A friend of mine bought a Remington 40x in .223 caliber a couple of weeks ago. It has been fit with a custom barrel (can’t remember the manufacture) we took it to the range Saturday and was shooting factory 45gr Winchester ammo. The ammo seemed too tight but would fit without a lot of effort closing the bolt. I looked at his cartridge necks and they did not have any powder discoloration after being fired. Upon inspection they did not seem to expand and look like they do when I size the shells in my Wilson Bench rest bushing neck size die. My assumption is that the chamber has a tight neck and the brass will need to be neck turned to fit properly.

How do I determine without doing a chamber cast how much to turn the necks down? I looked on the barrel for a neck size stamp but did not see one.

Also what brass would you recommend for this .223?

Your help will be appreciated.

Swede

The only sure way is a chamber cast but you can get a fair estimate of the chamber neck diameter by measuring several fired cases. They will not be exact since they do have to contract somewhat otherwise you couldn't extract them. I would then neck-turn them to allow whatever clearance you want, usually .001" each side minimum. Fire them again and then measure again to make sure you are getting some expansion from the loaded diameter. Do just a few cases (maybe 5) until you get the desired results before doing it to all your brass. The best brass depends on how much you want to spend and what you are using the rifle for. Good Luck.

Ray

If it is a custom barrel with a tight neck, it should have the diameter stamped on it. Can you seat a bullet in a fired case. If you can, you should be OK. If not, you may have to turn the outside. My Wilson only partially neck sizes the case. Does yours size the whole neck? Bottom line is it may be chambered to tight tolerances, but not necessarily a custom tight neck.
Peter.
Peter.

I use the Wilson Benchrest dies to load for a XR100 .223 rifle. I have not used them for the 40X .223 my friend wanted to make sure the rifle would fire properly first and how well it would shoot with factory ammo. He is not into reloading as much as I am.

I will have to check the barrel again for a neck size stamp but if it does not have one how do I determine how much to turn the necks down without a chamber cast?

Swede. Short answer is trial and error, but first make sure that you need to. You mention difficulty in chambering. Take a loaded round, chamber it, and then take the round out. Are there marks on the neck? Marks on the bullet (seated too long)? Are these factory rounds? Chamber clean? Don't look for problems that aren't there. I know this seems very basic. Outside neck turning is for two reasons: tight chamber or uniform the neck diameter. You want the diameter of the loaded round to be 2 or 3 thousandths of an inch less than the chamber size, but you don't know the chamber size, hence trial and error. Turning down necks is a pain in the butt so don't do it unless you have to. A 40X in 223 is not a competitive combination in BR shooting.
Peter.

Peter:
Yes there are marks on the neck. I do not believe the bullet (OAL)is to long but I will check with my Sinclair OAL gauge. Yes I know that this caliber is not competetive. If I asked this question in the reloading part of the forum they may not have been able to help me. I have a few of the shells my friend fired in his rifle but I will have to get the rest to have a neck size to start with. How much clearance do you think that I need on the necks for spring back?

Thanks for your help.

Well, if you have a loaded round that is hard to chamber and shows marks on the neck, mike it and see what it says. Then take one of your fired rounds (from the same rifle) and "clean up" the neck by turning the outside of the neck. (Before you do this, try seating a bullet in the fired case. If you have a tight neck, you might not be able to seat the bullet.) Resize the "cleaned up" case, seat a bullet and try chambering it again. Still tight? Remove the bullet using an impact puller or whatever, and trim the outside some more, this time turning the whole neck. repeat the procedure with dummy rounds til you have a loaded dummy round that chambers to your requirements. When it does, your neck turner is pretty well set.
Actually you should, as stated above, turn so that you have 2-3 thousandths of an inch clearance ie. 1 to 1 1/2 on each side. Opinions vary. Some folks like to just seat the bullet in the fired case! Rememeber you have to adjust loads at the end of all this. BUT, look for other causes first. Do have another 223? Try chambering the rounds in that. When you resized did the die push the neck back creating a ridge at the case neck. Just examine the unfired rounds.
peter.