The_Cheat,
I'm glad you asked. OK, I was looking for threads dealing with HS for the Troubleshooting FAQ and found your unanswered question.
To answer your question there is a good chance (say, greater than 50%) that your HS is fine. The HS of your rifle is prolly good too.[:D]
[b]But[/b], you do not know if the parts (barrel/bolt) are correct until you check the HS.
If the HS is off the rifle may not function perfectly. A short chamber (tight HS) can cause failure to eject due to the higher chamber pressures the interference fit creates. Very worst case scenario, and the chances are incredibly remote, is a kB.
On the flip side if the chamber is long (long HS) your accuracy can suffer, the life of your brass may be shortened, you may even see shortstrokes because the case cannot fully seal the chamber when the case obturates. You could see case head separations or blown primers and, on the other end of the sprectrum from tight HS kBs, there is a very remote chance you could get a kB because of a case head separation.
Now, all this fearmongering aside, the reason to check the HS on your rifle is that the HS on every fiream must be checked after it's assembled. Since you are in effect the assembler it is your responsibility to check it. As I stated earlier, if you do not check it you do not know it's status. Only a puke would build a firearm that sloppily. You wouldn't replace the engine in a car then hand it back over to the owner without bench testing it at least would you? The people that say, "don't worry about it the parts are all in spec" are saying, in effect, "it's a crate motor, of course it'll work."
So, now on the next pile of BS I've been reading on these HS threads. There seems to be an idea that you cannot use .223 gages in 5.56 chambers. This is complete garbage and shows a complete lack of understanding of the factors in play. HS gages measure one thing and one thing only, the length from the face of the bolt to the datum line on the shoulder of the chamber. In the case of the 5.56/.223 the datum line is the 0.330" diameter about halfway up the shoulder.
While .223 and 5.56 are different chamberings they are the same cartridge hence the datum line is in the same location. The problem with using .223 gages in 5.56 chambers is that the HS standards vary depending on the model of firearm. In general, self loading pieces need longer HS to operate than manual loaded pieces do and fully automatic pieces need still longer HS to continue to function especially after they heat up. Self loaders need the extra HS because they are trying to unlock while the case is still stretched. You won't encounter that problem with a bolt action because you can't physically open the action that soon after pulling the trigger.
Let me throw this in here now. You cannot use a loaded round or a fired round as a GO gage for the simple reason that you won't know which part ofthe case is hitting the chamber and the GO length is larger than an unfired round to allow the round to expand and seal the chamber and smaller than a fired round because the round did expand to fill the chamber. Clear as mud?
If you use a case you might start feeling resistance to the bolt closing as soon as the bolt touches the rear of case. Does that mean the HS is shallow? No, it means that the base of the cartridge swelled on firing and needs to be forced into the chamber to fit. You'll notice that HS gages do NOT look like cartridges, they are cylindrical, not tapered, for exactly this reason. Remember that all important datum line? Whether the case is fired or not, there is no guarantee where the datum line is located on a cartridge case, it's not a critical dimension during case manufacture because the case will swell to fit the chamber during firing and make up any slop.
Now, because the military doesn't like to see mistakes made they have a special set of gages that take into account the extra HS the M16 needs to operate. The military also has gages for the M249 SAW (also a 5.56 chamber) and they are even longer than those for the M16.
So, the thing to remember is that the GO (minimum) gage, be it military or civilian, is the same size. It's a SAAMI minimum, 1.464" or 1.4646"+0.0002" for the military. So, you'll need a GO gage of this length.
Now that we've established what the minimum length of our chamber is supposed to be what is the maximum length? Well, the military rejects HS when it reaches 1.4730"-0.0002". BUT, there is a a FIELD II gage out there too, it is 1.4736" long. You can see there is some latitude on what is too long. FWIW, the FIELD gage for the M249 SAW is 1.50216"-0.0002", quite a bit longer than that for the M16 and yet it shoots the same ammunition without difficulty.
New rifles should chamber a GO and and not chamber a NOGO, the military NOGO dimension being 1.4706".
Here is where the problem arises, a civilian ".223" NOGO gage is 1.467" and a civilian ".223" FIELD gage is 1.470". Both of them less than what the military considers to be NOGO HS.
Almost every military rifle I have checked would accept a civilian GO [b]and[/b] NOGO gage, a very few of those would accept the civilian FIELD gage.
What does all this mean? It means that you need a GO gage to check that your chamber is the proper length to load, fire and extract correctly. You need a FIELD gage as it is the longest HS allowable. In between those two dimensions there is a lot of room for discussion.
New rifles, or bolt/barrel combos are checked with a GO and NOGO. Rifles that have seen service, and have already been checked for the GO dimension, are checked with the FIELD.
A civilian FIELD (1.470") gage is close enough to a military NOGO (1.4706") to be used in its stead.
Edited to clarify, quantify, and sassify;
A new rifle or barrel/bolt combo must accept a GO gage, military 5.56 or civilian .223.
It should not accept the military 5.56 NOGO gage.
It might, but most likely won't, accept the civilian .223 FIELD gage.
It must not accept the military 5.56 FIELD.
It probably will, but may not, accept the civilian .223 NOGO gage.
Check annually with a military FIELD gage thereafter.