Colt upper question flat-top 20"

[ralfabco]

I have a Colt 20" A2 upper with the gov't barrel and fixed carrying handle

Can I use a stripped Colt flat-top upper with the M4 feed ramps ?

If not, what do I need to modify ? Will it be reliable ? Any advice ? Thanks in advance.

 

[Sterling Shooter]

You may have feeding problems and you will also shoot about 10 minutes too high when using mil-spec BDC carry handle sight with A2 rather than F marked front sight base. You can fix by milling barrel extension and replacing stock front post sight with one about 40 thousandths higher.

 

[Red_SC]

If your barrel doesn't have M4 ramps, it could cause a problem. If youre handy, you should be able to put ramps in using your all-purpose home gunsmithing tool, aka Dremel. Look at another barrel with ramps to see where to grind. Go slow and be careful, putting steel back is hard. Some here will pass out at the thought of a Dremel near your barrel, but many people have done it without a problem.

 

[ralfabco]

Thanks

I am interested in mounting
a tactical 1-5 optic. No carrying
handle.


Any method to take care of the feeding issues or potential issues ?

If it is not reliable I do not want to modify the existing factory A2 upper.

 

[Layton]

If you're handy with a dremel as mentioned this is really all you need to do.

 

[Redmanss]

Try this thread: http://www.snipershide.com/shooting...upper-receiver-without-m4-feed-ramp-cuts.html

ORD links to some very good proper options for your purpose.

I'd spend the money on the proper part first before I attempted to modify something not designed for that purpose, especially when it comes to taking a Dremel to the hardened steel of a barrel extension.

 

[ORD]

Try this thread: http://www.snipershide.com/shooting...upper-receiver-without-m4-feed-ramp-cuts.html

ORD links to some very good proper options for your purpose.

I'd spend the money on the proper part first before I attempted to modify something not designed for that purpose, especially when it comes to taking a Dremel to the hardened steel of a barrel extension.

+1 on the advice given by me and others in the thread linked to above. While I certainly don't hesitate to recommend the modification to the barrel extension where no other viable option exists, the best practice is to not engage in such action and instead source the proper part (in this case...a flattop upper receiver WITHOUT M4 cuts/feedramps) for the job. The first and last receivers I linked to in my first post in the thread above are both still in stock and available...the Fulton Armory one is currently on sale for $80.96 which is a GREAT deal. Add a FA assembly (~$15), port door rod and door assembly (another $15) and run the remainder of your upper receiver parts (BCG, barrel, etc.) as you would on the A2 upper (all of the above parts are in stock and available from Fulton if you buy from them so you can be in and done for ~$110 for a complete upper receiver ready for your bbl, gas system, etc.).

 

[ralfabco]

It will have a feeding problem. I emailed Wes Grant.


I assume Colt does not sell an A4 style stripped flat top upper for the 20" rifle ?

I also assume the FN stripped A4 upper is difficult to find ?




Thanks for the information and interest.