Armory Sponsor
Posted: 9/28/2004 12:04:03 PM EDT
|
Well, I should have my new non-ban upper for my DPMS AR rifle on the way soon. I have the old upper sold already and have a question. Can I safely use the bolt from my old upper with the new one? Should I get a new bolt for the new upper? How does one test and adjust headspace on an AR type rifle? Thanks in advance for any info! |
|
As far as I know, there is no way to adjust head space on an AR, short of putting a bushing in the chamber and recutting it. Even this may not be possible. Just put the thing together and either check the head space with your own gauge(s) or pay a gunsmith to do it. If head space proves to be out of specifications, you will have to swap parts around. If it checks good, leave everything alone. |
|
FWIW, every upper I buy has a complete bolt, carrier, charging handle, etc., from the same manufacturer, and is bought at the same time. I make a point of specifying this, and much prefer it to be so. Granted it is more expensive, but it lessens the possibility of different manufacturers working to different specs. Shouldn't happen, but it sometimes does. In the event of a problem, it also simplifies any possible warranty work. Just ship off the whole assembly (after all, it's all theirs!) and let them figure out where they screwed up. Haven't had that happen so far. In theory AR bolts should be interchangeable. Mebbe so. In that case, I have a lifetime supply of bolts in case TSHTF If you sell off an upper, makes sense to sell its matching (and perfectly functioning) bolt as well. A selling point IMHO. After all, the parts have worn-in together, and work fine. If it's a high mileage unit, than tell the buyer so, and adjust the price accordingly. Never had a problem with approach, and changeover is a snap. No fumbling for parts, etc. Just put a rubber band from charging handle to front of "handle", for insurance, and change away. YMMV. |
|
In this particular case, the upper is brand new, so I am trying to decide whether to get a new bolt for it or see if my current one will work ok. My current unit probably has about 3k rounds on it. In your various opinions should I use my current bolt or quit being a cheap bastard and get one new for $110? |
|
I'm w/ Raf, don't be a tight-wad, get the new bolt to go w/ your new upper (i also agree that ya should sell the old upper w/ the working b/bc/ch in it too, for the same reason, YA KNOW IT WORKS!). That said you should get yourself a set of go-no go gauges or a field gauge, (I have both) simply to check your new upper prior to "DETONATION" (just kiddin,  as mentioned it's probably okay but never hurts to check).Mike |
To be sure, get the correct gauges for your gun. Here's where there is difference, it's in the chamber sizes. The military 556NATO chamber is larger than the civilian 223Rem chamber even thought the ammo is the same, more or less. |
|
Not so much a matter of chamber size, the main difference in NATO vs SAAMI chambers is in leade, the throat. BUT there is a difference in semiauto chambers, which are generally larger, looser, for good feeding. In addition, they are looser, particularly for military rifles, to allow for ammo that is dirty, bent, not quite sized right, etc. So, the chambers for AR-15's/M16's are looser for both .223 and 5.56 vs the chambers of bolt actions. Using regular gauges on an AR-15 will show a new chamber to indicate being nearly worn out. You must get the proper M16 military type gauge. The worry about headspace on new uppers and bolts is way overblown. Unless a bolt AND barrel are both very high mileage it is just not a worry. The best reason for keeping a bolt dedicated to a particular barrel is that they set up a wear pattern together. They both wear slightly and obtain a good even fit. Swapping bolt to a new barrel will make it have to set up a new wear pattern, theoretically causing quicker wear. If you want to use another bolt and carrier for a while, fine, won't hurt a thing, but I would suggest getting a bolt carrier assembly for each upper. |
Armory Sponsor