Tight neck chamber

[Michael Eichele]

-Nevermind-

[mike33]

Originally Posted by Ackley Man

This is kind of a strange thread going from quesitons & comments concerning tight necked chamber to forming .270 Win brass from '06!

I have several tight neck chambered guns. First, a tight neck chamber is, as previously stated in the thread, a chamber with a neck dimension that is less than the minimum SAMI spec. Accordingly, it would be impossible to chamber a factory loaded round or factory brass into a tight necked chamber unless the so called tight necked chamber was not in reality a tight neck. A gun with a true tight necked chamber will be so marked on the receiver by the gunsmith that did the chambering - unless he was an idiot. To prep brass for a tight necked chamber you must use a neck turning tool that is really just a mini hand held lathe. Some machinest types have actually made some tooling so they can neck turn in a standard lathe. Neck turning is a slow process and constant measuring with a neck mic must be done to insure that you have 1 1/2 to 2 thousands clearance between the brass neck and the neck portion of the chamber. Accordingly, it would be a bad idea to try and use a tight necked gun for general hunting as a few grains of sand to prevent chambering. I don't believe tight neck chamber prolong case life since the necks are thinned and have a propensity to crack after repeated firings. Another thing that is necessary with a tight neck chamber is to body size and shoulder bump the cases about every five firings with neck sizing only in between. Don't get the thinking about case forming 06 to 270. Cant you still by 270? Why chance on overworking the brass and invite a case failure? Nuff Sed!

I had them when i was shooting bench rest 6ppc .262 neck. This was the best post i seen concerning the thread, well explained. I could not believe a standard round would chamber in a true tight neck chamber.
Mike

[Ackley Man]

I was in a rush when I posted the last reply and wanted to offer a couple other suggestions.

The purpose of a tight necked chamber is to keep the bullet in precise alignment with the bore. This can positively impact accurcy provided that bullet run-out is kept to an absolute minimum.

As previously stated, a tight necked chamber is not acceptable for standard hunting conditions. A couple of grains of sand can keep the round from chambering or cause a stuck case. Wose yet it could cause a live round to become stuck. If that should happen you would have a real mess on your hands. For hunting, a good alternative would be a minimum SAMI chamber neck. You don't have to turn necks and have the advantage of minimum clearance.

Another alternative for a tight necked chamber if you don't want to turn case necks is to buy a large supply of brass and cull it by using a neck mic for case neck thickness. Then make up a dummy round with one of the culls. With the dummy round in hand a gunsmith can order a special dimension reamer and cut the chamber neck so the loaded culls will maintain the 1 1/2 to 2 thousands clearance (per side). You then can have the benefits of a tight neck chamber without the labor pains of neck turning. The gunsmith may zing you for the price of the reamer but you would own it and could have it used in the future for other barrels.

[TOM H]

When I go into BR turning necks was part of the game most had two turners so it wasn't as slow as some make it out to be. We all use bushing type dies and you could get bushing in 1/2 tho size so you control neck tension that the part that most leave out. The amount of seating pressure for the bullet is one part of the accuracy game and thats the reason after I quit Br I still use bushing type dies and inline bullet seater.

Alot of guys I knew didn't like to turn necks always a place to buy prep brass so that wasn't a big deal and it didn't take alot of cases for the barrel life anyway. I always figured what I learned in BR made me a better reloader for the rifles I now shoot.