AR-15 full auto conversion

Armory » M-16

[ARCHIVED THREAD] - AR-15 full auto conversion

Posted: 9/26/2011 7:35:37 PM EDT

Just got our SOT in the mail!!

Have the whole MP5 thing figured out, as it will be our main focus, but we are looking to convert a couple of AR-15's to Post Sample demo guns. So assuming we have the properly shelved lower, a full auto trigger group, and the proper jig to drill the lower receiver to complete the lower. What do we need special on the upper? Do we need a full auto BCG or anything else?

Also, we will be using a PCF lower for our initial testing, once we have it figured out, what lower would you experts recommend for full auto use?

Thanks for the help!!!

Posted: 9/26/2011 7:55:14 PM EDT

[#1]

The upper needs to be sear-cut if you'll be using GI auto sears instead of drop-ins.

You'll need a full auto carrier, and complete full auto FCG.

You realize you need to hog out the lower to fit the auto sear, not just drill the sear hole, right?

Posted: 9/26/2011 8:12:00 PM EDT

[#2]

Quoted:
The upper needs to be sear-cut if you'll be using GI auto sears instead of drop-ins.

You'll need a full auto carrier, and complete full auto FCG.

You realize you need to hog out the lower to fit the auto sear, not just drill the sear hole, right?

+1.

There is no commercially sold AR15 lower that can accommodate a full-auto fire-control group without milling the interior. The conversion is way beyond just drilling a hole for the autosear pin.

So as far as which host lower receiver is best ... since you are completely redoing the inside dimensionally, the only issue is exterior cosmetics.

In addition, I'm wondering why an 07/02 would make their main focus the MP5, which is an out-of-production legacy SMG with no potential LE sales. LE looks to newer-generation SMGs today; you might as well focus on STEn gun production.

You are paying your ITAR fee, right?

Please, enlighten me ....

Posted: 9/26/2011 8:16:03 PM EDT

[#3]

Quoted:

Please, enlighten me ....

One would hope that someone going to that kind of effort would have researched and thought these thing through........

Talking out my ass here but why does the thought "can not obtain for the purposes of enhancing ones own collection" ring in my head. To OP....[Full legal disclaimer]Not necessairly implying that it just was the first thought in my head.[/Full legal disclaimer]

Posted: 9/27/2011 6:15:30 AM EDT

[#4]

Quoted:

Quoted:
The upper needs to be sear-cut if you'll be using GI auto sears instead of drop-ins.

You'll need a full auto carrier, and complete full auto FCG.

You realize you need to hog out the lower to fit the auto sear, not just drill the sear hole, right?

+1.

There is no commercially sold AR15 lower that can accommodate a full-auto fire-control group without milling the interior. The conversion is way beyond just drilling a hole for the autosear pin.

So as far as which host lower receiver is best ... since you are completely redoing the inside dimensionally, the only issue is exterior cosmetics.

In addition, I'm wondering why an 07/02 would make their main focus the MP5, which is an out-of-production legacy SMG with no potential LE sales. LE looks to newer-generation SMGs today; you might as well focus on STEn gun production.

You are paying your ITAR fee, right?

Please, enlighten me ....

Thanks for the info!!!

We have all the equipment to mill the interiors, but was hoping to buy them already milled.

None of the MP5's are full auto, just building nice SBR's/pistols, and we are paying all taxes and fees.

Posted: 9/27/2011 6:43:23 AM EDT

[#5]

Quoted:

Quoted:
Please, enlighten me ....

One would hope that someone going to that kind of effort would have researched and thought these thing through........
Talking out my ass here but why does the thought "can not obtain for the purposes of enhancing ones own collection" ring in my head. To OP....[Full legal disclaimer]Not necessairly implying that it just was the first thought in my head.[/Full legal disclaimer]

Yep - talking out your ASS

Anything FA we build will sold or legally demilled, and if you understand SOT rules, you can't keep them anyway!!!

BTW - your right, we should have researched this part better!!!

Posted: 9/27/2011 6:48:36 AM EDT

[#6]

Quoted:
Thanks for the info!!!

We have all the equipment to mill the interiors, but was hoping to buy them already milled.

None of the MP5's are full auto, just building nice SBR's/pistols, and we are paying all taxes and fees.

Ah! That explains it.

Nope, no manufacturer currently sells AR lowers to the public that are milled for FA FCG's but without the autosear hole drilled –– I suspect because they would be way too easy to convert.

However, some of the smaller-volume manufacturers will, when requested by other 07/02 SOTs, sell special-order batches of receivers that are premilled. You'll prolly have to document your FFL/SOTs and you will pay more for the extra work involved. Call around and ask.

HTH!

Posted: 9/29/2011 4:29:57 PM EDT

[#7]

Quoted:

Also, we will be using a PCF lower for our initial testing, once we have it figured out, what lower would you experts recommend for full auto use?

I used the cheapest ones I could find at the time, Superior Arms as they were also marked SAFE/SEMI/FULL. No sense spending a lot, since it is a Post-Sample and will be destroyed. Mine have worked fine. With a decent mill it is a 30 minute job.

For the MP5, I just did a trigger pack modification. That was 3 minutes with a mill.

Posted: 10/11/2011 6:31:38 AM EDT

[#8]

http://www.pcfmfg.com/index.php?option=com_content&view=article&id=47&Itemid=28

I SAW A POST SAMPLE AT A SHOOT A COUPLE MONTHS BACK . ALL THE GUY DID WAS DRILL 2 HOLES IN THE RECEIVER . THE WALLS OF THE RECEIVER GO STRAIGHT BACK NO MILLING REQUIRED AND IT IS A PLASTIC TYPE RECEIVER. ALL THE PARTS WILL FIT IN. AND IF IS A POST SAMPLE YOU CAN TRASH THE RECEIVER ONE DAY AND IT WAS VERY INEXPENSIVE . I CAN'T SEE ANOTHER CLASS 2 OR 3 WANTING TO BUY IT . THE ENTIRE LOWERS ARE 115. RETAIL.