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Tidbits About Bullet Seating - Mandrels, Neck Lube, etc.

Rocketmandb

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  • Nov 2, 2018
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    I'm working on testing methods and products and gathering data on bullet seating. I'll be posting some comprehensive data once I get to an appropriate point of collection, but I just got some interesting information that I though was worth sharing.

    I bought an AMP Press a number of months ago and have been testing different neck lubes, different processes, annealing vs. not, etc. Tomorrow I'm heading out to BLM land to do some ~2k yard ELR with my 300, and some closer in stuff with my 6 BRA, which means tonight I'm doing a bunch of loading. For my 300, I tried two slightly different processes:

    Process 1:
    - Anneal
    - Size
    - Lube necks with moly (topic for another post, but I've found moly to be the best neck lube on annealed brass)
    - Mandrel
    - Trim
    - Primer, charge, seat

    Process 2:
    - Anneal
    - Size
    - Lube necks with moly
    - Mandrel
    - Trim
    - Lube a second time
    - Primer, charge, seat

    Below are the graphs from the AMP Press showing the difference. I did 16 on process 1 and 46 on process 2.

    Process 1: Single neck lube before trim, primer, charge, etc.
    15-Dec-2023 18_39 1x moly.png


    Process 2: Neck lube before trim, then second neck lube before primer, charge, etc.
    15-Dec-2023 17_19 Lot PR0359 double moly.png


    Notes:

    - On process 1, some of the plots spike at the end because I needed to re-zero the press height
    - You can see that the extra lube step on process 2 pretty dramatically brought in spread. It's about a 30lb spread on process 1 vs. a 16lb spread on process 2.
    - I'll post the muzzle velocity results after I get back tomorrow.
    - I'm expecting somewhat of an SD improvement from the set of process 1 vs process 2, as I've already documented a correlation between seating force SDs and muzzle velocity SDs in my Mandrel Musings thread.
    - For my 6 BRA, the two different plots I've got show a stark difference - includes annealing vs. not for one firing. But there is also one other factor that plays a significant role that was unexpected. More on that later.
     
    Based off your other thread, I loaded up a series of test loads with some of my better 77 grain loads in 223. Did a 10x set with neck lube (Redding graphite) and 10x without… all the brass had been annealed, resized, trimmed, mandrel expanded, flash hole deburred…etc.

    This brass had been mandrel expanded with lanolin home brew lube in the necks that was later tumbled off. Some of the brass had it, others did not, but I had not considered lubing prior to seating before reading your thread.
     
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    Based off your other thread, I loaded up a series of test loads with some of my better 77 grain loads in 223. Did a 10x set with neck lube (Redding graphite) and 10x without… all the brass had been annealed, resized, trimmed, mandrel expanded, flash hole deburred…etc.

    This brass had been mandrel expanded with lanolin home brew lube in the necks that was later tumbled off. Some of the brass had it, others did not, but I had not considered lubing prior to seating before reading your thread.

    I appreciate the feedback. I've been doing a lot of testing with different lubes. What was interesting was that I kept hearing from people that graphite lube was only marginally effective on annealed brass. I was not finding that to be the case, but clearly others had different results. So, I started to look at why. I think I figured it out, and I'm going to post what I found when I have time to do additional testing to validate. In the mean time, for testing, I looked at HBN, moly, graphite, 50/50 mix of moly and graphite, neo-lube and just leaving carbon the necks (e.g. not cleaning the brass).

    Moly came out as the winner for lube, but I had to DIY my application media. You can get some stuff from 21st Century, but they use 2mm beads for application and common sense tells you that the larger the media, the less surface area is actually in contact with the neck wall. Additionally, the 2mm beads would bunch up and get stuck in smaller neck cases (in my case, my 6mm). I ended up finding a huge bag of 1mm plastic beads on Amazon and ordered that. The good news is that I've got a lifetime supply of 1mm media. The bad news is that I don't need a lifetime supply... pretty much one little jar lasts forever.
     
    How did the neo lube do?

    Full disclosure: it was my first time using it, so there could be some user error, but this statement in itself should say something...

    It did just okay. I did not see any sort of gain over some others that justifies what is, at least the way I reload (e.g. last minute), the added burden of applying it well ahead of when you plan to seat. EDIT: due to dry time required.
     
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    I may have missed this somewhere along the way... but do you brush the necks at all?

    I'm not talking scrubbing all the carbon out, just a quick in-twist-out to knock off the rough stuff.

    I've tinkered with neck lubes in the past... including the various dry graphite and moly lubes. Dipping the necks in ceramic beads with the dry lube always seemed to get more on the outside than the inside, which just bothered me. I was using a bore mop loaded with (IIRC) dry moly (honestly, I'd have to check the container as it's been a while) and that seemed to be working pretty well, but again, messy. More recently I tested brushed vs. brushed+NeoLube2 and ran some statistical tests. Very slight advantage to the latter, but it was there.

    I really need to get an AMP press 😁

    As an aside, have you seen @Bryan Zolnikov videos on different neck lubes?
     
    I may have missed this somewhere along the way... but do you brush the necks at all?

    I'm not talking scrubbing all the carbon out, just a quick in-twist-out to knock off the rough stuff.

    I've tinkered with neck lubes in the past... including the various dry graphite and moly lubes. Dipping the necks in ceramic beads with the dry lube always seemed to get more on the outside than the inside, which just bothered me. I was using a bore mop loaded with (IIRC) dry moly (honestly, I'd have to check the container as it's been a while) and that seemed to be working pretty well, but again, messy. More recently I tested brushed vs. brushed+NeoLube2 and ran some statistical tests. Very slight advantage to the latter, but it was there.

    I really need to get an AMP press 😁

    As an aside, have you seen @Bryan Zolnikov videos on different neck lubes?
    I found the same. Brush one pass, anneal, size, coat the inside of the neck and part of the bullet that is seated with Neolube2, let dry, prime, charge, and seat. The effect was not huge but statistically significant when compared to no Neolube and no anneal comparison groups. Sounds very similar to your findings.
     
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    Here's my schtick that works for me ...
    1. Decap
    2. Clean (wet tumble 90 min)
    3. Anneal (AMP)
    4. Lube
    5. FL size (Reading Type-S w/ SAC bushing)
    6. Trim (if required)
    7. Chamfer, Deburr, Brush neck
    8. Clean (wet tumble 60 min)
    9. Neck lube (NeoLube #2)
    10. Mandrel
    11. Prime
    12. Charge
    13. Seat bullet (AMP Press)
    14. Go to the range and shoot nice groups at long distances
    Note: I've found that there's enough residual NeoLube on the neck after the Mandrel step ... to allow for proper Seating. Inserting another neck-lube step just prior to seating did not improve my force curves or my SD's.
     
    Last edited:
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    I may have missed this somewhere along the way... but do you brush the necks at all?

    I'm not talking scrubbing all the carbon out, just a quick in-twist-out to knock off the rough stuff.

    I've tinkered with neck lubes in the past... including the various dry graphite and moly lubes. Dipping the necks in ceramic beads with the dry lube always seemed to get more on the outside than the inside, which just bothered me. I was using a bore mop loaded with (IIRC) dry moly (honestly, I'd have to check the container as it's been a while) and that seemed to be working pretty well, but again, messy. More recently I tested brushed vs. brushed+NeoLube2 and ran some statistical tests. Very slight advantage to the latter, but it was there.

    I really need to get an AMP press 😁

    As an aside, have you seen @Bryan Zolnikov videos on different neck lubes?

    I should have mentioned that I also tested not cleaning brass and brushing necks. I found similar to what you mentioned in that I got somewhat better results using a few of the lubes tested - but worse with others.

    As for using beads and dipping necks, yes, it is somewhat messy, but all I do is dip/spin the neck then wipe the outside with an old t-shirt. It's not that bad.
     
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    What moly are you using?

    The stuff from 21st century - I just needed to get my own beads (1mm) because for some reason 21st century uses 2mm beads that don't work so well. I also ordered some from Amazon, but I haven't needed it yet.
     
    Interesting tests, thank you for sharing. We have a guy in the MD area that has done a lot of the same kind of work. Question: The setup being used measures seating pressure, which we all assume is a proxy parameter related to "unseating" pressure upon firing. But is this so . . . ??? Could you not drill holes in the bases of a few cases, seat the bullets using the various protocols, and invert the seated rounds in some kind of holder (shouldn't be too hard to make something that would work) and use some kind of mandrel/rod through the case to measure the pressure required to UNSEAT the bullet? Might show something interesting, and at least would be a closer measurement to bullet release upon firing?

    FYI - I am now using a rotating bronze brush chucked in a small lathe to thoroughly clean the inside of case necks. This can be done to varying degrees of cleanliness, up to and including full shine. I'm also experimenting with craytex polishing of inside necks. Some testing includes moly application to the inside of necks using a suspension of moly powder in GunScrubber, and applied with a Q-tip. The case is inverted for the application and dries out very quickly to leave a uniform moly layer. I also dissolve lanolin in xylene (it does not dissolve in GS or isopropyl-OH) and again with the Q-tip. BYW - ALL centerfire bullets are moly coated.

    I also find that the trimming process, including careful inside/outside case mouth deburring always leaves a "sharp" surface close to the case mouth. This can best be seen by seating/unseating bullets and observing the scratch pattern on the pulled bullets. I have also noticed that wet tumbling with SS pins beats up the case mouth and usually produces outside and inside burrs. I now wet tumble for no more than 20 minutes, but I use hot ultrasonic solution for this process.
     
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    … and use some kind of mandrel/rod through the case to measure the pressure required to UNSEAT the bullet? Might show something interesting, and at least would be a closer measurement to bullet release upon firing?

    Since the case neck expands to the chamber wall during firing/bullet release, wouldn’t this be just another proxy measurement?

    Has there been any data correlating seating force with velocity or precision? I remember a lot of hype for the amp press, but I haven’t seen much since then. Maybe I just missed it.
     
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    Hi Rocket. I want to thank you for your help in the past. So here goes of the discovery I made this week regarding moly, resizing, and psi's with 308 Win.

    I recently received some Berger 30 cal 200.2. I was warned about moly disulfide from a respected shooter, who will remain un-named. I pretty much followed the routine of Rusty (above) in the past and was using moly to reduce my psi on seating. This time I left out the moly in the necks and found that the seating psi's increased significantly (65-over 100psi). I was reducing the neck size too much in just one operation. Around .005" using a .337 bushing in a fl s type sizing die. I went with a .338 followed by a .336 bushing in the same die. Voila, psi's decreased to the 35-45 psi range. I could dial in neck tensions from 1.5-2 thou. using the .337 and .336 bushings. Loaded od for the rounds was .339. Exactly the same as Berger manufactured ammo.

    On the range, I also experienced significantly improved es and sd. I achieved one group with an es of 6 with a 5 shot group. Other groups using the Berger 185 otm Juggs experienced great grouping with es' of 15-18....5 shot groups were very good at 100 yards. In previous times my sd's have been in the 20-40 range. So now I have a huge improvement, without the extra cost of the moly.

    For what its worth, I've heard the plus and minus of moly use. I came to the conclusion that I just didn't want to risk the effects of disulfite compound on the barrel and brass. Just my two...........
     
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    "Since the case neck expands to the chamber wall during firing/bullet release, wouldn’t this be just another proxy measurement?"
    I believe you are assuming that the neck expansion occurs before the bullet leaves the neck - highly unlikely (or at least highly undesirable). Even a small rise in chamber pressure should release the bullet, even when seated "into the lands". (Reloaders that accidently forget to add powder find the bullet stuck a ways down the bore from primer pressure alone.) Measuring pressure of bullet release might closely mimic seating pressure, or not (I think the curves would look radically different), and truthfully, would still be a proxy, albeit perhaps closer to what happens under fire. I believe that making the process of bullet obturation and transition into the bore is critical to precision in two main ways: firstly a smoother and less pressure intense transition results in a more consistent powder burn, without high resistance and potential inconsistencies in the millisecond burn/pressure of firing. (This would explain why significantly lower bullet seating pressure produces lower SD's.) The second is that if a lower pressure is required to transition the bullet into the bore, it is likely to do much more concentrically with a slower pressure build than a fast hard push that can force the bullet into the bore in a non-concentric manner. Of course, concentric seating of the bullet into the bore is critical to bullet flight characterictics and therefore precision and also wind resistance.

    I began using moly coated bullets after a demonstration I observed at a score benchrest match, probably in late 1990's. A local gunsmith had a piece of cut off barrel stub with the case part of the chamber cut off. He had a small mallet and two types of bullets - same brand and lot, but one set was bare copper and the other moly coated. The exercise was to place the bullet in the trucated neck portion and with the mallet, tap the bullet into the throat and barrel stub. It was almost impossible to get the copper bullet into the bore without some lopsidedness (non-concentricity) actually visible to the naked eye. On the other hand, a much lighter tapping on the moly bullet resulted in a smooth, visibly straight seating - every time. Go figgur . . .

    With respect to moly, I have been shooting ONLY moly coated bullets in ALL my centerfire rifles since the late 1990's including .21 Fireball, .223, 22BR, 22-250, 22-250AI, 6PPC, 6BR, 6.5x55Swede, 6.5CM, 30BR, .308 and 6.5x300WWH in both CM and SS match barrels. No issues whatsoever. Except perhaps longer throat/barrel life and improved precision. I consider the unfounded reports of damage attributed to the use of moly as "old wives tales" repeated over the years and quite frankly, from my many years of experience are total bullshit. The longer throat life is attributed to a lower pressure release of the bullet into the bore (see above), creating additional expansion volume at a lower pressure, and therefore lowering peak pressure and therefore temperature during the spike. This peak temperature spike is the cause of throat erosion, and if the temp/pressure spike is reduced significantly, less throat erosion occurs.

    Please note that I don't recommend or advise that anyone do anything of what I do, and am not trying to convince anyone to do anything. I have no horse in the game, especially with respect to moly coating of bullets, which was once a hotly debated topic. (Except perhaps if we shoot against each other in a match!) I am science oriented, and appreciate the sharing done by those shooters with enough curiosity to investigate and report, and do so when I can.
     
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    I should have mentioned that I also tested not cleaning brass and brushing necks. I found similar to what you mentioned in that I got somewhat better results using a few of the lubes tested - but worse with others.

    As for using beads and dipping necks, yes, it is somewhat messy, but all I do is dip/spin the neck then wipe the outside with an old t-shirt. It's not that bad.
    For those of you that are using the moly, I found that 91% alcohol mixed with microlube moly was a lot neater for applying to the necks with a swab. You don't have to mess with clean up and it dries with a very even consistency. These are the swabs that I used:

    https://www.texwipe.com/swabs
     
    For those of you that are using the moly, I found that 91% alcohol mixed with microlube moly was a lot neater for applying to the necks with a swab. You don't have to mess with clean up and it dries with a very even consistency. These are the swabs that I used:

    https://www.texwipe.com/swabs

    What's the ratio of moly to alcohol? Also, how well does it blend together?

    This is essentially what Neolube does, but with graphite instead of moly. My only beef with it is that you need to allow for a decently long dry time.

    Also, for others on this thread, I don't have data from this weekend's trip. My 300 was performing like absolute shit. To put it in perspective, we had a "warm up" target set at 1650 yards and a longer range one at 1833. With the last 20ish rounds from my 6 BRA, we decided to lob them out (20.9 mil elevation) at the 1650. The 300 was behaving so badly that we never moved off the warm-up AND the hit rate with the 300 was lower (by a fair margin) than the 6 BRA, which was close to 50%. So, the entire time with the 300 was fiddling trying to find the issue and not gathering data.

    The little black dot over my friend's right shoulder is a water tank, behind which is a slight hill where our shooting spot is.
    IMG_0869 copy.jpg


    From our shooting spot (and the water tank):
    IMG_0872 copy.jpg
     
    What's the ratio of moly to alcohol? Also, how well does it blend together?

    This is essentially what Neolube does, but with graphite instead of moly. My only beef with it is that you need to allow for a decently long dry time.

    Also, for others on this thread, I don't have data from this weekend's trip. My 300 was performing like absolute shit. To put it in perspective, we had a "warm up" target set at 1650 yards and a longer range one at 1833. With the last 20ish rounds from my 6 BRA, we decided to lob them out (20.9 mil elevation) at the 1650. The 300 was behaving so badly that we never moved off the warm-up AND the hit rate with the 300 was lower (by a fair margin) than the 6 BRA, which was close to 50%. So, the entire time with the 300 was fiddling trying to find the issue and not gathering data.

    The little black dot over my friend's right shoulder is a water tank, behind which is a slight hill where our shooting spot is.
    View attachment 8299571

    From our shooting spot (and the water tank):
    View attachment 8299573
    Here's what I used:

    Molybdenum DISULFIDE Moly MoS2 Powder 1-2 Micron Best LUBE Grade.​

    You'll find it on amazon and I think there are some utube vids of guys using it.

    So far as a mixing ratio, it's not that big of a deal. Just try at 4:1 of alc. to moly. More than likely, you'll dilute it further. A little moly goes a long way and the high concentration of 91% alcohol really dries in a matter of seconds. I just get the mixture to the point of watery slur. When it dries, it will look just like carbon layer in the neck after firing.
     
    Anyone else use lock-ease liquid spray? I’ve been using it for a few years now. Spray into an old bullet box, use a Qtip to apply to the inside of necks, after it drys, use a clean Qtip to remove excess. I haven’t done the type of testing the OP has, but it’s butter smooth seating bullets and can find the stuff at any hardware store
     
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    Anyone else use lock-ease liquid spray? I’ve been using it for a few years now. Spray into an old bullet box, use a Qtip to apply to the inside of necks, after it drys, use a clean Qtip to remove excess. I haven’t done the type of testing the OP has, but it’s butter smooth seating bullets and can find the stuff at any hardware store

    It's basically the same thing as neo lube and others. Graphite suspended in alcohol or other fluid.

    The downside to cutting out so much friction is that you may need to have a tighter interference fit to prevent bullets from moving during recoil and such.
     
    Not sure how important the 1st neck lube before expanding is, but definitely the lube before seating bullet produces some significant difference in terms of seating force and some what consistency.
     
    Not sure how important the 1st neck lube before expanding is, but definitely the lube before seating bullet produces some significant difference in terms of seating force and some what consistency.

    Agree - I'm only doing it to limit galling from the mandrel.
     
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