Just got back from the gunsmith after 3 1/2 hrs of dinking around trying to get a stuck live round out my AR. Apparently neck sizing just won't cut it with these machines. Funny though it was number 50 out of 50 that I loaded. So as soon as I get to work tomorrow I will be ordering a chamber gauge. I'll also be full length sizing for that gun from now on. On a positive note I now know how to completely disassemble and reassemble an AR. TC
Why You Need A Chamber Gauge For AN AR
- Thread starter trky chsr
- Start date
Bustercluck
CGN Regular
- Location
- Fort McMurray
I haven't reloaded for the ar yet, but I bought the rcbs small base dies for when I do. Which should be the next couple weeks
Been there, had the same experience. I got the case out without a gunsmith, but it wasn't a fun experience.
Sounds like the case necks aren't getting push back enough. Get yourself a case gauge and make sure you sizing die is set properly. Turning the sizing die in an additional 1/8th of a turn after it contacts the shell plate solved it for me. There is another thread in here that has a lot of great advice.
https://www.canadiangunnutz.com/for...time-chambering-case-after-full-length-resize
Sounds like the case necks aren't getting push back enough. Get yourself a case gauge and make sure you sizing die is set properly. Turning the sizing die in an additional 1/8th of a turn after it contacts the shell plate solved it for me. There is another thread in here that has a lot of great advice.
https://www.canadiangunnutz.com/for...time-chambering-case-after-full-length-resize
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Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Do you mean chamber gauge or case gauge? A chamber gauge is usually used to test chamber erosion/headspace (I.e. go, no-go, reject). A case gauge will test if your cases are the correct length for a certain chamber spec. A few case gauges (JP Enterprises and Sheridan Engineering) will test if the the case diameter is in spec.
While you now know why neck sizing for a semiauto is a bad idea you should also be aware that there is significant variability in AR chamber dimensions.
Not all 5.56 or 223 chambers will be the same even if they claim to be NATO or SAAMI spec, let alone 223 Wylde or some other spec. That said, small base dies and a case gauge such as mentioned offer the best chance of avoiding a mishap as you just experienced.
While you now know why neck sizing for a semiauto is a bad idea you should also be aware that there is significant variability in AR chamber dimensions.
Not all 5.56 or 223 chambers will be the same even if they claim to be NATO or SAAMI spec, let alone 223 Wylde or some other spec. That said, small base dies and a case gauge such as mentioned offer the best chance of avoiding a mishap as you just experienced.
My terminology is probably wrong but I'm looking for a device to test whether my ammo will fit (a go/no go scenario). We have them at work but they are multi caliber devices. The first batch of 100 I full length sized and had no issues but after loading 10's of thousands of pistol loads I find the lube process to be a pain in the butt so that's why I got a 4 die Lee set with the neck sizer and factory crimp. I loaded 50 with just neck sizing and had 2 stuck cases, The first one I was able to reset the bolt and fire it off the second no such luck. TC
You want a case gauge but as Jerry mentioned how do you know it is the same as your guns chamber? He was politely telling you they aren't the be all and end all for checking ammo.
If you want as close to flawless function on a semi-auto you need to full length size. Some guns require small based dies as mentioned already.
Neck sizing is for brass you have fired out of your gun as the case is now fire formed to that particular chamber. It is a tight fit. This is normally only ever done for bolt (or single) action guns.
Water soluble lube may be easier cleanup for you?
BigUglyMan
CGN Ultra frequent flyer
- Location
- New Scotland
^ This.
Cameron SS
CGN Ultra frequent flyer
- Location
- Ground Zero
+1 I just keep a separate batch of untreated tumbler media specifically for removing lube. Or It could just be the last use for your normal media before the garbage.
Its been a while since i have read much about reloading for semi auto, but I always thought full length sizing was standard practice, especially for the harder cycling actions.
Sherlock Gnomes
CGN frequent flyer
- Location
- St.Catharines
https://www.canadiangunnutz.com/forum/showthread.php/1594604-So-I-just-ordered-a-Dillion-550c/page2
Look at ganderite advice. I use this method for my ar brass for lubing. I always full length size,trim and remove primer crimp as needed. I use a 223 calibre gauge as well to be sure it will chamber smoothly.
Look at ganderite advice. I use this method for my ar brass for lubing. I always full length size,trim and remove primer crimp as needed. I use a 223 calibre gauge as well to be sure it will chamber smoothly.
I've loaded for many AR's and never needed anything other than a regular full length sizing die set down to where the press handle cams over. Neck sizing for a semi auto is a bad idea and rarely works out. The tiny improvement in accuracy seen in a bolt action rifle does not warrant the lost reliability in a semi auto and since 223 brass is so easy to find and is so cheap that doing it to be easy on your brass is pointless.
I never anneal and I always full length size all my brass from my 17 fireball through to 338 Lapua and every cartridge in between and I've had plenty of sub moa loads and I get plenty of reloads before my brass is junk.
People tend to get carried away with things like neck sizing and other tricks that competitive shooters use, all those little tricks return a fraction of an moa improvement in accuracy but when done right can take a cartridge from 1 moa down to between half and three quarters of an moa. It won't turn a 2 moa AR into a sub moa rifle and as you've found typically causes reliability issues. Long range competitive shooters are separated from each other by millimeters at 1000 yards so for them everything they can do to improve consistency is worth it but for the average shooter with a rifle that's only capable of 2-3 moa it's pointless.
You mentioned you wanted to skip the case lube portion of reloading to speed things up, well that's tough, there are no shortcuts to reloading, you either do it right or you should buy factory ammo for blasting at the range and keep the tailored handloads for when you sit down and put the rifle on a proper rest and go for the moa challenge.
I never anneal and I always full length size all my brass from my 17 fireball through to 338 Lapua and every cartridge in between and I've had plenty of sub moa loads and I get plenty of reloads before my brass is junk.
People tend to get carried away with things like neck sizing and other tricks that competitive shooters use, all those little tricks return a fraction of an moa improvement in accuracy but when done right can take a cartridge from 1 moa down to between half and three quarters of an moa. It won't turn a 2 moa AR into a sub moa rifle and as you've found typically causes reliability issues. Long range competitive shooters are separated from each other by millimeters at 1000 yards so for them everything they can do to improve consistency is worth it but for the average shooter with a rifle that's only capable of 2-3 moa it's pointless.
You mentioned you wanted to skip the case lube portion of reloading to speed things up, well that's tough, there are no shortcuts to reloading, you either do it right or you should buy factory ammo for blasting at the range and keep the tailored handloads for when you sit down and put the rifle on a proper rest and go for the moa challenge.
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Unfortunately, this has become a blanket statement which is just as "wrong" as not sizing at all.
To keep it simple, range use ammo, headspace should be 3 to 4 thou SHORTER then the chamber.. always function test sized dummy cases to ensure 100% chambering.
Body should be 2 thou NARROWER then the chamber with a light contact for the bottom 1/4 of the case (just ahead of the extractor groove). That is the goal... the problem is the variations in the dies and the chambers ... and the cyclic force of the rifle itself. Many semis are overgassed so they can function in the muck... that is rarely ever good for brass longevity.
If the FL sizer pushes back the shoulder more then 4 thou vs the chamber headspace, case head separation will occur in a firing or two. Leaving 2/3's of a case lodged in the chamber is no fun to resolve... let alone any other excitement along the way.
If you need to size more then 7 thou vs the fired brass length to reach the proper headspace, consider checking the function of the rifle and adjusting load and/or gas system. The cases is expanding way too much during the firing and ejection process.... we aren't loading for open bolt machine guns.
The semi chamber varies a tremendous amount... They can be so wide that a ridge forms on the base of the case just ahead of the case web.
So the real answer is to measure the fired case and compare to the sized case. Yes, FL sizing COULD work... maybe you need a Body die... maybe a Small base die... maybe you need a FL sizer from one company vs another. Stuff has tolerances and the semi market is the widest range of specs possible.
Measure what you have THEN seek the right tool to create safe ammo for YOUR rifle.
Jerry
I used a Hornady cartridge case headspace gauge to measures my fired cases to adjust shoulder bump.
Below a fired case from one of my AR15 rifles, and my dies are then adjusted for .003 shoulder bump.
Below a Wison, Dillon and JP Enterprise case gauges with .223/5.56 cases reversed and placed into the gauge. And as you can see the red JP Enterprise gauge has a smaller inside diameter.
I use the JP Enterprise gauge for the final loaded round check to ensure the cartridge will fit in any of the AR15s I load for. The JP Enterprise gauge is closer to minimum SAAMI dimensions than the Wilson and Dillon case gauges.
I buy bulk once fired Lake City 5.56 cases and size them first with a small base die to reduce brass spring back and insure the brass will chamber freely. Thereafter once the cases have been fired in my rifles I use a standard Forster full length die.
Bottom line, if you buy once fired brass or use range pickup brass you may need a small base die to compensate for cases fired in a larger chamber.
Dies and chambers vary in size, and as a example I have a standard Lee .223 die that will reduce case diameter and push the shoulder back further than my .223 small base die.
So as stated above measure your fired cases and ensure the sizing die reduces the case diameter enough. For a semi-auto rifle it is recommended the resized case should be .003 to .005 smaller in diameter than its fired diameter. This allows the case to spring back from the chamber walls when fired and have reliable extraction.
Below a fired case from one of my AR15 rifles, and my dies are then adjusted for .003 shoulder bump.
Below a Wison, Dillon and JP Enterprise case gauges with .223/5.56 cases reversed and placed into the gauge. And as you can see the red JP Enterprise gauge has a smaller inside diameter.
I use the JP Enterprise gauge for the final loaded round check to ensure the cartridge will fit in any of the AR15s I load for. The JP Enterprise gauge is closer to minimum SAAMI dimensions than the Wilson and Dillon case gauges.
I buy bulk once fired Lake City 5.56 cases and size them first with a small base die to reduce brass spring back and insure the brass will chamber freely. Thereafter once the cases have been fired in my rifles I use a standard Forster full length die.
Bottom line, if you buy once fired brass or use range pickup brass you may need a small base die to compensate for cases fired in a larger chamber.
Dies and chambers vary in size, and as a example I have a standard Lee .223 die that will reduce case diameter and push the shoulder back further than my .223 small base die.
So as stated above measure your fired cases and ensure the sizing die reduces the case diameter enough. For a semi-auto rifle it is recommended the resized case should be .003 to .005 smaller in diameter than its fired diameter. This allows the case to spring back from the chamber walls when fired and have reliable extraction.
This is what I do.
