308 Sizing Question

[sisyphus]

My Redding 308 FL sizing die was not doing the job. No matter whether I adjusted it down to barely tickling the shell holder or all the way down to a firm handshake, all my cases _just_ failed the case gauge. Close, but no cigar.

I would experience about one round per magazine that would not go completely into battery and click no bang. Those rounds always fired on the second try, because the bolt carrier finished sizing the cases.

So I bought a small base 308 FL sizing die, because there was nowhere else to go with the regular FL.

I set it up today, and most of my cases now pass the case gauge, with maybe 1 in 15 _just_ failing. This might be all it takes, since most of my rounds functioned before, and now they are clearly getting more sized than they were with the old die. I'll have to take one of the 308s to the range and test it with this new batch of ammo.

If I wanted to shoot for 100% passing the case gauge, would the Redding Competition Shellholders be the way to get that extra little bit of sizing, or are they just for bumping the neck back?

Lastly, on this small base sizing die I can really feel the resistance from the neck sizer. It made me wonder if the $39 for a carbide neck insert would be a good investment for this die.

Thanks guys, I appreciate any insight, your knowledge and experience is much appreciated.

 

[Spare Parts]

Try a Sharpie. Color the important bits - case neck, shoulder, rim, etc. Insert brass into the gauge and twist. May need a sacrificial case. Maybe thread the flash hole. Find where it rubs. May take a few tries.

Been there myself. Good luck.

Edit: I was struggling with a 9mm EGW gauge. Looking at the SAAMI mechanical drawings and measuring the finished round. Then noticed there was a "large ogive" product - the case gauge manufacturer occasionally admits they didn't read the spec.

 

[Varminterror]

Are you using Redding shell holders?

 

[sisyphus]

Are you using Redding shell holders?

yes, everything is Redding

 

[Varminterror]

yes, everything is Redding

Pick up a set of competition shell holders, you’ll find the depth you need there.

 

[Blue68f100]

How many firings on the brass?

May be work harden to the point it's needing annealed.

 

[bullseye308]

When you resize the case, spin it 180* after the first resize and do it again. I don't know why, but it has worked for me in the past with 308 machine gun brass.

 

[JFrank]

My Redding 308 FL sizing die was not doing the job. No matter whether I adjusted it down to barely tickling the shell holder or all the way down to a firm handshake, all my cases _just_ failed the case gauge. Close, but no cigar.

I would experience about one round per magazine that would not go completely into battery and click no bang. Those rounds always fired on the second try, because the bolt carrier finished sizing the cases.

So I bought a small base 308 FL sizing die, because there was nowhere else to go with the regular FL.

I set it up today, and most of my cases now pass the case gauge, with maybe 1 in 15 _just_ failing. This might be all it takes, since most of my rounds functioned before, and now they are clearly getting more sized than they were with the old die. I'll have to take one of the 308s to the range and test it with this new batch of ammo.

If I wanted to shoot for 100% passing the case gauge, would the Redding Competition Shellholders be the way to get that extra little bit of sizing, or are they just for bumping the neck back?

Lastly, on this small base sizing die I can really feel the resistance from the neck sizer. It made me wonder if the $39 for a carbide neck insert would be a good investment for this die.

Thanks guys, I appreciate any insight, your knowledge and experience is much appreciated.

Changing to a taller shell holder will not increase the amount of radial sizing the die is capable of producing, competition shell holders won’t increase the shoulder set back either, In theory the case base is unsupported for .125 which just happens to be the basic height of a standard shell holder but unfortunately chambers are not perfect so reducing a shell holder works quite well.

 

[GW Staar]

When you resize the case, spin it 180* after the first resize and do it again. I don't know why, but it has worked for me in the past with 308 machine gun brass.

I've done that too. It does work on MG brass! In fact once, just as an experiment, I resized 50 MG cases 4 times each, at 0 degrees, 90, 180, & 270 degrees. The result was......concentricity .00 to .01 on all 50.....not only did it chamber nice and easy, accuracy was better in my AR-10 Remington clone "hunting rifle", which was already a very accurate AR. Will I do that for all .308/7.62? No......less effort is good enough for what I shoot. Non-competitive only for me. I shoot for fun, not for stress. That test was just feeding my curiosity. I've never had to reduce shellholder thickness so far, using my favorite Gold Medal RCBS die sets. (.223 and .308) Have not tried the newest incarnation of them. (MatchMaster)

 

[lightman]

Changing to a taller shell holder will not increase the amount of radial sizing the die is capable of producing, competition shell holders won’t increase the shoulder set back either, In theory the case base is unsupported for .125 which just happens to be the basic height of a standard shell holder but unfortunately chambers are not perfect so reducing a shell holder works quite well.

I agree with this. Competition shell holders are going the wrong direction. The last time that I had this problem I considered my options to be to either shave a little material off of the mouth of the die or to shave a little material off of the top of the shell holder. I chose the shell holder because it was cheaper than the die. Another option that may help is to cut some shims from an aluminum can and run them into the shell holder between the base of the case, thus reducing the play between the two.

 

[Slamfire]

I have had this experience a number of times with a number of sizing dies. The problem is, the base to shoulder distance within the die is too long for your rifle. The cure to this is grinding a couple of thousandths off the bottom of the sizing die. Firstly, remove the decapping spindle, and carefully spin up a bench grinder, and I turn the thing off and let it spin down to maybe half speed, and then touch the base to the flat side of the wheel. Do your best to make the grind perpendicular to the axis of the die.

Then size a case and see if the first grind was enough. If not, try again, always being cautious not to grind too much for too long. Then size a case and see if the next attempt at reduction was enough. Rinse and repeat, so to say, until you have reduced the base to shoulder distance enough, that the case will size to gauge minimum. And stop there.

I consider grinding shell holders to be bad practice as the shell holder top may crack off.

 

[The Glockodile]

The last time that I had this problem I considered my options to be to either shave a little material off of the mouth of the die or to shave a little material off of the top of the shell holder.

It's been an old presupposition of mine that more often than not, the shell holder is the most likely culprit behind undersized brass (all due diligence being done) - with the reason being this is the cheapest, lowest - quality part there is in the chain.

 

[JFrank]

I have had this experience a number of times with a number of sizing dies. The problem is, the base to shoulder distance within the die is too long for your rifle. The cure to this is grinding a couple of thousandths off the bottom of the sizing die. Firstly, remove the decapping spindle, and carefully spin up a bench grinder, and I turn the thing off and let it spin down to maybe half speed, and then touch the base to the flat side of the wheel. Do your best to make the grind perpendicular to the axis of the die.

Then size a case and see if the first grind was enough. If not, try again, always being cautious not to grind too much for too long. Then size a case and see if the next attempt at reduction was enough. Rinse and repeat, so to say, until you have reduced the base to shoulder distance enough, that the case will size to gauge minimum. And stop there.

I consider grinding shell holders to be bad practice as the shell holder top may crack off.

You may be correct, IDK but the shell holder seemed easy for me as in about 39 seconds on a belt sander to take off a bit and it doesn’t have to be perfect either as the base of the SH remains untouched.

 

[Slamfire]

You may be correct, IDK but the shell holder seemed easy for me as in about 39 seconds on a belt sander to take off a bit and it doesn’t have to be perfect either as the base of the SH remains untouched.

I would agree that shell holders are a lot cheaper to replace than dies, if one grinds off too much!

 

[Varminterror]

Is Redding not offering their shorter shell holders any longer? All I’m seeing are the + sets. Yes, this situation needs a - height shell holder. Belt sander works fine, as long as 1) you don’t want to size based on shellholder dead length and 2) sand away enough that the shellholder doesn’t make contact anywhere.

 

[Blue68f100]

For a temp fix use a shim under the cartridge head and shell holder. This will push the brass further up into the die. Normally there is a 0.010" gap to play with.

 

[BushMaster-15]

I'd first determine WHERE the errant case is hitting in the case gauge ,then Measure the difference between a case that does go .
IS the Base diameter just above the rebated rim the culprit ?. I can tell you from personal experience ,I've got a Hornady case gauge and Hornady dies and They DIDN'T jive up either . The cases I have needed annealing and by doing so solved MY problem ,they were just a few thousands over but weren't staying bumped back . Trimming after annealing 2.005- 2.003 " also makes the cases right with the world .

FYI : I've always had to run the FL die down on to the base plate ( shell holder ) with ALL slop removed , as I mostly run gas guns ,otherwise it' small base dies ,those are last resort IMO . I can tell you that No Matter what one does ,you CAN'T decrease the case diameter just above the rebated rim back to factory specs . I've No less than #9 brands of 7.62x51mm and .308 commercial and FL sizing dies are a few 0.002-4 over ALL of their diameters . Commercial cartridges as well as Military are ALL undersized ,so as to FIT ANY chamber .

Last but certainly IMPORTANT ,is the base rim hanging up from going into the case gauge fully ?. Again extractors can Burr the rim and I have a rotary file for fixing that very problem . M60 - M249 cases are notorious for that problem .

 

[JFrank]

For a temp fix use a shim under the cartridge head and shell holder. This will push the brass further up into the die. Normally there is a 0.010" gap to play with.

Yes but unfortunately the shim did not survive the experience.

 

[Bcwitt]

When you resize the case, spin it 180* after the first resize and do it again. I don't know why, but it has worked for me in the past with 308 machine gun brass.

Ditto. I have done this also. It helps.

 

[Bcwitt]

I have had this experience a number of times with a number of sizing dies. The problem is, the base to shoulder distance within the die is too long for your rifle. The cure to this is grinding a couple of thousandths off the bottom of the sizing die. Firstly, remove the decapping spindle, and carefully spin up a bench grinder, and I turn the thing off and let it spin down to maybe half speed, and then touch the base to the flat side of the wheel. Do your best to make the grind perpendicular to the axis of the die.

Then size a case and see if the first grind was enough. If not, try again, always being cautious not to grind too much for too long. Then size a case and see if the next attempt at reduction was enough. Rinse and repeat, so to say, until you have reduced the base to shoulder distance enough, that the case will size to gauge minimum. And stop there.

I consider grinding shell holders to be bad practice as the shell holder top may crack off.

Also, if you use same shell holder for a differnt application & it was ground down you migh have increased headspace.

 

[243winxb]

I would experience about one round per magazine that would not go completely into battery and click no bang. Those rounds always fired on the second try, because the bolt carrier finished sizing the cases.

To much crimp can bulge the case shoulder. Dont crimp or trim all brass to the same length.

RCBS makes a taper crimp die set for autos. https://www.midwayusa.com/product/1012080214

Lube the inside of the case necks. Helps the expander pull thru.

Guns need the headspacing checks. Bolt and barrel should be of the same manufacture on ARs.

Range brass being used?

 

[greyling22]

I'm late to the party, but +2 or 3 to the shellholder to the belt sander trick. it solved a problem I had once upon a time.

 

[sisyphus]

lots of good ideas here, thank you much gents

 

[lightman]

Also, if you use same shell holder for a differnt application & it was ground down you migh have increased headspace.

This is true! I spray painted the one that I sanded down to avoid accidentally grabbing it by mistake.

 

[BushMaster-15]

Caution although altering a reloading component can seem like a good solution ,it's NOT really addressing the actual problem .

Reloading components are machined to a high degree of tolerance ,they're not some piece of gas pipe scrunched in a vice with a weld on it .

Think for a moment the manufacturer used SAAMI specs ,in creating the reversal of the cartridge case and those SPECS conform within degrees of tolerances to every Guns chamber specs . I'm betting his cases need TRIMMING and possibly annealing ,so as to be restored within allowable specification . Remove the FL die take spray cleaner brake cleaner whatever and CLEAN your die , reassemble and use if possible a Once fired case . Reset the FL die lube case and do the 180 two stroke sizing and then report back . BEFORE altering anything .

FYI : When I disassemble clean dies ,I lube MY Dies inside with either mold release wax or Boeshield T9 BEFORE resizing with a properly lubed case . You will be amazed at the reduced effort required to size a case ,similar to hot knife through butter

In all My years of reloading and that's 54 -55 now , I've altered NOTHING and load for #19 different calibers ,excluding shotgun which adds #3 additional ,12 ,20 and 28 gauge .