It takes a lot of force for me to close the bolt when chambering a round in my AR50.

I don't have any layout fluid, so I used a Sharpy marker on a
Talon ball round.

Because I can push the bolt all the way forward, and the only difficulty
is when I try to push the bolt handle down, I assume the problem is in that
last eighth of an inch or so the bolt pushes the cartridge forward.

So I closed the bolt, lifted the handle up and down several times to really
make a harsh mark on the cartridge.

I really only found one mark.
And it is on the bullet.

You can see very light marks going around the bullet where my
micrometers scuffed the ink. The bullet seems to be round.
0.510 to 0.5105"... although that 0.0005 was probably due to
me not being able to hold the cartridge perfectly perpendicular
to the calipers as I spun it with my fingers.

I know other people have had similar issues with stiff bolts.
Is there an actual problem, or is this common?

thanks,

I have the same issue, i make sure to keep it lubed in that area, such a large surface area on the bolt, it seems to dry out, and become hard to slide back in after pulling it out. So i keep some spray oil with me, also, you're seating a big round into the bolt, i can understand how it would be stiff.

AR-50's are know to have a LONG throat so I do not believe this to be the problem.  I think the mark is where the round touched the throat of the chamber when it was pushed forward.

Look at the "scuffed" marks around the outside of the shoulder of the case.  I think the problem is the cartridge case needs the shoulder pushed back just a tad.  I have had this problem in the past with other caliber cases.

I too have this observation with my AR-50 with a loaded round.  With no round in the chamber, there is no extra force needed to close the bolt.  

I have bought a extra Lee FL sizer die and will be removing a slight bit from the bottom of the die to allow the die to move the shoulder a bit to the rear.  Also, while the die is at the lathe, I plan on opening the neck and the area above the neck a bit so that if this solves the problem I can use the die as a body die to very carefully size some of my loaded ammo.  This will be similar to the body dies that Redding sells.

George

Originally Posted By George Toney: I have bought a extra Lee FL sizer die and will be removing a slight bit from the bottom of the die to allow the die to move the shoulder a bit to the rear.   George

Interesting idea.  

Have you tried chambering any brass that has been full length resized with
the Lee die as is?  

I don't have a bullet puller to see if a piece of Talon brass is hard to chamber
without the bullet.  But I do have some resized brass I can try.  

I use a Lee die to full length resize and have no problems chambering in my AR50


Nick

I had a set of CH dies that would not size the case enough to chamber in my State Arms and had to chuck it in the lathe and take about .060" off to correct it.

There seems to be some interference on the shoulder and the base.

The base measures 0.800" diameter, and it is not out-of-round.

Mine also did this at first. After 150 rds through it and it has started to close alot easier now thatn it did when it was new.

Mine did the same thing.. Just shoot it and it will loosen up..
I also found if you push the bolt forwand then down in one motion it seems easier than if you push it all the way forward and stop then try to pusn down..
Hope that makes sense..

Quoted: Mine did the same thing.. Just shoot it and it will loosen up.. I also found if you push the bolt forwand then down in one motion it seems easier than if you push it all the way forward and stop then try to pusn down.. Hope that makes sense..

+1 most definitely - do not try to push it forward, pause, and then close.  Slam it home and turn in one solid and fluid motion.  Keep the bolt lubed with Mil-Comm TW25B or some other grease so it stays slick.  It will get easier with time and more ammo.  

These are not delicate actions and they most certainly are not the type a sniper can slowly and quietly close like a worked over remington 700.  Close the bolt like you mean it.

Has anyone but me read their owners manual? It specifically says a stiff bolt is pretty much normal.

Quoted: Has anyone but me read their owners manual? It specifically says a stiff bolt is pretty much normal.

Owners manual?  

I think I might remember that it came with one.  Never even looked at it though.

<--- embarassed

Here are some quotes taken directly from the operators instruction manual of my AR-50.
Section III A-1 states:
"The Ar-50 is a large rifle, and the bolt will be harder to turn than you're used to."
Section III C-4 states:
"Push the bolt forward forcefully so that the extractor snaps over the case rim. You will feel fairly strong resistance as the ejector is pressed back into the face of the bolt."

Isn't that pretty much what he was already told to do?

Normally, I have to give the bolt a running start.

I slide the shell in as far as it will go with my finger,
then I slam the bolt forward as hard as I can to get
the extractor over the head.

Then I hit the bolt down with the palm of my hand.

After a dozen rounds or so, my palm hurts much worse
than my shoulder.

But if this is normal, and it loosens up with use, then fine.

Quoted: Isn't that pretty much what he was already told to do?

Yes but I thought he may take more comfort in the fact that the manufacturer itself described his issue as normal. So bite me.

Quoted: Quoted: Isn't that pretty much what he was already told to do? Yes but I thought he may take more comfort in the fact that the manufacturer itself described his issue as normal. So bite me.

Sensitive, aren't you?  Didn't mean to offend you .

Quoted: Normally, I have to give the bolt a running start. I slide the shell in as far as it will go with my finger, then I slam the bolt forward as hard as I can to get the extractor over the head. Then I hit the bolt down with the palm of my hand. After a dozen rounds or so, my palm hurts much worse than my shoulder. But if this is normal, and it loosens up with use, then fine.

That sounds a little extreme to me so you may actually have a problem outside of the normal stiffness.  First I would try not pressing the fresh round in as far as you can, just kind of lay it in the action with most of the round where you can still see it from the side.

Also, try some Barrett ammo or Summitt or TTI armory if you can get a few rounds and see if you still have a problem with it.  I have found that the Talon is harder to chamber in mine than the TTI and others.

FL sized or neck sized, it doesn't matter for me and my AR-50.  Stiff closing bolt.

I had the same problem and it was that the bolt face was not concentric with the bore.I re-worked the face of the bolt without changing the headspace.I also discovered that the only markings on the bolt were where the bolt handle goes against the frame.There were no marks on the lugs after 10 rounds. Ten thousands out of the frame set the lugs in place without causing a problem with the headspace.Perhaps some of this may HELP you?