Ok. I build a lot of ar15's and I have come across a lot of problems everyone needs to know about.
1. Everybody coats differently
2. Everybody has there own idea on what the tolerances should be.
3. Everyone thinks SAAMI spec is SAAMI spec, its not.
Here we go.
1. Coatings:
Almost everyone in the industry sends their stuff out to get coated. Not to many coat their own stuff. While things get coated, the coatings might be applied thicker than need be. So for this I use 080-598-180WB 1 3/16"-16 tpi Tap from Brownells to run the threads on the castle nut and lower receiver to clean out the threads from over coating and burs. I use 100-016-681WB AR-15 Buffer Tube Die 1 3/16"-16 on all my buffer tubes. I use 100-016-682WB AR-15 Upper Receiver Die 1 1/4-18" on the barrel nut threads. I use 080-598-528WB 1/2"-28 AR-15/M16 Tap on the Flash Suppressor bird cage, and 080-598-529WB AR-15/M16 Flash Suppressor Die. using these will clean up all threads and everything will mate faster and better.
2. Tolerances:
Ok after the machining process is completed and the part is in its raw state, all tolerances might be into spec. Now they go get coated and depending on who is coating them depends on if they stay in spec. I buy .250 reamers from Pacific Tool and Gauge to run my front and back take down pin holes.
3. SAAMI spec.:
Now I know I'm going to run into resistance on this but this is how it was explained to me by a renown know barrel reamer manufacture. There are 3 types of chamber specs out there. 2 SAAMI and 1 that is what ever the manufacture thinks it need to be. Now with that said, SAAMI has a semi auto spec and a bolt gun spec. Semi auto has to feed and extract automatically. So the chamber is loose. With a bole gun the chamber is tight. That's why bolt gun guys use SB die sets to get down to a tight tolerance for their chambers. I buy reamers for all my barrels just because I found out not everyone corks their barrels before coating. I have found a lot of chambers and land and grooves have been coated in the barrel coating process and I have lost chamber tolerance. A light reaming and polishing is what I do to every barrel before installation.
That's just my 4 cents on the matter. I have fu%$ed up a lot of stuff and had to learn. Just passing it on so you don't waste any of your money on fu$# ups.
1. Everybody coats differently
2. Everybody has there own idea on what the tolerances should be.
3. Everyone thinks SAAMI spec is SAAMI spec, its not.
Here we go.
1. Coatings:
Almost everyone in the industry sends their stuff out to get coated. Not to many coat their own stuff. While things get coated, the coatings might be applied thicker than need be. So for this I use 080-598-180WB 1 3/16"-16 tpi Tap from Brownells to run the threads on the castle nut and lower receiver to clean out the threads from over coating and burs. I use 100-016-681WB AR-15 Buffer Tube Die 1 3/16"-16 on all my buffer tubes. I use 100-016-682WB AR-15 Upper Receiver Die 1 1/4-18" on the barrel nut threads. I use 080-598-528WB 1/2"-28 AR-15/M16 Tap on the Flash Suppressor bird cage, and 080-598-529WB AR-15/M16 Flash Suppressor Die. using these will clean up all threads and everything will mate faster and better.
2. Tolerances:
Ok after the machining process is completed and the part is in its raw state, all tolerances might be into spec. Now they go get coated and depending on who is coating them depends on if they stay in spec. I buy .250 reamers from Pacific Tool and Gauge to run my front and back take down pin holes.
3. SAAMI spec.:
Now I know I'm going to run into resistance on this but this is how it was explained to me by a renown know barrel reamer manufacture. There are 3 types of chamber specs out there. 2 SAAMI and 1 that is what ever the manufacture thinks it need to be. Now with that said, SAAMI has a semi auto spec and a bolt gun spec. Semi auto has to feed and extract automatically. So the chamber is loose. With a bole gun the chamber is tight. That's why bolt gun guys use SB die sets to get down to a tight tolerance for their chambers. I buy reamers for all my barrels just because I found out not everyone corks their barrels before coating. I have found a lot of chambers and land and grooves have been coated in the barrel coating process and I have lost chamber tolerance. A light reaming and polishing is what I do to every barrel before installation.
That's just my 4 cents on the matter. I have fu%$ed up a lot of stuff and had to learn. Just passing it on so you don't waste any of your money on fu$# ups.