DD5V1 buffer, need some help!

[JimmyT]

I bought a DD5V1 used. The buffer in it was a PWS H4 that was too heavy/ long to let the rifle cycle properly. I’m going to have to het a new one, and wondered if the OEM one was 2.5” long. If anyone has replaced the syste, what did you get?

thanks in advance

 

[msgriff]

Measure the inside depth of the receiver extension. If it's 7", it requires the 308 carbine buffer (2.5"). If the RE is 7.75" inside depth, it uses a standard AR-15 carbine buffer (3.25"). Springs are not interchangeable between the two, with a couple of exceptions.

 

[JimmyT]

So replaced the AR15 buffer with Aero precision AR10 buffer and spring…still no joy. Daniel Defense does not have DD5V1 parts for sale in their catalog. I think I can fix it with one or two options 1) start clipping coils off the spring until it cycles or 2) see if I can get all replacement parts from DD….

 

[hlee]

Was the previous buffer too heavy or too long? Those are different problems. Does the rifle lock back manually? If it does, you have a weight problem. If it does not, you have a length problem- and maybe a weight problem. Was the rifle sold to you as nonfunctional?

 

[msgriff]

So replaced the AR15 buffer with Aero precision AR10 buffer and spring…still no joy. Daniel Defense does not have DD5V1 parts for sale in their catalog. I think I can fix it with one or two options 1) start clipping coils off the spring until it cycles or 2) see if I can get all replacement parts from DD….

Aero's 308 carbine buffer is notoriously underweight (3.8oz). You want to be in the mid-5oz range, probably higher for suppressed. Cutting action spring coils falls in the WECSOG category.

 

[wade2big]

The dd5v3, 4, 5 uses a longer receiver extension and a standard carbine sized buffer. I believe mine had an H2 in it from the factory.

 

[JimmyT]

Was the previous buffer too heavy or too long? Those are different problems. Does the rifle lock back manually? If it does, you have a weight problem. If it does not, you have a length problem- and maybe a weight problem. Was the rifle sold to you as nonfunctional?

It was a PWS H4 and a springco red spring for an AR10. Made the DD5 a musket. Would not push the bolt back far enough to eject. Rifle was sold used as is. Seller is footing the parts bill for me to make it work.

 

[JimmyT]

I bought a Hot White springco action spring, so it’s back to the range for a bit of T&E time…

 

[JimmyT]

And need a lighter spring. I’m getting occasional ejection but BCG does not come back far enough to lock back on empty mag or strip a new round. This DD5V1 is way under gassed compared to other AR10s I have shot before.

 

[hlee]

I assume you have confirmed that it locks back manually… Also, have you checked gas block alignment? That’s the best use for a bore scope that I have found…

 

[JimmyT]

I assume you have confirmed that it locks back manually… Also, have you checked gas block alignment? That’s the best use for a bore scope that I have found…

I have not. I think the upper receiver has not been touched due to absence of any tool marks except for the muddle break replacing the DD flash mitigation device. The rifle will lock back on an empty magazine when I manually cycle the bolt. I’m going to order a springco white spring for a normal AR 15 and do more T&E.