REARSPROCKET

So the KAK pins came Sat. and they are .945 as well, so waiting on the RCA ones but they are probably the same length ? Why are these split tip solid pins all too long and the solid pins without the split in the end are shorter ? Think I'll just add a 1.5x3 o-ring under the head side of the pin and "Just Send It".

Thanks guys, I ordered a few different pins from KAK, RCA and some regular cotter pin style, so I'll see what shakes out with them when they get here. I noticed Toolcraft uses the cotter pin style in their 308 carriers so that might be the best way to go.

Thanks, I looked up the KNS pins and they are not available for the 308 only 5.56 on their site ? I was thinking maybe a small o-ring under the head side of the pin would keep it centered and not protruding ?

Hemi would you know what brand or who the manufacturer is ? Seems there are other pins out there that are the same length as mine.

Thanks I'm glad it's not the carrier.

I measured with caliper it sticks out .045 and the OAL length of the solid pin is .945 so I guess I need a .900 length pin. Could someone measure the length of their pin so I know if this one is out of spec ?

So I ordered some S&W M+P10 retainers and they arrived today, it seems S&W uses the smaller 5.56 FP retainers in their 308 platform?. The original FP retainer's split end sticks out about 3/32 - 1/8 past flush. If I shorten the tip the chamfered nose of the split will be gone. I measured the diameter of the solid pin at .123 so it seems they are 1/8". I forgot to measure the length to see if there is a shorter cotter pin style I can modify to use.

The Aero carrier I have came with the solid pin, but when installed the tip with the split end sticks out the side of the carrier too far and will contact the upper. So I need a shorter solid pin or a cotter pin style .

Haven't seen this discussed here, seems the AR10 and the 308AR BCG take a (larger?) specific firing pin retaining pin. I have seen both the original AR style solid pin with a split on the end used and the newer cotter pin style. Where is the best place to source the cotter pin style FP retainers ?

Does anyone make a 7075 AR-10 pistol buffer tube with the correct 7+5/8" inner depth and 1.2" or more OD besides Vltor ? I need to mount a SB-Tac SOB on a M5 lower. Thanks

Relax about the Vltor, I told you from memory so I guess I was wrong about the Vltor depth, I remember selling it cause I didn't like the slightly loose thread fit in the lower. I do have a Larue still that I just remeasured again at exact 7+11/16. The POF was just a 1/32" over 5/8" not enough to matter. But there are a few 308 tubes well over 7+5/8". I like Vltor products and have a few of their other products. I've heard the Marine history of the A5 system before many times. Anyway this is off my OP question, how does extra depth length affect operation if there is no BCG contact with lower and bolt face is in good relation to ejection port window ?

Off the top of my head Larue, POF, Zev, and Vltor, most are 7+11/16" which is only a 1/16" over 5/8" but some (I don't remember which) are closer to 7+3/4 or more. I measured a few on my last build and from what I remember Larue, POF, and Vltor were 7+11/16"

and the bolt face is still in good relationship area with the ejection port opening at full rearward travel ?

Hello everyone, new to this forum. Looking forward to learning more about the ARs big brother on here.

Hello everyone 😁 new here and have a question that I haven't seen covered before on AR10/LR308 specific buffer tubes. I know that Armalite, KAC, Noveske, and LMT 308 tubes have a inner depth of 7+5/8" which is the original Armalite spec, but there are a LOT of other upper and mid tier companys making tubes with a 7+11/16" or more inner depth. What is the big difference between 7+5/8" and all the other deeper length tubes if the BCG doesn't come in contact with the lower @ 7+11/16 or more depth ?