Don't expect an answer. I still don't have one for how much force is actually being exerted.
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Excessive bullet seating force despite using mandrel expander
- Thread starter machjett
- Start date
In my process it would be the primer. After that powder.
I’m not sure what you keep trying to get across with sizing your necks with the bullet - feel free to follow whatever reloading practice you want. I’m sure your grasp on the subject is second to none.
Yes it's clear that you're missing the point. A mandrel and a bullet are both mandrels.
Use the appropriate sized bushing and eliminate the mandrel. Seat your bullet and viola! Your neck gets mandreled at the same time.
My thought process on mandrels, bushings etc...
Lets assume slight variances in thickness around the circumference of the neck.
When you neck or bushing size, those variances would move to the inside of the case mouth.
A mandrel would then make the inside of the neck perfectly round, moving the variance to the outside.
Am I on the right track here?
That's how I assume it to work.
If your turning necks, I would assume most of that would be a moot point.
Just here to learn.
Lets assume slight variances in thickness around the circumference of the neck.
When you neck or bushing size, those variances would move to the inside of the case mouth.
A mandrel would then make the inside of the neck perfectly round, moving the variance to the outside.
Am I on the right track here?
That's how I assume it to work.
If your turning necks, I would assume most of that would be a moot point.
Just here to learn.
So, how does the brass react differently using an undersized bushing and a mandrel, vs the appropriately sized bushing and just seating a bullet?
Let's pretend that all variance in neck thickness is pushed to the outside by mandrel (it isn't), but not buy a bullet. What advantage does that give you for the time you've wasted doing it?
I had some sig 300 win mag brass that deformed the bullets trying to seat them.
Vld chamfer
Graphite the necks.
Tried three different seating stems.
It did it with the first and second firing, the third firing they were fine. I took is as springback in the neck.
Vld chamfer
Graphite the necks.
Tried three different seating stems.
It did it with the first and second firing, the third firing they were fine. I took is as springback in the neck.
Despite the bickering one of a few things is happening.
-Your hole is too small, too much neck tension.
-Your squeaky clean and annealed brass is creating some friction
You can rule out tension by grabbing a pin guage, all the other methods are prone to not giving you realistic results. Pin gauges are cheap, and nice to have around to check neck tension in subsequent firings.
The friction from squeaky clean and annealed brass can be a pain. Graphite dosnt always stick to a freshly annealed neck, so sometimes other lube is needed. Brushing the necks sometimes helps as well.
The Wilson die let’s you know if there’s a problem you probably wouldn’t feel on a larger press.
-Your hole is too small, too much neck tension.
-Your squeaky clean and annealed brass is creating some friction
You can rule out tension by grabbing a pin guage, all the other methods are prone to not giving you realistic results. Pin gauges are cheap, and nice to have around to check neck tension in subsequent firings.
The friction from squeaky clean and annealed brass can be a pain. Graphite dosnt always stick to a freshly annealed neck, so sometimes other lube is needed. Brushing the necks sometimes helps as well.
The Wilson die let’s you know if there’s a problem you probably wouldn’t feel on a larger press.
Depending on how much material is on the inside, that can have some negative effects on the bullet. Such as scratching the jacket and such.
Generally speaking, we don’t want the bullet doing that work.
My reference of a bullet being the same as a mandrel was in response to the argument that hard brass resists sizing, but doesn’t “grab” more when seating. “Grab” wasn’t the correct term of course, but inserting a bullet has the same sizing effect that a mandrel of the same size would have. Therefore harder brass resisting it all the same.
However, during that process, if the bullet is the first sizing from the inside, there is the potential for scratching the jacket and therefore increasing the SD of bullet BC.
Excessive force is what was said.
Does that mean it was slightly harder than normal to seat or does it mean I had to hang my whole body off the handle to seat ???
There might be a tiny bit of difference between the two.
Excessive force means the seater stem is damaging the bullet nose. Generally that occurs above 100 PSI of seating pressure.
I have always liked 60-70 PSI. No bullet damage and excellent performance. The other day I was messing around different seating pressures and found 40 PSI to be the minimum that produced full velocity from my particular combo. 30 PSI was 20 FPS less and 20 PSI was lower still.
I have always liked 60-70 PSI. No bullet damage and excellent performance. The other day I was messing around different seating pressures and found 40 PSI to be the minimum that produced full velocity from my particular combo. 30 PSI was 20 FPS less and 20 PSI was lower still.
Oh ok, I guess that's the only way to get that kind if measurment then? I really didn't think of too little pressure being an issue for accuracy, just durability of the round itself.
K&M makes an arbor press with what they call a force pack, a series of compression washers tied to a dial indicator. It’s a cheaper setup but doesn’t give you psi. At least you can compare the seating effort from one round to the next by looking at the indicator tho.
I may get there, but I'm not there yet..... this rabbit hole never really ends so, I probably will get there, just not this week...
Hello -- I ended up using a VLD chamfer and it made a big difference -- thank you
Ah, so....without the VLD seating stem your bullet's nose impacted the end of the stem before the bottom of the stem contacted the ogive so your bullets were not going in straight and hence the seating force issue...maybe?????
Not certain that I have an answer, but I follow much the same process that you do. I clean with SS pins, anneal, and use a 21st Century expander using Redding neck lube. I would add that I use a 21st Century black nitride mandrel. Huge difference over SS or carbide! I then use a bore brush to clean (or brush the graphite Redding neck lube) through the neck. Then seat the bullet. Sometimes the seating force is so low that I have to test it by pushing the bullet against the reloading bench to see if it moves with minor pressure. Give one of those 21st Century black nitride mandrels a try with Redding neck lube, then brush the inside of the neck.
FWIW. I also wet tumble Lapua brass. One of the downsides is lack of lube in the case neck. So after wet tumbling, I anneal and resize FL followed by a mandrel and chamfering. Then I dry tumble to get rid of the case lube. Since I use Hornady One-Shot case lube and use Dillon Case polish, some of both of those remain in the case mouth. I have little trouble seating a bullet using the same K&M seating press and Wilson Seating Die. Could it be that tumbling step that make the difference?
I'm with the mandrell camp.
Since I started using them every load improved, any brand of brass for me.
I am also under the theory that with a mandrell all slop goes to the outside of the case.
None of my chambers are neck turn tight. One rabbit hole too deep for me.
I didn't do well with bushings when I tried them. Probably user error and inexperience to be truthful.
I do like the fact that now I never have to measure a neck again any brass any caliber.
Mechanically the same accross the board. Idiot proof, (goog thing, I know).
The remaining difference in spring back due to hardness of the brass is small compared to the preparation of the brass as in tumbling regiments and lubrication.
If a .002 mandrell is to stiff to seat well you have a problem in your brass prep before that step.
You could try a .001 mandrell but I will bet no joy for you as well on that.
You don't have to use a primer or throw powder to test any of the several different methods and probably more than one will work for you if you diligently apply the method.
Run a dummy load test of 3 per method and at least one should seat smoothly and still pass a simple shove against the bench hard by hand test.
The .002 neck tension seems to still be working in our ar's but we don't do large mag dumps anymore
Would .001 do better for some competition guns, maybe yes I think but I would have to measure the damn things again.
Arg
Been working on a batch of gassers for a while. How many of you prefer a .001 mandrell for bolt guns?
Since I started using them every load improved, any brand of brass for me.
I am also under the theory that with a mandrell all slop goes to the outside of the case.
None of my chambers are neck turn tight. One rabbit hole too deep for me.
I didn't do well with bushings when I tried them. Probably user error and inexperience to be truthful.
I do like the fact that now I never have to measure a neck again any brass any caliber.
Mechanically the same accross the board. Idiot proof, (goog thing, I know).
The remaining difference in spring back due to hardness of the brass is small compared to the preparation of the brass as in tumbling regiments and lubrication.
If a .002 mandrell is to stiff to seat well you have a problem in your brass prep before that step.
You could try a .001 mandrell but I will bet no joy for you as well on that.
You don't have to use a primer or throw powder to test any of the several different methods and probably more than one will work for you if you diligently apply the method.
Run a dummy load test of 3 per method and at least one should seat smoothly and still pass a simple shove against the bench hard by hand test.
The .002 neck tension seems to still be working in our ar's but we don't do large mag dumps anymore
Would .001 do better for some competition guns, maybe yes I think but I would have to measure the damn things again.
Arg
Been working on a batch of gassers for a while. How many of you prefer a .001 mandrell for bolt guns?
The bushing pushes the brass inward. Differences in neck thickness case to case will cause different interior diameters, and hence a different seating force. The mandrel pushes everything back outward, making the inner diameter more uniform - not perfectly so, but much better than not doing it. This means more uniform force when seating.
If you neck turn, using a mandrel has low to no effect. I hate neck turning, so use a mandrel
If you want to see exactly how much variance there is both with and without using a mandrel, I measured such in a thread called "Mandrel Musings." The difference in seating force consistency in using a mandrel (and not) was significant.
6 BRA experiment:
Seating force over 10 rounds:
With a mandrel: 1.6 lb SD
Without a mandrel: 11.5 lb SD
Muzzle velocity over 10 rounds:
With a mandrel: 5.88 fps SD, 20 ES
Without a mandrel: 8.7 fps SD, 31 ES
Do those imperfections not get pushed out by the bullet also?
I found the opposite to be true in my BR. Mandrel gave greater es than bushing alone over 100 shots.
A year ago I would have sworn by mandrelling. I have many in varying sizes, materials, and surface treatments. I’m now leaning more heavily on the correct size bushing for THAT load in THAT rifle and quality brass.
I found the opposite to be true in my BR. Mandrel gave greater es than bushing alone over 100 shots.
A year ago I would have sworn by mandrelling. I have many in varying sizes, materials, and surface treatments. I’m now leaning more heavily on the correct size bushing for THAT load in THAT rifle and quality brass.
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Yeah sort of but they also impart that same uneven force on the bullet so trying to level it out before hand helps.
I’d be curious if it’s not the mandrel but the difference in interference fit after using it between what the bushing left you. Maybe if you had used a mandrel that’s .001 smaller than you did it would even out the pressure but keep it at the same level of force on the bullet when seated as just the bushing.
I’ve tried mandrels from .001”-.003” under bullet diameter, and found that I can get as consistent or better ammo for this load and eliminate a pull of the handle for each bullet. But that’s what works for me.
One of the first things I noticed with a setup that utilizes a properly set up mandrel is how uniform the seating pressure felt across the whole lot of brass. Even after annealing and bushing dies before the mandrel, I’d get one that felt quite a bit harder to seat every 10 cases or so.
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I'm not even entertaining the idea of using a bushing with no mandrel. Not saying it won't work well with the appropriate size bushing, but therein lies the problem.
Forget imperfections getting pushed to the outside. There is a much better reason to mandrel. Brass neck thickness variation between head stamps.
The bushing sets your tension/interference based on brass neck thickness. Any variation in neck thickness = different tension when using only the bushing.
I'm currently working on 6ARC loads. Hornady brass loaded neck diameter is .26805. Lapua loaded neck = .2705. If I were to use a bushing to set tension I'd need 2 different bushings or I'd get + .002 interference on the Lapua. I just use the same bushing for both followed by the same .2405 mandrel (gas gun). The mandrel eliminates that significant tension variation I would have had.
I've got like 7 different head stamps for 308, x 4 for 6.5C, X 2 for 6GT etc. The fuck if I'm going to try dialing in a bushing size for each one.
I just did a 6ARC load ladder that shows the value of using the same mandrel to set tension on Hornady & Lapua.
All brass trimmed same length. Loaded same BTO, loaded in once fired brass, annealed, LE Wilson FL bushing sized, .2405 mandrel.
29.3 Lapua = 2729 Hornady = 2733
29.6 Lapua = 2748 Hornady = 2760
29.9 Lapua = 2779 Hornady = 2784
30.2 Lapua = 2831 Hornady = 2835
Different bullet
30.3 Lapua = 2773 Hornady = 2770
Maybe I could get similar results with 2 different bushings?
Here is neck lubing tip that's been working great for me.
Just take the next size down VFG pellet on their mandrel soaked with the imperial graphite & brush it through the necks. The pellet holds the graphite in the fibers well & doesn't make a mess. I tap the pellet over the graphite container as you don't want a bunch of loose graphite caked on the pellet, just even coating in the fibers. This has by far given me the most consistent seating pressure.
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Forget imperfections getting pushed to the outside. There is a much better reason to mandrel. Brass neck thickness variation between head stamps.
The bushing sets your tension/interference based on brass neck thickness. Any variation in neck thickness = different tension when using only the bushing.
I'm currently working on 6ARC loads. Hornady brass loaded neck diameter is .26805. Lapua loaded neck = .2705. If I were to use a bushing to set tension I'd need 2 different bushings or I'd get + .002 interference on the Lapua. I just use the same bushing for both followed by the same .2405 mandrel (gas gun). The mandrel eliminates that significant tension variation I would have had.
I've got like 7 different head stamps for 308, x 4 for 6.5C, X 2 for 6GT etc. The fuck if I'm going to try dialing in a bushing size for each one.
I just did a 6ARC load ladder that shows the value of using the same mandrel to set tension on Hornady & Lapua.
All brass trimmed same length. Loaded same BTO, loaded in once fired brass, annealed, LE Wilson FL bushing sized, .2405 mandrel.
29.3 Lapua = 2729 Hornady = 2733
29.6 Lapua = 2748 Hornady = 2760
29.9 Lapua = 2779 Hornady = 2784
30.2 Lapua = 2831 Hornady = 2835
Different bullet
30.3 Lapua = 2773 Hornady = 2770
Maybe I could get similar results with 2 different bushings?
Here is neck lubing tip that's been working great for me.
Just take the next size down VFG pellet on their mandrel soaked with the imperial graphite & brush it through the necks. The pellet holds the graphite in the fibers well & doesn't make a mess. I tap the pellet over the graphite container as you don't want a bunch of loose graphite caked on the pellet, just even coating in the fibers. This has by far given me the most consistent seating pressure.
Edit Pic added:
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The bullet does, but it’s under tension unevenly. The mandrel relieves the uneven tension that would be put onto the bullet. And that tension varies in location on the brass neck so each case would be grabbing the bullet in different spots inside the neck.
Plus, there is the fact that copper and lead could give a little especially if the uneven tension is strong enough.
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Technically if you have dented necks with new brass you can just seat a bullet and push them out. But there’s a reason some don’t do that.
Admittedly I do seat bullets on slightly dented necks on new brass because I don’t load for serious precision till after the second firing. But people who load for precision right out of the box, will run them thru a die to get the necks right.
If you’ve ever turned the high spots off of the outside of the neck you’d see how uneven the thickness is even with the most expensive bass. No two pieces will have the same amount turned off of them. It’s the same inside the neck too.
I use a mandrel for reliving the uneven tension introduced on the bullet and get acceptable runout with one stroke of the press. I feel it when I seat the bullet, it’s noticeably consistent across the whole lot of brass. I use to fight FL dies to try to eliminate run out, now I just screw the mandrel in and enjoy.
How do you quantify uneaten tension?
Shooters who could shoot the difference have been saying for a while that in testing runout up to 10 thou, it doesn’t matter. The bullet only has some much clearance in the throat before it’s forced back into alignment.
Shooters who could shoot the difference have been saying for a while that in testing runout up to 10 thou, it doesn’t matter. The bullet only has some much clearance in the throat before it’s forced back into alignment.
Your missing the whole point. Forget imperfections in the neck. Forget run out. Consistent tension matters most IMO.
If you use only a bushing, then consistent neck tension is 100% dependent on brass thickness of the necks. i.e. that bushing set up will work with that lot of that head stamp brass. Re-read my example. 6ARC Lapua necks are .001 thicker then Hornady. If the same bushing is used you've just set neck tension +.002 higher on the Lapua. With a mandrel, it sets the interference bullet seating has to overcome (tension) from the inside. Seating pressure will be the same no matter the brass thickness. That is assuming the brass hardness is the same for all. It eliminates one of the variables.
Edit: 308 example My head stamps are PPC, Lapua, Hornady, Black hills, Lake City, Federal, Winchester, Norma, AMTC, & RWS.
To use the bushing only to hit a target tension/interference I'd have to measure the necks on 10 different head stamps and do the math to select the correct bushing based on each. Screw that use a mandrel.
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That’s completely different.
The total sum of neck tension (when jumping bullets) directly effects ignition which is reflected with chrono data.
IE, if one neck holds the bullet longer, more pressure builds and thus more velocity.
You can see this with tighter interference fit or if you use a lube that drastically cuts down on friction.
Conversely, when seating into or jamming lands, neck tension starts becoming almost inconsequential.
Now, there’s another conversation to be had if force gauges and amp presses can tell use when something is different.
Lots of people don’t care about runout or uneven tension and shoot pretty good groups. I look at it as tolerance stack, uneven tension, bad runout, a bad scale. All leads up to chasing your tail trying to find problems with the load. So I eliminate as many variables as I can. I usually get my loads figured out with less than 20 rounds and single digit SDs by doing so.
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Well that goes back to what I said about having the correct bushing.
I don’t have inconsistent tensions and my single digit ES and sub 1/3moa group sizes seem to verify it.
