Excessive amount of 5.56 not passing the checker

[Walt84]

Hi all,

Since I bought a 5.56 /223 checker I've been having a lot of reject rounds (like 15%). I honestly didn't even check them before because I only had bolt actions, but with semi-auto it's a necessity. Funny thing is that I tried my rejects later and they all fed and run great! I use an EGW ammo gauge, would like to know if any of y'all had something similar happen and how you addressed it!

Thanks.

 

[Haney]

The Sheridan gauge with window will show you whats going on with your loaded rounds .

https://sheridanengineering.com/product/223-rem-ammunition-gauge/

 

[spife7980]

Actually measuring will get you actual answers.

Gauges are for fudds who can’t do simple arithmetic. Assign a value to the dimension instead of pass/fail and you’ll be worlds ahead in knowing your brass chamber relationship.

 

[Walt84]

The main issue that I see with it is that it is a single round gauge (I currently have a 7rnd gauge). Also, why would you choos slotted vs non slotted?

 

[remaction]

I've never used a checker, but I believe they only check OAL, right?
I assume you are reloading. If so, the bullet profile between bullets (not each bullet in a lot, but different bullets such as A-Max vs Berger) vary, such that the ogive of the bullet you are using is further toward the point, i.e not as streamlined than some others. If so, could the ogive be contacting the lands, and getting re-seated a bit deeper, such that it chambers the next time? Maybe load a few dummies with the bullet seated .010", then .020" deeper, etc. and see if that fixes the issue.

 

[mtrmn]

My checkers are from JP and they are actually cut with a chamber reamer, which means they check ALL dimensions that would prevent a round from chambering.
Go to this page and click the reloading banner

JP - Maintenance

ETA: I load bulk 556 and 762 that MUST WORK WITHOUT FAIL in any number of assorted ARs. Since these gages check all dimensions rather than just certain lengths, I drop every round in one of these gages before storage. If it fits this gage it fits in the chamber. Much faster than measuring each round and I can rest assured that if I have a malfunction it is NOT the ammo. I'm loading with reliability as the primary objective. YMMV

 

[remaction]

OP, as Spife said, measure. Take a round that has not been chambered. Measure oal and measure base to shoulder if you have the tools for that. Then chamber the round and re-measure those two dimensions. What changed (you said they chamber the second time you try them)? As far as needing a checker, I’ve never used one and have never had an issue, but I measure…

 

[redneckbmxer24]

I don’t even trust EGW to make a straight picatinny rail, no way would I trust the results of a $25 ammo checker tool. Considering the rounds it “failed” still ran fine just confirms that.

I’d address it by throwing that thing in the trash.

 

[alamo5000]

 

[remaction]

View attachment 8296986

If that reamer has zero free-bore, then it should be good to go.

 

[alamo5000]

If that reamer is a zero freebore .223, then it should be good to go.

My point is that possibly the OP doesn't understand (or didn't take into consideration) what SAAMI specs actually are.

The TLDR version is they list the dimensions yes-- but its a RANGE of dimensions of acceptable tolerances. In other words if the wigit falls in between X and Y measurements then it is 'in spec'.

This gauge is supposedly cut to the very minimum of that range. Unless the OP has a chamber that is cut to min spec (on this rifle or any other) then the ammo is more than likely just fine and are not 'rejects' at all.

If I were manufacturing ammo on a commercial scale that will be sold to tens of thousands of people, then yes, it's worth the effort to make all the ammo to absolute min spec dimensions. For the average person that has anywhere from one rifle to 20 of them, it's not really worth the effort to chase down all the tooling needed to match a gauge.

Also, unless the brass is all from the exact same manufacturer and the exact same lot #, then chasing down every little nuance on 'mass production' is going to be difficult.

This is a situation where 'good enough' definitely applies.

 

[alamo5000]

I will go ahead and add the caveat that these types of gauges are NOT meant to be a 'good vs bad' ammo checker in an absolute sense of the word. Not at all.

They are more like 'guidelines' to see where you are at--and this is especially true in the context of being an at home reloader.

To go around loading ammo and every single case that doesn't fit exactly flush, to toss it out as a 'reject' isn't a good idea. This is especially true when using range brass or mixed brass or something like that.

This type of gauge allows the reloader to pick up on any major defects rather quickly. It should not be treated as the final arbiter of all things 'good'.

 

[Haney]

Actually measuring will get you actual answers.

Gauges are for fudds who can’t do simple arithmetic. Assign a value to the dimension instead of pass/fail and you’ll be worlds ahead in knowing your brass chamber relationship.

Well no shit captain obvious . The guy called it a "checker" tells me he is new to this, simple may be the way to start for him .

 

[Haney]

I will go ahead and add the caveat that these types of gauges are NOT meant to be a 'good vs bad' ammo checker in an absolute sense of the word. Not at all.

They are more like 'guidelines' to see where you are at--and this is especially true in the context of being an at home reloader.

To go around loading ammo and every single case that doesn't fit exactly flush, to toss it out as a 'reject' isn't a good idea. This is especially true when using range brass or mixed brass or something like that.

This type of gauge allows the reloader to pick up on any major defects rather quickly. It should not be treated as the final arbiter of all things 'good'.

https://sheridanengineering.com/product/223-rem-ammunition-gauge/

 

[alamo5000]

https://sheridanengineering.com/product/223-rem-ammunition-gauge/

I don't have one of those but they are certainly interesting. I do have a case gauge for 300 BLK but this is primarily because I am sometimes using mixed and/or cut down brass.

That said, if I were going to buy those I would get the slotted version for sure.

 

[hlee]

The gauge only confirms that the ammo fits in the gauge.

What is the relationship between the gauge and the chambers and the rifles it is meant to represent? If the only answer is “they all have the same cartridge markings” then we are back to my first statement.

If all of the rounds that failed the gauge fired fine in your rifle (15%), then your gauge has an observed false negative rate of 15%. Is that acceptable for the gauge meant to confirm ammunition functionality?

 

[Doom]

Case gauges are designed and intended to check and insure the case will fit in a SAAMI minimum chamber. Most commercial chambers exceed the SAAMI minimum chamber so just because a full length sized case doesn't fit the gauge doesn't mean it won't fit the rifle, especially in a rifle it was fired in. Neck sized cases almost never fit the gauge but can usually be fired in the rifle they were fired in.

With semi autos it not unusual for the case rim to receive some damage (often a burr) and often though fully sized will not fit into the gauge.

 

[jet_lagged]

Take a look at the the cases that don't pass. If I run reloaded round throught my Dillon case gage, sometime there is just a little "tag" on the case rim where the rim is larger than standard in one small spot. But that case will actually fit fine into the rifle chamber, and feed/fire/extract, etc.

 

[supercorndogs]

Actually measuring will get you actual answers.

Gauges are for fudds who can’t do simple arithmetic. Assign a value to the dimension instead of pass/fail and you’ll be worlds ahead in knowing your brass chamber relationship.

This.

Why not work with known variables. A hornady comparator set is not expensive. ITs also not a final answer. I have bumped .001-.002 and found I need a little more for a round to chamber easily. Measure your bump, check it your chamber. If it fits it ships. If it doesn't fit and bumping it a little more doesn't help. You have some more homework to do with those calipers you bought to measure shoulder bump, case length, and OAL.

 

[Doom]

The problem, especially with semi auto rounds, is that the ejection begins with some pressure left in the barrel and the portion of the case just above the web becomes unsupported and the brass expands. Also semi auto chambers tend to be a little more generous in terms of dimensions (other than headspace). Some dies do not size this portion of the case enough. This is why small "base" dies exists. If most of the resized brass fits it's likely that this is the problem not an issue with the datum dimension.

This is easy to check with a caliper. Simply check the diameter at the base (not rim) above the extraction groove (0.376" dimension) and if any part of the body is larger than that dimension then the case is blown out and not resized.

To see a full diagram of the cartridge and chamber go to SAAMI.ORG and download the Center fire rifle ammunition spec SAAMI Z299.4 – 2015.

 

[Rocketvapor]

For "MUST WORK WITHOUT FAIL" rounds I suggest a real chamber check, watch out with loaded ammo, maybe a cut pin.

 

[hlee]

For "MUST WORK WITHOUT FAIL" rounds I suggest a real chamber check, watch out with loaded ammo, maybe a cut pin.

Or, chamber check the resized brass. Measure the base to ogive for your rifles(s) and keep your loaded rounds within that measurement. No chamber checking of loaded cartridges required.

I do just this for my match rifle, after experiencing a couple “hard to chamber” rounds on the clock.

 

[Doom]

Or use a small base die.

 

[Walt84]

Actually measuring will get you actual answers.

Gauges are for fudds who can’t do simple arithmetic. Assign a value to the dimension instead of pass/fail and you’ll be worlds ahead in knowing your brass chamber relationship.

Well the problem is that in my opinion the measurments needed to make sure that the chamber is up to spec is not really easy to take. That is why the pass/ no pass gauge is usually a good solution. OAL is not my issue here, it's probably due to deformation of the brass case which makes it loose its concentricity. Concentricity measuring devices are expensive and take a lot of time to use so it's not a good solution in my opinion.

 

[Walt84]

Thanks for all your input guys!

 

[TheOfficeT-Rex]

Well the problem is that in my opinion the measurments needed to make sure that the chamber is up to spec is not really easy to take. That is why the pass/ no pass gauge is usually a good solution. OAL is not my issue here, it's probably due to deformation of the brass case which makes it loose its concentricity. Concentricity measuring devices are expensive and take a lot of time to use so it's not a good solution in my opinion.

No.
Highly unlikely concentricity has anything to do with it.

Unless your reloads are coming out visibly banana shaped.

 

[mtrmn]

Well the problem is that in my opinion the measurments needed to make sure that the chamber is up to spec is not really easy to take. That is why the pass/ no pass gauge is usually a good solution. OAL is not my issue here, it's probably due to deformation of the brass case which makes it loose its concentricity. Concentricity measuring devices are expensive and take a lot of time to use so it's not a good solution in my opinion.

Walt84 are you crimping your rounds?

 

[memilanuk]

Take a look at the the cases that don't pass. If I run reloaded round throught my Dillon case gage, sometime there is just a little "tag" on the case rim where the rim is larger than standard in one small spot. But that case will actually fit fine into the rifle chamber, and feed/fire/extract, etc.

I ran into something similar a while back when I was loading some bulk 223 practice ammo for the local Junior HP program. Had a few rounds that would hang up or not chamber fully. I had most of the available tools for checking headspace and measuring anything I cared to. It wasn't until I tried dropped the cases in my Wilson case gauge that I realized that the oddball rounds had some heavy gouges in the extractor rim - not some place that I would normally check with any measuring tool. I started using the case gauge as a go/no-go checker on sized cases, and any that didn't pass went in the recycle bin.