Problem with brand new .308 cases

vpsalin

vpsalin

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So I just started getting into reloading and I already came across my first issue on my first batch of brass.

I bought 100 ct of PPU 308 cases.

I started FL resizing them and priming them. That's done. Now I started making my first dummy round, trying to get COAL of 2.780. So I made my first round and tried chambering it into my rifle, the bolt is very stiff on the down stroke. So went back to the press and tried 2.777 COAL, no change bolt is still just as stiff on the down stroke. I started thinking it's maybe not the bullet but the case's fault.

So I tried some empty FL resized cases alone with no bullet and tried chambering them into my rifle, cases that measure 2.008 OAL are just as stiff to close as cases which measure 2.005 OAL... My once fired winchester brass is smooth as silk at 2.008...

What's going on? Should I just forget about it at least fire them all at least once before passing judgement?
 
The OAL has nothing to do with your problem, the shoulder of the new Prvi cases were not bumped back far enough.

You need a Hornady cartridge case headspace gauge to measure your cases. The Hornady gauge measures from the bottom of the case to the shoulder, that way you can measure a fired case and a resized case for correct shoulder bump.

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Each brand of cartridge case will have slightly different brass qualities, I think the Prvi brass "sprang back" further than your Winchester brass. I use special shim washers under the die lock rings and custom shell holders that are .002 to .010 taller than a standard shell holder to control shoulder bump.

With the Redding shell holders you set the die to contact the shell holder and the press cams over.

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With the shimming washers you adjust the die to contact the shell holder and make the press cam over. You then add the shims and adjust for proper shoulder bump. The same basic adjustment can be done by placing feeler gauges between the die and the shell holder and controlling the the "gap" between the die and shell holder.

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For your new Prvi cases set your resizing die down to make hard contact with the shell holder and let the press cam over. Set this way a full length resizing die will normally push the shoulder of the case back at least .002 smaller than the GO gauge or minimum chamber length.

With the Hornady case gauge on a bolt action you would bump the shoulder back .001 to .002 smaller than its fired length and on a semi-automatic .003 to .006 smaller.

Again I think you did not bump the shoulder of the case back far enough and your Prvi cases do not have any "head clearance" making your bolt harder to close.

Your resized case are rubbing against the bolt face making the bolt harder to close because they are too long from the datum line to the bolt face.

Headspace_2_lg.jpg


Head clearance is the "air space" between the bolt face and the rear of the case, you need .001 to .002 head clearance on a bolt action rifle for normal operation.

Below a cartridge case with proper head clearance being fired, once the chamber pressure returns to zero the brass will try and spring back to its original length.

HeadClearance_zps03634b1b.gif
 
Check the headspace. It's possible that you need to bump the shoulders back a hair. I had this problem as well when I started reloading bottle neck cases. If you don't have a headspace gauge, your can try this...

Tighten your die a small increment like 1/8 of a turn, resize the case, wipe off the lube, check in your rifle. Repeat until it fits normally. Once you get it sized right. Lock that die into place and you're good to go. I would definitely look into getting a headspace gauge and bullet comparator gauge to your list of reloading tools.
 
vpsalin said:
In other words my resizing die was not screwed down far enough?
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To quote the instructions in a Redding die set:

"To size cases so they will freely chamber in any firearm, the full length sizing die must make firm contact with the shellholder during case sizing"

Raise your ram to the highest position with shellholder installed, screw the die in until it firmly contacts the shellholder. That's the short version. Lee says the same, as well as RCBS.
 
cosmic said:
Why did you bother to resize your new brass? If you've still got some virgin brass, try chambering it...
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Good idea, I just tried that and its exactly the same, veryyyyyyy stiff. It will be hard for me to tell if there are presure signs from my loads as almost every extraction is guaranteed to be uber stiff...!?
 
Occasionally brass is formed out of spec when new. Just last month a member posted his blunder when he loaded virgin brass without sizing only to find the shoulders were too far forward and the rounds would not chamber. He had to break them all down, size them and do it all over again. My latest batch of Lapua .308 brass had a couple that were a little tighter in the chamber than the rest after neck sizing. Its a good idea to FL virgin brass even though its usually not needed.

cosmic said:
Why did you bother to resize your new brass? If you've still got some virgin brass, try chambering it...
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vpsalin said:
The problem is that's exactly what I did, maybe it was firm enough? They meant really really firm?
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I do not know what type press you have but cam over is the ram and linkage going over center. You want the shell holder to make hard contact with the bottom of the die and feel a little thump as the press goes over center. Sometimes you may have a chamber near minimum headspace and a resizing die near maximum headspace. And when this happens the cases do not get resized enough, meaning the shoulder of the case is not pushed back far enough. "Sometimes" you "may" need to to sand/lap the top of the shell holder and remove a few thousandths to allow the die to push the shoulder back further.

You could have a defective shell holder or a defective resizing die, you either make the shell holder shorter, remove a few thousandths from the bottom of the die or try buying a new die and shell holder. The simplest thing to do is lap the top of the shell holder because it is the cheapest component and easily replaced.

Bottom line, "YOU" need to find out "WHY" your resized cases are too long for your chamber.
 
Could my problems be caused by the fact that my lever arm hits my work bench? I compensated by putting the dies further down but that may not be enough? When you say 'cam-over' you mean the lever arm needs to really bottom out on it's own with no interference? Mine bottoms out on the side of my work bench, may be that wasn't such a good idea?
 
Bingo! The lever has to bottom out on its own, and furthermore, when you set the die, RCBS suggests raising the ram, screwing the die down to touch the top of the shell holder, then lower the ram, turn the die in an additional one-eighth or one-quarter additional turn, and then locking it. Full length re-sizing means just that.
 
Sometimes shell holders are out of spec, so if you've adjusted your FL sizing die correctly and the problem persists, you can trim the height of the shell holder (slightly) checking as you go till you find that the shoulder has set back enough.
 
When first setting up your FLS die with a different rifle, always test chamber the first two or three to see if everything is copacetic before going hog wild on your whole batch of brass. If not, you can have a crappy time at the range when you can't chamber all your new loads you meticulously measured powder charges for.
 
Live and learn I guess. I will reposition my press on a different spot on my bench and I will let you know how it goes from there. Thanks for the tips so far.
 
vpsalin said:
Good idea, I just tried that and its exactly the same, veryyyyyyy stiff. It will be hard for me to tell if there are presure signs from my loads as almost every extraction is guaranteed to be uber stiff...!?
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No Your brass was made a bit long (or your chamber is tight). Either way a start load will extract easily and your brass will now match your chamber.
 
Ganderite said:
No Your brass was made a bit long (or your chamber is tight). Either way a start load will extract easily and your brass will now match your chamber.
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Ganderite

"BEFORE" the last few thousandths of upward movement of the ram the squeezing action of the resizing die is actually making the case "LONGER" than chamber headspace. During the "LAST" few thousandths of ram movement the shoulder of the die is pushing the shoulder of the case back and making the case headspace "SHORTER".

If the press arm movement is restricted on the down stroke the case may still be in the "growing" mode and "not" reaching the "shrinking mode" with the die pushing the shoulder of the case back to minimum dimensions.

The OP needs some "air space" or "head clearance" between the rear of the case and the bolt face. One simple way to check head clearance is to take a full length resized case and using just your fingers start a fired spent primer into the primer pocket. Now chamber the test cartridge using the bolt to seat the primer as the bolt is closed. Extract the case and the amount the primer is protruding above the rear of the case is your head clearance or the "air space" between the bolt face and the rear of the case.

HEADCLEARANCE-a.jpg


Getting the proper gauges takes the guesswork out of how much shoulder bump is actually needed and getting the correct "air space" behind the case.

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The top Hornady cartridge case headspace gauge is all that is needed for any cartridge case and you do not have to buy a gauge for every cartridge.
 
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P51 - I agree with your comments. In fact, I had a similar ram issue hitting the bench with a press installation. The point I was making was that his long brass (referring to the shoulder) will be ok after he fires it. It will extract just fine.

But the press still will need relocating.
 
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