Hopefully I’ll find time today to check it out myself. I have a good bit of sizing to do today with the SAC. the last 5 I’m going to pull the mandrel out, size with the bushing only, put the mandrel back in and size the neck pushing. I’ll take measurements and record it here.
-
Having trouble using the site?
Contact support
Do you use expanding mandrels after a full-length bushing die for neck sizing?
- Thread starter Western Living
- Start date
Interesting results. It appears the shoulder is shorter on the pull than on the push. I thought I might have gotten confused so I replicated it. Only an assumption but is it possible the lack of time between the bushing and the mandrel on the pull…. Hell I don’t know.
Push 1.6611 average .0004898 sd
Pull 1.6568 average .0008124 sd
Two things are certain. The push is more consistent and I refuse to tell how I determined my sd in light of recent events.
In conclusion is far too small of a sample with on 5 each to draw any serious conclusions BUT there was zero overlap between the two.
Push 1.6611 average .0004898 sd
Pull 1.6568 average .0008124 sd
Two things are certain. The push is more consistent and I refuse to tell how I determined my sd in light of recent events.
In conclusion is far too small of a sample with on 5 each to draw any serious conclusions BUT there was zero overlap between the two.
Attachments
It’s also worth noting that the push is longer than my fired brass. I double checked that as well. My die is set up for the pull with a .002” bump. 1.6590” fired.
It’s also interesting that my bushing is .308” but bushing only yields .306”. I would have thought bigger if anything.
No, I’m not drinking, yet, and I do understand numbers, maybe.
It’s also interesting that my bushing is .308” but bushing only yields .306”. I would have thought bigger if anything.
No, I’m not drinking, yet, and I do understand numbers, maybe.
Last edited:
My takeaway from all this was: You only have 4 rifles?
Well, four precision rifles. The others don't really count, now do they
IMHO, the main advantage I see from using a mandrel, at least for me, is that the mandrel step seems to turn good ammo that's already decently consistent, into great ammo that's super consistent... The difference is pretty small, but there is a difference, and since adding the extra mandrel step to my process is fairly painless (it's easier than just about every other step), I continue to do it. The mandrel step does seem to reliably and repeatedly lower my SDs, but it's not going to make up for anything else or really do shit for guys who haven't got their process already mostly figured out.
I too have done a couple/few different non-scientific "this vs that" comparisons like @morganlamprecht mentioned... and like him, in general, the main thing I learned is that a ~$20 Lee sizing die is just as good as any other sizing die (sorry if anyone reading this has fallen for any of the $300-600 sizing die grifts out there, it's all BS lol). But, for me, the stuff that had seen a mandrel was always better, again, the difference wasn't huge, but there was a difference.
All that said... I mentioned it before, but I probably noticed the biggest difference once I realized that I should wait on running the mandrel through the brass until after I'd already lubed, sized, and then tumbled all the sizing lube off... the mandrel really does seem to "fix up" the case mouths/necks post-tumble to where it's noticeably better than hitting the mandrel before I'd tumbled all the lube off (hear me now believe me later, try it).
So, arguably, the positive effects I've seen with using a mandrel might have more to do with fixing up my mouths/necks post-tumble versus anything else...
I too have done a couple/few different non-scientific "this vs that" comparisons like @morganlamprecht mentioned... and like him, in general, the main thing I learned is that a ~$20 Lee sizing die is just as good as any other sizing die (sorry if anyone reading this has fallen for any of the $300-600 sizing die grifts out there, it's all BS lol). But, for me, the stuff that had seen a mandrel was always better, again, the difference wasn't huge, but there was a difference.
All that said... I mentioned it before, but I probably noticed the biggest difference once I realized that I should wait on running the mandrel through the brass until after I'd already lubed, sized, and then tumbled all the sizing lube off... the mandrel really does seem to "fix up" the case mouths/necks post-tumble to where it's noticeably better than hitting the mandrel before I'd tumbled all the lube off (hear me now believe me later, try it).
So, arguably, the positive effects I've seen with using a mandrel might have more to do with fixing up my mouths/necks post-tumble versus anything else...
related to this...i have 2 steps in my process that address the mouth/neck post tumble also. i want the inside finish left a certain way, as consistently as possible, right before it sees the bullet...its possible i could swap those steps for a mandrel run and see the same results, but i never tested that method
I actually stumbled upon doing it the way I'm doing it now by mistake... I had sized a batch of cases and thrown them in the tumbler to get the lube off and was like "shit, I forgot the mandrel..." so I did the mandrel step after, and ended up with a batch of ammo that hammered with impacts on top of one and other like I hadn't seen very often... so I've kept doing it that way lol.
FWIW, I care about the finish before I seat bullets too, so I also do a super quick/light inside chamfer on the mouths before seating bullets (just so the bullet's jackets don't get scratched and I get all the BC I paid for). Just a super quick "one Mississippi" with very little pressure against the cutter until the case whistles, that's it. In hindsight, the mandrel step probably makes this process go faster/smoother too.
After, seating bullets is super smooth and I don't have to dick around with lubing necks or messing with dipping bullets in graphite dust like some do.
Last edited:
Interesting. Did you replace the mandrel with a regular decapping rod?
I don't own one, but - I know you can adjust the headspace of those dies with shims, I don't know if running rod-less (giggity) affects how the collet system and/or neck shoulder bushing sits.
wrt to SAC bushing die "mandrel"....to me, this is just a long expander ball. What would be the difference?
Now, I'm not saying it doesn't work...never used one. Probably works very well.
And I'm not saying that pushing a mandrel vs pulling a long expander ball generates better results. I defer to the testing gurus here for that.
But, IMO the terminology has gotten beaten up a bit for marketing purposes.
Now, I'm not saying it doesn't work...never used one. Probably works very well.
And I'm not saying that pushing a mandrel vs pulling a long expander ball generates better results. I defer to the testing gurus here for that.
But, IMO the terminology has gotten beaten up a bit for marketing purposes.
If all this push vs pull determines the tool then how many of you remove the expander ball from the sizing die to size, then put it back in to push it through the neck? Wouldn’t this just make it a round mandrel with your thinking?
I think we’re losing sight of the benefits of the mandrel.
I think we’re losing sight of the benefits of the mandrel.
Depends. Is the benefit:
-The bearing surface
-The pushing through
-Combination of both
If its the bearing surface, then no, it wouldn't make the ball the same as pulling a mandrel through.
This is why the last few times I've just put my brass (after sizing and all) in a bucket (with hot water, dawn, lemishine, and some simple green), and just stir them around good with my hands and then rinse them off vs tumbling the lube and stuff off.
Actually I have experimented with that. When comparing unlubed case necks through a conventional FL die setup, to what you described (pushing the expander ball into the neck in a second op) I did get better results the second way in the form of less runout and increased accuracy.
But no, that doesn't make an expander ball a mandrel; a mandrel is a specific shape and is not determined by the effect or how it's used.
Regarding the benefit though, part of the benefit of a mandrel is pushing into a case, and part is the straight section which guides the neck into alignment to some degree. That second part depends a lot on state of the brass hardness with respect to # of cycles sized/fired since annealing, as well as how thoroughly that annealing was done.
I put my cases in a Ziploc bag and spray them generously with a homebrew 14:1 alcohol/lanolin case lube then shake them up good inside the bag. This gets enough lube inside the necks to keep my expander ball wet. Pretty standard way to lube before FL sizing.
To remove the lube, like you I don't tumble. After sizing I throw them into a jug of isopropyl alcohol. Stir them up good then strain off the alcohol to be used again next batch. Alcohol is cheap and the case lube dissolves away easily.
An added benefit to this is the alcohol rinse would theoretically leave behind a thin film of lubricant all over the case. Including the neck. And since the solution is homogeneous, the amount of lube left behind everywhere would be equal. Which should promote consistent bullet neck tension. Theoretically.
Yeah that's similar to what I've been doing lately. I use 99% alcohol (I initially used 70% because we had some and it also worked just dried slower), and mix rcbs lube at 10:1 ratio in a spray bottle and spray them, then put em in a bag and spray a little more and mix em around. Then I let the alcohol flash off with this "grass matt" (it's from when we had baby bottles for my boys and it's used to dry the bottles. It looks like thick plastic grass blades sticking up in a plastic bin that's a few inches tall. Works outstanding for anything where you want to hold about 300 cases neck down)
It does take a min to put them all in the grass Matt thingy but once they are there you can take em from there directly to the press one at a time really easily but I wouldn't mind an easier method to let em flash the alcohol off without losing the lube. Might go back to a cardboard box but the grass thing works really well and most of the time my boys help put em in there so that makes it a ton faster.
The RCBS lube dissolves in water too so cleaning the brass off just takes some hot water and lemishine and whatever little bit of degreaser you have arouns with dawn. I use very little of each so it's mostly just hot water. It leaves carbon inside the neck but gets the brass very clean and doesn't peen any mouths or anything.
I do something very similar, both the spray bag (works great, and is the fastest way to lube larger batches of brass) and the rinse, although I use lacquer thinner and then light the brass in a metal pan to burn off the excess while agitating them. I’ve found that’s not only faster but also distributes any remaining lube more consistently vs just letting cases lay there to dry.
Something I’ve discovered in that process, because I’m saving the rinse for multiple uses, is that it builds up enough lanolin to work as a viable method of lubing cases prior to sizing and thereby lubed inside the necks just as well. I then rinse in a separate batch afterwards.
I’ve experimented with intentionally adding lanolin to the first rinse to accomplish this, and it does work pretty well. I use a couple of larger pickle jars to rinse and drain the solvent, and end up with a “lube” batch and a “clean” batch. It may sound complicated but it’s pretty fast and easy when working with batches of a few hundred rifle cases at a time.
Disclaimer- my shop layout allows me to burn solvent off the cases in an area that’s safe and well away from any powder or primers; no concerns there. I wouldn’t recommend doing that in the reloading room of course, or not at all if someone is uncomfortable working with open flame and understanding how to be safe with it.
...it sounds like I'm not the only one who's figured out that beating up your cases after you've sized them isn't the best idea and might require some extra attention lol...
I also initially lube my cases for sizing using the 1:10 lanolin/IPA and big ziplock bag method, which works great...
In fact, that's now my first step: I don't clean my cases anymore before sizing (unless my brass landed in serious mud ala Gap Grind 2021 lol), just ziplock/lube, then size, then into the tumbler... then mandrel, quick inside chamfer, prime, powder, bullets.
I also initially lube my cases for sizing using the 1:10 lanolin/IPA and big ziplock bag method, which works great...
In fact, that's now my first step: I don't clean my cases anymore before sizing (unless my brass landed in serious mud ala Gap Grind 2021 lol), just ziplock/lube, then size, then into the tumbler... then mandrel, quick inside chamfer, prime, powder, bullets.
It's interesting how much that ziploc bag lube method has caught on now; good to see other people enjoying the benefits. I didn't come up with it, but remember using it when very few other people did, maybe 6-8 years ago, and people were arguing silly stuff about it being slower and messier, etc. It's not of course, but some people will argue anything to defend their own way of doing something.
I use it all the time now, even with high volume pistol brass. It's not necessary with carbide dies, as we all know, but just a mild film of lube (lanolin) makes it a lot easier to crank that press handle 1K times in a row. For the pistol stuff though I either lube very sparingly, or not at all and just let the brass pick up leftover lube in the bag from last time.
I use a type S Redding bushing die and adj the bushing sizing depth to a point above the typical 'donut' area of the neck shoulder junction. My thoughts are that the un-sized portion of the neck aids in maintaining bullet concentricity in my factory sized chambers. Also the possible 'donut' then becomes irrelevant. I use the adjustable Starrett small hole gages to verify.
Are you still bumping the shoulders, but spacing the bushing up far enough for partial neck sizing? That can be a great trick for maintaining bullet/bore alignment in the chamber, as long as the case neck is long enough.
Hey, Obi_WanKannoli,
Is it this one?
Nope, that one is only for people who neck turn. I have this one;
Black Nitride Expander Mandrel
21st Century Shooting is excited to unveil a brand new product! Introducing the Slippery black Expanders, this new products will revolutionize the way you reload. Based on our proven technology these products will reduce friction and galling, they are as hard as carbide and as slick as graphite...
I use the turning arbor. I’d so most try for the .002 below bullet diameter turning arbor for expanding necks to seat bullets.
Nope, that one is only for people who neck turn. I have this one;
Black Nitride Expander Mandrel
21st Century Shooting is excited to unveil a brand new product! Introducing the Slippery black Expanders, this new products will revolutionize the way you reload. Based on our proven technology these products will reduce friction and galling, they are as hard as carbide and as slick as graphite...21stcenturyinnovation.com
Thank you for coming back and responding, but now I am a little confused.
The one you linked is .0008" under bullet size.
This is pretty normal for an expander mandrel according to the pages I read here, as expander mandrels are typically .001" under bullet size, and turning mandrels are .002" under bullet size.
The one I linked is .002" under because it is a turning mandrel, as you point out.
My confusion comes from your statement that it is "only for people who neck turn." Can it also be used to size the inside diameter at .002" under prior to bullet seating?
Your bullets stay in place just fine at only eight ten thousandths under as the inside diameter? Can you elaborate just a little on why you chose this size instead of .002" and how it works for you (results)?
The same one in my link?
I got the stainless Sinclair and TiN 21st from before the nitride came out but yes, same diameter turning arbor being .002 below.
I am new to this, but I am assuming if I want .002" under bullet diameter for the inside measurement of my case neck, then the turner mandrel I linked will do what I am asking.
https://21stcenturyinnovation.com/buy-online/ols/products/black-nitride-turning-arbor/v/NBT24
https://21stcenturyinnovation.com/buy-online/ols/products/black-nitride-turning-arbor/v/NBT24
Yes. They just call it a turning mandrel but you don't have to use it for only turning. Many use them for expanding the necks before seating, as I do.
It should be 0.002 below, that's likely a typo on their site. I'd send them an email. I'll measure mine tonight and post a photo.
Could be but I would be surprised if they goofed up on a detail that important.....? 0.008" under does seem excessive.
0.002" under has been the sweet spot for me so I would get the turning mandrel, pretty sure I have heard many people on here say they use them as expanding mandrels with no issues.
This is the direction I would go were it not that I was already setup with another brand.
Not .008" but .0008" - you're off by a factor of 10. It is less than .001"
here i am doing a seating test . LE Wilson dies ,hydraulic arbor press. a recent session showed good results with low seating pressure,20 psi and lower. i roll in my own cannelure ring to the bullets and do a light crimp . to get that low of psi its anneal,size ,then use a 224 mandrel .then seat a 224 bullet . its a test to confirm what I found a few days ago
I'm like you. I still use a bushing die. Maybe I'll try a mandrel one day. My current reloads perform pretty dang good though.
I’m using the bushing/mandrel combo. My measuring devices say it’s better than the bushing alone. My rifle says whatever bitch.
I’m not reading all this, but the reason you want your mandrel to be .001” under bullet diameter is because there’s going to be spring back and you’ll end up with .002” neck tension.
Not to open old wounds (threads), but what made you depart from bushing dies? I am thinking about getting one. My current practice is to FL resize clean brass and then use a mandrel .002 under after the fact. Im looking at bushing dies to eliminate the need to expand after FL resizing (thus eliminating a step)... what is the downside of the bushing / resize dies in your opinion?
Bushing dies do not eliminate the need to use an expander, they reduce the need to use one to control the amount interference fit. However, as it relates to taming consistency, when you size, any inconsistencies in brass neck thickness translate to the inside diameter of the neck, which then has a significant impact on interference fit, and thus seating forces and effective neck tension. Inconsistency here will raise your SDs.
Using a mandrel pushes all those brass thickness inconsistencies to the outside of the neck, making the seating process much more consistent.
Using a mandrel does push neck thickness inconsistencies outward. . .but not quite a 100%.
It certainly does make for a much more consistent interference fit. I know, I know. . . . but isn't it fun splitting hairs?
Using a mandrel does push neck thickness inconsistencies outward. . .but not quite a 100%.
I know, I know. . . . but isn't it fun splitting hairs?
Not really splitting hairs at all. Thicker necks mean more spring back and more neck inconsistency. EDIT: I mean by this that if you have inconsistency - thick vs. thin, the thicker will spring back more than the thin. This was proven to me when I switched from ADG to Lapua. Both are quality brass, but the necks were not as consistent on ADG. I could get the same SDs after neck turning, but why go through that when Lapua gives it out of the box?
That said, you can still get some incremental gains neck turning Lapua. I'm likely going to test how much at some point...
Last edited:
Yes, because I'm after as much consistency in my cartridges as possible, this is the main reason I turn necks on all my brass. Though, my recent purchase of Alpha brass, it's so consistent I'm debating with myself whether I'll do it with them. But I do think a little thinner necks seem to produce better SD's.
Interesting. I have resisted the urge to neck turn. I had erroneously thought the ADG brass was comparable to Lapua. I’m using ADG for my 6.5 PRC. Ugh, I may need to start neck turning them.
For my 300 PRC, my measured SDs with base ADG were in the 8.x range, neck turned it went down to 6.x. Lapua delivers 6.x with no neck turning. Frankly, I do not like neck turning, which is why I switched to Lapua. I've got hundreds of ADG cases sitting on my shelf in those nice orange boxes.
Single use, as in, you use them in one single case in the neck, and then you have to disassembly your die, remove the mandrel, replace the mandrel with a new one, and then do one more brass case neck?
Similar threads
