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Brillo

Moly Coated Bullets (Why)

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I have a few queries about moly coated bullets.

What are the advantages and disadvantages?

Does their use increase or decrease barrel life of not make any difference?

I’m told they increase bullet velocity but then also told they require more propellant because they cause reduced pressure due to the extra slip. This sounds contradictory.

I’m told that once you start using them that you can’t use non moly coated bullets in the same barrel. Wouldn’t normal cleaning remove any coating from the barrel?

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Some intriguing points raised there. From a metallurgical point of view, we'd expect that a well applied coating would protect the barrel from erosion, corrosion and tribological wear but of course the devil is in the detail. It'll be interesting to hear from those with real world experience of how they perform.

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Firstly, real world - shooting moly coated bullets doesn't extend barrel life.

It reduces the friction between bore and bullet so less pressure is created and thus velocity is lower.  Yes, you may (try and) recoup that lost velocity with more powder but that will certainly reduce barrel life. Barrels don't wear out - they burn out.

Does it reduce the need to clean the barrel?  The barrel may keep shooting accurately for longer using moly bullets but sometime you gotta clean. Personally I find it easier to clean after every match - then you know where you are with your barrel.

The badger mentions a 'well applied coating' - you ain't going to get that by shooting a few dozen bullets up the barrel - try digging a moly coated bullet out of the backstop - still has moly on it - the moly will just be missing where the sharp edges of the rifling has cut through the moly. Very little must be left in the barrel. 

If you shoot in an 'accuracy' comp that requires a lot of rounds and gives no opportunity to clean then maybe moly has some merits - otherwise, IMHO it's just another variable.

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 A wise man once told me “it’s just another thing to try”

Reading Vince’s comments about increasing powder charge to overcome the velocity loss due to lower friction bullets, then I’d say that any perceived advantages are lost and the whole process is self defeating, as one of the espoused benefits is you can shoot accurately for longer without cleaning, but if you clean after every outing then where is the benefit?

Furthermore, the contact points between the bullet and land/groove are small, so again is there any gain?

If you look at minimum effort for maximum return, the amount of Pfaffing you have to do with sourcing, tumbling, sifting and a new cleaning/conditioning regime vs just getting a box of bullets and loading them makes me wonder why?

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Been there,  done that many years ago,  used moly bullets,  coated the barrel as well,  no difference noted in performance so have used out of the box bullets for the past 12 years or so.

Don't waste your time unless your rattling hundreds of bullets down range in one day.

As Vince says,  just another variable and something else to worry about.    Keep it simple stupid!

 

 

 

 

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If you fancy trying a bullet coating then boron might be one.

There was a discussion on this not so long back and it's the same principal with a different material,less friction needs more powder to get the speed up unless your happy with the speed.

The general concensus was it could be fairly dust, some on here are trying it out and it would be good too hear accurate feedback 👍.

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I'm using boron nitrided bullets in my 6x47..........200 rounds of the Tubb boron'd 115gn DTAC's to date on a virgin barrel. (Bergara 6mm 8 twist s/steel)

I use the VFG cleaning system, dry only, no cleaning fluids, and after a session shooting 30 or 40 rounds, the first felt through is light grey, the second is clean.

Borescope shows no copper so far. (I don't "break in" barrels). I can't comment on the effect on MV as the barrel has only been used with HBN'd bullets, but I'd say it's worth doing.

I'm monitoring it regularly, and also hoping that the temperature tolerance of HBN will bring something to the party as far as  throat erosion is concerned. It is a ceramic, after all.........

I'll post some borescope pics shortly.

Pete

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I built a 6mmBr for myself many years ago, and fitted a cut rifled Border to it.

I sold it recently having had 800 rounds down it.

The gun never shot anything but 90 grain silver scenars [ factory moly coated ]

Its barrel, when borescoped, before selling, was absolutely pristine. It looked like it had never been fired. The loads were hot too.

Thats my one experience of moly coated bullets. I have to say, lapua's moly coating and subsequent waxing, is far superior to some home done efforts, where the moly goes everywhere.

If Lapua hadn't have discontinued the silver scenar range, I would have continued to use them in other guns.

800 rounds and no visible wear anywhere, is very unusual indeed, in ANY calibre.

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I use Boron in my 6mm SLR that Baldie built for me .

Given barrel costs these days its in hopes of an extended life for a relative barrel-burner.

Can I scientifically prove extended barrel life..no.

Application is dead easy and no great effort and its clean.

There is little or no fouling of carbon and copper.

To me its worth the minimal effort and it shoots really well.

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Every day is a learning day so they say.

I recently rebarrelled a customers TRG in 6mm Creedmoor. Its already had 3 6.5 creed moors on it, and all were superb. The chap fancied trying the 6.

He is a big fan of Boron.

This barrel, a Sassen cut rifled blank, was superb internally, as they all are.

He started off straight away with boron coated 110 grain bullets.

The gun shot ok, producing 3/4" groups with a variety of powders/seating depths.

We were scratching our heads a bit. Wondering how to wring a bit better out of it. This was about 100 rds down the tube.

He cleaned it out, and rattled 20 rounds of naked ammo down it.

Cleaned again, treated the bore with boron, and shot the same loads he had been using.

It instantly starting shooting 1/4" 5 round groups.

I deduced several things from that, and what i've always suspected.

1. Barrels DO break in. Seem it so many times, usually around 20 shots, and the results show at the target.

2. I firmly believe that barrels reach their optimum at around 200 rounds, and I've always considered them fully good to go at that.

3. Using boron from the get go, didn't allow the barrel to break in, in this instance.

4. If it slows down break in to that degree, it therefore must surely extend life at the other end.

Maybe David Tubb, and his abrasive coated break in bullet procedure was onto something. They are not something I would use, but there are similarities in findings.

 

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I've used the Tubb boron coated 115grn DTAC's in a new 6x47 barrel from day one, and what amazes me is how clean the bore remains.

One VFG felt after 40-50 rounds comes out very slightly off-white, and the second one is clean. No trace of copper seen, either.

Pete

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Very interesting comments on Boron treatment and I confess that I’d never heard of it until I asked the question about moly coating.

So, how is is boron applied to the barrel and bullets, and does a barrel require frequent treatment or is it a one-off?

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I clean bullets in washing up liquid, dry then tumble in plastic jar in a vibratory tumbler plus tiny ball bearings to impact boron onto bullet.

Barrel can be coated with mop soaked in a solution of boron in isopropyl alcohol.

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+1 on the above, though after cleaning I heat the bullets in the oven at 100 degrees C for 10-15mins before I impact plate them in the vibratory tumbler. I've read heating the bullets aids with the impact plating process. Though I confess I've not tried both methods to see which is best.

Very quick and simple to do overall.

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Agreed above...forgot to list that step although coating seems to work without it well enough.

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I forgot to ask, from where do I purchase boron?

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59 minutes ago, Brillo said:

I forgot to ask, from where do I purchase boron?

I've bought from TAI Lubricants in the States.

There's this stuff also:

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F281209478350

Im sure there's distributors in the UK but you might need to buy larger bulk quantity.

A little does go a long way (aprox a 1/2 tip of a screw driver with HbN to coat 100x 6.5mm bullets).

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Brillo

I got mine from a UK supplier but its not cheap as I had to buy  about .5 kilo.

I can let you have some if you want to collect for trials.

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50 minutes ago, DaveT said:

Brillo

I got mine from a UK supplier but its not cheap as I had to buy  about .5 kilo.

I can let you have some if you want to collect for trials.

Thanks Dave. I’ll message you.

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11 hours ago, Catch-22 said:

I've bought from TAI Lubricants in the States.

There's this stuff also:

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F281209478350

Im sure there's distributors in the UK but you might need to buy larger bulk quantity.

A little does go a long way (aprox a 1/2 tip of a screw driver with HbN to coat 100x 6.5mm bullets).

I’ve bought this stuff too. 

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Got mine here:

https://www.ebay.co.uk/itm/MICROLUBROL-1-oz-HEXAGONAL-BORON-NITRIDE-hBN-Powder-ULTRA-FINE-0-5-micron/281209478350?epid=1664883666&hash=item4179641cce:g:af0AAOxyRNJSiUTo&frcectupt=true

Very quick delivery.........and 25 gms will go a VERY long way.............

Pete

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