Need help with bump sizing.

Hello,

I started reloading a couple months ago and everything was easy to understand once I learned to set the dies but I started with Neck Sizing and didn't like how tight and pain in the ass it was working the bolt. I then was told to try bumping the neck by .002 and immediately liked how everything felt but trying to figure out how much I bumped it is confusing. I don't know if I actually bumped it only .002 but I bought the Hornady Headspace Comparator Kit, Sinclair Case Trimmer and Redding Competition Shell Holders and can't find good info or a good video showing how to actually do it in the correct steps. Any info would be great. I'm loading for a Model 12 LRP in 6.5

Thanks.

The Hornady Headspace Comparator kit is the right tool to use. The correct expression is bumping the shoulder back, not bumping the neck.

The goal is the bump the shoulder back .001-.002.
Use the correct gauge for your cartridge (I believe the one labeled 400 is the one you want for 6.5 creed).
Take a measurement on a fired case.
Then turn your FL sizing die a tiny bit. Run the case through and take a new measurement. When the measurement is .001-.002 shorter, then your die is in the correct position. Locked the dies retaining nut to that position.

For semi-autos you want to bump it back a little more, .003-.004.

It might take you a few cases to get it just right.

Hope that helps!

Use the Hornady Comparator to compare a resized (with your regular shell holder) vs. a fired case. As a rule of thumb: whatever you measure use the next size smaller holder. So, if you get a 0.005" difference, try the Redding 0.004" sell holder and reload a few and repeat.

If you are only neck sizing it may not show much or any difference between resized and fired.

The case trimmer is used as cases stretch. Check after you have reloaded them a few times and trim to proper case length as needed.

Quote:

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Originally Posted by 88Magnum

Hello,

I started reloading a couple months ago and everything was easy to understand once I learned to set the dies but I started with Neck Sizing and didn't like how tight and pain in the ass it was working the bolt. I then was told to try bumping the neck by .002 and immediately liked how everything felt but trying to figure out how much I bumped it is confusing. I don't know if I actually bumped it only .002 but I bought the Hornady Headspace Comparator Kit, Sinclair Case Trimmer and Redding Competition Shell Holders and can't find good info or a good video showing how to actually do it in the correct steps. Any info would be great. I'm loading for a Model 12 LRP in 6.5

Thanks.

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You measure a few fired cases with your Hornady cartridge headspace gauge and then adjust the die for .001 to
.002 shoulder bump measuring the cases again after sizing.

The variations in length you get are due to brass spring back after firing and sizing. When resizing if you pause for 4 to 5 seconds at the top of the ram stroke it will greatly reduce brass spring back and the shoulder location will be more uniform.

One of the best dies on the market for those who neck size and want to bump shoulders is the Forster Neck Size/Shoulder Bump Bushing Die. Rather than using a FL sizing die that's backed off this die allows you to set the amount of neck sizing by using different bushings. The die then bumps the shoulder back he desired amount but it also makes sure the Shoulder OD is also sized to prevent any bulge from forming in this area. The majority of the case wall is untouched, just the junction of the case wall to shoulder.

Once bushing is selected and die adjusted you can turn out cases that chamber like silk and bullet seating that is just right every time.

The first time I read "The cartridge should fit the chamber like a rat turd in a violin case" was at the old German Salazar's The Rifleman's Journal web site. And it means the case is full length resized and the body of the case does not touch the chamber walls. Meaning the case give the bullet "wiggle room" to be self aligning with the bore.

Below are Kevin Thomas and Erik Cortina of Team Lapua USA


https://i.imgur.com/Y3IiYL5.jpg

https://www.youtube.com/watch?v=lLG2kSrD40g

Below Mr. Salazar is responding to a question about "partial full length resizing" vs complete full length resizing. And the benefits of how full length resizing helps accuracy. Keeping in mind that a case with unequal case wall thickness will expand more on the thin side of the case and warp and become banana shaped. And a warped neck sized case can push the bullet out of alignment with the axis of the bore.


Reloading: Partial Neck Sizing
by German A. Salazar
http://riflemansjournal.blogspot.com...ck-sizing.html

"Now the last scenario, a full-length sized case in which the neck is also fully sized. There is clearance at the neck and in the body of the case, the closest fit anywhere is the bullet in the throat. If the neck to bullet concentricity is good (although it needn't be perfect), then the bullet will find good alignment in the throat and the case body and neck will have minimal influence. Let's not forget that the base of the case is supported by the bolt face or the extractor to a certain degree as well; this is yet another influence on alignment. As you can see, there are several points from base to bullet that can have an effect. My procedure is to minimize the influence of those that I can control, namely the case body and neck, and let the alignment be dictated by the fit of the bullet in the throat and to some extent by the bolt's support of the base. Barring a seriously out of square case head, I don't think the bolt can have a negative effect on alignment, only a slightly positive effect from minimizing "case droop" in the chamber. Given that a resized case will usually have a maximum of 0.001" diametrical clearance at the web, this isn't much of a factor anyway."

"AND" at the Whidden custom die website they tell you they get the most concentric cases with non-bushing full length dies. This is because any time you reduce the neck diameter .004 or more with a bushing die it can induce neck runout. Also a neck sizing die does not fully support the case body, meaning the case body and case neck are not held in perfect alignment within the die. Bushing dies work best in custom tight neck chambers with neck turned brass where the case neck does not expand over .003 when fired.

Ultimate 6.5 creedmoor sizing die comparison

https://www.youtube.com/watch?v=9I2pwRDxDOQ

Thanks for all the quick replies, very helpful.

This guy does a better job of explaining it all than I can.
https://www.youtube.com/watch?v=ldtbsym650k

https://www.youtube.com/watch?v=Qd583ZMYncE

Quote:

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Originally Posted by PaddyD

This guy does a better job of explaining it all than I can.
https://www.youtube.com/watch?v=ldtbsym650k

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That's one of the ones I watched and it just left me even more confused.

Pull the decapping rod and expander ball out. Screw your FL die in so it just barely, barely touches the ram. Size a case and try it in the gun. If the bolt still closes tight, screw it in 1/4 turn and try it again. Rinse and repeat until the case chambers with no drag. Then put the die back together and go on about your business. It doesn't have to be complicated or expensive.

Quote:

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Originally Posted by gbflyer

Pull the decapping rod and expander ball out. Screw your FL die in so it just barely, barely touches the ram. Size a case and try it in the gun. If the bolt still closes tight, screw it in 1/4 turn and try it again. Rinse and repeat until the case chambers with no drag. Then put the die back together and go on about your business. It doesn't have to be complicated or expensive.

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I've read about pulling the decapping rod before but no one explained why. What's the reason for doing this? As for decapping, do I do it with a seperate decapping die or use the same FL die once I figure out the right setting? Believe me, I'm trying to make it easy but the videos I've seen either tell you what to do without explaining why or they leave out some steps and I end up confused. I'm getting close to understanding it all.

Thanks.

Quote:

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Originally Posted by Zero333

https://www.youtube.com/watch?v=Qd583ZMYncE

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This one was much better, the best one so far explaining everything, thanks.

Quote:

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Originally Posted by 88Magnum

I've read about pulling the decapping rod before but no one explained why. What's the reason for doing this? As for decapping, do I do it with a seperate decapping die or use the same FL die once I figure out the right setting? Believe me, I'm trying to make it easy but the videos I've seen either tell you what to do without explaining why or they leave out some steps and I end up confused. I'm getting close to understanding it all.

Thanks.

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Let the expander in the die and size the case as you "normally" would, there is no reason to remove the expander. All you need to do is measure the case before and after sizing for the correct amount of shoulder bump. Meaning .001 to .002 below the red dotted line below, even if the die barely touches the shell holder you could still push the shoulder back too far. Example I have a .223 Lee full length die that will push the case shoulder back .009 shorter than the chamber if the die contacts the shell holder.

https://i.imgur.com/wm05ArY.gif


Chambers and dies vary in size and the dies have threads to adjust them up and down.

Before I had case gauges I would use feeler gauges starting with a .010 feeler gauge between the die and shell holder and work down in thickness until the case chambered freely. And sometimes you might even need to lap the top of the shell holder to be able to push the case further into the die for the correct amount bump.

https://i.imgur.com/7FfXhJ7.jpg

I like biged's sizing dies compared post, Thanks for posting that one. I have a 6.5 Creed barrel coming but after 55 years of reloading don't have a single thing for 6.5"s. Not even a pilot for the Forster trimmer in all the boxes of junk so I'm starting from scratch on this one.

Quote:

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Originally Posted by bigedp51

Let the expander in the die and size the case as you "normally" would, there is no reason to remove the expander. All you need to do is measure the case before and after sizing for the correct amount of shoulder bump. Meaning .001 to .002 below the red dotted line below, even if the die barely touches the shell holder you could still push the shoulder back too far. Example I have a .223 Lee full length die that will push the case shoulder back .009 shorter than the chamber if the die contacts the shell holder.

https://i.imgur.com/wm05ArY.gif


Chambers and dies vary in size and the dies have threads to adjust them up and down.

Before I had case gauges I would use feeler gauges starting with a .010 feeler gauge between the die and shell holder and work down in thickness until the case chambered freely. And sometimes you might even need to lap the top of the shell holder to be able to push the case further into the die for the correct amount bump.

https://i.imgur.com/7FfXhJ7.jpg

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That pictures explains some of my confusion well, now I understand what it actually does. I measured a few fired cases at 1.539 with the hornady headspace kit/gauge and set the die to shoulder bump but getting it to bump at exactly .002 or .003 is getting to be a pain in the ass. Maybe once I get the competition shell holder set it'll be easier. After sizing it, I found that the best, smoothest bolt cycling was at 1.533, 1.534 which is more than .002 or .003 bump. Should I just say screw it and forget the .002 or .003 bump and size it to 1.533,1.534? I'll keep messing with the die until I get exactly .002 or .003 but with my gorilla hands, I keep screwing up how much I turn because the hornady rings I use are very smooth and slick.

Thanks a million for the help.

On this video that PaddyD (I bet you're one tough sob with that name, must have gotten in 100s of fights...:bolt:) provided.
https://www.youtube.com/watch?v=ldtbsym650k

The guy went from shell holder 10 down to 4 at .002" increments so around .006" bump correct? That's more than the .002 people recommend. I'm also confused about the part where he says, "I call that zero" which means it's close to being where he wants it. Do you bump the shoulder .002 after this so called zero to get the shoulder bump we're after or do I bump it from the start of the fired case? This is where all this leads to confusion but even with all the confusion, I can get this process down the best and smoothest for my rifle. I actually did the above in the video without knowing anything but again, it was far more than .002" shoulder bump. If I go about it this way in the video, I can get to what I'm after it just seems more than a .002" bump to me.

Quote:

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Originally Posted by 88Magnum

That pictures explains some of my confusion well, now I understand what it actually does. I measured a few fired cases at 1.539 with the hornady headspace kit/gauge and set the die to shoulder bump but getting it to bump at exactly .002 or .003 is getting to be a pain in the ass. Maybe once I get the competition shell holder set it'll be easier. After sizing it, I found that the best, smoothest bolt cycling was at 1.533, 1.534 which is more than .002 or .003 bump. Should I just say screw it and forget the .002 or .003 bump and size it to 1.533,1.534? I'll keep messing with the die until I get exactly .002 or .003 but with my gorilla hands, I keep screwing up how much I turn because the hornady rings I use are very smooth and slick.

Thanks a million for the help.

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With the competition shell holder it allows the die to make hard contact with the shell holder with press cam over. This takes all the slop out of the press and thus more uniform shoulder location.

You can also pause at the top of the ram stroke for 4 or 5 seconds and this will greatly reduce brass spring back. The more the case neck and shoulder are work hardened the more spring back you will have that effects bullet grip and shoulder location.

The best part about the Redding competition shell holders is you never have to touch the die to adjust the amount of shoulder bump.

Can someone please answer this question from earlier for me?

Quote:

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On this video that PaddyD (I bet you're one tough sob with that name, must have gotten in 100s of fights...

:bolt:

) provided.

https://www.youtube.com/watch?v=ldtbsym650k

The guy went from shell holder 10 down to 4 at .002" increments so around .006" bump correct? That's more than the .002 people recommend. I'm also confused about the part where he says, "I call that zero" which means it's close to being where he wants it. Do you bump the shoulder .002 after this so called zero to get the shoulder bump we're after or do I bump it from the start of the fired case? This is where all this leads to confusion but even with all the confusion, I can get this process down the best and smoothest for my rifle. I actually did the above in the video without knowing anything but again, it was far more than .002" shoulder bump. If I go about it this way in the video, I can get to what I'm after it just seems more than a .002" bump to me.

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I saw this video yesterday and now in this one, the guy makes the case longer. From 2.471 to 2.474 where he calls it the sweet spot. I thought I was making the cases shorter?? ?? Is there a site or some book, or in depth guide for this? One that explains what happens when you do it, if it grows or shrink, and tells you why. As I said earlier, my cases were 1.539 to 1.540 using the headspace gauge and when I did the FL sizing they shrunk to 1.534-1.535 and they fit perfectly. Now this guy is talking about making it LONGER. If I could get an answer for the question above on the "How To Size Case And Set Headspace" video, then I'll stick with this method.

https://www.youtube.com/watch?v=T-ObwIYb0SM

Just measure a few fired cases with the Hornady cartridges case headspace gauge and then set the die to bump the shoulder back .001 to .002.

After firing the case springs back from the chamber walls and is smaller than chamber dimensions. This is good because the case can be extracted without binding and easy bolt movement.

This is where the expression "the cartridge case should fit the chamber like a rat turd in a violin case" came from.

Your shoulder bump is the head clearance when the cartridge is chambered. And as long as the head clearance is .001 to .002 on a bolt action, it is well within the elastic limits of the brass. Meaning the case will not stretch and thin in the base that can cause case head separations. Meaning the case can stretch and spring back without thinning in the base.

https://i.imgur.com/HK76WCp.jpg

Below a .303 British cartridge with excessive head clearance with the case stretching and thinning to meet the bolt face. And at maximum military headspace you can have .016 head clearance on a Enfield rifle.

https://i.imgur.com/sHgqVJR.gif

Bottom line, anyone can make a YouTube video, but only "YOU" can measure a fired case and set the die for the proper "minimum" shoulder bump of .001 or .002.

https://i.imgur.com/Y3IiYL5.jpg

Quote:

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Originally Posted by bigedp51

Just measure a few fired cases with the Hornady cartridges case headspace gauge and then set the die to bump the shoulder back .001 to .002.

After firing the case springs back from the chamber walls and is smaller than chamber dimensions. This is good because the case can be extracted without binding and easy bolt movement.

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^^^That.

You want the case close to the size of a fired case. BUT not so close that "in the field" in hunting/dirty/different temperatures it doesn't close in the action. Measure the shoulder on a fired case and measure the shoulder on a resized case. Use the case holder that is just below that difference.

(I thought I did answer that question up above(?))

Quote:

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Originally Posted by bigedp51

With the competition shell holder it allows the die to make hard contact with the shell holder with press cam over. This takes all the slop out of the press and thus more uniform shoulder location.

You can also pause at the top of the ram stroke for 4 or 5 seconds and this will greatly reduce brass spring back. The more the case neck and shoulder are work hardened the more spring back you will have that effects bullet grip and shoulder location.

The best part about the Redding competition shell holders is you never have to touch the die to adjust the amount of shoulder bump.

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The Redding Competition shell holders should also be used in conjunction with the rifle you are loading the ammo for. Following Redding's instructions one starts with the largest number shell holder and after sizing checks for fit in the rifle chamber. (Ideally with a stripped bolt the first time) If the case doesn't fit well, and bolt closure is hard, use the next lowest number (.002" more "bump") and repeat until the case fits and the bolt closes "just right". Once this is done then that number shell holder can be used for all cases being sized for that rifle. When using a press that has a decent amount of "cam over" makes for exceptionally uniform case dimensions.

Remember that when sizing a case with any taper in it, different shoulder set backs also means different case dimensions all along the case wall, from shoulder to head.

I did measure with the hornady gauge and my measurements were 1.538 to 1.539 so a .002 bump would give me around 1.536 and some were 1.535 to 1.536.5 unless my calipers are not that good (I'm getting a Mitutoyo set) and this gave me a good bolt close and bolt open so I think I finally got it. The competition shell holder set made it much easier, I think I was screwing things up by over and under adjusting the die.

Thanks all for the time and all the help. :rockon:

Whats so awfully wrong with just following the simple instructions that come with the dies?
I always have full length resized because I'm primarily a hunter, that's what i was recommended to do.
Ive never in over 60 years had any problem by adjusting the die down till i get the bump the directions recommend.
As Salazar said, primer pockets always go first anyway, especially with the large capacity magnums.

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Originally Posted by yobuck

Whats so awfully wrong with just following the simple instructions that come with the dies?
I always have full length resized because I'm primarily a hunter, that's what i was recommended to do.
Ive never in over 60 years had any problem by adjusting the die down till i get the bump the directions recommend.
As Salazar said, primer pockets always go first anyway, especially with the large capacity magnums.

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Chambers and dies vary in size meaning in diameter and headspace length. Example I have a Lee .223 full length die that will push the shoulder back .009 shorter than a GO gauge if setup per the directions. On top of this the same lee die will reduce the case diameter more than my RCBS small base die.

The reason they tell you to use .001 to .002 shoulder bump is this is well within the elastic limits of the brass when the rear of the case stretches to meet the bolt face.

This doesn't mean every die will push the case shoulder back too far. But what it does mean is you can adjust the die for minimum head clearance which is the same as shoulder bump on a chamber cartridge.

https://i.imgur.com/HK76WCp.jpg

Below there is a big difference between .001 to .002 below the red dotted line and .009 shorter than a GO gauge close to the green dotted line.

https://i.imgur.com/wm05ArY.gif

Bottom line there is a reason why Redding makes their competition shell holder that let you push the case from .002 to .010 "LESS" into the die.

Another example, if I use my RCBS .223 die and shell holder with the die adjusted per the instructions the shoulder will be pushed back .007. But by using the Redding +.004 competition shell holder I will have .003 shoulder bump for my AR15.

In the past reloaders would use feeler gauges to adjust the die and the amount of shoulder bump as pictured below.

https://i.imgur.com/7FfXhJ7.jpg

Bottom line, if your cases fail of cracked necks before you have a case head separation your die is a good match for your chamber. "BUT" if you have a case head separation after just a few reloads you are bumping the case shoulder back too far.

Below a example of firing a military .303 British Enfield rifle at max military headspace of .074 and a rim thickness of .058 with .016 head clearance. Meaning it is the excessive head clearance that causes case head separations. And again your shoulder bump is equal to the head clearance when the cartridge is chambered.

https://i.imgur.com/sHgqVJR.gif

I full length size my cases and bump my shoulders back.0015. When adjusting the die, the shoulder will actually move forward until you start getting the die adjusted properly. When the die squeezes the case sides in, it displaces the brass forward and increases the length. Keep adjusting the die downward in very small increments until you get the measurements you need. Once adjusted, tighten the lock ring and you are good to go.

Quote:

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Originally Posted by OLEJOE

I full length size my cases and bump my shoulders back.0015. When adjusting the die, the shoulder will actually move forward until you start getting the die adjusted properly. When the die squeezes the case sides in, it displaces the brass forward and increases the length. Keep adjusting the die downward in very small increments until you get the measurements you need. Once adjusted, tighten the lock ring and you are good to go.

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Try this..go into powerlifting most of your life, set deadlift records and squat records at the 222 lb weight class as a teen, go up to 275lbs and push thousandths of lbs every week for over 20 yrs. Now, grab a sensitive piece of machine like die set with very fine adjustments and start adjusting. Just make sure you don't break many things after the first 2 hrs you keep over adjusting and under adjusting because you just can't get it to a fine enough adjustment. Remove the die with gorilla hands and mess the whole thing up and have to start over again losing your place, try this a few hrs and then see how easy it is. Some of us break things just by looking at them, I already came close to snapping the arm on the rock chucker and screwed up the threading on it. My work has banned me from working with canvas because I rip $5000-$7000 graphics by pulling on them. Others tug away with two people with no issues, I tug on it and I rip it 4 yds. Some of us are a little different my man.

Well “My Man” get your wife or girlfriend to do it for you. Maybe a kid from the neighborhood.

Quote:

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Originally Posted by OLEJOE

Well “My Man” get your wife or girlfriend to do it for you. Maybe a kid from the neighborhood.

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I already explained that I got it down with the competition shell holders. Everyone else was very helpful or at least tried to help, why did you bother to comment? Following the instructions won't work with every rifle, I tried that with my first set of dies, Lee, and I had to back it off by more than what it says.