300BlkTalk

I would be careful with a primer hole that deep on loading a round. Primer too soft , or pin , or bolt out of tolerance.

When you decide on an ammo , you can tune the ejector spring to set your ammo so it doesnt hit when it ejects. The best way is to order a couple ejector springs and pins and use the one in there as the control length. Sometimes the spring hole is too short or they installed the wrong spring. Grind t...

amazon has the p-300blk nikon under 200.00.
you can use the nikonhunting.com/spoton to match the scope to a cartridge

The AR has transformed for so many years it would be hard to better in----price,weight, accuracy, trigger pull. Before I would go with cool factors at that price I would get a JP upper and put 300 in a trigger system. There is nothing wrong with 77 gr. 223. Going to a short barrel a 300 BK in an AR ...

Then its probably just an extra bolt catch spring.

The height of the gas block ,so it will fit under the hand guard is the issue. Most can be adjusted through the hand guard openings or a small access hole can be drilled. Look at the Mid West Industries hand guards and their inner size . www.midwestindustriesinc.com

I was thinking more about the mass weight and the follow up shots. Actually, I prefer a very light weight carrier like a JP. Those m4's are real thumpers and if your not full auto I dont see any advantage.

Clamp on gas block vs set screws.

Just an opinion. You can get an Aero complete M4E1 upper from the factory for 440. Its a 1 in 7 twist and the barrel mounting system is stronger. The lighter ar15 carrier to me is better than the m16. What you have picked out is good.

If the receiver was never a rifle,and you dont have a stock from another rifle in your possession, I believe you can go ahead and put a rifle tube on it. Later you could get a stock and the ones that lock tight in the desired length or notch are the best.