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Posted: 5/23/2005 5:52:19 PM EDT
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OK so, I now live in WA and as anyone whom lives here can tell you, you can't be an AR15 enthusiast without stopping in for an Oly part at least once. I think Oly makes good products overall despite some complaints about q/c in the past (I too have seen one of the problems). While there I asked one of the employees why they do not use chrome lined BC and barrels (one reason why I don't use their BC and barrels). His response was the same as every barrel manufacturer that does not use them- problems with the process, loss of accuracy etc. They do use what they call "Tac Black" on their BCs. They claim that this new process is just as viable as chrome lining inresisting corrosion and increasing longevity. He showed me some salt water submersion tests that they did to prove it (I have no idea if it was a scientific test or not, I don't assume it was or it wasn't) and they looked pretty promising. They also have introduced "Max Hard" metal treatment that is supposed to raise their barrel hardness to 62Rc. Now, I am not a metal specialist and I don't know what that means (maybe someone could shed some light on the Rockwell hardness scale and where a normal chrome moly barrel lies, also what sort of hardness does chrome lining add). Wasn't Robinson Armament as a part of their XCR developement supposed to come out with a new type of lining or treatment that was supposed to be better than chrome lining? All of this got me thinking if anyone else has ever heard of other types of linings? I do not intend to start an Oly bashing thread- lets keep it civil and as factual based as possible- we all know their past and are aware of the q/c issues- lets drive on. Opinions? Other thoughts? |
Stickman, have you had any reliability issues with the "Black Tac" over standard Chrome Lining? Specifically during extended "dirty" use? |
No, but I will also add that I have not done any extended long term testing of a Black-Tac carrier or bolt leaving the weapon dirty for extended periods. I recently completed a dry lube test, and wasn't real impressed with that after 500-700 rounds on a BT carrier and bolt, but I doubt the BT finish had much to do with that. After 700 rounds things went down hill.... |
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Does anyone know where to find the thread about the company that makes M2 barrels and now AR15s? I did a search but could not find it. I would like to e mail them about the Stellite lining. Stickman- I have never done a dry test before on mine- always run them with lube- I might have to try that. |
I did not run a dry test, I ran a test and evaluation of a dry lubricant. There is a huge difference. |
I think you probably found that dry lube is as good as no lube. Essentially what you did is a dry test. I have yet to find a dry lube that is worthy of serious weapons work. I would expect my rifle to run for 700 rds dry, therefore, dry lube did not add anyhting significant to the test. |
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Stickman- I didn't mean to get under your skin. I have tried two (not very many, but enough to draw some sort of a conclusion) kinds of dry lube with not so great results. While I was on TDY in AZ, I used one to avoid the dust gumming up my weapon. It worked great for that purpose but not so well for lubricating. It was Militec. I had about the same performance that you had (slightly over 500 rds) before failures. The other lube I had was a cheaper dry lube made by Hoppe's (I think). It had even poorer performance. What type were you running? My point was that with only about 600 rds worth of performance from the lube, you could probably run your weapon dry and get the same performance. I have not tested any of the newer bake on dry lubes but, would like to see their performance. Most dry lubes work great on low fricion parts like mags, receiver extensions, etc. For actions, I prefer wet lubes- even in dusty environments (I don't mind the extra maintnence). This is way off my original point of this thread so................... Does anyone have any useful information about the processes mentioned in this thread (metals etc.)? I am close to giving up on this all together. |
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I got in touch with Sabre Defence and got a response on the Stellite lining: Alan, Thank you for checking out our AR rifle line! As you noted the 50 M2 barrels that we manufacture all have a stellite liner this helps prolong the life of the barrel by almost twice. The main reason is that the stellite liner resists flame cutting of throat erosion due the 50BMG being very "over bore capacity" simply meaning that the size of the case (powder capacity) is out of proportion to the bore diameter but this is not a wimpy target cartridge but a real "kick ass" battle tool meant to break down heavy vehicles and building material to even light armor so less powder is not an option. also most belt feed weapons put extra stress on the throat area because of the high heat generated by the large amounts of ammo these weapons are expected to fire between breaks. The M16/5.56 has some erosion problem but not to the extent the M2 or many belt feed Machine Guns have and the stellite liner make up about 2/5th's of the cost of a barrel as the stellite is very hard to machine and fit into the barrel and then chamber thru. The stellite liner is a short sleeve made from a rod or casting of solid stellite , then turned,bored,rifled then inserted into the barrel as the rifling is matched up to the rifling that is all ready in the barrel, under great pressure and locked into place by a machined retainer as opposed to a coating of some kind like the chrome lining of most all military barrels (even the stellite lined barrels still get the chrome lining as well). Then the chamber is reamed thru the retainer and a portion of the stellite liner so as to leave the longest part of the stellite to serve as the throat of the chamber. To sum it up you could buy two chrome lined AR 15 barrels for the cost of one stellite lined barrel which would only last for 3/4 longer than a non stellite lined barrel. We do however take every step reasonable to make the best AR15/M16 barrel available by using the same high vanadium alloy steel the U.S. Government demands on all of there machine gun barrels which gives much better throat life than even 4150 and a chrome lining. We do offer hard chrome lining of the chamber and bore for those who might need it for sustained full auto fire or to offset the lack of maintenance while in the field, however there is a slight decrease in accuracy due to the chrome lining as compared to the same barrel with out the chrome. I hope this long winded explanation helps out. Grant Morgan Commercial Products Manager Sabre Defence Industries LLC, 450 Allied Drive Nashville Tn. 37211 Phone (615) 333-0077 Fax (615) 333-6229 (www.sabredefence.com) |
Nope, regular 4140 and 4150 chrome moly barrels contain no vanadium. IIRC, this was discussed recently on another Sabre Defence thread and Tweak post the specifics about the different barrel steels. |
Yojimbo, do you have a link to the old thread? I did a search but could not find it. |
Okay, I got off my lazy ass and found the link. Tweak posts the barrel material info near the end of the thread. www.ar15.com/forums/topic.html?b=3&f=118&t=235033 |
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