I am new here and this will be my first post. I decided to build my own AR platform rifle at home instead of buying an off the shelf rifle again. First Ill list the parts and then my question.

Palmetto State Armory Lower

PSA lower parts kit including buffer tube, spring and butt stock.

Tactical Ambush Upper (I am on a budget)

PSA Bolt Carrier Group and Charging Handle

I have not yet bought a barrel or gas block and tube. I have a set of M.P. handgaurds but thats irrelevant.

My problem is that the rifle does not seem to cycle as easy as it should, It was very hard to pull the charging handle back compared to others I have felt. I did some reading here and decided to sand and polish the buffer spring which did help and also made the cycle much more quite. I noticed after cycling the weapon to help things break in that the charging handle was creating wear marks on the grey coating in the upper. Since its a cheap T.A. upper I thought maybe with it being mil spec it may have a tolerance stacking problem. I used 1000 grit paper on the charging handle wear and also in the upper a bit. Nothing crazy. Now the action is much better but still not as easy as others I have seen. I have seen people pull the charging handle back with one finger which is very difficult for this rifle (I have had others stronger than I try, so its not just my weak ass). But it becomes extremely hard to pull the charging handle when the trigger is forward. I have been trouble shooting, reading everything and looking but cannot find an answer. With the trigger back and weapon on safe you can cycle the action much easier after I polished the spring and sanded the CH. But with trigger forward it feels almost seized yet never even fired and takes a lot of force to charge. If anyone needs pictures I can provide. I just do not understand what is wrong. Is it the cheap upper? or what could cause this?

Thank you for any help....

Not sure if you have done this, but give this a try.

- Take some lube and coat the inside of your buffer tube, also put some lube on the buffer and spring.
- Lube up the BCG, the inside of your upper receiver and lube up the charging handle

If the tolerances are tight it would cause wear on the top of your upper from the charging handle, I'm pretty sure that's normal, I have that happening on a couple of my rifles.

Lube is an AR's best friend.

Try putting a little lube on the lugs of the bolt. If it's dry it will stick till it's broken in.

Right now I am running Rem Oil on the BCG, CH and buffer spring. After polishing the buffer spring it made a world of difference in the ease of pulling the CH back. Since I do not have a barrel yet I only let the BCG go forward with my hand still giving resistance because I have seen people say it will cause damage without have a barrel and chamber. I thought I had solved the problem until I decided to try and charge the rifle with the hammer forward. I am going to make a video and upload some pictures which may help. I have been around firearms my whole life. I have my carry permit and armed security license and carry for a living.  I just cant figure this one out and know there are a ton of knowledgeable people here, this is my first build. I can go take a MP15 off the shelf and take it apart and put it together and have no issues.

The action is not hard to pull back once you get the initial break if you know what I am saying. Once you get the force to move the BCG back everything is smooth since I polished the buffer spring and the light wet sanding on charging handle. Its quiet and just fine. It is the initial force required to get things in motion so to speak that is concerning. I have never felt a rifle as difficult before. Like I said before, Ive seen people pull the charging handle with one finger, which with this rifle is hard for myself and people stronger.  The only thing I can think is that some how the rear of the full auto BCG is having trouble entering the buffer tube? Is that nuts or possible?

I have looked at the hammer and trigger group and all seems to be normal. It is still a little stiff to charge with hammer down but I think that will get better with a couple 100 rounds. But I am at a lose for why it is so hard to charge with the hammer forward.

You don't have a barrel and you're worried about how it cycles?

Getting ahead of yourself a bit aren't you?

You are right, It just shocked me once I had the lower and upper receiver assembled. Because charging the rifle doesn't have anything to do with the barrel or gas system. Now I am worried I may have to scrap everything but the lower, especially since I cannot find anyone with the same problem. Since it is a mil spec build maybe the tolerance of different parts didn't add up...

The cam pin is probably lodging itself in the cutout since the bolt face isn't contacting anything, check it after you get a barrel installed.

Thank you! You were right, I took the bolt and cam, firing pin out of the carrier and ran the charging handle with the just the carrier. It was normal. Thank you, I had not even thought of that, should have started simple. I was thinking it was something worse.

This is why you worry about function checking the charge after installing barrel

If anything else feels gritty when you finish your build, just douse it with oil and let it wear in naturally.  

The few small contact points will smooth up by themselves.  Step AWAY from the sandpaper.