Couple Questions About AR9 Build

[Grogmister]

I have decided to build and AR9 and have a couple questions for the ”pros.” Everything is AP EPC upper/lower and handguard with Faxon BCG and 8.5” Faxon barrel with a Biden brace. I’m down to buffer, spring and charging handel. I don’t want to cheep out at the end but how important is it spend alot on these 3 items. I’m about $50 over budget now and want to keep it reasonable. The AP 7.7oz and .308 spring is $85 plus shipping and tax and charging handles are $10-100 depending on what you buy. Thanks for the help!!!!

 

[gmcttr]

Looks like $30-35 for the AP EPC buffer and $5 for the spring. The trick is to find them in stock. You can get a buffer and spring for a few dollars less but not much.

Stay with the heavy weight and longer length. Don't get one of the 5oz buffers some sell.

The KAW Valley AR9 buffer and spring are in stock at Joe Bobs for $40 + shipping.

The charging handle isn't subject to anymore stress than in any other AR so get what you like.

 

[Grogmister]

Looks like $30-35 for the AP EPC buffer and $5 for the spring. The trick is to find them in stock. You can get a buffer and spring for a few dollars less but not much.

Stay with the heavy weight and longer length. Don't get one of the 5oz buffers some sell.

The KAW Valley AR9 buffer and spring are in stock at Joe Bobs for $40 + shipping.

The charging handle isn't subject to anymore stress than in any other AR so get what you like.

The only AP buffer and spring I have seen was being sold for $75 on gunbroker. I’m not wanting to spend that unless I have no choice. I will keep the weight as close to the 7.7lbs recommend by AP as possible. Thanks for the help.

 

[gmcttr]

Go with the KAW Valley set.

 

[Grogmister]

Go with the KAW Valley set.

That’s exactly what I did. Thanks for the heads up on Joe Bobs. I have never been on their website. Pretty good deals.

 

[Cameramonkey]

And make sure you have the right size buffer. It takes a heavy, specialized buffer for them to run right.

A buddy took his lower and bought a QC10 9mm upper. It just wouldnt run right. He checked the extractor, mags, everything. Well, ALMOST everything. Turns out he was still running his 223 buffer. Swapped to the heavier 9mm buffer and now works perfectly.

 

[Grogmister]

I purchase a 7.5 oz buffer. AP’s is7.7 oz so hopefully I won’t notice any issues.

 

[IndyDave1776]

And make sure you have the right size buffer. It takes a heavy, specialized buffer for them to run right.

A buddy took his lower and bought a QC10 9mm upper. It just wouldnt run right. He checked the extractor, mags, everything. Well, ALMOST everything. Turns out he was still running his 223 buffer. Swapped to the heavier 9mm buffer and now works perfectly.

As I read (and haven't yet reached the poing of testing) the combined moving mass (bolt assembly plus buffer) for a blowback 9mm like a QC10 needs to be about 23 ounces.

 

[gmcttr]

I purchase a 7.5 oz buffer. AP’s is7.7 oz so hopefully I won’t notice any issues.

You should be good. The KAW V buffer is the correct longer length needed for 9mm.

 

[Grogmister]

Well here she is. Still need to finish tightening things up and then decide on what muzzle break I’m going to add. Can’t wait to shoot it.