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Posted: 10/23/2010 7:03:29 AM EDT
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I have a 16" HBAR Middy Rock River Chrome lined barrel with a YHM Diamond Rifle length rail. It is just stupid heavy. Wish I had a rail like a JP VTAC or similar, don't need all that rail. Just a scope,, flashlight, foregrip, and an old holosight! Was thinking of doing a "Heavy Feather" ie., custom profile. This is for my hillbilly SPR type use- day/night varmints etc. Thinking of going gas block dia. from chamber area to gas block, then about ".68 ish to the muzzle.....Will re stamp twist and whatnot on barrel.
I did put this upper together and it shoots great, and have a friend with a lathe. Was going to bead blast when done and cold blue. What says the hive? This is a no money type mod, my favorite! Weight savings worth it? Will get back to you this afternoon, thanks Lockstep. Update––- O.K. Sunday evening finds the project home parkerized. I'm waiting till tomorrow to wipe the oil off the barrel and see how I did. As far as re stamping the barrel, the original marks are still near the chamber area which was not cut down there. I guess this is a Wilson sold to Rock River, I did look online for some info about it, but didn't try to hard since I already knew what I had- Have box and papers. For the Park I used a recipe I found online,- One gallon distilled water, 1/3 cup Kleen strip phosphate stripper, manganese phosphate from one D cell alkaline battery (the black stuff) and some steel wool four ought. Today I did make my own tank from an old stainless steel fire extinguisher cut in half lengthwise, and took before and after pics of the barrel, my homemade barrel wrench and related things. Will try to post these tomorrow for others to learn from... I think the finish might be thin, and I will re bead blast and try again tomorrow. The whole point of the exercise was to do it all myself, learn a lot, spend very little -14$ so far, and to remain self reliant as possible. Lockstep |
| just recently posted about doing this to my h-bar. i was happy with the end result. i to have a "friend with a lathe." but he is a well accomplished machinist, and did great work. the accuracy was not affected on the barrel at all from what i've shot it so far. this could go either way. you will love the weight savings but will sweat the effect on accuracy till you know for sure how it shoots. my barrel was a dpms 16 in 1in9 twist run of the mill h-bar. if it got ruined , i just would have tossed it and bought another. all worked out well for me but, YMMV. the question is, can you afford another barrel if this goes bad on you? |
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Your friend will want/need to recrown the muzzle to insure the best outcome. I suggest anything but cold blueing, it rarely looks very good when finished. Osphor Blue cold blueing (spelling?) as sold by Brownells has a good reputation but still is less attractive then your other options.
Sending the barrel to ADCO after machining will get it refinished in any color you like for around $25.00 I think. Reparkerizing is an option too, it isn't costly like a professional blueing job. It will look as good as, if not better than new, when done right. I like the heavier front end on HBAR barrels. I feel that's the proper diameter for an AR15. Something along the lines of .800" under the handguard is plenty sturdy for my purposes and leaves a nice shoulder for the gas block to butt against. 9" to 10" float tubes fit me fine, my arms don't need anything longer than that. |
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I did this some time back on the HB on my Oly carbine. Turned it down to a sort of medium profile. .75" dia. aft of the GB. .65" dia. forwards of it. No taper or anything fancy. Took over a pound of steel off it in the process. Still more accurate than I am.
But for gosh sakes don't cold blue it! At least use something like moly resin or park. Both are easy enough for the home hobbiest to do. Once I had the barrel off and taken down it was just 30 minutes work on the lathe. My lathe holds run out to five ten thousandths. I believe three ten thou is standard for match good grade work. It was close enough for me. It sure made that carbine handier! |
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I cheated and had ADCO do mine. They turned the 16 HBAR midlength (heavy SOB) to a MedCon profile and then chopped/crowned/pinned the barrel at 14.5 to get a 16" OAL.
LOVE it. You could hit it with AlumahydeII park and that shoudl hold up well. it has on my pistol, an AK, and the barrel of one of my ARs. |
Well, It's turned down now. The Length was not changed, just re contoured. The profile is now like a featherweight, except at the thin points it is .650" in dia. instead of .550". My own "Heavy Feather". Thanks for all the input and good advice. Took a lot longer than bargained for, setup was fun. The tailstock on the lathe came out of its threads because the three small screws that held it together decided to let go while removing the morse taper drill chuck! Then the lathe speed we wanted to run didn't work. Too fast or too slow was all that was available, so I opted for slow..... Tomorrow I will bead blast it and visit the gun shop for some finish other than cold blue. I did mock it back together and it is quite a bit lighter. 
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Quoted:
Well, It's turned down now. The Length was not changed, just re contoured. The profile is now like a featherweight, except at the thin points it is .650" in dia. instead of .550". My own "Heavy Feather". Thanks for all the input and good advice. Took a lot longer than bargained for, setup was fun. The tailstock on the lathe came out of its threads because the three small screws that held it together decided to let go while removing the morse taper drill chuck! Then the lathe speed we wanted to run didn't work. Too fast or too slow was all that was available, so I opted for slow..... Tomorrow I will bead blast it and visit the gun shop for some finish other than cold blue. I did mock it back together and it is quite a bit lighter. You know the deal, pics or ...... |
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Quoted:
Well, It's turned down now. The Length was not changed, just re contoured. The profile is now like a featherweight, except at the thin points it is .650" in dia. instead of .550". My own "Heavy Feather". Thanks for all the input and good advice. Took a lot longer than bargained for, setup was fun. The tailstock on the lathe came out of its threads because the three small screws that held it together decided to let go while removing the morse taper drill chuck! Then the lathe speed we wanted to run didn't work. Too fast or too slow was all that was available, so I opted for slow..... Tomorrow I will bead blast it and visit the gun shop for some finish other than cold blue. I did mock it back together and it is quite a bit lighter.
OK, now send it to ADCO and shorten it to 14.5 and you're done. |
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Quoted:
Quoted:
Well, It's turned down now. The Length was not changed, just re contoured. The profile is now like a featherweight, except at the thin points it is .650" in dia. instead of .550". My own "Heavy Feather". Thanks for all the input and good advice. Took a lot longer than bargained for, setup was fun. The tailstock on the lathe came out of its threads because the three small screws that held it together decided to let go while removing the morse taper drill chuck! Then the lathe speed we wanted to run didn't work. Too fast or too slow was all that was available, so I opted for slow..... Tomorrow I will bead blast it and visit the gun shop for some finish other than cold blue. I did mock it back together and it is quite a bit lighter.
OK, now send it to ADCO and shorten it to 14.5 and you're done. If he can reprofile and restamp the marking he can probably do a cut  But he said in his opening post it is a varmint gun. Also said it is no budget project. further more why would you want to cut a middie to 14.5?
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Here is pics
Parts, homemade wrench and turned down barrel, soon to be cut in half fire extinguisher. 
Heavy Feather .650" Barrel about to be cooked a bit 
Cooking on the second attempt, first time it didn't "Stick" well.? 
Oiled barrel after second attempt, looks exactly the same as first failed try to me.... and some bolts for my car restoration project 
If this second try does not produce a good result–– park thick enough, I think I'll cold blue over the top and call it a day on this project. Wish I had figured out the park process two years ago, for my car resto. To sum up- a big PITA Lockstep |
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Have you conditioned your park solution?
It needs used and abused a bit before you get good results with no splotchiness. Disolve a bisquit of steel wool in it. parks some saned scrap steel. let the solution heat up and cool down a few times. Add more demin water to make up for boil off. After the solution has been used like that a while it gives far better results than when new and fresh. I have a SS restaurant steam table pan that I place over a camp stove. Works great. ETA. Some abrasives lie aluminum oxide can put aluminum into the steel and prevent good parking too. I use sand paper, not emory cloth for prep work. My blast cabinet uses a mix of sand and beads. No aluminum oxide. I learned my lesson when I turned down my Oly Hbar. I just polished it up with emory cloth while I had it chucked in the lathe. I even solvent cleaned the steel afterwards. But the park would just NOT work on the steel. So I just moly resined it and baked it. Tried some experiments after that. It was the abrasive that messed it up. I should have used plain sand paper or just blasted it afterwards. |
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