shoulder bump problem

[rdr59]

got a new 22-250. my old lee die wont bump back the shoulder enough.it took about 10 sec to sand off .004 with belt sander. here my question the shell holder still contacts the die .the chances of the die still being square are not good. should i sand enough off so shell holder does not contact the die ? its an rcbs rocker chucker supreme thanks for your help

 

[rdr59]

got a new 22-250. my old lee die wont bump back the shoulder enough.it took about 10 sec to sand off .004 with belt sander. here my question the shell holder still contacts the die .the chances of the die still being square are not good. should i sand enough off so shell holder does not contact the die ? its an rcbs rocker chucker supreme thanks for your help

ok i found out something with this problem. its easy to remove material from the bottom a die and keep everything square .

 

[LoneTraveler]

The shell holder contacting the die is a dead STOP so the head space stays in desired tolerance. I would do all sanding and adjusting on the die now you have started on it. To get the shoulder bump right.

Since the shell holder is of the 30-06, 308 family of shells could cause you problems with other die set ups, With a modified shell holder affecting their head space.

 

[Bravo 4]

Use a shim between the shell holder and bottom of case to give a little more set back of the shoulder.

 

[WildRose]

I would just get one of the Redding competition shell holders which are already cut down a bit to get the proper clearance and keep everything square or take what you have to a local machinist to square it off.

Redding is cheaper.

 

[bigedp51]

I would just get one of the Redding competition shell holders which are already cut down a bit to get the proper clearance and keep everything square or take what you have to a local machinist to square it off.

Redding is cheaper.

Redding competition shell holders will "NOT" push the case as far into the sizing die as a standard shell holder. There are 5 shell holders in the Redding set and the deck heights are .002 to .010 "LOWER" than a standard shell holder. The deck hight on a standard shell holder is .125 and the +.002 shell holder is .127, +.004 = .129, +.006 = .131, +.008 = 133, +.010 = .135

Bottom line the Redding shell holders give you "LESS" shoulder bump and still allows the die to make hard contact with the shell holder. This means the die is never touched or adjusted for shoulder bump and changing the shell holder controls the amount of bump in .002 increments.

If the die does not push the shoulder back far enough, the simplest and cheapest thing to do is lap the top of the shell holder. And doing this will push the case further into the die giving you more shoulder bump.

Just remember we live in a plus and minus manufacturing world and your problem shell holder deck hight may be more than .125 and causing the problem.

 

[bigedp51]

The shell holder contacting the die is a dead STOP so the head space stays in desired tolerance. I would do all sanding and adjusting on the die now you have started on it. To get the shoulder bump right.

Since the shell holder is of the 30-06, 308 family of shells could cause you problems with other die set ups, With a modified shell holder affecting their head space.

All you need to do is keep the lapped shell holder in the die box and it will not get mixed up. I use a red felt tip marker and color the top of lapped shell holders.

On top of this it is far easier to lap a shell holder and use a vernier caliper or micrometer to make sure the shell holder is straight and level.

 

[WildRose]

Redding competition shell holders will "NOT" push the case as far into the sizing die as a standard shell holder. There are 5 shell holders in the Redding set and the deck heights are .002 to .010 "LOWER" than a standard shell holder. The deck hight on a standard shell holder is .125 and the +.002 shell holder is .127, +.004 = .129, +.006 = .131, +.008 = 133, +.010 = .135

Bottom line the Redding shell holders give you "LESS" shoulder bump and still allows the die to make hard contact with the shell holder. This means the die is never touched or adjusted for shoulder bump and changing the shell holder controls the amount of bump in .002 increments.

If the die does not push the shoulder back far enough, the simplest and cheapest thing to do is lap the top of the shell holder. And doing this will push the case further into the die giving you more shoulder bump.

Just remember we live in a plus and minus manufacturing world and your problem shell holder deck hight may be more than .125 and causing the problem.

I have shell holders from several different companies and no two of them have the same deck height which is why I suggested it.

I found this elsewhere and it might be helpful.

The practice of grinding dies and or shell holders was never necessary. there is nothing that can be accomplished by grinding that can not be accomplished with a feeler gage, I form/size cases for short chambers from .016 shorter than a go-gage length chamber to infinity (or a more practical .016 thousands longer than a minimum length, commercial, store bought, full length size case) with an RCBS shell holder, add a few when using a Lee shell holder, and forget it if a Herters shell holder is used, but that is another story.

As explained and is accepted by most the deck height of a shell holder is .125, the +.010 Redding shell holder has a deck height of .135 meaning the deck of the shell holder is .010 thousands further from the shoulder of the die , the added .010 adds to the length of the sized case from the head of the case to it's shoulder (when measuring the length of the case is the .010 added to the length of the case from the shoulder forward to the mouth of the case?).

Grinding the die and or shell holder has nothing to do with the Redding Competition shell holder, just the opposite, grinding would reduce the length of the case from the head of the case to it's shoulder, the Redding + shell holders add to the length of the case from the head of the case to it's shoulder.

If a reloader believes he/she can benefit from grinding a shell holder to size cases for a short chamber they should be able to determine 'by this much' before grinding, BY simply placing a feeler gage between the deck of the shell holder and head of the case when sizing, this method does not work or produces mixed results when the head of the reloader is as hard as the case being sized, in the prefect world nothing worked better than a new, never fired case, after that the results gets progressively worst, then we get into jump back, memory, recovery or spring back, I have 243, 6mm, 257 Roberts etc that have absolutely no memory of what they were before being formed from 30/06, the only way I can keep up with it is the head stamp. a 257 Roberts with a military head stamp and no mention of 30/06.
To accomplish the same results as the Redding + shell holder I use the feeler gage, the companion tool to the press, I adjust the die off the shell holder with a leaf that has no limit in thousands as in .001, .002 etc all the way to infinity, but we all know that is not practical for most so I use .016 thousands to adjust the die to the shell holder for a chamber that is .002 thousands over a field reject length 30/06 chamber.

Field reject length chamber for the 30/06 is .014 thousands over a minimum length, full length sized case, or about .009 longer than a go-gage length chamber. Things I have no control over, the rifle was built that way and has been that way for the last 100 years, it is an Eddiestone M1917. I determine head space first, then form then fire this method leaves me with firing the rifle with .002 head space,for the Eddystone, this is not an exception.

When I purchase fired brass at the range I hope the brass I purchase has been fired in a tranche old chamber, again, I am not a fan OF fire to form, i am a fan of form first then fire, and the difference between fire to form and form then fire is time, and that is impossible for the reloader to understand.

When trimming cases for the Eddystone with .016 thousands added length to the chamber from the face of the bolt to the shoulder of the chamber, I add .014 thousands to the length of the case body, to determine where the extra length is added, use a L. E. Wilson case length gage, it measure from the shoulder back and from the shoulder forward, the neck of the case does not protrude from the top of the case gage but protrudes on the case head end .014 thousands, and in all fairness because I do not get benefit from the commercial side of reloading, the Wilson case gage can be used to measure a case from the shoulder to the head of the case in thousands with a straight edge and the companion tool to the press the feeler gage, those that are on the commercial side of reloading omit the precision of the Wilson case gage.
F. Guffey

fguffey, Apr 23, 2011 #7

 

[bigedp51]

I have shell holders from several different companies and no two of them have the same deck height which is why I suggested it.

I found this elsewhere and it might be helpful.

The problem with using feeler gauges is it can restrict the case movement in the shell holder. And if there are dings in the rim and extractor groove it can cause the case to tilt.

At AccurateShooter.com and other information websites they tell you to remover the shell holder retaining clip from the top of the ram and use a o-ring to hold it in place. This allows the shell holder to "float" giving the case more room to self center inside the die.

The dings on the rim and extractor groove can also cause the case to tilt on the down stroke of the ram and pull the case necks off center and induce runout.

This is where the Forster full length benchrest dies are heads above the rest. The Forster high mounted floating expander enters the case neck when the case neck is still held and centered in the neck of the die. And even if you have chewed up case rims the case can not tilt on the down stroke of the ram. This is very noticeable if you have a over gassed AR15 that dings up the rim and extractor groove causing the case to tilt with a standard die.