feed ramp debate

[ARBLDR]

I was just wondering what all you felt about not using the M4 style feed ramps when building a long range DMR I think LWRC is building a DMR not using the M4 style.:suicide::suicide::suicide::suicide:

[evolixsurf]

If this is for a long range rifle that you are not going to be rapid firing or taking to war, I wouldnt worry about it.

[fdxpilot]

If you are indeed building a DMR style rifle, the chances are high that you will at least occasionally use non "military-style FMJ" ammo. When you start using soft-point or ballistic tipped ammo, the M4 ramps will help insure reliable feeding.

[Sgt_Gold]

M4 reed ramps are not necessary on a rifle length system. The M4 has a shorter dwell time that the M16. The magazine spring doesn't have enough time to push thee next round all the way up, so you get a jam. If M4 feed ramps were necessary in a rifle, high power shooters would be using them, and I don't know a single HP shooter using M4 feed ramps. AFAIK the SDM rifles don't use them either.

[adam155724]

Would rifle ramps also work well with a 14.5 barrel and a mid length gas system?

[Sgt_Gold]

I can tell you that rifle feed ramps work on my 16" middy with everything from Wolf steel cased to 75gn Hornady A-Max ammo. It should work on your rifle.

[MarkG]

The feed ramps are not feed ramps. They are clearance cuts. Feed ramps only exist in the barrel extension. Under most circumstances, ammunition never touches the upper receiver . If it did, the anodizing would be capturing a nice coat of copper and more than likely wearing through at some point.

The clearance cuts are necessary because the carbine barrel extension has feed ramps that are 52 degrees, compared to a rifles 45 degrees, and they break the edge of the barrel extension. Without the the clearance cuts, the cartridge would have to negotiate a 90 degree corner on the upper receiver before it got to the feed ramps in the barrel extension.

[carbine85]

Feed ramps are not needed unless it's full auto. Not a single one of my rifles has failed from a lack of feed ramps. With that said, most uppers are made with the feed ramp cuts so you may as well build it feed ramps. Feed ramps are not a deal breaker for me.

[glocktogo]

For long range accuracy, I'd think anything that aided in smoothing out the feed cycle would benefit accuracy. What we need is someone with a concentricity guage that can measure before and after bullet runout, when chambering rounds after a shot is fired from an AR with rifle ramps and another with M4 ramps. So long as bullet runout is not affected, the type of ramp shouldn't be an issue.