Testing melonited barrel, need suggestions for experiment

[lennyo3034]

I currently have an 18" Douglas match SS barrel spun by CLE on my SPR. I just received this:
18" Special Purpose Rifle (SPR), 'Terebratus', with Hard Blue - Superior Barrels

Which is essentially the same barrel but has been melonited (they call it hard blue).

I will shoot a control test with the Douglas before taking it off and putting the new one on.

At the moment my plans are to shoot it with the following:

Geco .223
My reloads tuned for the current barrel (69gr SMK, 24.0 gr RL-15)
Some reliable 77gr factory ammo

I plan to record accuracy and velocity from each sample.

My questions are:

1. How many rounds per load would be a large enough sample size? I'm thinking 3 groups of 5 rounds each
2. Any recommendations on the control 77grain factory? Must be in stock so I can order it now
3. Being an SPR/3 gun build, I'm only using a 1-6 optic. I feel I can shoot my groups 90% as well as I could with a precision benchrest optic, but what are the opinions of people interested in this experiment? Would you be more confident in the results if I threw on an optic from my F-class rifle? I'm hesitant because I'm lazy and don't want to re-zero.
4. Is there anything I'm leaving out? I'm welcome to suggestions.

For the accuracy test, to minimize outside factors such as wind/atmosphere I plan to shoot this at 100 yards. My purpose for buying the barrel was mainly to satisfy my curiosity, as well as barrel life. However I will not be testing barrel life in this experiment.

 

[shoot4fun]

I think you will like what you see. I have been shooting melonited barrels on AR platforms for a couple of years now and find them to be just as durable as chrome lined and possibly more accurate. I handed one rifle to an exuberant group of young men with over a dozen fully loaded 30 rd Pmags. They ran all those rounds thru the gun in under 15 minutes full throttle. Smoke was boiling off it and the guard became so hot they had to wear gloves to finish shooting. After cooling and cleaning it still shot just under MOA and bore scoping showed no effects from the heat.

 

[LRRPF52]

Bore sight the benchrest scope, and mount checklist it before heading to the range.

If you can get Mk.262 77gr, that is an extremely consistent load that works superbly in 18" guns.

Depending on the mount, you might want to settle the gun with a group before recording for accuracy. Three 5rd groups would be a minimum snap shot in time that wouldn't convey much of anything conclusive, unless there were drastic and consistent differences.

I would also like to see the chrono data, and will hypothesize that the melonited barrel will shoot a little slower, but extreme spread should be tighter. The difference will be so minimal that it could get lost in the characteristics of each barrel, as there can be 100fps variance from barrel to barrel from the same maker back-to-back.

 

[hrfunk]

My concern about melonited chambers/bores has little to do with accuracy and/or barrel life. I suspect it is comparable to chrome in regards to those qualities. What I'm worried about is melonite's ability to prevent rust from forming. I have seen surface rust form on melonited handguns, and I'm worried the same thing could happen inside a barrel. We know the early M16's in Vietnam suffered failures to extract due, at least in part, to rust forming in their chambers. Chrome lining cured that problem.

For rifles that live most of their lives in climate controlled safes, etc. this is less of a concern than for those that live in vehicles and other places where they are exposed to the elements and/or heat and humidity variations. I would like to see how a melonited barrel fares after 12-18 months of living in a vehicle or a tent.

HRF

 

[Ballista One]

Terebratus, really?

Then the fail...

"We strongly suggest purchasing a specifically head spaced bolt for your barrel, as these chambers are cut tight."

Based off this single statement, this is not a company I'd be willing to do business with.

 

[SomeOtherGuy]

Then the fail...

"We strongly suggest purchasing a specifically head spaced bolt for your barrel, as these chambers are cut tight."

Based off this single statement, this is not a company I'd be willing to do business with.

I don't see the fail. Home AR builders treat barrels and bolts as mix and match, but there are tolerances, and there can be parts outside of those tolerances, and someone using a bolt that is one or beyond one the tight end of the tolerance range could have problems with a barrel that will work just fine with a bolt in the middle of the range. It's a good idea to check headspace with any new bolt, and I don't think it's unreasonable for them to recommend a bolt that's been checked, instead of "you take your chances" otherwise. Anyone who wants to can use their own bolt and just check the headspace themselves.

(I have no affiliation with or any experience dealing with this company, btw)

 

[SomeOtherGuy]

My concern about melonited chambers/bores has little to do with accuracy and/or barrel life. I suspect it is comparable to chrome in regards to those qualities. What I'm worried about is melonite's ability to prevent rust from forming. I have seen surface rust form on melonited handguns, and I'm worried the same thing could happen inside a barrel. We know the early M16's in Vietnam suffered failures to extract due, at least in part, to rust forming in their chambers. Chrome lining cured that problem.

Which handguns and what conditions? Was it an early production XD?

I have a bunch of melonited parts, barrels, and handguns. The only rust I've seen is on a few parts that came to me, factory sealed, with apparent rust or orange discoloration on them. The nitriding process uses a salt bath and the salts have to be removed a certain way. I have yet to see anything that was melonited (or Tenifer Glocks, which is another brand name for basically the same process) that came in good condition and later corroded. YMMV, curious to hear about the handguns you've seen.

 

[lennyo3034]

Terebratus, really?

Then the fail...

"We strongly suggest purchasing a specifically head spaced bolt for your barrel, as these chambers are cut tight."

Based off this single statement, this is not a company I'd be willing to do business with.

Compass Lake Engineering suggests the same. I actually got most of my information about Superior Barrels from CLE who supplies them with the completed barrels.

 

[308sako]

I have a Rock Creek 5R .223 Wylde 1 in 8 that has 4,300+ documented rounds. I also have a Rock 6.5/284 which has been melonited.

What do you hope to learn here? Accuracy and velocity differences will be about meaningless as your sample size is 2.

That said I am a believer in the process being good for rifle barrels.

 

[delixe]

Holy crap, ar15performance.com sells 5R wylde chambered melonited barrels for half that.
Barrels
I've built several uppers with the 16" barrels, all sub MOA with 75 gr Hornady Match HPBT hand loads.

As for a specific bolt for the barrel, I've measured all of the bolts I've ever purchased (width of the lugs minus depth of the bolt face) and all were within .0005" (half a thousandth) of one another.

I bought go/no go gages early on in my AR addiction. Every new barrel/bolt combo gets headspaced.

If you don't want to spring for gages and don't mind the ride, bring your stuff here to south eastern PA.

 

[Ballista One]

Compass Lake Engineering suggests the same. I actually got most of my information about Superior Barrels from CLE who supplies them with the completed barrels.

I'm not sure you are reading this statement the same way I am. Sending a bolt to the barrel manufacturer to have them head space it when the barrel is mated to the barrel extension is one thing. Building a barrel then "purchasing a specifically head spaced bolt for your barrel" is something all together different. Maybe it's nothing more than their poor command of the English language. Who knows...

As for a specific bolt for the barrel, I've measured all of the bolts I've ever purchased (width of the lugs minus depth of the bolt face) and all were within .0005" (half a thousandth) of one another.

I bought go/no go gages early on in my AR addiction. Every new barrel/bolt combo gets headspaced.

A. 0.0005 is one-half of ten-thousands, not half a thousandth.
B. If you purchase your barrel assemblies and bolts from reliable sources, verifying head space is wholly unnecessary. Doing such is the culinary equivalent of visiting an all you can eat buffet on Whilshire Blvd in Los Angeles and then asking where the meat came from after an hour of dining...

 

[Matno]

A couple of comments here imply that the accuracy from a melonite barrel is on par with chrome. From what I've read (can't speak from much experience though I have both), the main benefit of melonite is the durability of chrome while maintaining the smooth surface of softer steels. It's not a coating, it changes the surface steel so there's no rough extra layer added. My melonite barrel shoots well under MOA if I do my part. Then again, RRA guarantees sub MOA on all of their barrels, which I believe are mostly chrome lined.

 

[Wolf22]

I'd consider 5 of 5 per load, and are you set on RL15? How about 8208xbr, Varget, BL-C2, TAC or H335/322?

Very curious with the Hard Blue barrels as well, having several ARP barrels shoot extremely well for 200 bones or less. Superior states that their Hard Blue is NOT a Melonite product, or something similar to that statement……everyone has to have their claim to fame.

Also, if the Melonite coated barrel hasn't been cleaned/lapped or whatever you wish to call it, you will need to clean the bore et al and get it nice and 'smooth' - for those trying to test accuracy of a newly received barrel.

Ballista - great analogy. Colon Blo usually tells you where the meat came from, or at least that sprint into the ditch in hopes of finding a bush 1/2 hour after you left the area. Anyone for "the Drive Thru". ROLMAO -

 

[hlee]

I'm not sure you are reading this statement the same way I am. Sending a bolt to the barrel manufacturer to have them head space it when the barrel is mated to the barrel extension is one thing. Building a barrel then "purchasing a specifically head spaced bolt for your barrel" is something all together different. Maybe it's nothing more than their poor command of the English language. Who knows...

A. 0.0005 is one-half of ten-thousands, not half a thousandth.
B. If you purchase your barrel assemblies and bolts from reliable sources, verifying head space is wholly unnecessary. Doing such is the culinary equivalent of visiting an all you can eat buffet on Whilshire Blvd in Los Angeles and then asking where the meat came from after an hour of dining...

A 0.5 = 5/10
0.05 = 5/100
0.005 = 5/1000
0.0005 = 5/10000 = 1/2000 = 0.5/1000 = half a thousandth

 

[lennyo3034]

Here are some of the velocity results:

Douglas Stainless:
Geco .223: 3063 average with 23 fps standard deviation
Black Hills MK262 Mod0: 2623 average with 25 fps standard deviation
Reloads (69gr SMK, 24.0 RL-15): 2735 average with 28 fps standard deviation

Superior Barrels:
Geco .223: 3011 average with 32 fps standard deviation
Black Hills MK262 Mod0: 2618 average with 30 fps standard deviation
Reloads (69gr SMK, 24.0 RL-15): 2681 average with 32 fps standard deviation

So it looks like a drop of 50 fps going with the treated barrel. Not really a surprise, but I was hoping for a tighter SD, not larger. Accuracy was embarrassingly bad all around with only the Geco .223 producing sub-MOA 5 shot groups. In the past the Douglas barrel has really liked the reloads, but has not in the last two outings. I developed the load and shot well with it when it was 30 degrees, so maybe it has something to do with the temperature sensitivity of RL-15. Or I just suck at reloading.

I shot 2 5-shot groups, and 1 10 shot group for each ammo/barrel combination. Whenever I switched ammo types, I fired 5 fouler rounds before taking data. Optic was a 6X as my 56mm bell on my benchrest scope would not fit correctly. I have plenty of ammo, so I plan to do a real accuracy test when I get a chance. Accuracy can be worked on with the right equipment for shooting groups, however the change in Standard Deviation is disappointing and I can not recommend this barrel at this time.

 

[bustin]

I'd consider 5 of 5 per load, and are you set on RL15? How about 8208xbr, Varget, BL-C2, TAC or H335/322?

Very curious with the Hard Blue barrels as well, having several ARP barrels shoot extremely well for 200 bones or less. Superior states that their Hard Blue is NOT a Melonite product, or something similar to that statement……everyone has to have their claim to fame.

Also, if the Melonite coated barrel hasn't been cleaned/lapped or whatever you wish to call it, you will need to clean the bore et al and get it nice and 'smooth' - for those trying to test accuracy of a newly received barrel.

Ballista - great analogy. Colon Blo usually tells you where the meat came from, or at least that sprint into the ditch in hopes of finding a bush 1/2 hour after you left the area. Anyone for "the Drive Thru". ROLMAO -

Hard Blue is a gas heat treat. Melonite is a liquid heat treat.
The heat treat doesn't make the barrel shoot well it's the quality of the work under the heat treat that makes the barrel.

 

[2ndamendfan]

A 0.5 = 5/10
0.05 = 5/100
0.005 = 5/1000
0.0005 = 5/10000 = 1/2000 = 0.5/1000 = half a thousandth

I was going to post the same thing.