i have a 338 wm in an encore. it has a long chamber. in the reloading book says it should be 2.170 to the top of the sholder and my once fires factory brass is 2.193 what is too long? and down by the belt the factory brass is .509 and once fired brass is .515.want is the asme spec.? is it what is in my reloading books or is there a nother place to look? i can only shoot my brass 3 times with starting loads. i have sent the barrel back to t/c costom shop and they sent me another barrel and the chamber is the same. if i full lenght size after the first shot the case will split. can any one help? thank you allen

sure sounds like they have a bad chambering reamer to me

All your 338 Win Mag cases are quite short of the chamber shoulder in most guns. Standard dies set the shoulders pretty far back if you full size each time with the die hitting the shell holder. You situation is not unusual.

You can help considerably by setting the shoulder back when you size only enough to enable easy chambering of the round, about .001" or .002". You can set your die with the use of a Stoney Point Chamber All tool available most anywhere pretty inexpensively.

You can further help by fireforming your brass intially firing it without a bullet. Prime the brass and use about 18g of a fast pistol powder. Put a ¼ sheet or less of toilet paper in there and fill the case with Cream O' Wheat or corn meal, and top that with another ¼ sheet of TP as a "bullet" and fire away. When you resize, set the shoulder back as above, no more than .002".

If you want to completely eliminate the problem use 358 Norma Mag brass. The body is .040" longer than our domestic 338 Win Mag brass. Size as above and you eliminate the need to fire form. I've been doing this for many years and I have yet to lose ANY cases. I have over 18 reloads on the first lot I bought over 10 years ago and it shows no signs of separation.

Lastly, get a dental pick, or make a "tool" out of a straightened paper clip. Put a small 90° bend on one end and check the inside circumference of your brass all the way around. You'll feel a tell tale ridge when the separation starts. If you follow either procedure above you should get about 7-10 reloads on domestic brass and who knows how many out of the 358 Norma Mag brass.

In any of my single shots, it's important to size the case to just allow you to chamber it. This is especially true w/ belted cases & rimmed bottleneck cases.

It doesn't matter what the SAAMI specs are .When you size your cases do it to fit YOUR chamber .When belted mags became popular manufacturers sometimes were sloppy about the shoulder dimensions ,obviously this is still a problem.

T/C chambers are always long. They do this on purpose to allow easy closing of the action. Factory brass headspace varies by .010", and the action requires an additional amount of slack.

You should FL size .005" under to ensure proper chambering in your gun. This allows for easy closing and you will get more than 10 reloads from your brass.

Standard base size is supposed to be .513--Use the advice giev above and resize so headspace is set for your chamber---
Now measure your case base after you resize it and if it is
a lot less than the .513, you are overworking the brass.
For your Encore your should be about .512.I've had dies that took belted cases 6-9 thousands smaller than needed, and I
honed them out.Honing dies take time but if you do it a little at a time you can try them and you should get to where the brass
isn't being overworked and will last a dozen rounds.Some die makers can also work them over for you.Ed.