HBN bullet coating
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I have read that this reduces ES and SD specially in old loaded ammo, I wonder if you can verify or disprove this information? please comment your experiences.
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I have some on order to try for this very reason. My question is do I need to clean the barrel really good prior to shooting the coated bullets or leave it fouled.
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Can't help you, sorry I have no experience with HBN. But I would clean it really good before trying it. I ordered an expander die and dry neck lube to lube the bullets before seating them, if that doesn't lower my SD and ES enough then I'll try with HBN.
Here are two links to read about HBN coating, if it is not allowed to post links please simply delete them.
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@toni
My main reason is to reduce or illuminate the lock for lack of better words the bullet and brass form over time. I see a difference in loads that have been loaded 4 or 5 weeks vs loaded for a few days. I’m pretty happy with my ES and SD’son freshly loaded rounds anyway.I’ll read those links later tonight thanks
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@bull81 said:
@toni
My main reason is to reduce or illuminate the lock for lack of better words the bullet and brass form over time. I see a difference in loads that have been loaded 4 or 5 weeks vs loaded for a few days. I’m pretty happy with my ES and SD’son freshly loaded rounds anyway.I’ll read those links later tonight thanks
You evidence of fresh loads over 4-5 week old ammo??
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@martino1 said:
@bull81 said:
@toni
My main reason is to reduce or illuminate the lock for lack of better words the bullet and brass form over time. I see a difference in loads that have been loaded 4 or 5 weeks vs loaded for a few days. I’m pretty happy with my ES and SD’son freshly loaded rounds anyway.I’ll read those links later tonight thanks
You evidence of fresh loads over 4-5 week old ammo??
I don’t have copies of the chronograph results to post but yes I see higher ES and SD’s with ammo that’s been loaded 4 or 5 weeks vs loaded a few days.
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@bull81 hmmm. Would that be the brass slowly creeping and relieving stress and thereby changing neck tension?
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I have observed that as well.
My hypothesis is that it is the similar metals “sticking” to each other, which varies bullet release.
I no longer US clean for this reason, unless it’s AR blasting brass.
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@hypo said:
@bull81 hmmm. Would that be the brass slowly creeping and relieving stress and thereby changing neck tension?
Can’t really say for sure either way. I would think if that was the case it would relax and reduced neck tension not increase it though. My average MV will stay the same but the ES is what really suffers the most on ammo that’s been loaded for a while.
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@tackyp said:
I have observed that as well.
My hypothesis is that it is the similar metals “sticking” to each other, which varies bullet release.
I no longer US clean for this reason, unless it’s AR blasting brass.
I only clean with rice and have for several years, I do use a US for pistol stuff though. I’ve pulled bullets that have been loaded for a year or longer and they were very hard to pull and very inconsistent. Some would make a popping noise when they broke loose. I’m “thinking” that the increase in ES on ammo loaded for a month or so is in the first stages of this bonding and is the cause of the inconsistency
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If HBN bullet coating actually reduces ESs and SDs, it seems to me one might find evidence for that when looking at reduced axial force due to the more slippery HBN coating (much like what's going on when looking at the difference between a very clean neck and one with the carbon coating left on after being fired).
I came across an posting I found interesting and gave me a little more insight into neck tension, so I thought I'd share it . . . here: Case Neck Tension - A Stress Analysis
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Got some HBN in last week and coated 200 bullets messing around with it. Had to increase my charge weight by .3’s to get velocity back up to where it was before but that was expected. My first batch was not as consistent as I would have like but didn’t show any negative affects as far as accuracy goes, but my first round was consistently 30 fps slower which is odd because that’s what this coating is supposed to eliminate. My uncoated rounds are usually around 15 fps slower in the first round out the barrel. I used bullets from that first batch and won the 1000 yard match this past Saturday, but every relay the first sighter round was .2 Mil low. I just coated a second batch and followed the direction (didn’t have the directions for the first batch) and they turned out much more consistent and are slippery as hell, they are hard to pick up they are so slick. Gonna do some more testing and see if this helps with the first round velocity. As for the ES and SD mine stayed pretty much the same but my regular uncoated load had very low numbers to start with. I’ll update this thread after testing the second batch in the next few days.
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You seem to be encountering the very thing I've read regarding this and other bullet coatings; consistency.
The issue seems to be the batch to batch consistency of the application. Then there is the argument as to whether the coating/treatment behaves desirably over time. Does it soak up contaminants from the air? Will it hard-lock with case necks if left loaded for long?
I've been anxious for this testing, because based only on what I've read it seems as if these things increase variables quite a lot... and I'm a fan of removing variables. I'll continue to watch this with interest. :)
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Ok coated my second batch as per the instructions and had much better results. With naked bullets I had around a 15 fps drop in velocity cold bore, after that first shot the rifle would have to sit for quite some time before the first round would drop in velocity again. After coating the bullets in HBN the first time I had a very repeatable 30 fps drop in velocity for the first round but the drop in velocity would reoccur much sooner than before. The first batch of bullets didn’t look to be coated as uniformly as I expected, but after finally getting the instructions by email I followed them exactly for the second batch. The second batch turned out extremely uniform and extremely slippery. They are actually hard to hold on to if your not paying attention. I fired 5 rounds yesterday from the second batch and five rounds today and had zero drop in velocity for the first round either time. Below is a picture from the chronograph today, yesterday’s results were the same I just didn’t take a picture.
I understand this is a small batch of data but at this point it’s showing promise. Everything I’ve been able to find states HBN is not affected by moisture once it’s applied but if any moisture were on the bullets themselves during the coating process it would create issues which is understandable. My main purpose was to see if the coating could help reduce or prevent the bonding between the bullet and brass over time, I’ve heard mix reviews about this though. I plan on loading 20 rounds and let them sit for at least 6 weeks and then compare the results against freshly loaded rounds. I will say that I do believe the barrel is running cooler during long strings with the coated bullets vs uncoated. I noticed at the match last weekend the barreled cooled down to the touch very fast between relays compared to a friend of mines barrel shooting the same cartridge and same barrel contour. I know that’s not very scientific but I thought it was worth noting.
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Those are some very good numbers, what numbers did you have with uncoated bullets in your previous load?
Have you used dry graphite or imperial wax in the neck of the cases too?
This is what I like of this site, experiences rather than theory. Thanks for sharing Bull81
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@toni
My uncoated number are pretty much the same for 5 rounds minus the cold bore shot. This coating seems to eliminate the cold bore drop in velocity when applied correctly. I’ve never tried the graphite or any other neck lub. I just clean with rice and use a nylon brush to brush the dust out of the necks prior to charging powder and seating bullets.I’m hopping the coating reduces the inconsistencies I see in ammo loaded for extended periods of time, so time will tell.
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@bull81 said:
I’m hopping the coating reduces the inconsistencies I see in ammo loaded for extended periods of time, so time will tell.
I'm very interested in this factor, as well as what happens to your barrel over time.
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@orkan
It’s had about 200 rounds through it since I started coating. I’m gonna run a bore scope in it next week and see what it looks like then clean it and see how it cleans. It’s supposed to drastically reduce copper and carbon fouling. I’ll update the thread after it’s been scoped and cleaned next week.
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I’m not going to be able to run the bore scope down the barrel like I had planned this week cause my smith is out of town. I just cleaned the rifle with 200 plus rounds since last cleaning. This is what I use normally as a round count between cleanings and I’m very familiar with what it takes normally to clean. Normal cleaning before using the HBN coating was between 8 and 10 wet patches with 8 to 10 dry patches. Below is the results of cleaning with the coated bullets.
Patches on the top were the wet patches the bottom row were the dry ones. Notice how little fouling is on the first patch. Seems the coating has drastically reduced the amount of fouling deposited in the barrel and could probably extend the round count between cleanings.
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Regarding the bullets sticking to the neck, I just pulled two uncoated ones from very old factory ammo (never fired cases) more than 10 years old and they were not welded. What comes to mind watching this is that carbon and other debris accumulated in the necks from previous firings can be what causes that welding, just my thoughts.
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@toni
When you pulled the bullets were they hard to pull? It’s hard to tell but looks like marks on the bullets from the jaws of the puller slipping. Also factory ammo is going to have a higher neck tension than typical hand loads which may make it harder to detect some of the bonding affect. I’m not disputing what you are saying just throwing thoughts of my own out there as well.
Even if this coating doesn’t help reduce the bonding, I’ve been impressed with it so far and will likely continue using it unless I see some negative affects that start to show up later.
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Yes, they were hard to pull. I used the 7mm collet to pull those 30.06 bullets and it slipped a bit but it did not look like they were welded. Really hard to tell, I expected to hear a click or something similar but I was surprised that it was not the case, and seeing that the part that was inside the neck was in such good condition, then I thought if it could be due to the absence of carbon... just another possibility.
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Smith ended up coming back in town early so was able to run the bore scope down the barrel. Absolutely zero build up present from the coating. No copper or carbon present either so the three patches required to clean it did remove any and all fouling that existed. I plan to extend the round count between cleanings this time around and see how it does.
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I’ve put 290 rounds on my 223 since last cleaning. After cleaning the last time I treated the barrel with HBN and started running coated bullets. Just checked the barrel out with a bore scope to see how the foulings was looking. There was almost none present, only a few greyish black smudges with no copper fouling or carbon ring forming. I didn’t fire 300 rounds without cleaning and check for fouling prior to using HBN so I don’t have anything to compare the results to, but I’ve clean enough barrels with wat fewer rounds down the tube to know that this has made a drastic improvement.
