500psi. I can go back thru all the email tracking and pull the numbers. I know at 2000 rounds they tested a new powder and a 120gr bullet (barrel was SAAMI spec and 1-8 twist) and that new powder and bullet shot groups in the .4 to .59 range. Again they are shooting box match ammo thru it.

The other thing noted by them and others who have tested the material and no one was comparing notes. We we're just collecting the data was that everyone made pretty much the same comment that the barrels seem to foul less and clean easier. I know the previous lab melts of material we tested they didn't clean any worse than the standard 416 material but if they are truly fouling less and cleaning easier it just ends up being a bonus that we didn't plan on.

Later, Frank

[Frank Green]

The total running costs should be lower and that would be a trade off with the higher fixed cost. People already paying nearly $1100 to have a top smith fit and supply now. Postage costs are also through the roof. Agree with Matt that reamers are harder to get and may wear faster. Reamer wear maybe marginal if combined with a suitable lubricant. Time will tell. Always a minor hiccup, but I am sure the top boys won't worry about money in FOpen.

We will wait and see.

That's the idea and something I've been looking for...for over 20 years. A material that would last longer....the benefits would be that the gun stays in tune longer, and with the barrel lasting longer the shooter won't go thru the barrels as fast. So even if the barrels cost more but you are buying less and as well saving on the gunsmithing costs to install the barrels. You should be saving money. Even if the barrels only go 50% longer. If you normally go thru 6 barrels a year....now your only going thru 3 year.

From what we see and what my gut tells me the reamers won't last as long but I don't feel it's nothing that is going to be a deal breaker for anyone. We are watching our bore reamers to see how long those go. We don't mix our bore reamers between 416 SS and the CM steel as well as we don't interchange between the 416 and the new 400MOD material.

Later, Frank

[Rich4]

Is that for your own tool tracking? Or some contamination issues? I have a feeling most small gunsmiths would use their reamers for both, especially at the moment

[Frank Green]

Is that for your own tool tracking? Or some contamination issues? I have a feeling most small gunsmiths would use their reamers for both, especially at the moment

Rich4, as far as the bore reamers go it’s for our own tool tracking.

As far as chamber reamers go we typically will use them in either material. 99% of the barrels we are chambering now a days is SS. The first thing that goes on the reamer is the throat as it’s always cutting. So some of the newer designed chambers that throat tolerance has gotten tighter. So not just now but in the past when we chamber ammunition test barrels we will measure the chamber to make sure the reamer is cutting to spec. On gov’t test barrels in 5.56, 7.62 and 50bmg we have to inspect and measure the chambers in 10 different areas and check dimensions before we ship the barrels. Some test barrels we’ve sat down with the customer and will agree on what part of the chamber we have to check/inspect. More often than not it’s a couple of ball gauges to check the throat area of the chamber.

We’ve seen issues where for example on 300AAC Blackout. The rocket scientist that designed it spec’d a throat diameter of .3090” and the max tolerance allowed for ammunition is that the bullet can be as large as .3090” diameter as well. Well hello that is size on size. We seen an issue where a brand new reamer cut the throat to .3088” to .3089”. So only a .0001” to .0002” undersize. When the the 30cal bullets where at standard dimensions of .3080” and a little over like a .0001” or .0002” etc...there where no issues with the pressure. Nothing that pointed to a problem at all per say but when they ran a given spec lot of reference ammunition and the bullets where at .3090” that minor difference made the pressure jump 8k to 10k psi.

So to your original question....no we don’t have different chamber reamers for a different type of steel barrel.

Later, Frank

[DenisA]

I imagine that if all goes well with the new barrel steel a key advantage will be delayed throat erosion meaning it will hold a tune longer without chasing lands and making adjustments. That would be quite a positive through out the course of an F-Open meeting.

Frank has it been determined in testing whether the the leading edge of the lands holds its form by the same percentage of increased barrel life?

[Frank Green]

I imagine that if all goes well with the new barrel steel a key advantage will be delayed throat erosion meaning it will hold a tune longer without chasing lands and making adjustments. That would be quite a positive through out the course of an F-Open meeting.

Frank has it been determined in testing whether the the leading edge of the lands holds its form by the same percentage of increased barrel life?

The wear is different. The throat is holding up better etc...a couple of examples in 6mm.

6x47 Lapua running 105 hybrids at 3125fps. RL26 powder exclusively. 24” long gas gun barrel (AR10) being shot in PRS matches. 940 rounds and .028” of throat erosion. From 940 to 1280 rounds only eroded .006” more. That load in a gas gun and those velocities he is not being nice to the barrel. At 1280 rounds he won the gas gun class at a PRS match. Shooter is in the special forces. His barrels in standard material he normally doesn’t make it to 900 rounds and the barrel is pulled from service.

6BRA barrel. The throat thru out the course of shooting had like two thirds less wear at all round counts than a standard 416ss barrel we made. I’ve got the numbers at work. He normally pulls his barrels at about 1800 rounds. Barrel was pulled at 3400 rounds because it lost 50fps. He put the barrel on his wife’s rifle and currently has 3900 and still shooting small groups and no more loss in velocity.