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Begginers question: does screwing the die deeper in press bumps shoulders more?

siemkapl

I am relatively new to reloading and I am sure this question has poped up a few times, but
I couldnt find a definite answer with search.

I usually screw the die (lee full length) die into the press (rcbs partner) so that it touches the shellholder with the ram al the way up, and then I screw the die a bit more (1/8 of the turn).
If I screw the die more, do I bump the shoulders of the case further down, will I create excessive headspace on the cases this way?

Yesterday I was shooting my load for bergara hmr in 308 and I got bigger groups than usual, instead of 12mm they were like 60,70mm.
A friend of mine instantly checked for headspace by putting pieces of paper on bolt face, and then chambering a round. We could put 3 or 4 pieces of paper with some rounds.
If I remember correctly, I might have screwed the die a bit more than usual last time, but I was under the impression (and told so by more experienced reloaders) that it
doesnt matter how much I screw the die in the press, the shellholder is the full stop and it wont have any impact on case shoulders.
 
You need to get yourself a comparator, measure a fired case and record the dimension. After that you screw your die down until you get the desired shoulder bump you want. If you can slide 3 or 4 pieces of paper in there, that is too much.
 
Once the ram contacts the die, you cannot squish the brass up in the die any further.

Sounds like you need to back the die out a bit. It is a lie that the ram has to touch the die to be set correctly. Most of us adjust the die to where we are getting the the brass resized enough to chamber easily and the shoulder is bumped about .003 (the thickness of a piece of paper).

I hope this helps
CW
 
Like these guys said, you need a comparator with a set of calipers. You can’t know how much to size unless you measure from the base to the datum of shoulder after sizing. Sounds like you are oversizing.
 
If you don't have a comparator you can set you shoulder bump the old time way. Now this doesn't work with a bushing die. Best way with a bushing die is remove the bushing. Screw the die in with the brass at the top of the stroke until you feel resistance. That should be the shoulder.

Chamber your unsized, unloaded, fired brass. If it chambers easily it doesn't need to be bumped. Back your die out about a quarter of an inch. Size a piece of brass. You might not even touch the neck. If not with the brass at the top of the stroke screw the die in till you feel resistance. Now start sizing the brass, look at the neck you should see how much has been sized, screw the die in a little each time watching how much has been sized. Keep doing that until there is just a little bit of the neck unsized above the shoulder. Now you can size necks without bumping shoulders. I lock it down with a lock ring at that point.

When your brass gets to the point that a piece of fired and unsized brass chambers tight you are ready to set your shoulder bump. Onlock the lock ring and carefully turn the die a tiny amount clockwise. Size a piece of brass and chamber it. If it chambers easily you are there. If not tighten the die a tiny bit more. Repeat to success the lock that die down. Shouldn't have to mess with it unless after repeated firings and no annealing the brass work hardens and won't hold the bump
 
Most my dies I use the most have 3 shell holders and
spaced in thickness .002 apart. My initial die set is on a
.004 steel shim to the thickest holder. This gives me a
simple range of adjustments by just swapping holders.
 
siemkapl said:
We could put 3 or 4 pieces of paper with some rounds.
Click to expand...
When you set the shoulder back too much, because you didn't set the die properly, can result in incipient case head separation, you DO NOT want that. To get an idea of how little die rotation can cause changes in your case head to datum length.
Die Adjustment.jpg Incipient Case Head Separation.jpg
 
siemkapl said:
I am relatively new to reloading and I am sure this question has poped up a few times, but
I couldnt find a definite answer with search.

I usually screw the die (lee full length) die into the press (rcbs partner) so that it touches the shellholder with the ram al the way up, and then I screw the die a bit more (1/8 of the turn).
If I screw the die more, do I bump the shoulders of the case further down, will I create excessive headspace on the cases this way?

Yesterday I was shooting my load for bergara hmr in 308 and I got bigger groups than usual, instead of 12mm they were like 60,70mm.
A friend of mine instantly checked for headspace by putting pieces of paper on bolt face, and then chambering a round. We could put 3 or 4 pieces of paper with some rounds.
If I remember correctly, I might have screwed the die a bit more than usual last time, but I was under the impression (and told so by more experienced reloaders) that it
doesnt matter how much I screw the die in the press, the shellholder is the full stop and it wont have any impact on case shoulders.
Click to expand...

As you're new to reloading I get your concern. And to answer your question, yes, screwing the die in further does affect case length, infact you will use this to adjust your case length during sizing.

When sizing brass after initial firing, and especially with a new barrel who's dimensions I'm not intimately familiar with, I will neck size the brass instead of full length sizing. Load and shoot again and then rechamber the shot brass to see if it the bolt will close without extra effort. If it does, I will neck size again and repeat until I get a slightly stiff bolt close. At this point I know the brass is fully fireformed to fit the chamber. This is important! I measure the base to shoulder datum and record this dimension as well as mark and keep the case as a set up tool.

Then when setting up my shoulder bump or FL sizing die, I will know exactly what my case should measure when the shoulder is bumped back a thousandth or two. Having a comparator gage or ability to measure this dimension is essential.

Another critical dimension is the case OAL, base to mouth. All loading manuals quote an OAL trim dimension. This is important to preclude an overpressure event caused by the case mouth pinching the bullet at the chamber throat. If the case neck is too long, it may jamb into the barrel throat and have nowhere to expand during firing, pinching or holding the bullet too securely and possibly causing a barrel burst.

The problem with using OAL as a definitive dimension is that if you bump the shoulder back too far, the case will measure OK but will index too deeply in the chamber and potentially allow the mouth of the case to jam in the throat. This is because with most ammo the case indexes off the shoulder, not the head which is the convenient datum point used for measuring case OAL.

Another problem with sizing a case too much occurs during the ignition cycle. When the firing pin hits a case that is too short after sizing, it drives it forward until the shoulder stops it in the chamber. Many times this will reduce firing pin effort sufficiently to where the primer will not detonate.

I remember talking to a guy at the range who was complaining he had a bad batch of primers. Only 2 or 3 out of 10 would fire. I asked him how he measured his should bump while sizing and the deer in the headlights look I got told me I needed to put away my rifles and have a conversation with him.

I would like to suggest that you invest in some good measuring equipment, tooling and most of all a borescope camera like the inexpensive Teslong Borescope. Do some reading in your manuals and online and don't be afraid to ask questions here.

Also you might want to upgrade your subscription so you can access more information as well as send and receive PM's. This will help you immensely.

Hand loading is not rocket science, but that doesn't mean you can't launch your firearm into orbit by not obeying some basic rules, and possibly getting a ride to the hospital in the process.

Good Shooting and take good care.
 
Texas10 said:
As you're new to reloading I get your concern. And to answer your question, yes, screwing the die in further does affect case length, infact you will use this to adjust your case length during sizing.

When sizing brass after initial firing, and especially with a new barrel who's dimensions I'm not intimately familiar with, I will neck size the brass instead of full length sizing. Load and shoot again and then rechamber the shot brass to see if it the bolt will close without extra effort. If it does, I will neck size again and repeat until I get a slightly stiff bolt close. At this point I know the brass is fully fireformed to fit the chamber. This is important! I measure the base to shoulder datum and record this dimension as well as mark and keep the case as a set up tool.

Then when setting up my shoulder bump or FL sizing die, I will know exactly what my case should measure when the shoulder is bumped back a thousandth or two. Having a comparator gage or ability to measure this dimension is essential.

Another critical dimension is the case OAL, base to mouth. All loading manuals quote an OAL trim dimension. This is important to preclude an overpressure event caused by the case mouth pinching the bullet at the chamber throat. If the case neck is too long, it may jamb into the barrel throat and have nowhere to expand during firing, pinching or holding the bullet too securely and possibly causing a barrel burst.

The problem with using OAL as a definitive dimension is that if you bump the shoulder back too far, the case will measure OK but will index too deeply in the chamber and potentially allow the mouth of the case to jam in the throat. This is because with most ammo the case indexes off the shoulder, not the head which is the convenient datum point used for measuring case OAL.

Another problem with sizing a case too much occurs during the ignition cycle. When the firing pin hits a case that is too short after sizing, it drives it forward until the shoulder stops it in the chamber. Many times this will reduce firing pin effort sufficiently to where the primer will not detonate.

I remember talking to a guy at the range who was complaining he had a bad batch of primers. Only 2 or 3 out of 10 would fire. I asked him how he measured his should bump while sizing and the deer in the headlights look I got told me I needed to put away my rifles and have a conversation with him.

I would like to suggest that you invest in some good measuring equipment, tooling and most of all a borescope camera like the inexpensive Teslong Borescope. Do some reading in your manuals and online and don't be afraid to ask questions here.

Also you might want to upgrade your subscription so you can access more information as well as send and receive PM's. This will help you immensely.

Hand loading is not rocket science, but that doesn't mean you can't launch your firearm into orbit by not obeying some basic rules, and possibly getting a ride to the hospital in the process.

Good Shooting and take good care.
Click to expand...


Great info here and in the other replys. What press are you using, adjusting die last contact puts more force through the press, and each respond differently. I do have a few die / shell holder combos that needed "cam-over" on my RCBS rockhucker; but the right fix is a different shell holder with that die, or machine one and keep for use with that die.

Redding has a series of "deck heights" of shell holders I believe they're listed under "competition" and different brands of sizing dies setup differently. Though back to measuring the brass before and after to know what you need first. Personally, I like the RCBS precision mic style tool, Hornady has a similar more modular tool that clamps to caliper jaws.

Oh, and if in your shoulder bump or brass sizing searches come across any FGuffey posts, you may want to skip over them for others.

-Mac
 
If you have a caliper or micrometer large enough to measure case length, you can take a sized case and thumb seat a FIRED primer and chamber and close the bolt. The amount of protruding primer is approximately the headspace you are sizing brass to. 0.0015-0.0025 should work well for hunting rifles add an extra 0.001 for semi -auto rifles. Try the fired primer trick on several pieces of brass for an average and also to see how consistent your sizing operation functions. I use a case trimmed to minimum case length for this. Back the die out to reduce the primer protrusion on the next case.
 
siemkapl said:
I am relatively new to reloading and I am sure this question has poped up a few times, but
I couldnt find a definite answer with search.

I usually screw the die (lee full length) die into the press (rcbs partner) so that it touches the shellholder with the ram al the way up, and then I screw the die a bit more (1/8 of the turn).
If I screw the die more, do I bump the shoulders of the case further down, will I create excessive headspace on the cases this way?

Yesterday I was shooting my load for bergara hmr in 308 and I got bigger groups than usual, instead of 12mm they were like 60,70mm.
A friend of mine instantly checked for headspace by putting pieces of paper on bolt face, and then chambering a round. We could put 3 or 4 pieces of paper with some rounds.
If I remember correctly, I might have screwed the die a bit more than usual last time, but I was under the impression (and told so by more experienced reloaders) that it
doesnt matter how much I screw the die in the press, the shellholder is the full stop and it wont have any impact on case shoulders.
Click to expand...
when you screw the die in to touch the shell holder and then size a brass, look at the distance between shell holder and die with the case still up in the die. youll see there is some space between the shell holder and die. this is because the force of sizing pushes the press apart. So yes you can size a case to much by screwing the die in past the point it touches shell holder.. do like these guys said and use one of the methods to set your die so it sets the shoulder back the correct amount -- usually .002 ro .004 inches. dont know what that is in metric. ill check. Its good to see you here all the way from Poland.
 
Listen to these fellows....you don't want to get yourself into big problems.
Comparator is your friend...and a set of good calipers....hell any calipers for that matter.
 
Some good advice here and I'll try not rehash too much of it. PROPERLY RESIZING CASES IS AN IMPORTANT STEP IN RELOADING FOR BOTH ACCURACY AND SAFETY REASONS.

The most precise way to set your full length resizing die is to use one of the many gauges made for this purpose. As said by others, you measure the fired case (primer removed but not sized) with the gauge. Then you adjust your die (turning down to increase sizing - turning out to decrease sizing) a little at a time until you reach a .001 to .002" (bolt rifles) shoulder set back.

There are competition shell holders and shims sold to make fine adjustments as cases age or if you change brass lot or brand which sometimes may require you to reset the die to obtain the proper shoulder set back. These devices are especially useful for those who reload multiple rifles of the same caliber so you don't have to keep changing the lock ring setting on the die. Shoulder set back is changed by merely using a different shell holder or shim under the die.

However if you are loading for one rifle of one caliber you can use the "old school" method of trial and error by sizing a case and trying it in your rifle until the bolt closes with just a slight bit of resistance. To do this more precisely however you should remove the firing pin assembly of the bolt so you can get a better feel of the resistance in closing the bolt.

Personally, even for one rifle, I'd opt for one of the gauges and measure the shoulder set back. An effective but economical way is to purchase a Widden Gun Works bump gauge that is caliber specific. I believe they are under $20. The only other piece of equipment you need is a caliber which you should have anyway for other purposes such as measuring over all length of the case. You can get a reasonably reliable caliper on Amazon for a fairly reasonable price. I personally prefer the "dial" type caliber since they don't require a battery and don't seem to drift as much as the electronic calibers. Once you set the die up for the proper shoulder set back you should be good for several reloads on that specific rifle and lot of cases. As cases age you should periodically check a sized case in your rifle to see if some die adjustment is necessary.

No matter which method you use you should always inspect case every time you reload for incipient separation and other wear defects.

All this assumes you are using new cases of the same brand from the same lot.
 
K22 said:
Some good advice here and I'll try not rehash too much of it. PROPERLY RESIZING CASES IS AN IMPORTANT STEP IN RELOADING FOR BOTH ACCURACY AND SAFETY REASONS.

The most precise way to set your full length resizing die is to use one of the many gauges made for this purpose. As said by others, you measure the fired case (primer removed but not sized) with the gauge. Then you adjust your die (turning down to increase sizing - turning out to decrease sizing) a little at a time until you reach a .001 to .002" (bolt rifles) shoulder set back.

There are competition shell holders and shims sold to make fine adjustments as cases age or if you change brass lot or brand which sometimes may require you to reset the die to obtain the proper shoulder set back. These devices are especially useful for those who reload multiple rifles of the same caliber so you don't have to keep changing the lock ring setting on the die. Shoulder set back is changed by merely using a different shell holder or shim under the die.

However if you are loading for one rifle of one caliber you can use the "old school" method of trial and error by sizing a case and trying it in your rifle until the bolt closes with just a slight bit of resistance. To do this more precisely however you should remove the firing pin assembly of the bolt so you can get a better feel of the resistance in closing the bolt.

Personally, even for one rifle, I'd opt for one of the gauges and measure the shoulder set back. An effective but economical way is to purchase a Widden Gun Works bump gauge that is caliber specific. I believe they are under $20. The only other piece of equipment you need is a caliber which you should have anyway for other purposes such as measuring over all length of the case. You can get a reasonably reliable caliper on Amazon for a fairly reasonable price. I personally prefer the "dial" type caliber since they don't require a battery and don't seem to drift as much as the electronic calibers. Once you set the die up for the proper shoulder set back you should be good for several reloads on that specific rifle and lot of cases. As cases age you should periodically check a sized case in your rifle to see if some die adjustment is necessary.

No matter which method you use you should always inspect case every time you reload for incipient separation and other wear defects.

All this assumes you are using new cases of the same brand from the same lot.
Click to expand...
The OPs got alot of good info but i almost feel sorry for him--hes probably overwhelmed. These helpful Americanos lol
 
Thanks for the advices guys, I will need some time to go through all this :)

I do have a set of calipers and a hornady headspace gauge, but the problem is that I was led to believe that however I set the die (screwed until it hits the shellholder or screwed in more), I will always get the same result - brass will be in some SAMI specs and shoulder bumped some minimal ammount. So thats why I didnt check for excessive headspace, and was even beginning to ask myself why did I buy the comparator.
 
siemkapl said:
Thanks for the advices guys, I will need some time to go through all this :)

I do have a set of calipers and a hornady headspace gauge, but the problem is that I was led to believe that however I set the die (screwed until it hits the shellholder or screwed in more), I will always get the same result - brass will be in some SAMI specs and shoulder bumped some minimal ammount. So thats why I didnt check for excessive headspace, and was even beginning to ask myself why did I buy the comparator.
Click to expand...
You are on the right track now..... always ask why!
CW
 
Here's my simple method.
Measure to get datum on fired case, before sizing. I start with a .010 feeler gauge between shell holder and die. Size and measure.
Did case grow in length, stay the same, or bump back?
Now subtract the difference from your .010 feeler gauge and use that feeler gauge to set up die.
Easy!!
If brass has only 1 firing I like to note measurement and keep shoulder at that point and not bump until 2nd or 3rd firing.
 
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