Lower Receiver life expectinecy?

**Greyman** · 09-21-10, 19:28

I have finally completed my AR15.

One question looms on my mind.

How durable is a lower receiver. Since this is the part that is required by law to register in my state it is now the most important part to keep in good order, whats the average abuse it can take in terms of bullets being fired from it to the point it just warps

If it helps I have an MP15 lower 7075 T6 Aluminum hard coat black. I dont plan to be dropping this on the dirt, cement or being to *rough with it

**ForTehNguyen** · 09-21-10, 19:31

its a non stress part, unlike the upper. It wont warp under normal use

**Greyman** · 09-21-10, 19:33

Originally Posted by ForTehNguyen

its a non stress part, unlike the upper.

Are you sure with this answer? If this is true this is GREAT news if not this is BAD news :-(

So would you say that it can last almost a lifetime with proper care??

I doubt this slightly? So after dumping 10,000 to 15,000 rounds of 5.56 I am to see no wear on the lower per say?

**Heavy Metal** · 09-21-10, 19:52

Bushmaster had one in-house about ten years ago that they estimated had over 250,000 rounds on. It was used to test completed upper reciever assemblies.

They said they had replaced FCG parts but the reciever was still in-spec.

I am curious if they still have it.

**Hmac** · 09-21-10, 20:07

Originally Posted by Greyman

I doubt this slightly? So after dumping 10,000 to 15,000 rounds of 5.56 I am to see no wear on the lower per say?

You might see some enlarging of the FCG pin holes. You might see some slop develop between upper and lower from slight enlargement of the takedown and pivot pin holes. All easily remedied without throwing out the receiver. And even if you do, just get a new one. If you're worried about it, buy a replacement now and stick it in your safe. It would cost you about $60-120 for that piece of mind.

**Col_Crocs** · 09-21-10, 20:12

Originally Posted by Greyman

Are you sure with this answer? If this is true this is GREAT news if not this is BAD news :-(

So would you say that it can last almost a lifetime with proper care??

I doubt this slightly? So after dumping 10,000 to 15,000 rounds of 5.56 I am to see no wear on the lower per say?

It should last you a long time. Ive seen heavily dinged and worn down to bare aluminum M16A1 lowers from years of no-care-use that are still perfectly functional. No egging out of the hammer and trigger pin holes, whatsoever. Personally, I'd be more worried about an improperly installed RE.

**ForTehNguyen** · 09-21-10, 20:19

Originally Posted by Greyman

Are you sure with this answer? If this is true this is GREAT news if not this is BAD news :-(

So would you say that it can last almost a lifetime with proper care??

I doubt this slightly? So after dumping 10,000 to 15,000 rounds of 5.56 I am to see no wear on the lower per say?

the lower doesnt take the stress of firing, the upper and BCG do.

**Captains1911** · 09-21-10, 20:26

Originally Posted by Greyman

Are you sure with this answer? If this is true this is GREAT news if not this is BAD news :-(

So would you say that it can last almost a lifetime with proper care??

I doubt this slightly? So after dumping 10,000 to 15,000 rounds of 5.56 I am to see no wear on the lower per say?

Wearing and warping are two completely different things. No, your lower won't warp. It will wear in certain areas, like the pivot and takedown pin holes, but not nearly enough to render the lower useless. The FCG and buffer parts will also wear, but are all easily replaceable.