Hi Fellow Builders,
I'll start like others by stating I am very new, very green - spent my life on pistols and shotguns, and decided to be an architect on a Semi Auto - and I picked about the biggest and more complicated in the land to tangle with first, of course. So be merciful on me...the more info you can give me, the better builder I will be.
After stumbling through the typical 'DPMS doesn't match to Armalite' bungle, I have an interesting question. I've gotten some clarifications from manufacturers but I wanted everyone's in the field take on this as well...
I have a DPMS A3 type upper receiver - I've noticed that DPMS, as well as just about everyone else - doesn't mention M4 Feed Ramps on their Receivers. DPMS says this is because no 308/7.62 was approved for Mil-Spec back in the day, so no M4 Feed Ramps were ever included on ANY 308 receiver, let alone theirs. (although it should be noted that Armalite does have them on current models). I have also purchased a Rainier Arms 20" Ultramatch SS Barrel, which says it's DPMS compatible - but it DOES have M4 Feed Ramps.
DPMS was a bit vague on their response if both would work well together without gunsmithing. Rainier Arms' tech was helpful, nice, etc - he said I should have no issue, because of a general rule: Receivers with M4 Ramps
MUST use M4 Ramped Barrels, whereas Receivers with no M4 Ramps are interchangeable, and can be used with
either a M4 Ramp Barrel, like mine, or a Non-M4 Ramped Barrel.
How confident is the AR world this is true? I've not seen much of this subject touched in your threads I can see - it would give me much better peace of mind I can make this work like the piece of art it should be when done...let me know...sorry for lengthy post, but it's a brain teaser for me...Thanks all for your expertise!