I have been working on refining my loading techniques, and came up on a problem. I have two sets of dies. An old bonanza benchrest set for .308 and a rcbs set in .308. I have tried to set the shoulder back .002 in., measured with a Sinclair bump gauge, but I am only resizing the neck partially. If I adjust the FL die down far enough to get the neck fully resized, the shoulder is set way too far back. Is this normal when using a FL die to just bump the shoulder back .002?
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Bumping shoulder with FL Sizer
- Thread starter Dusty
- Start date
Re: Bumping shoulder with FL Sizer
No. Could be that the Sinclair gauge and your dies don't agree. I like to use my rifle's chamber as a "gauge". I do it by using a case that has been fired in that rifle, and lubeing it, then full length size it with the die backed off the shell holder by about 2 turns. Wipe it dry and try it in the rifle. Usually it will chamber easily. Keep doing the FL sizing and trying turning the die in an 1/8th of a turn at a time. As you keep trying the case in the chamber and as you progressively size the case it begins to lengthen and won't chamber easily or sometimes at all. As you get to the point where you are bumping the shoulder, it will suddenly chamber easily or with just a slight resistance. I use that as my bumping point and lock the die ring there. I'd almost bet you will also have full sizing on the neck. When you finish, swab out the sizing lube from your chamber. JMHO
No. Could be that the Sinclair gauge and your dies don't agree. I like to use my rifle's chamber as a "gauge". I do it by using a case that has been fired in that rifle, and lubeing it, then full length size it with the die backed off the shell holder by about 2 turns. Wipe it dry and try it in the rifle. Usually it will chamber easily. Keep doing the FL sizing and trying turning the die in an 1/8th of a turn at a time. As you keep trying the case in the chamber and as you progressively size the case it begins to lengthen and won't chamber easily or sometimes at all. As you get to the point where you are bumping the shoulder, it will suddenly chamber easily or with just a slight resistance. I use that as my bumping point and lock the die ring there. I'd almost bet you will also have full sizing on the neck. When you finish, swab out the sizing lube from your chamber. JMHO
Re: Bumping shoulder with FL Sizer
There HAS to be a happy medium where the die sizes the case to the proper setback. The setup procedure will have you back the die out, and then proceede to turn the die 1/16 turn size a case then check it in the guage,
relube, turn 1/16, size, measure, loop until done.
1/16 turn is just under 0.001" whereas 1/8 is just under 0.002" (1:14 threds)
There HAS to be a happy medium where the die sizes the case to the proper setback. The setup procedure will have you back the die out, and then proceede to turn the die 1/16 turn size a case then check it in the guage,
relube, turn 1/16, size, measure, loop until done.
1/16 turn is just under 0.001" whereas 1/8 is just under 0.002" (1:14 threds)
Re: Bumping shoulder with FL Sizer
I think I found the problem, I took a sized .40 case and measured the set back with it. When the Sinclair bump gauge showed .002 set back, the .40 case showed the shoulder growing. Bolt was getting resistance while closing. Sized down until the .40 case showed .002 set back and the entire neck was sized. Measured it with the bump gauge and it showed .008 set back.
I took a sharpie and colored the shoulder of a piece of brass, inserted it in the bump gauge and spun it a few times. The only part making contact was the outside edge.
I think I found the problem, I took a sized .40 case and measured the set back with it. When the Sinclair bump gauge showed .002 set back, the .40 case showed the shoulder growing. Bolt was getting resistance while closing. Sized down until the .40 case showed .002 set back and the entire neck was sized. Measured it with the bump gauge and it showed .008 set back.
I took a sharpie and colored the shoulder of a piece of brass, inserted it in the bump gauge and spun it a few times. The only part making contact was the outside edge.
Re: Bumping shoulder with FL Sizer
I also had a Sinclair bump gauge that I would get false reading with. Use your chamber as the gauge, that's the easiest way.
I also had a Sinclair bump gauge that I would get false reading with. Use your chamber as the gauge, that's the easiest way.
Re: Bumping shoulder with FL Sizer
You'll have to fine tune in smaller increments than 1/16 to get sizing just right. 1/72 of a turn is ~0.001" ( 1 turn is ~0.072")
You'll have to fine tune in smaller increments than 1/16 to get sizing just right. 1/72 of a turn is ~0.001" ( 1 turn is ~0.072")
Re: Bumping shoulder with FL Sizer
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dusty</div><div class="ubbcode-body">I think I found the problem, I took a sized .40 case and measured the set back with it. When the Sinclair bump gauge showed .002 set back, the .40 case showed the shoulder growing. Bolt was getting resistance while closing. Sized down until the .40 case showed .002 set back and the entire neck was sized. Measured it with the bump gauge and it showed .008 set back.
I took a sharpie and colored the shoulder of a piece of brass, inserted it in the bump gauge and spun it a few times. The only part making contact was the outside edge. </div></div>
After reading your post, I was curious since I use a Sinclair bump gauge. I took a F/L sized 308 case and inked the shoulder with a marker. I spun it in the gauge and I got full shoulder contact.
I would get ahold of Sinclair. Maybe they will exchange it for you.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dusty</div><div class="ubbcode-body">I think I found the problem, I took a sized .40 case and measured the set back with it. When the Sinclair bump gauge showed .002 set back, the .40 case showed the shoulder growing. Bolt was getting resistance while closing. Sized down until the .40 case showed .002 set back and the entire neck was sized. Measured it with the bump gauge and it showed .008 set back.
I took a sharpie and colored the shoulder of a piece of brass, inserted it in the bump gauge and spun it a few times. The only part making contact was the outside edge. </div></div>
After reading your post, I was curious since I use a Sinclair bump gauge. I took a F/L sized 308 case and inked the shoulder with a marker. I spun it in the gauge and I got full shoulder contact.
I would get ahold of Sinclair. Maybe they will exchange it for you.
Re: Bumping shoulder with FL Sizer
ok , iv been told that it is best to remove the firing pin when trying to " use your chamber as a gauge " so how do you remove a savage firing pin ?
ok , iv been told that it is best to remove the firing pin when trying to " use your chamber as a gauge " so how do you remove a savage firing pin ?
Re: Bumping shoulder with FL Sizer
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">No. Could be that the Sinclair gauge and your dies don't agree. I like to use my rifle's chamber as a "gauge". I do it by using a case that has been fired in that rifle, and lubeing it, then full length size it with the die backed off the shell holder by about 2 turns. Wipe it dry and try it in the rifle. Usually it will chamber easily. Keep doing the FL sizing and trying turning the die in an 1/8th of a turn at a time. As you keep trying the case in the chamber and as you progressively size the case it begins to lengthen and won't chamber easily or sometimes at all. As you get to the point where you are bumping the shoulder, it will suddenly chamber easily or with just a slight resistance. I use that as my bumping point and lock the die ring there. I'd almost bet you will also have full sizing on the neck. When you finish, swab out the sizing lube from your chamber. JMHO </div></div>
I concur, although I use a different method taught to me by an old H.O.G. (Honest To God) Vietnam 11 Delta 30. He taught me to hold the shoulder of the case in a candle flame to get a thin layer of carbon on it, then repeat process of advancing the die 1/16 of a turn at a time until you just got a circular mark on the shoulder from the sizing die. Stop there and lock the die collar. Since then I havven't used a collar gauge.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">No. Could be that the Sinclair gauge and your dies don't agree. I like to use my rifle's chamber as a "gauge". I do it by using a case that has been fired in that rifle, and lubeing it, then full length size it with the die backed off the shell holder by about 2 turns. Wipe it dry and try it in the rifle. Usually it will chamber easily. Keep doing the FL sizing and trying turning the die in an 1/8th of a turn at a time. As you keep trying the case in the chamber and as you progressively size the case it begins to lengthen and won't chamber easily or sometimes at all. As you get to the point where you are bumping the shoulder, it will suddenly chamber easily or with just a slight resistance. I use that as my bumping point and lock the die ring there. I'd almost bet you will also have full sizing on the neck. When you finish, swab out the sizing lube from your chamber. JMHO </div></div>
I concur, although I use a different method taught to me by an old H.O.G. (Honest To God) Vietnam 11 Delta 30. He taught me to hold the shoulder of the case in a candle flame to get a thin layer of carbon on it, then repeat process of advancing the die 1/16 of a turn at a time until you just got a circular mark on the shoulder from the sizing die. Stop there and lock the die collar. Since then I havven't used a collar gauge.
Re: Bumping shoulder with FL Sizer
I got a replacement bump gauge from Sinclair. Same results. I measured the cases using a .40 deprimed case and I get .0015 -.002 set back. Using the Sinclair bump gauge I get .008 set back. Neck is resized all the way down. It still only touches the outside of the shoulder. I tried it on once fired, virgin, and resized brass, and all just touch the outside of the shoulder. Anyone else encountered this problem?
I got a replacement bump gauge from Sinclair. Same results. I measured the cases using a .40 deprimed case and I get .0015 -.002 set back. Using the Sinclair bump gauge I get .008 set back. Neck is resized all the way down. It still only touches the outside of the shoulder. I tried it on once fired, virgin, and resized brass, and all just touch the outside of the shoulder. Anyone else encountered this problem?
Re: Bumping shoulder with FL Sizer
Get your money back and just use the rifle as the gauge. Evidently your chamber and dies were cut with a different reamer than Sinclair's gauge. JMHO
Get your money back and just use the rifle as the gauge. Evidently your chamber and dies were cut with a different reamer than Sinclair's gauge. JMHO
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