Gunsmithing Nitride Barrel Treatment - what do you know

[harloe]

Re: Nitride Barrel Treatment - what do you know

my 6.5x47 barrel just came back from nitriding - went from shooting better than half moa while breaking in to six plus moa (6+) I've had another barrel treated with great success. I'm hopeful that a lot more judicious cleaning will show different results next week. Still a bit panicked though, this was certainly unexpected.

Update; it's all good now. After several weeks - the trick was: Cleaning, cleaning, more cleaning, iosso, more cleaning, more iosso, more of everything then repeat.

 

[Lofty]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: harloe</div><div class="ubbcode-body">my 6.5x47 barrel just came back from nitriding - went from shooting better than half moa while breaking in to six plus moa (6+) I've had another barrel treated with great success. I'm hopeful that a lot more judicious cleaning will show different results next week. Still a bit panicked though, this was certainly unexpected. </div></div>

DOH!!

Well that certainly sucks.

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: harloe</div><div class="ubbcode-body">my 6.5x47 barrel just came back from nitriding - went from shooting better than half moa while breaking in to six plus moa (6+) I've had another barrel treated with great success. I'm hopeful that a lot more judicious cleaning will show different results next week. Still a bit panicked though, this was certainly unexpected. </div></div>

Where did you send it? MMI?

I sure hope smore cleaning gets it straightened out!!

 

[average_freak]

Re: Nitride Barrel Treatment - what do you know

So, my question is, is there any difference between doing these treatments with cut rifled barrels or button pulled? I would think that the cut rifling would hold up a lot better.

 

[Turk]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lance Criminal</div><div class="ubbcode-body">So, my question is, is there any difference between doing these treatments with cut rifled barrels or button pulled? I would think that the cut rifling would hold up a lot better. </div></div>
Because...?

 

[harloe]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: harloe</div><div class="ubbcode-body">my 6.5x47 barrel just came back from nitriding - went from shooting better than half moa while breaking in to six plus moa (6+) I've had another barrel treated with great success. I'm hopeful that a lot more judicious cleaning will show different results next week. Still a bit panicked though, this was certainly unexpected. </div></div>

Where did you send it? MMI?

I sure hope smore cleaning gets it straightened out!! </div></div>

Cleaning did do the trick, I was very happy today with the results today.

With a borescope I could see the residue in the barrel, but for the longest time I didn't think the cleaning was making a difference. After a few large helpings of iosso (ignoring rule #1, use sparingly) I could see this residue diminish and the mirror finish returning.

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: harloe</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: harloe</div><div class="ubbcode-body">my 6.5x47 barrel just came back from nitriding - went from shooting better than half moa while breaking in to six plus moa (6+) I've had another barrel treated with great success. I'm hopeful that a lot more judicious cleaning will show different results next week. Still a bit panicked though, this was certainly unexpected. </div></div>

Where did you send it? MMI?

I sure hope smore cleaning gets it straightened out!! </div></div>

Cleaning did do the trick, I was very happy today with the results today.

With a borescope I could see the residue in the barrel, but for the longest time I didn't think the cleaning was making a difference. After a few large helpings of iosso (ignoring rule #1, use sparingly) I could see this residue diminish and the mirror finish returning. </div></div>

Great news.

Currently, I'm not digging H&Ms "3-5 day" lead time. Currently sitting at 15 days. Sure would like my stuff back. My only accurate rifle in inventory right now is my TRG42 in 338. I like it, but want my moderate rifles back.

 

[ranger1183]

Re: Nitride Barrel Treatment - what do you know

So post-nitriding/meloniting it looks like some barrels require a "break-in", so to speak, of cleaning/bore conditioning. If this really fixes the post-nitriding accuracy problems this will put the nitriding method back on the table. Has anyone else been able to cure their accuracy problems this way?

 

[lw8]

Re: Nitride Barrel Treatment - what do you know

Can you nitride an action...say a 700 without affecting the factory heat treat and warpage?

Does it matter if its stainless or carbon steel?

Can you do the whole action including the bolt without the soldered bolt handle coming off?

Isn't the receiver supposed to be harder than the bolt?

Galling?

 

[Brandon05_88]

Re: Nitride Barrel Treatment - what do you know

If I had it to do over, I wouldn't mess with nitride.

I did an initial load work-up yesterday with my Surgeon and Bartlein that were nitrided. I pulled the firing pin by inserting a dime in the cut in the cocking piece. I like to bump the shoulder 0.001" and see how it feels closing a sized case without the firing pin assembly.

10 AM this morning, I pulled the firing pin, and left the dime in the slot holding the firing pin just slightly back. Set-up my sizer die, sized 50 cases, lunch, run to the grocery store, etc. Around 4:30 PM (6.5 hours), I went to put the bolt back together to shoot tomorrow. I usually dry fire the rifle before storing it. Dry fire and a chip flys backs and hits my hand. WTF. Look at bolt and half of the rear of the cocking piece chipped/blew out. Awesome. Dry fire again and the rest of it pops. The part that fills in the 'circle' at the back of the bolt shroud is gone. I can see the rear end of the firing pin. Still functional, but ugly as hell.

Guess I better call H&M Tuesday and see if they found a fix for the goofed muzzle threads and brittle cocking piece.

 

[ranger1183]

Re: Nitride Barrel Treatment - what do you know

How does nitriding "goof" muzzle threads? Or were they banged up somewhere along the line? Have any pictures of this that you can post?

 

[Brandon05_88]

Re: Nitride Barrel Treatment - what do you know

I'm not saying nitride itself will mess them up. The prep and company doing it is everything. I'm fairly positive H&M treated my barrel with my RAD brake installed. The instructions listed that the brake was shipped on the muzzle to protect it. They also listed to not treat the bolt that indexes the brake.

You can see not all of the threads were treated. The black area on the threads was where the cut in the brake was indexed to. Note the brake cross bolt is treated until the very end of the threads. It was installed. Note the condition of the brake threads. The threads in the upper left is the bolt handle threads of the bolt. They should have all looked like the bolt handle. I could have lived with them treating the brake bolt, no biggie. However, the brake would thread on a few turns then hit a wall. No go. Before melonite this brake, a thread protector and TBAC 30P-1 thread over the muzzle just fine.

They didn't follow my instructions. Either a corner was cut, they were in a hurry and/or the person doing them was inexperienced.

Fast forward to today. The cocking piece breaking. The bolt had 27 rounds of live fire and about 150 rounds of dry fire on it after melonite. I'm not a heat treat specialist, but how could this break? It must be brittle. How could it get this brittle? Was H&M in a hurry to process my lot of parts? Was the temperature not monitored correctly? Was the prep not consistent with other parts?

Sort of makes you wonder about the action doesn't it?

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

Brandon, could you post a pic/pics of the broken bits?

Sorry about the troubles!

 

[Brandon05_88]

Re: Nitride Barrel Treatment - what do you know

turbo, no need to apologize. It just sucks that after researching, saving, ordering, selecting a smith then waiting that little things pop up.

PM sent.

 

[SPAK]

Re: Nitride Barrel Treatment - what do you know

I've had a howa 1500 action nitrided before with no problems. Yet

However, they only did the receiver and the bolt body. All the small parts i.e. extractor, springs, firing pin assembly and cocking piece were not melonited.

Seems to be holding up ok.

Did they nitride your entire bolt assembly???

 

[lw8]

Re: Nitride Barrel Treatment - what do you know

This is what I was wondering....nitride could easily undo the factory heat treat and leave you with a brittle piece. Solder, multi piece bolts, ect...

 

[Turk]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: harloe</div><div class="ubbcode-body">my 6.5x47 barrel just came back from nitriding - went from shooting better than half moa while breaking in to six plus moa (6+) I've had another barrel treated with great success. I'm hopeful that a lot more judicious cleaning will show different results next week. Still a bit panicked though, this was certainly unexpected.

Update; it's all good now. After several weeks - the trick was: Cleaning, cleaning, more cleaning, iosso, more cleaning, more iosso, more of everything then repeat. </div></div>
I realize they say the process penetrates the surface , but after all of that cleanning w/ Iosso is there any treatment left???

 

[RWSGunsmithing]

Re: Nitride Barrel Treatment - what do you know

I would like to see pictures of the damage as well.

 

[Brandon05_88]

Re: Nitride Barrel Treatment - what do you know

Entire bolt assembly was not treated. The treated the bolt, bolt shroud, cocking piece and 2 bolt knobs. The action, barrel and brake were also treated.

Today I did some load development again. Everything seemed fine at the range. I get home and the bolt will not lift. Awesome. I pulled the barrelled action out of the stock, scope off, then trigger off. The front end of the cocking piece broke off.

Doesn't quite look normal. Guess I'm going to have to call H&M now.

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

Brandon, I'd sure like to know case hardness and core hardness on that broken cocking piece. Do you have anyone local that can ping it?

If not, I can do it if you mail it to me. I'd need to do some cutting/grinding to prep those parts though, if thats an issue.

I'm still confused how 1050-1075°F was able to get alloy steel <span style="font-weight: bold">harder</span>… I know ammonia is a Nitrogen-rich chemical that can be used instead of cyanide to provide Nitrogen atoms for the nitro-carb process. It is also a very Hydrogen-rich chemical, and Perhaps what we're seeing here is hydrogen-embrittlement...?

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

Those fracture surfaces clearly indicate a "brittle failure". There is no evidence of any material deformation.

 

[lw8]

Re: Nitride Barrel Treatment - what do you know

That's what makes me wonder about using this process on actions....seems like it could cause the action to be brittle. Not to mention bolts and whatnot.

 

[Brandon05_88]

Re: Nitride Barrel Treatment - what do you know

turbo, PM me ya address, and I'll get it out to ya. It wouldn't bother me a bit if ya cut on it to test it. I doubt it's still usable.

 

[Turk]

Re: Nitride Barrel Treatment - what do you know

The more I see stuff like this either I would deal w/ Joel Kendrick or not do it all.

 

[Adam B]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">The more I see stuff like this either I would deal w/ Joel Kendrick or not do it all.</div></div>
+100000000000

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Adam B</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">The more I see stuff like this either I would deal w/ Joel Kendrick or not do it all.</div></div>
+100000000000 </div></div>

In all fairness, y'all have NO idea what went wrong in Brandon's case, or who to blame.

Furthermore, heat treatment facilities get stuff wrong occasionally (more often than many other industries)...period. MMI is no different.

Don't forget that:

1. H&M built the facility that now is MMI.
2. Dozens of top-flight firearms manufacturers use H&M.

I don't have any dog in this fight - but think it's important to keep things in perspective.

 

[Turk]

Re: Nitride Barrel Treatment - what do you know

Really? How many possibilities do you see that are responsible for messing up?

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">Really? How many possibilities do you see that are responsible for messing up? </div></div>

How about flawed material? Steel mills don't make "perfect" material every time you know...

ETA: Look, I'm not trying to absolve H&M of responsibility. I am, however trying to not jump to conclusions.

 

[Turk]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">Really? How many possibilities do you see that are responsible for messing up? </div></div>

How about flawed material? Steel mills don't make "perfect" material every time you know...

ETA: Look, I'm not trying to absolve H&M of responsibility. I am, however trying to not jump to conclusions. </div></div>
I guess it's possible that the brake and the cocking peace are flawed eventhough they are from different manufacturers!!!

 

[Adam B]

Re: Nitride Barrel Treatment - what do you know

Having had 30+ complete rifles of my own treated, I can say without a doubt that Joel Kendrick knows what he is doing. I feel sorry for the OP because he is going to be out some hard earned cash and may have more issues down the road if his treatment wasn't done correctly as it appears to not have been.

 

[ddavis]

Re: Nitride Barrel Treatment - what do you know

I've had a whole rifle done by H&M and am very pleased with the results. So far nothing has shattered. Please let us know what they are able to do for you.
-Dan

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body">Really? How many possibilities do you see that are responsible for messing up? </div></div>

How about flawed material? Steel mills don't make "perfect" material every time you know...

ETA: Look, I'm not trying to absolve H&M of responsibility. I am, however trying to not jump to conclusions. </div></div>
I guess it's possible that the brake and the cocking peace are flawed eventhough they are from different manufacturers!!!

</div></div>

You're right on account of the brake - it was clearly treated while installed.

I was referring primarily to the broken cocking piece.

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Adam B</div><div class="ubbcode-body">Having had 30+ complete rifles of my own treated, I can say without a doubt that Joel Kendrick knows what he is doing. I feel sorry for the OP because he is going to be out some hard earned cash and may have more issues down the road if his treatment wasn't done correctly as it appears to not have been. </div></div>

That is great! I'm sincerely glad you've had great luck with MMI, and it seems they do a great job.

That said, H&M treats all Smith/Wesson M&P pistols, so they too, can point out thousands of success stories.

 

[Turk]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Adam B</div><div class="ubbcode-body">Having had 30+ complete rifles of my own treated, I can say without a doubt that Joel Kendrick knows what he is doing. I feel sorry for the OP because he is going to be out some hard earned cash and may have more issues down the road if his treatment wasn't done correctly as it appears to not have been. </div></div>

That is great! I'm sincerely glad you've had great luck with MMI, and it seems they do a great job.

That said, H&M treats all Smith/Wesson M&P pistols, so they too, can point out thousands of success stories. </div></div>
Or that they don't treat the individual the same! And how do you know S&W doesn't catch their messup's and you never hear about them?

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Adam B</div><div class="ubbcode-body">Having had 30+ complete rifles of my own treated, I can say without a doubt that Joel Kendrick knows what he is doing. I feel sorry for the OP because he is going to be out some hard earned cash and may have more issues down the road if his treatment wasn't done correctly as it appears to not have been. </div></div>

That is great! I'm sincerely glad you've had great luck with MMI, and it seems they do a great job.

That said, H&M treats all Smith/Wesson M&P pistols, so they too, can point out thousands of success stories. </div></div>
Or that they don't treat the individual the same! And how do you know S&W doesn't catch their messup's and you never hear about them? </div></div>

I'm sure they DO mess up S&Ws stuff sometimes! Nature of the heat treat business. Point being, S&W (and other top flight firearms companies) continue to use them.

 

[Adam B]

Re: Nitride Barrel Treatment - what do you know

personally, I think you will get better service with Joel, I know I have but YMMV

 

[Turk]

Re: Nitride Barrel Treatment - what do you know

Thanks, I'll keep them in mind when I want to refinish a M&P; in the mean time all the precision stuff goes to Joel.

 

[Brandon05_88]

Re: Nitride Barrel Treatment - what do you know

I spoke with Shade at H&M this morning. He apologized for not getting back with me. No biggie, I understand they're busy. He mentioned the muzzle threads would have to be chased. The brake may or may not be able to be worth it. I sent the barrel and brake to a reputable and experienced gunsmith on the Hide. He made both the barrel and brake right.

Shade offered to re-run my barrel and brake. I declined the barrel since it is on the action, and I've started load development. I am sending the brake to be coated in black oxide to match the melonite.

I mentioned the cocking piece. He said it's the first time they've ever heard of it happening. He asked to send that also for testing. I'm sending them both today. He even mentioned they've process numerous Surgeon actions, and this has never happened. The small parts were treated at the lowest possible temp to nitride for a duration of 30 mins.

I give H&M my respect to try and make this right. I never intended this to become a pissing match between nitriding companies. I intended to offer someone my experience with nitriding. I think it is a great no-maintenance finish. I will say I am hesitant to recommend it for anything for the utmost in precision.

 

[Brandon05_88]

Re: Nitride Barrel Treatment - what do you know

I got off the phone with Shade at H&M. The Surgeon cocking piece was made out of tool steel that was already 60 Rockwell. Since the piece was actually polished in the rear, they thought it was stainless and treated with the rest of the parts at the lowest possible temperature for 30 minutes.

They process all chromoly/stainless gun parts at the lowest possible temp for 30 minutes. Tool steel parts are normally run at the lowest possible temp for 7 minutes. Since the tool steel part was ran for 30 mins, it became fairly hard...80 Rockwell hard. He mentioned he was not suprised it broke from being so hard.

He assured me that the chromoly action/bolt/brake and stainless barrel/bolt shroud/bolt knobs were fine. So far she is shooting good. I'll have a load tied down tomorrow hopefully.

Shade was great to work with through this. He received the part this morning, tested the part and called me by 2 PM with the results.

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

Thanks for the update, Brandon...

...though I am confused by Shades analysis.

Steel does not get to 80Rc. Steel can get to ~61-63Rc depending on alloy. Regardless, to achieve that, it must be heated above the transfer temp, and put into the martensite phase, which is generally about 1575°F. The grains must be given time to grow, and then they must be frozen by quenching. No amount of heat and no quench type can get steel to 80Rc.

FNC (ferritic nitro carburizing) achieves 70+ Rc on the surface only, because nitrogen atoms are diffused into the material, and oxides form. The "steel" doesn't achieve 80Rc, the oxides do. The penetration is low - on the order of .005"-.015".

Meanwhile, the ~1050°F temperature actually tempers (softens) the base metal.

If you had a piece of tool steel at 60Rc, and soaked it at 1050F for hours and hours, it would come out at ~30Rc.

...would love to hear more details, cuz this doesn't add up, according to my understanding of metallurgy.

 

[Lofty]

Re: Nitride Barrel Treatment - what do you know

How would one get in touch with Mr. Kendrick?

 

[308sako]

Re: Nitride Barrel Treatment - what do you know

xxx

 

[Edds]

Re: Nitride Barrel Treatment - what do you know

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Thanks for the update, Brandon...

...though I am confused by Shades analysis.

Steel does not get to 80Rc. Steel can get to ~61-63Rc depending on alloy. Regardless, to achieve that, it must be heated above the transfer temp, and put into the martensite phase, which is generally about 1575°F. The grains must be given time to grow, and then they must be frozen by quenching. No amount of heat and no quench type can get steel to 80Rc.

FNC (ferritic nitro carburizing) achieves 70+ Rc on the surface only, because nitrogen atoms are diffused into the material, and oxides form. The "steel" doesn't achieve 80Rc, the oxides do. The penetration is low - on the order of .005"-.015".

Meanwhile, the ~1050°F temperature actually tempers (softens) the base metal.

If you had a piece of tool steel at 60Rc, and soaked it at 1050F for hours and hours, it would come out at ~30Rc.

...would love to hear more details, cuz this doesn't add up, according to my understanding of metallurgy. </div></div>
I know it's tough to give a diagnosis about something when you haven't examined it but what is your best guess about what went wrong with these parts?

I don't know anything about metallurgy but those broken parts look like a casting to me.

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

The crystalline structure appears much finer than a casting normally does to me. Obviously, the failure is a brittle one, there are zero signs of necking/bending at the failure points. I just don't buy the core harness being 80Rc. Goes against EVERYTHING I know about metal... ...I'm not a metals Einstein, but I've studied it, been interested in it, and worked in the field a fair amount. The fracture surfaces show no sign of "blackening", which I'd expect to see from the treatment if it had an existing crack.

So, assuming no material flaw and assuming the part simply got too hard and brittle, we have to consider the part was "embrittled".

There are two key embrittlement processes: hydrogen embrittlement and temper embrittlement.

Hydrogen EMB comes from hydrogen atoms diffusing into the metal at high temp, just the same way FNC relies on nitrogen atoms to diffuse into steel (melonite). Any high-temp steel processing requires care to keep hydrogen are away. Simple negligence or incompetence is often the root cause of hydrogen embrittlement.

Temper embrittlement is a huge decrease in fracture toughness (ability to not break when whacked by a hammer), due to processing at elevated temperatures where tempering takes place. Mainly, between 850°F and 1115°F. This effect is hugely dependant on alloy, and impurities in the steel. Essentially, Manganese, Chromium and Nickel are the alloying elements in steel to make it susceptible to temper embrittlement. The higher the percentage, the more brittle the steel becomes. Phosphorus is the key impurity that really makes the brittleness bad.

Now, Brandon's cocking piece was said to be "tool steel"...whuch really doesn't mean mych because there are dozens of different types of tool steel, with widely varying chemical makeups... What does Surgeon use? I have no idea. D2 is a lovely tool steel, that is very strong and provides very good corrosion resistance. It also has lots of Chromium in it.

This is just a WILD ASS GUESS here, but maybe what Shade claimed, regarding cycling the part (had he known alloy) for much less time actually jives, because the core of the part wouldn't have had time to get into the embrittlement temperature region. Cycling for 30 minutes guarantees the entire part got to full temp.

Again, this is just pure speculation....and completely goes against the tenants of PROPER failure analysis, so take it for what it's worth - which probably ain't much. I encourage anyone interested to read up on temper embrittlement and post your thoughts!

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

And, I'm rather pissed at H&Ms quoted 3-5 day processing leadtime...

They've now had my parts 3 weeks. Twice now I've been told "should ship tomorrow"...

They are 1 shipping day away from me - They received my parts the morning after I shipped them, which means I've now been mislead/lied to 3 times regarding the timeline of my parts.

Tonight, I just learned there is an outfit 20 minutes from my house that does saltbath FNC. Think I'll be talking with them.

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

So, my parts finally arrived from H&M. There were lots of little bits/pieces...as in every part of a Savage and an FN SPR, save for the springs. None were lost! The finish turned out beautiful and they did a great jib ckeaning - no crud on anything, except for inside the bores.

Speaking of which...

It is not easy to clean a bore after melonite!

I tried water, alcohol, acetone, Sweets, Gunslick foam and Iosso paste. What finally seemed to work was scrubbing the shit out of the bore with a nylon brush with Iosso.

I put the muzzle against a wall, and stroked the brush back and forth 10 times, dipped the brush in water, stroked, water, stroke. Patched it out, then repeated. Took a good 10 cycles to get it clean. Probably spent 3 hours on it.

Took the rifle out today - no idea on velocity, but my ladder tests show promise. Looks to be some good nodes in there.

Also, everthing went back together nicely.

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

Now that I've cleaned up 4 melonited barrels, I've got the technique down pretty well. Here's what I've come up with:

Supplies:

Cleaning rod that allows the shaft to spin and follow the rifling
nylon brush for your caliber
spear-tip jag for your caliber
patches for your caliber
Soapy water
Iosso bore paste

First, you need to get the heavy stuff out. Get a cup of hot, soapy water, dip your nylon brush into the cup, and stroke 5-10 times (both ways is fine, you're not going to hurt a damn thing). Rinse the brush in your cup, and keep stroking. Do this routine 5-10 times altogether, dipping/rinsing your brush every 5-10 strokes.

Dry patch the bore

Install your jag, dope up a patch with some Iosso paste, put your muzzle up against the wall (makes it easy to reverse the jag/patch in the bore, because the jag doesn't come out the end of the muzzle), and "lap" the bore with a couple strokes. Pull the jag/patch out, dip it in clean water, and "lap" the bore with a few more strokes. HINT: Your Iosso'd patch will turn brown very quickly.

Dump the foul soap/water solution, and prepare a new, clean one. Reinstall your nylon brush and go back through the stroke/rinse routine you did previously.

Dry patch

Repeat the jag/patch/Iosso routine

Repeat the nylon brush/soapy water routine

Look into the bore, particularly at the grooves. They should now be 99% mirror smooth, with the exception of the appearance of a "film" or "residue" in some spots. If the grooves don't look 99% beautiful, continue the above process until it is.

I found that I simply could *not* get the bore 100% beautiful no matter how much I scrubbed it. However, I've also found that once the bore is 99% clean, if you fire a couple shots and then clean again, it will be 100%

I've also seen that accuracy for those "cleaning shots" is garbage. The latest barrel was a 7mm-08. I got it 99% clean, fired a 5 shot group that measured about 3 MOA, then spent about 5 minutes doing the final clean. The next group was 3/8 MOA.

Here are a couple pics of my 284. All the metalwork has been melonited...

 

[SPAK]

Re: Nitride Barrel Treatment - what do you know

Turbo

How often do you clean your bore with the melonite ??

I've been using hoppes 9 and kroil in a 50/50 mixture soaking the bore really well and letting it soak for about 10-15 min then Dry patching out. After that I spray wipeout foaming cleaner and let that sit for about 15 min and then dry patch it. All I get are just a few specks of blue for the first two or three patches then just a slight brown residue on my patches.

It takes a while until the patches come out completely white..but eventually they do.

How do you inspect the grooves if you don't have a borescope?? Do you just look at the muzzle end??

I'll have to try the soapy water and iosso. Doesthe brown color on the iosso patch mean anything in particular as far as what it's bringing out of the bore??

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

I just hold the barrel up to the light and look in. It is NO substitute for a borescope, but I've learned to get a decent look this way.

I do plan to purchase a scope soon - a partner and I have put in for our FFL to manufacture... Just have to recover from the recent equipment purchases!

I don't have enough rounds through yet to have a feel for how often to clean. I can say that with other barrels, I'm used to seeing a very dark royal-blue patch after an hour soak with gunslick foam, after 100+ rounds.

This barrel, after 150 rounds, only yielded a blue twinge from the gunslick...

 

[turbo54]

Re: Nitride Barrel Treatment - what do you know

An addendum to what I wrote a couple posts above regarding getting your bore totally cleaned up after melonite:

I posted this in another thread, so I'm just gonna copy/paste it here for posterity...

Update:

My rifle wasn't acting like a rifle with H4350. I cleaned the bore and tried H4831sc. It acts like a rifle, and works nice with the 180s, but is just too sliw for 162s.

I noted, after initial melonite cleanup, there was some kind of "film" in the grooves I couldn't remove. I tested H4350, bad results, but after I cleaned before trying H4831sc, the grooves in the bore looked great.

I decided to try H4350 again. Night and day difference!

I'm now seeing 2850fps with 51gr, up to 3050!!!! at 55gr. 55gr is too much - hope to find accuracy at ~2950 or so with the 162s.

Here is a shot of the chrono at 52gr...