Lee case trimmer

[Lvacgar]

A co worker and I are in line waiting for whisper barrels and an upper. We are wanting to prep some brass and were wondering what the exact case length should be. Below is a link to the Midway site and the Lee trimmer that should be coming in, but no length is given. My buddy is awaiting a Del-ton upper and I want to have a barrel made...

http://www.midwayusa.com/viewproduct...tnumber=136009

[hitman49]

Might want to know that that same case length gauge has been showing coming soon for over a year. Lee will make you a custom one but it cost around $20. I called and asked when they would have the 300 whisper gauge out and was basically told not to hold my breath.

[txjm]

If you buy the 762x39 trimmer, I think you can touch the tip of the pilot on a grinder enough to shorten it to the correct length. Try it, not much lost if it won't shorten that much. You can trim cases to play with the length as you shorten.

[ctnsupra1]

http://www.leeprecision.com/html/cat...ASELENGTHGAUGE Here's the link to order a custom length gage from Lee. Better than waiting around forever to save $15

[Lvacgar]

And 1.355", according to the sticky in this forum, is the correct trim to length? I will definitely buy the custom guide as opposed to waiting around. I certainly appreciate the heads up!

[jayvee]

Seems like the .221 Fireball trimmer could also be made to work, the trim-to lengths given are all over the place anyway. The .221 is 1.390 trim length.

1.355 trim-to length? Seems pretty short to me. I saw the sticky, nothing in there seems authoritive except for 'check in your chamber'.

I've seen 1.5 as the 'proper' case length, as well as 1.40 too.

[pug]

Case trim length in the reloading manuals is 1.355". Remember this cartridge was developed from the 221 Fireball case and that is only 1.4" to start with. Resizing it and trimming shortens the case from there. Whatever trimmer you will use will need to have a 30 caliber pilot on it to trim accurately. The pilot bushing of the 7.62x39 case length guide bottoms out against the web only allowing you to trim to a minimum of 1.375". If you were to cast the chamber of your barrel you may find that 1.355" length is indeed a little on the short side but then if you were to cast another chamber you would find it to be exactly the right length. It is best to keep the length shorter unless you know for sure.

[jayvee]

I just got my brass from SSK, it's new stuff, marked .300 Whisper on the bottom. ( I love the sound of new brass.)

It mostly measures raw from the bag at 1.345" long. Some a couple thou shorter, and quite a few from 1 to 4 thousandths over. But most are right about 1.345.

Very interesting. I might have to do the chamber cast on my barrel, just to see what I have.

[pug]

If its an AR chamber (or other) you are going to cast, push the cotton or cloth plug for the bore just a little ways into the throating and don't worry about trying to cast a lot of rifling. Also line the inside of the extension with cotton or rope to keep any runaway casting material from getting behind the lugs.

The chamber to be cast should be well cleaned and oiled but all residual oil should be removed by using dry patches.

My poor mans method for casting, for those interested, is to take the bottom cut off half of an aluminum drink can and form a spout shape in the edge. Put the cerrosafe alloy in it and heat it up on the hot plate. I line and plug barrel as above and then heat it up to a warm touch with a heat gun (or hair dryer) just so the chamber isn't cold. Stand barrel on end with chamber up, pick up can with pliers and gently pour melted (molten?) casting material in chamber and stop just as chamber fills and a little bulge of material is on top of chamber but not running everywhere. Wait for it to cool for a few minutes and then tap the casting out using a cleaning rod. Put the casting aside and wait for 1 hour for the casting to expand to correct dimension and then measure what I need to measure.

This will give a lot of good measurements especially the neck diameter of your chamber. One of the tougher measurements to get from it is overall case length. If I want to know that I make a overall case length gauge. Take a empty case and trim the neck so you know it is way to short. Make or purchase a .30 caliber case length gauge button (Sinclair International) and insert it in the case mouth only a little ways. The overall length of this assembly should be way more than your case could ever be. Gently chamber the assembly and allow the bolt to close. The button will be shoved back in the case and when the assembly is removed the overall length will be that of the overall case length of your chamber. Repeat several times to make sure you get consistant readings. I think this is a better gauge of how long your brass will need to be. Sorry for the long winded post but maybe some can use the info. In my above post I may have pushed the idea that casting is a good way to get measurements but a case length gauge is the way to go for overall case length.