Help -bumped shoulder cases wont chamber?

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chappo555

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SOLVED -bumped shoulder cases wont chamber?

Righto heres the problem.
I have just purchased a Stolle Grizzly II with a Krieger 6.5*47 Lapua .292 nk barrel used but only 850 rounds fired.
I got 200 Lapua cases that have had 4 firings each. The previous owner had used graphite as a case lube and the cases were filthy. I tumbled and ultrasonic cleaned them up and then neck sized using a redding type S match die with a .289 bushing.

I tested some empty neck sized cases in the action and bolt was firm but not tight to close. I then thought Id bump the shoulder using the Redding body die. I set the die up with 40 thou clearance between the bottom of the die and the shell holder and sized two cases.

I then attempted to chamber these cases and they would not chamber at all. You would need two hands on the bolt to close it up.

Now ive checked the chamber and its free of obstructions. No marks on chambered cases either. I then measured some necked cases compared to the two ive FLS/Body sized.
NK / Body sized
Neck outside diametre .289 / .289
Web of case .471 / .471
overall length 1.8474 / .1.8470
Max overall length for 6.5*47 Lapua is listed as 1.854.

Based on these measurements I cannot understand how a FLS/body sized case will not chamber but a NK sized one will.

Have I missed something simple or are there strange forces at work well beyond my simple brain ?
All help and suggestions appreciated.

Cheers and thanks in advance
Chappo555
 
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Compare the width of the case down the length of the case. Maybe when you pushed the shoulder back, it buldged the body of the case a bit?
 
chappo555,

Paint your sized case with a felt tip pen and attempt to chamber it. The marks where the chamber wipes the marker dye off the case will reveal where the case/chamber interference occurs. What a body does to a fired case depends on what the chamber does to the case first. A body die is not a shoulder bump die. A body die is intended to reduce the dimension of the body and shoulder, everything except the neck. A clearance of 0.040" between shell holder and die pretty much insures that you won't get the results you seek. Partial sizing with a body or FL die can actually move the shoulder forward as the body is squeezed to a smaller diameter. Tighten up the shell holder/die gap a lot and keep working with the marker to monitor what is happening to case clearances until you get the sized case to chamber fit you want.

Greg
 
Try the marker trick but I used to have this happen and not understand why. Your not sizing the cases is the problem. .040 between the shell holder on a fairly good matched die is the clue...it's to much. Screw that die down a little at a time until they chamber and then take measurements. I bet the problem is solved.

What is happening is one of two fold problems. The one already mentioned is probably the culprit, the die is bulging the cases. The other common problem is if the die does not touch the shoulder, it will also lengthen the case just a tad...it can do this two ways. One, by pushing the brass forward as it tries to size the body or two, if your close to the shoulder, it can change the shoulder angle slightly (and unmeasurably), thus causing hard chambering.

Unlike what most will say on here, when dealing with dies and chambers, I get the die to size the case to chamber by feel and then measure and see if the die is sizing the brass to much. If it is, I look for a different die. I know people who measure brass and size it the correct amount and just deal with hard chambering, etc...and in my opinion, all your doing there is flirting with galling, slowing down the reloading process and shortening brass life (in the since that it won't chamber).

Basically, take the firing pin out of the bolt and screw that die down until the handle falls to 90 degrees and pushes on down with one finger, then measure the case. It's obvious by what your feeling and the web measurement, that your not there yet.

Hovis
 
If you have a tool for measuring the length of cases from their shoulders to their heads, it will tell you what is going on. As was explained in previous posts when the die does not touch the shoulder, reduction of the diameter of the body moves the shoulder forward. Continuing to adjust the die downward, in very small increments will eventually give you the shoulder bump that you are looking for, as the shoulder of the case finally meets and is "bumped: by the die. In making your adjustments is is good to remember that a full turn of the die lowers or raises it by about .071, so it is easy to go to far with an adjustment due to impatience. In most cases, you would probably be safe starting .010 off of the shell holder's highest position in the ram's stroke. I have seen cases where the die was too large (in diameter at its base) to properly size brass from a given chamber, This is why it is important to measure bump, rather than do it by feel, and there is no disadvantage to measuring. Once when a friend was arguing against measuring, I challenged him to reset his die several times by feel, using a different case each time. He did, and after we measured them for bump, he had proof that his method was not as consistent as he had thought. After that he went home and made a bump gauge. If a die does not give the desired feel, with the desired bump, you need a different die. The only way to determine that this is the case is by measuring.
 
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Cases even in tight chambers expand and if those cases had been fired four times with only neck sizing the bodies of the cases have expanded, maybe only slightly, but when you run them into a body or FL die the expansion of the bodies has to go somewhere. The only place for the brass to go is forward toward the shoulder. Instead of bumping the shoulders back you've pushed them forward. This is one of the major problems with the idea of "partial sizing" with an FL die instead of neck sizing with a neck sizing die too.

As others have suggested adjust the body die downward in small increments, 1/8th or 1/6th turn, try the case, screw it down a bit more and try the case. There are two ways to do this, the "feel" method or by direct measurement with a case "headspace" measuring tool as sold by Hornady (formerly Stoney Point) and I believe Sinclair Int'l. The bolt needs to be stripped so that you can feel the bolt face contact the head of the case, which is okay, but not as accurate or reliable as measuring the amount the case shoulder is bumped back. The shoulder will need to be bumped back 0.001-2" for easy chambering.
 
update

OK heres where Im up to.
The die is a Redding Comp type S set with a BODY die.

I screwed the die down in increments of one turn all the way until the bottom of the die contacted the shell holder at the TDC of the ram stroke. Cases still need both hands on the bolt to close.

Next I tried using a marker on the case and chambered them. Only a small mark from .250 to .400 above the head of the case. No marks on the neck or shoulder.

Next I put a NK and a body sized case into my RCBS range master guage. All measurements from the shoulder to the web indicated that the body sized case was .002 smaller than the NK case. Measurements taken from shoulder/body junction all the way to web of the case. Cases are still under max listed OAL length.

The only part of the case that I cannot accuratly measure is the shoulder to headstamp length. I have a foster OAL and COAL kit but dont have an insert to measure the shoulder. However no marks on the case in the shoulder area using the marker/texta.

At this stage I dont have a bolt disassembly tool for the stolle.

Im open to any suggestions.
Thanks again guys in advance
Chappo555
 

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Will the original cases still allow the bolt to close?
I had a similar problem last year and found that the shoulder just was not being pushed back like I thought it was.
You need a shoulder bump gauge to use with your caliper to see if the shoulder is indeed moving any compared to the untouched cases.
How does the bolt close without anything in the chamber?
Could try a go gauge to verify the head space.
 
Vern said:
Will the original cases still allow the bolt to close?
I had a similar problem last year and found that the shoulder just was not being pushed back like I thought it was.
You need a shoulder bump gauge to use with your caliper to see if the shoulder is indeed moving any compared to the untouched cases.
How does the bolt close without anything in the chamber?
Could try a go gauge to verify the head space.
Click to expand...

Empty chamber the bolt closes like butter. One finger on the bolt handle does the job. With a NK case its firm but doable with just the palm of your hand.
The rifle has won its last four LR comps down here so there shouldnt be anything wrong with its set up including headspace.
I'll start searching for a shoulder bump guage.

Cheers and thanks for the help so far guys. Appreciated
Chappo555
 
Chappo one thing else.
Make sure to grease the lugs when applying that much pressure.
One of the competitors in a match here last month broke the handle off his bolt. Dont know if he was closing or opening but he was unable to finish the match and was not back this month.
 
chappo555 said:
OK heres where Im up to.
The die is a Redding Comp type S set with a BODY die.

I screwed the die down in increments of one turn all the way until the bottom of the die contacted the shell holder at the TDC of the ram stroke.
Click to expand...

Is that with a case being sized or just until the shell holder touches the die? Does your press cam over? With a case in the shell holder run the case into the die and use a feeler gage to see if there is any clearance between the shell holder and die. - nhk
 
I've had a similar experience with a Redding body die not being small enough to do the job. Never had a problem with a Redding FL die, and since with a bushing FL die I can size everything all at once to the size I want I quit buying body dies or NS dies and just get a bushing FL die. Properly adjusted and with the correct neck sizing bushing caes life isn't reduced, cases always chamber easily, and I don't have to worry about that sort of stuff anymore. Of course there is the minor problem of seeing what I'm shooting at, but a guy can't have everything I guess.
 
too-small chamber.jpg


Here's a pic of a case that's been sharpied to see where it's hitting. This case is binding down near the web, the chamber's too small for the die. (A very common occurrence)

In this pertickler case you could set the die down til the cows come home and accomplish nothing other than blowing the case apart. SETTING RESIZING DIES BY FEEL IS A DANGEROUS PRACTICE!

This is a WSM case, the appropriate fix was to chuck the barrel in the lathe and spin out several thou from the rear of the chamber, enlarging it to fit the die. If I continue to build rifles using this reamer I'll have to make an appropriate die or buy a fatter reamer..

al
 
Problem solved

OK,
My press does cam over and as I said I screwed down the die in one turn increments testing each time until the press "just" cammed over and the shell holder was touching the bottom of the die and still couldnt chamber a case.

Working in 1/8 turn of the body die increments I screwed the die further down and kept trying, each time the press was camming over just that bit firmer. At a one half full turn of the die into the shell holder I got cases to chamber using only my little finger on the bolt. I backed off 1/8 turn and tried again and again got a case that wouldnt chamber so screwed down again 1/8 turn and got the desired result.

Looking at a sized case it appears the most "work" done by the die was just behind the shoulder/body junction of the case, even though I couldnt detect any difference with the vernier calipers that was obviously the issue.

I would like to say a BIG thanks to everyone who replied to help me out. Cheers guys and thanks a million.

Chappo555
 
Get a Wilson case gage and it will simplify the checking to see if they will chamber. After using one for a hundred cases it will be very apparent as you start to drop each case into the gage if it is going to go or not!
 
langenc said:
Get a Wilson case gage and it will simplify the checking to see if they will chamber. After using one for a hundred cases it will be very apparent as you start to drop each case into the gage if it is going to go or not!
Click to expand...
Thanks mate. Got one on the way from Sinclairs as we speak.
 
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