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Prepped .223 brass drops into JP case gauge--but sticks in chamber


Kasteel

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You have a SAAMI .223 resizing die and the "ONLY" control you have is shoulder bump no matter what type chamber you have. A .223 die is already smaller in diameter than a Wllde or NATO chamber by at least .002. The only thing stopping the case from going into the gauge the correct distance is shoulder location. Buy the Hornady gauge and be done with it, you measure a fired case and then bump the shoulder back .003 to .006 for reliable chambering in a semiauto.

762chamberreamer.jpg

223-556-b.jpg

"WHY" spend so much money buying a gauge for each caliber when the Hornady will measure them all.

Picture009.jpg

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Those chamber checkers are hit or misses. You need to fire some cases from your rifles and use the RCBS Mic or the Hornady mic to measure the brass and set your dies.

http://www.midwayusa.com/product/477756/rcbs-precision-mic-223-remington

http://www.midwayusa.com/product/479704/hornady-lock-n-load-headspace-gage-5-bushing-set-with-comparator

Or you can keep on screwing down your die until the cases stops sticking in all of your rifles.

Problem with this is you don't know if you have overdone it until you fire the rounds.

Simple check for head clearance or the air space between the rear of the case and the bolt face.

1. Full length resize a case and measure the length of the case and write it down.

2. Using a fired spent primer take the primer and start the primer into the primer pocket just seating it enough to keep it from falling out.

3. Now chamber this "empty" test cartridge and let the bolt seat the primer making sure the bolt is fully closed.

4. Eject the case and measure the case again and write it down.

5 Now subtract the first case measurement from the second case measurement and this will be your head clearance.

HEADCLEARANCE-a.jpg

Your head clearance will be the amount that you bumped the shoulder back, if its less than .002 you will need to bump the shoulder back further when resizing your AR15 cases.

NOTE: On gas operated rifle the majority of them are "over gassed" to ensure reliable functioning with low powered ammunition. The problem with this is the bolt can move to the rear while the case is still gripping the chamber walls. When the case releases it grip from the chamber walls there still can be chamber pressure in the bore. This chamber pressure and with the bolt moving to the rear can cause the shoulder of the case to move forward "and make the case longer than the chamber" and give a false reading on case length. This is where the spent primer trick in the primer pocket will give you a better case reading on head clearance.

Warning, the worst headspace you can ever encounter will be found in dimly lit bars and is caused by unscrupulous bartenders.

excessheadspace.jpg

Edited by bigedp51
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A normal full length resizing die at a minimum should when it makes hard contact with the shell holder bump the shoulder back .002 shorter than a GO gauge for that caliber. I have seen new cases that were over .009 shorter than the GO gauge and were .011 shorter than my chamber.

If you repeatedly bump the shoulder of the case back too far it can cause case head separations, the general thumb rule is on a bolt action you bump the shoulder back .001 to .002 and on a semiautomatic .003 to .006.

Below is what happens when you do not measure your fired cases and set up your dies as per the instructions with the press caming over. (maximum shoulder bump)

The .308 cases below were fired in a new Savage bolt action rifle, BUT the author did not measure the cases or have an idea where the rifles headspace was set at. Meaning the author did not say how much head clearance these cases had after being full length resized.

308fail-1.jpg

308fail2-1.jpg

Edited by bigedp51
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Some simple ways to control shoulder bump.

These washers below are placed under the die lock ring to control shoulder bump.

shims.jpg

The Redding Competition shell holders are .002, .004, .006, .008 and .010 taller than a standard shell holder and also control sholder bump.

customSH_zpse491c13b.jpg

reddingshellholders.jpg

Edited by bigedp51
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I spent some time comparing factory ammo and reloads in the JP Gauge last night. Factory ammo sat at least flush with the bottom step of the gauge--maybe just a hair below, such that when examining the cartridge in the gauge you can see a bit of beveled red from the gauge all around the circumference of the case rim--including the portion of the rim abutting the bottom step of the gauge.

The time and care needed to perceive the distinction, at least for me, makes it worth it to just chamber a few random cases in a gun with a Wylde chamber during the reloading process to ensure that my tolerances are good.

In short, I have come to the same conclusion as stated by one of the contributors above: chamber checkers/gauges are a hit or miss proposition. The timed saved isn't worth the risk of cranking out a pile of out-of-spec ammo.

I'll definitely being investing in one of the Hornady gauges though! Thanks for turning me into that tool. Looks like it'll be good for finding the proper seating depth for precision ammo to set the ogive of the bullet the optimum distance from the lands. Useful gadget.

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A quote from another post: .223 Am I sizing enough?

"If you are loading on a Dillon, you do not want the die touching the shellplate. Did that the first time I loaded .223 on my 550 and set the shoulder back too far. The AR extractor will NOT hold the round against the bolt face to fire. You must use a guage. Pulling 300 rounds and trashing the cases taught me that lesson."

Is this comment specific to the 550? This comment seems to imply that setting the sizing die too deeply could bump back the shoulder so far that the cartridge will fit so far into the chamber that the firing pin won't get a solid hit on the primer.

Anyone know anything about this???

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Pushing the shoulders too far back will definitely cause such problems, but since you have measured your brass in your chamber and have found the need to cam it over, I think your method will work for you. No two chambers, presses or dies are exactly the same. Due dilligence is required by each reloader to make safe effective ammunition.

I'm confident you are where you need to be with your press and your chambers with this round. Go shoot some and update us.

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Also, remember that looking at the steps on the gauge is not necessarily required for every round. You use the gauge to set the sizer die up for a given brand/lot of brass. Once it's set, you should be good. I still drop all my finished rounds through the gauge just to make sure they drop free after final bullet seating and crimping but I don't look TOO closely at where the head is relative to the steps on the gauge. I use it more by feel than sight after the dies are adjusted and sized brass chambers/extracts easily from the rifle. I just run my finger over and make sure I can feel that it's below the top step and go.

One thing I've noticed is that brass that has been sized such that it is between the steps on the JP gauge and then fired in my rifle will still fit the gauge after firing. The head on the fired cases is just a little above the top step, but the brass is not so fat around the circumference of the body that it won't fit into the gauge. Very tight chambers on these JP rifles! :)

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Just got off the phone with Dillon. The tech was familiar with the issue under discussion in this thread. He said that adjusting the die past light contact with the shellplate to achieve proper sizing WILL LEAD TO PREMATURE WEAR AND BREAKAGE of the machine, I.e., the Dillon 1050 Super. The tech advised having the die machined down about .005" to solve the problem.

Now, I've used the cam over method to reload 2,500 rounds, and the ammo gauges, chambers and functions great, and my machine is fine so far, but a trip to my machinist buddy is on the schedule.

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I hope the word gets out. I know there are many who have been camming over for thousands of rounds and haven't given it a second thought. I have purchased alternate shellplates and have machined those, but that could give slightly different results.

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Personally I'm going to keep on caming over.

If you look at the sizing die instructions for RCBS and lee:

http://www.rcbs.com/downloads/instructions/ReloadingDieInstructions.pdf

http://leeprecision.com/cgi-data/instruct/RM3508.pdf

They basically tell you to cam over.

You guys can try Hornady dies if you don't like camming over. Hornady die instructions tell you not to.

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I was aware that the Lee instructions promote camover, but I think that's because the Lee presses have purposely designed play (detractors call it "slop") into the design. Interestingly, that play often works to compensate for a beginner's sloppiness. Anyone who started with a Lee Classic or similar press will see no problem with camming over if the result is a good round. Dillon and Hornady presses have no play, so excessive pressure may result in worn pivot points or bent surfaces.

Caspian, lots of ways to do it. I used a dremel grinding wheel in a small drill press to take a bit off a shell plate for a troublesome 6.8 die. It was a slow process, but 100% effective. If you're thinking of shortening a carbide die, ask yourself if a thinner shell holder might give you the results you seek. Carbide dies should probably be ground by a machinist.

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Caspian Guy: The Dillon tech said using a a fine grit wet/dry sand paper and moving the die in a figure "8" pattern would be a way to go (if you don't hit carbide!) if you didn't have access to a lathe or a machinist. I dropped my die off at my friendly neighborhood gunsmith this morning.

As to the "to cam or not to cam" contraversy: the solution to my problem is specific to my set up. If you are using RCBS dies in a Dillon machine, or using Dillon dies in a Lee or Hornady press, the solution may or may not work for you. Ditto a Dillon machine other than the Super 1050.

I will say this: applying a solution developed for a Dillon Super 1050 using carbide .223 dies to any other combination of machine and die is no more or less likely to yield the desired results than using load data some shooter gave you that he developed for HIS gun using a given bullet, primer, case and powder combination. Depending on your level of knowledge/expertise (or ignorance/ineptitude) you may succeed or have a very bad day.

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An update per request: I went out and fired 30 rounds sized without cam-over and 30 with cam-over.

The rounds using cam over functioned flawlessly in four different guns: one Wylde chamber(LaRue Stealth) one with 5.56 NATO chamber (Daniel Defense) one very old Colt with the triangle style hand guards, and one frankengun of dubious lineage.

The problematic rounds sized without cam-over fired and ejected just fine with two exceptions: The Daniel Defense gun experienced one failure to chamber a round after firing. This gun has a 14.5" barrel with a mid length gas system, and my best guess is that the extra force required to extract the case from the gun caused the BCG not to travel sufficiently far back so as to strip a round from the magazine. These insufficiently re-sized rounds tended to stick in the chambers of the LaRue and Daniel Defense guns when I attempted to manually extract a chambered round.

Even these problem rounds, however, extracted manually from the two older guns.

The only other malfunction was a failure to fire in the Frankengun. Observation of the extracted round revealed a very light primer strike that I attribute to the "customized" trigger group of that gun.

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I have a 650 and have been caming over for years.

Me too. And when I set up my press the tech at Dillon told me to adjust with a bit of cam-over. By now you would think they would have made the change to their dies to avoid this.

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The instructions for the 650 appear to differ slightly from the instructions for the 1050 Super. Perhaps cam over is not an issue with the 650 as it is with the 1050 Super.

Trodrig, Rigger: these last two replies are interesting. First, I've definitely started doubting that I was reading my JP gauge correctly. But after reading Trodrig's reply, I went in and squinted at a few of the cases I prepped for a while under a good light in the gauge. The cases are definitely below the highest step--and very close to, if not actually, flush with the bottom step.

I love JP, but if I have to squint and ponder so closely, then I save no time over just loading up a bunch of randomly selected cartridges in a mag and working the charging handle every so often. And if the cases are sitting how they are supposed to sit, then it may be that having this gauge is worse than having NO gauge.

Rigger: your description of the shoulder/neck junction may be spot on. I'll try to capture what I'm seeing in some pictures tomorrow. What I'm seeing in the cases that function nicely after adjusting the die down (until "cam over") reminds me a bit of an Ackley-esque sort of junction: sharper, just like I think you're getting at. Does that sound right?

My boggle: why are the cases that stick in my chambers dropping into the gauge?? Is my die somehow slightly out of spec? Did I get a bad gauge? I guess I'll have to see what JP has to say.

In the meantime, adjusting the die down to the point where I get the "cam over" effect has done the job. I'm not seeing any flex in the shell plate, but I just can't help but wish that adjusting the die as Dillon instructs would work!!!

But, I see plenty of people on these forums using the cam over method.

Not sure what 1050 instructions say but my XL650 and the Dillon die instructions both say "Re adjust the die as nedded to achive proper headspace". It's pretty clear the back off 1/2 turn is just a starting point. I do feel that it's odd to adjust it to cam-over, but that's what's needed. Dillon instructed me to do it when I called them during set up of my press. As to your gauges, that doesn't seem right that they indicate good ammo when it's not. Prior to adjusting to cam-over my Dillon gauge was giving me a no-go reading. I'd call JP and see what they say.

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Also, I mentioned to a very knowledgeable friend of mine that I'd removed the firing pin from my BCG to do an actual chamber check on my rounds. Apparently I got lucky. If you try this, your bolt cam pin may get out of battery and lock up your gun very, very badly. If you want to use your gun to check rounds, better file down a firing pin instead of taking it out!!

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Die is back from the machinist. Turning it down .005" appears to have done the trick. Cost me $20.

When I took the die in and explained that I was having to give the die a full half turn to get the result I wanted, the gunsmith looked at the die, noted that it was 16 threads per inch and figured he needed to remove a minimum of about .00312".

I gave it a try before leaving for my shift, and the results were good with the die lightly touching the shellplate. I'll update when I can do a better examination.

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  • 4 weeks later...

Holy freaking hell Batman. This thread is enough to give a newbie like me a heart attack! Very informative. I've just started reloading 223 on my 550. I have been neck sizing only for a bolt action rifle. Had several rounds that were extremely difficult to extract and some moderately difficult to chamber. ALL of them fit great into the Dillon case gage. After reading this my faith in case gage is completely blown...

Thank you thank you thank you to Ed for the great illustrations and advice in this thread. The case separation pic was especially scary...

After reading all of this I am certain that my issues must also be due to improper shoulder size/aspect....as overall length was <2.255, cases trimmed to 1.74-1.75, 55gr PSP bullet...

Now I just need to learn how to "bump the shoulder" that people are referencing! Obviously its done with a FL die...(right?) or one of these specialized dies. It would seem Neck sizing isn't worth the trouble and probably doesn't make much of an accuracy difference.

How in the world is one supposed to find out about all these odd fixes/problems (grinding dies, specialized shell holders, bullet comparators etc etc) it's enough to just buy factory ammo and be done with it!

Night

Edited by Talan2000
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I had the same problem until I read on the dillon page that the dillon resizing die is a small base die..

And that the sizing die should be set low enough to put a small amount of pressure on the shell plate .

Try it, if you backed up the sizing die by even a small amount your brass can stick..

Here's the source..

http://m.dillonprecision.com/mcontent/p/98/catid/15/artid/700

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