5.56 throat reamer

[freebullet]

Have a tight throat 5.56 barrel and would like to open it up a little. Any experience or input on what tool is best for the job would be very helpful. In my searching there are several styles available and prices are all over the place aswell.

I can't get any boolit I've tried to load/unload with the check in the neck. I can get a 55 cone point to load /unload but the check is just below the neck. It seems the cheap barrel didn't get finish reamed enough.

What reamer is best for this?

[B R Shooter]

A typical throating reamer will extend the leade so your bullets will seat where you want them. Unless you have oversize bullets, you may have to get one specially made. I have one for j-bullets, but may not work for yours.

[Skipper]

You can rent one from 4-D. They waive the deposit if you pay with a credit card.

http://4-dproducts.com/displayitem.php?rowid=349&tname=rental

[freebullet]

That sounds like a great option, thanks for the link.

[Nobade]

I would recommend caution when using a throater. It takes almost no pressure or time to make the throat a lot longer than you intended.

If you know a gunsmith or someone who has a 5.56 NATO reamer, I would recommend first trying that. Turning it with a T handle and letting the weight of the reamer push it,(with the barelled action held in a vise with the muzzle pointing down) you can cut until you feel it touch the shoulder and stop. Doing it this way won't change the headspace and the NATO spec throat will likely be all you need to get boolits to chamber properly. You can also likely rent this reamer if you can't find anybody who has one. Plus doing it this way you don't have to pull the barrel off the receiver.

-Nobade

[freebullet]

Thanks for the advice.

I haven't had to do this to any others yet but am purty handy.

Only local gunsmith I know does mainly shotguns. He has no 556 reamer. Going to call around to a few well regarded Smith's locally. If that fails I will probably rent one.

The barrel is marked 5.56 but I can barely seat 55gr fmj past the cannelure before they hit the throat. Doubt I could even load 65-75 jbulls for it right now.

[Whiterabbit]

any special alignment tricks? or do these reamers align themselves, what with the pilot and all?

[freebullet]

Yep the throating reamers have a pilot. They work the throat/lead only. You can over do it with them.

I think Nobade was suggesting I just use a 5.56 NATO spec chamber finishing reamer as they work the throat a little too. That's the one I'd rent because they are around 140$ vs. 40$ for the throating reamer.

[Nobade]

Yes, I was referring to a finish reamer. The reason for that is to keep the throat aligned and not go too deep. If you use a reamer extension that fits reasonably close to the bolt raceway (11/16 for Remington and many others) and a piloted reamer it is no problem to keep it straight.

I can do this in the shop in minutes for people, but if I am going to use a throater I'll pull the barrel and set it up in the lathe so I can get exactly the right depth. There is no way I would use a hand turned throater without some way to measure how far it has cut, it's just too easy to go too far. They also have a tendency to chatter if not used properly.

If you can't find anybody who has the reamer, I'd just rent one. The NATO chamber is throated just about perfect for cast boolits where the .223 Rem has no throat at all, just a bevel at the start of the lands. There's not much change there, only about .075" difference in length and the angle is shallower on the NATO throat.

-Nobade