When your cases become hard to extract, or you feel a stiff bolt lift when removing a cartridge, it’s probably time to full-length size your cases, and “bump” the shoulder back. We generally recommend bumping shoulders each time you reload, after the initial fire-forming. Benchrest and F-Class benchrest shooters, running relatively high pressures, typically full-length size every load cycle, bumping the shoulder .001-.003″. High Power shooters with gas guns generally full-length size every time, and may need to bump the shoulders .003″ or more to ensure reliable feeding and extraction.
Use Shims for Precise Control of Shoulder Bump
Some shooters like to set the “default” position for their full-length die to have an “ample” .003″ or .004″ shoulder bump. When they need less bump, a simple way to reduce the amount of shoulder movement is to use precision shims in .001″ (one-thousandth) increments.
Here are reports from Forum members who use the shims:
“Great product. I have my die lock ring(s) adjusted for the shortest headspace length on my multiple chambers 6BRs and 6PPCs. When needing a longer headspace, I just refer to my notes and add the appropriate shim under the lock ring. Keep it simple.” — F.D. Shuster
Mats Johansson writes: “I’ve been using [shims] since Skip Otto (of BR fame) came out with them. I set up my dies with the .006″ shim, giving me the option of bumping the shoulder a bit more when the brass gets old and hardens while still having room to adjust up for zero headspace, should I have missed the original setup by a thou or two. Hunting rounds can easily be bumped an extra .002-.003″ for positive, no-crush feeding. Being a safety-oriented cheapskate, I couldn’t live without them — they let me reload my cases a gazillion times without dangerous web-stretching. Shims are a must-have, as simple as that.” — Mats Johansson
Sinclair Die Shim Kit — Seven Shims for $14.99
Sinclair Int’l (through Brownells) offers a seven-piece set of Sizing Die Shims that let you adjust the height of your die (and thereby the amount of bump and sizing) in precise .001″ increments. Sinclair explains: “Some handloaders will set their die up to achieve maximum sizing and then progressively use Sinclair Die Shims between the lock ring and the press head to move the die away from the shellholder. Doing this allows you to leave the lock ring in the same position. These shims are available in increments of .001″ and work very well.”
Seven Shims from .003″ to .010″
Sinclair’s $14.99 Die Shim Kit (item 22400) includes seven shims in thicknesses of .003, .004, .005, .006, .007, .008, and .010. For ease of use, shim thickness is indicated by the number of notches cut in the outer edge of each shim. Even without looking you can “count” the notches by feel.
L.E. Wilson Case Gage Depth Micrometer Tool Hands-On Tool Review by F-Class John
Are you looking for a better way to measure shoulder bump when sizing brass? When it comes to measuring your shoulder bump there has traditionally been just one way to do it and that’s with a set of calipers and some type of tool attached to a calipers jaw which contacts the case shoulder. While this method has worked well for decades there’s always been some inherent lack of consistency and repeatability. While a minor issue, the inability to get the exact number in completely dependent on the user’s pressure applied and the angle at which the jaws push on the brass.
Enter the L.E. Wilson Case Gage Depth Micrometer with its simple but effective use of Wilson case gauges to ensure a perfect measure of shoulder bump every time. The unit comes with the micrometer top as well as a check gauge which allows you to easily calibrate the micrometer whenever needed. On top of the micrometer unit, you’ll also need to purchase the appropriate case gauges for each of your cartridge types and then you’re ready to go. No other measuring instruments are needed (yep, no calipers are required).
Using the Wilson Depth Micrometer (perhaps a better name is Shoulder Bump Micrometer) is a straightforward process. Simply take your fired brass and insert it into the case gauge and place the micrometer top onto the primer side of the gauge. While holding the micrometer top firmly against the case gauge in one hand, slowly turn the micrometer until you feel it stop. You can back off and turn it again to verify the stop point and once you have it, look at the measurement on the micrometer. Now insert a sized piece of brass and repeat the procedure. Take note of the new number and subtract it from the fired brass number and you now have an exact amount of shoulder bump. Continue to adjust your sizing die until you have the correct amount of shoulder bump and you’re ready to size all your brass.
Watch Video to See how Shoulder-Bump Measuring Micrometer Tool Works
Guys, in this case a VIDEO is worth more than a thousand words. In may not be obvious from the photos how this system works. In fact, it is fast and easy. Drop brass into cartridge-specific case gauge, then put the Micrometer unit on top, and dial to touch. The video shows how this works.
SUMMARY — Tool is Fast, Precise, Repeatable, and Easy to Use — We Like It
The beauty of this tool is the simplicity with which it works. It uses a very accurate micrometer to simply measure how much further your brass is sitting forward inside the case gauge. After a couple uses, you’ll find that this tool is fast, accurate and incredibly repeatable. That gives you confidence that your brass is being sized properly. Ultimately, I found that using the micrometer top really became a joy as I set up a new set of dies and as I sized my brass, I could easily check the consistency as brass came off my press. If you’re looking to improve your sizing game, give the L.E. Wilson Case Gage Depth Micrometer a try. MSRP is $140.00.
I have seen it time and time again, shooters on the line wrestling with their rifle trying to get the bolt closed while the wind is switching. They were too focused trying to get their bolt to close and getting their rifle settled back on the bags that they missed the wind switch. Bang… Eight! The straw that broke the camel’s back for me was at the 2017 Canadian Nationals. I was paired up with a young girl and she would try really hard to close the bolt on her rifle. The majority of the time she would get it to close, but often times she could not even get the round to chamber. She was focused on her rifle the entire time rather than on the conditions. When we completed our strings, she had five rounds that did not chamber our of 15! That is way too many!. I told her she needed to think about Full-length sizing with 0.002″ shoulder bump, or Controlled Full-length Sizing like I call it. I told her not to worry about losing accuracy. I told her that I full-length size all my rounds and asked if she noticed how smooth my bolt was and noticed my score. She said yes, they were both great!
Controlled Full-length Sizing Does NOT Harm Accuracy
I have found that Controlled Full-length Sizing does NOT hurt accuracy or shorten brass life. I find that I can focus much more on the conditions when I don’t have to think about chambering a round nor extracting it. It has become second nature. After firing, I keep my head welded to the stock, I open the bolt by placing my thumb on top of stock and rotating hand upwards. I reach in and retrieve spent case, place it back in ammo box, and pick up another loaded round and put in chamber. I verify conditions and when ready, I push the bolt in and close it with my index and middle finger.
With Controlled Full-length Sizing you “bump” the shoulder around .002″ for bolt guns.* Image courtesy Sinclair International which carries a variety of Full-length dies.
Whidden Full-Length Sizing Dies by AccurateShooter.com Editor
For proper full-length sizing, you want a quality die that’s a very good match to your chamber. For our project rifles we usually turn to Whidden Gunworks which offers both bushing and non-bushing FL dies. And if you want the hot new option, check out Whidden’s patent-pending, click-adjustable FL-sizing die. This gives instant, precise control over shoulder bump. It works great.
*With gas guns, such as the AR10, you may want to increase shoulder bump to .003″ or more. With some benchrest cartridges, .0015″ bump may prove optimal. But .002″ is a good starting point.
When your cases become hard to extract, or you feel a stiff bolt lift when removing a cartridge, it’s probably time to full-length size your cases, and “bump” the shoulder back. We generally recommend bumping shoulders each time you reload, after the initial fire-forming. Benchrest and F-Class benchrest shooters, running relatively high pressures, typically full-length size every load cycle, bumping the shoulder .001-.003″. High Power shooters with gas guns generally full-length size every time, and may need to bump the shoulders .003″ or more to ensure reliable feeding and extraction.
Use Shims for Precise Control of Shoulder Bump
Some shooters like to set the “default” position for their full-length die to have an “ample” .003″ or .004″ shoulder bump. When they need less bump, a simple way to reduce the amount of shoulder movement is to use precision shims in .001″ (one-thousandth) increments.
Here are reports from Forum members who use the shims:
“Great product. I have my die lock ring(s) adjusted for the shortest headspace length on my multiple chambers 6BRs and 6PPCs. When needing a longer headspace, I just refer to my notes and add the appropriate shim under the lock ring. Keep it simple.” — F.D. Shuster
Mats Johansson writes: “I’ve been using [shims] since Skip Otto (of BR fame) came out with them. I set up my dies with the .006″ shim, giving me the option of bumping the shoulder a bit more when the brass gets old and hardens while still having room to adjust up for zero headspace, should I have missed the original setup by a thou or two. Hunting rounds can easily be bumped an extra .002-.003″ for positive, no-crush feeding. Being a safety-oriented cheapskate, I couldn’t live without them — they let me reload my cases a gazillion times without dangerous web-stretching. Shims are a must-have, as simple as that.” — Mats Johansson
Sinclair Die Shim Kit — Seven Shims for $14.99
Sinclair Int’l (through Brownells) offers a seven-piece set of Sizing Die Shims that let you adjust the height of your die (and thereby the amount of bump and sizing) in precise .001″ increments. Sinclair explains: “Some handloaders will set their die up to achieve maximum sizing and then progressively use Sinclair Die Shims between the lock ring and the press head to move the die away from the shellholder. Doing this allows you to leave the lock ring in the same position. These shims are available in increments of .001″ and work very well.”
Seven Shims from .003″ to .010″
Sinclair’s $14.99 Die Shim Kit (item 22400) includes seven shims in thicknesses of .003, .004, .005, .006, .007, .008, and .010. For ease of use, shim thickness is indicated by the number of notches cut in the outer edge of each shim. Even without looking you can “count” the notches by feel.
I have seen it time and time again, shooters on the line wrestling with their rifle trying to get the bolt closed while the wind is switching. They were too focused trying to get their bolt to close and getting their rifle settled back on the bags that they missed the wind switch. Bang… Eight! The straw that broke the camel’s back for me was at the 2017 Canadian Nationals. I was paired up with a young girl and she would try really hard to close the bolt on her rifle. The majority of the time she would get it to close, but often times she could not even get the round to chamber. She was focused on her rifle the entire time rather than on the conditions. When we completed our strings, she had five rounds that did not chamber our of 15! That is way too many!. I told her she needed to think about Full-length sizing with 0.002″ shoulder bump, or Controlled Full-length Sizing like I call it. I told her not to worry about losing accuracy. I told her that I full-length size all my rounds and asked if she noticed how smooth my bolt was and noticed my score. She said yes, they were both great!
Controlled Full-length Sizing Does NOT Harm Accuracy
I have found that Controlled Full-length Sizing does NOT hurt accuracy or shorten brass life. I find that I can focus much more on the conditions when I don’t have to think about chambering a round nor extracting it. It has become second nature. After firing, I keep my head welded to the stock, I open the bolt by placing my thumb on top of stock and rotating hand upwards. I reach in and retrieve spent case, place it back in ammo box, and pick up another loaded round and put in chamber. I verify conditions and when ready, I push the bolt in and close it with my index and middle finger.
With Controlled Full-length Sizing you “bump” the shoulder around .002″ for bolt guns.* Image courtesy Sinclair International which carries a variety of Full-length dies.
Whidden Full-Length Sizing Dies by AccurateShooter.com Editor
For proper Full-length sizing, you want a quality die that’s a very good match to your chamber. For our project rifles we usually turn to Whidden Gunworks which offers both bushing and non-bushing FL dies. And if you want the hot new option, check out Whidden’s patent-pending, click-adjustable FL-sizing die. This gives instant, precise control over shoulder bump. It works great.
*With gas guns, such as the AR10, you may want to increase shoulder bump to .003″ or more. With some benchrest cartridges, .0015″ bump may prove optimal. But .002″ is a good starting point.
When your cases become hard to extract, or you feel a stiff bolt lift when removing a cartridge, it’s probably time to full-length size your cases, and “bump” the shoulder back. Short-range benchrest shooters, running high pressures, typically full-length size every load cycle, bumping the shoulder .001-.002″. The vast majority of mid-range and long-range F-Class shooters also full-length size every time. High Power shooters with gas guns should definitely full-length size every time, and may need to bump the shoulders .003″ or more to ensure reliable feeding and extraction.
Use Shims for Precise Control of Shoulder Bump
Some shooters like to set the “default” position for their full-length die to have an “ample” .003″ or .004″ shoulder bump. When they need less bump, a simple way to reduce the amount of shoulder movement is to use precision shims in .001″ (one-thousandth) increments. Sinclair Int’l offers a set of seven (7) shims for your standard 7/8-14 FL sizing dies for $14.99.
Sinclair explains: “Each shim is notched for easy size identification. Just set your die using one of the middle thickness shims. Adjustments can be made easily by changing shims to increase or decrease die depth without changing the stem setting. This is a great upgrade for non-micrometer adjustable dies.”
Here are reports from Forum members who use the shims:
“Great product. I have my die lock ring(s) adjusted for the shortest headspace length on my multiple chambers 6BRs and 6PPCs. When needing a longer headspace, I just refer to my notes and add the appropriate shim under the lock ring. Keep it simple.” — F.D. Shuster
Mats Johansson writes: “I’ve been using [shims] since Skip Otto (of BR fame) came out with them. I set up my dies with the .006″ shim, giving me the option of bumping the shoulder a bit more when the brass gets old and hardens while still having room to adjust up for zero headspace, should I have missed the original setup by a thou or two. Hunting rounds can easily be bumped an extra .002-.003″ for positive, no-crush feeding. Being a safety-oriented cheapskate, I couldn’t live without them — they let me reload my cases a gazillion times without dangerous web-stretching. Shims are a must-have, as simple as that.” — Mats Johansson
Brownells offers the seven-piece set of Sizing Die Shims that let you adjust the height of your die (and thereby the amount of bump and sizing) in precise .001″ increments. Sinclair explains: “Some handloaders will set their die up to achieve maximum sizing and then progressively use Sinclair Die Shims between the lock ring and the press head to move the die away from the shellholder. Doing this allows you to leave the lock ring in the same position. These shims are usually available in increments of .001″ and work very well.”
Seven Shims from .003″ to .010″
For use with 7/8-14 threaded dies, Sinclair’s $14.99 Die Shim Kit (Sinclair item 22400 or Brownells Code 749-001-325WB) includes seven shims in thicknesses of .003, .004, .005, .006, .007, .008, and .010. For ease of use, shim thickness is indicated by the number of notches cut in the outer edge of each shim. Even without looking you can “count” the notches by feel.
NOTE: These shim sets can also be use to adjust bullet seating depth for dies that lack micrometer adjustment. Use the same 7/8-14 shims with your non-micrometer seating dies.
Shims for Arbor Dies
Do you seat with an Arbor Press? No problem…
Brownells offers a $14.99 10-shim Arbor Die set for use with L.E. Wilson seating dies employed with arbor presses. Frankly we prefer micrometer-top Wilson dies, but if you have the standard Arbor dies, these shims come in handy. Order either Brownells Code 749-001-370WB (.22 to .243 caliber) or Brownells Code 749-001-326WB (.25 to .30 caliber).
Harrell’s Precision sells “semi-custom” full-length bushing dies for the PPC and 6BR chamberings. While the Harrell brothers do not cut the die to spec, they carry a large selection of dies made with slightly different internal dimensions. When you send in your fired brass, the Harrells choose a die from inventory with just the right amount of sizing (diameter reduction) at the top and bottom of the case. Given the quality, and precise fit, Harrell’s full-length dies cost $115.00 plus shipping. These are currently available for PPC family, 6mmBR, 6mm Dasher, and 6.5×47 Lapua. The folks at Harrells recommend checking if you have questions about die sizing: “Unless you know exactly which die you need, do not order online. We have 8 different sizes of each caliber. Please call (540)380-2683.”
Bump Measuring Collar
The Harrell brothers provide a nice bonus item with each full-length die — a neat, little shoulder bump measuring device as shown in the photo at right. Hornady sells a stand-alone tool that does the same job, but the Harrell’s bump collar is simpler and faster. To measure your shoulder bump, simply place the Harrell’s bump collar over the front of your deprimed case (before sizing) and measure the OAL with your calipers. Then size the case in your full-length die, replace the collar and repeat the measurement. You want to set your die so the shoulder moves back about .001″ to .0015″ for most applications. (With semi-auto guns you may want more shoulder bump, perhaps .003″.)
When your cases become hard to extract, or you feel a stiff bolt lift when removing a cartridge, it’s probably time to full-length size your cases, and “bump” the shoulder back. Short-range benchrest shooters, running high pressures, typically full-length size every load cycle, bumping the shoulder .001-.002″. The vast majority of mid-range and long-range F-Class shooters also full-length size every time. High Power shooters with gas guns should definitely full-length size every time, and may need to bump the shoulders .003″ or more to ensure reliable feeding and extraction.
Use Shims for Precise Control of Shoulder Bump
Some shooters like to set the “default” position for their full-length die to have an “ample” .003″ or .004″ shoulder bump. When they need less bump, a simple way to reduce the amount of shoulder movement is to use precision shims in .001″ (one-thousandth) increments. Sinclair Int’l offers a set of seven (7) shims for your standard 7/8-14 FL sizing dies for $14.99.
Sinclair explains: “Each shim is notched for easy size identification. Just set your die using one of the middle thickness shims. Adjustments can be made easily by changing shims to increase or decrease die depth without changing the stem setting. This is a great upgrade for non-micrometer adjustable dies.”
Here are reports from Forum members who use the shims:
“Great product. I have my die lock ring(s) adjusted for the shortest headspace length on my multiple chambers 6BRs and 6PPCs. When needing a longer headspace, I just refer to my notes and add the appropriate shim under the lock ring. Keep it simple.” — F.D. Shuster
Mats Johansson writes: “I’ve been using [shims] since Skip Otto (of BR fame) came out with them. I set up my dies with the .006″ shim, giving me the option of bumping the shoulder a bit more when the brass gets old and hardens while still having room to adjust up for zero headspace, should I have missed the original setup by a thou or two. Hunting rounds can easily be bumped an extra .002-.003″ for positive, no-crush feeding. Being a safety-oriented cheapskate, I couldn’t live without them — they let me reload my cases a gazillion times without dangerous web-stretching. Shims are a must-have, as simple as that.” — Mats Johansson
Brownells offers the seven-piece set of Sizing Die Shims that let you adjust the height of your die (and thereby the amount of bump and sizing) in precise .001″ increments. Sinclair explains: “Some handloaders will set their die up to achieve maximum sizing and then progressively use Sinclair Die Shims between the lock ring and the press head to move the die away from the shellholder. Doing this allows you to leave the lock ring in the same position. These shims are usually available in increments of .001″ and work very well.”
Seven Shims from .003″ to .010″
For use with 7/8-14 threaded dies, Sinclair’s $14.99 Die Shim Kit (Sinclair item 22400 or Brownells Code 749-001-325WB) includes seven shims in thicknesses of .003, .004, .005, .006, .007, .008, and .010. For ease of use, shim thickness is indicated by the number of notches cut in the outer edge of each shim. Even without looking you can “count” the notches by feel.
NOTE: These shim sets can also be use to adjust bullet seating depth for dies that lack micrometer adjustment. Use the same 7/8-14 shims with your non-micrometer seating dies.
Shims for Arbor Dies
Do you seat with an Arbor Press? No problem…
Brownells offers a $14.99 10-shim Arbor Die set for use with L.E. Wilson seating dies employed with arbor presses. Frankly we prefer micrometer-top Wilson dies, but if you have the standard Arbor dies, these shims come in handy. Order either Brownells Code 749-001-370WB (.22 to .243 caliber) or Brownells Code 749-001-326WB (.25 to .30 caliber).
Some of our readers have questioned how to set up their body dies or full-length sizing dies. Specifically, AFTER sizing, they wonder how much resistance they should feel when closing their bolt.
Forum member Preacher explains:
“A little resistance is a good, when it’s time for a big hammer it’s bad…. Keep your full-length die set up to just bump the shoulder back when they get a little too tight going into the chamber, and you’ll be good to go.”
To quantify what Preacher says, for starters, we suggest setting your body die, or full-length sizing die, to have .0015″ of “bump”. NOTE: This assumes that your die is a good match to your chamber. If your sizing or body die is too big at the base you could push the shoulder back .003″ and still have “sticky case” syndrome. Also, the .0015″ spec is for bolt guns. For AR15s you need to bump the shoulder of your cases .003″ – .005″, for enhanced reliability. For those who have never worked with a body die, bump die, or Full-length sizing die, to increase bump, you loosen lock-ring and screw the die in further (move die down relative to shell-holder). A small amount (just a few degrees) of die rotation can make a difference. To reduce bump you screw the die out (move die up). Re-set lock-ring to match changes in die up/down position.
That .0015″ is a good starting point, but some shooters prefer to refine this by feel. Forum member Chuckhunter notes: “To get a better feel, remove the firing pin from your bolt. This will give you the actual feel of the case without the resistance of the firing pin spring. I always do this when setting up my FL dies by feel. I lock the die in when there is just the very slightest resistance on the bolt and I mean very slight.” Chino69 concurs: “Remove the firing pin to get the proper feel. With no brass in the chamber, the bolt handle should drop down into its recess from the full-open position. Now insert a piece of fire-formed brass with the primer removed. The bolt handle should go to the mid-closed position, requiring an assist to cam home. Do this several times to familiarize yourself with the feel. This is how you want your dies to size your brass, to achieve minimal headspace and a nearly glove-like fit in your chamber.”
We caution that, no matter how well you have developed a “feel” for bolt-closing resistance, once you’ve worked out your die setting, you should always measure the actual amount of shoulder bump to ensure that you are not pushing the shoulder too far back. This is an important safety check. You can measure this using a comparator that attaches to your caliper jaws, or alternatively, use a sized pistol case with the primer removed. See Poor Man’s Headspace Gauge.
Sinclair International has created a series of helpful articles on rifle cartridge reloading. Today’s feature lists ten basic steps for precision hand-loading, with links to longer, detailed Sinclair Int’l technical articles providing more complete information. There’s a lot of helpful info here guys, if you click all the links to access the ten “long form” articles.
Tying It All Together: 10 Steps To Precision Handloads
Feature based on article by Roy Hill, Brownells/Sinclair Copywriter
Sinclair International offers a series of detailed articles on hand-loading precision rifle ammunition. The articles are included in Sinclair’s GunTech Articles Archive, but sorting through the index to find each article takes time. To help you access all these articles quickly, here’s a handy summary of ten key topics, with links to longer articles covering each subject in detail.
Part 1: The first step in making high-quality handloads is to carefully choose the best brass for your application. You need to know how to identify the different types of brass and how to choose the best kind for the ammo you want to load. CLICK HERE for Part 1.
Part 2: Even high-quality brass can have burrs around the flash hole that can interfere with the primer flame and cause inconsistent ignition – which can lead to shot groups opening up. Flash hole deburring is a critical step in making sure primers ignite powder consistently. CLICK HERE for Part 2.
Part 3: The next step is to make sure the primer pockets are square and uniform. Like flash hole deburring, primer pocket uniforming may reduce variations in primer ignition by ensuring more consistent primer seating. CLICK HERE for Part 3.
Part 4: Making sure all your cases are precisely the same length is crucial, especially when you use cases that have been fired before. Case trimming is the way to get there. CLICK HERE for Part 4.
Part 5: After trimming, cases still have to be resized. In order for them to work through the resizing die, they have to be lubricated. The case lube method you choose is crucial to making precision handloads. CLICK HERE for Part 5.
Part 6: Now it’s time to choose the dies that will resize your cases. There are several important options to consider in selecting the right sizing dies. CLICK HERE for Part 6.
Part 7: Wait! You’re not quite ready to start sizing yet. There’s yet more to consider before you start cranking cases through the press. Learn more about setting up and adjusting your sizing dies. CLICK HERE for Part 7.
Part 8: Once the cases are completely prepped, it’s time to start putting fresh components back into them. We start off by seating primers. CLICK HERE for Part 8.
Part 9: After the primers are seated, it’s time to drop in the powder. There are several tools that will help you handle powder for precision handloads. CLICK HERE for Part 9.
Part 10: The final step in the process is carefully seating the bullet to just the right depth. And then… you’re ready to try your loads at the range. CLICK HERE for Part 10.
Shims for Arbor Dies
Bump Measuring Collar
To quantify what Preacher says, for starters, we suggest setting your body die, or full-length sizing die, to have .0015″ of “bump”. NOTE: This assumes that your die is a good match to your chamber. If your sizing or body die is too big at the base you could push the shoulder back .003″ and still have “sticky case” syndrome. Also, the .0015″ spec is for bolt guns. For AR15s you need to bump the shoulder of your cases .003″ – .005″, for enhanced reliability. For those who have never worked with a body die, bump die, or Full-length sizing die, to increase bump, you loosen lock-ring and screw the die in further (move die down relative to shell-holder). A small amount (just a few degrees) of die rotation can make a difference. To reduce bump you screw the die out (move die up). Re-set lock-ring to match changes in die up/down position.
