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View Full Version : Quick ? About AR 15 Quality Control


DanThaMan1776
July 27, 2010, 11:22 AM
I understand certain trade-offs like chrome lining the barrel and accuracy, compactness of barrel and velocity, twist rates, etc...

What I don't understand is why every AR 15 doesn't have a chrome lined chamber and m4 feed ramps. What do you loose with these features??

thesheepdog
July 27, 2010, 11:28 AM
I am pretty sure if your bore is chrome-lined, your chamber is too.
M4 feed ramps were made for full-auto weapons to increase feed reliability. If you don't have M4 feed ramps, it's not a big deal, unless your ramps are mismatched (rifle ramps with M4 extensions)

DanThaMan1776
July 27, 2010, 11:31 AM
But what is lost by having m4 feed ramps? Why not have than extra millimeter of ramp to ensure the round chambers every time even on a rifle?

thesheepdog
July 27, 2010, 11:33 AM
Nothing is lost. Your chances of having a FTF without M4 feed ramps/extensions compared to a setup with M4 feed ramps/extensions, are very, very slim. I actually have a Grendel upper with mismatched feed ramps/extensions, and haven't had a FTF yet.

DanThaMan1776
July 27, 2010, 11:37 AM
Interesting.. Thanks for the info

thesheepdog
July 27, 2010, 11:48 AM
Anytime.

smoakingun
July 27, 2010, 11:56 AM
why do all ar's need chrome lined chambers and bores?

thesheepdog
July 27, 2010, 12:00 PM
why do all ar's need chrome lined chambers and bores?

Mil-Spec requires chrome-lined for longer barrel life. You really don't need a chrome lined barrel. I prefer them, because they are more durable than non-chrome barrels. Stainless barrels don't need chrome because stainless is very wear resistant and corrosion resistant.

smoakingun
July 27, 2010, 12:04 PM
i understand the why, but i jus wondered whe dantheman thought it was a need?

Bartholomew Roberts
July 27, 2010, 12:44 PM
What I don't understand is why every AR 15 doesn't have a chrome lined chamber and m4 feed ramps. What do you loose with these features??

Money. The average AR owner will probably not appreciate the minor operational difference between having those features and not having; but they'll certainly notice the cost difference of having them - even if it is a small difference.

And while some AR makes do chrome the chamber and not the bore (Colt comes to mind), most either do both or neither. So in the "typical AR owner" world, accuracy is another quality that many shooters can appreciate right away.

What you see on the shelves is a direct reflection of what people are buying. However, one reason you see much better choices these days is buyers are better educated about the different features available.

Powderman
July 27, 2010, 01:11 PM
Why chrome line the chamber and bore at all?

Chrome lining these areas greatly increases the service life of the rifle. It was spec'd by the military as part of the change/upgrade that changed the M16 to the M16A1.

Also, Colt does chrome line the chamber and the bore.

zombieslayer
July 27, 2010, 02:08 PM
My piston M&P came with all kinds of QC issues.

demigod
July 27, 2010, 03:17 PM
Piston ARs are inherently problematic. The irony is pure and lovely.

thesheepdog
July 27, 2010, 03:20 PM
Piston ARs are inherently problematic. The irony is pure and lovely.

Haha, way to put it. Don't fix something that aint broke!!

zombieslayer
July 27, 2010, 04:50 PM
Well fwiw- mine had out-of-spec chambers, and defective bcg's. Had nothing to do with the piston. SW farms out their work for the uppers on their AR's.