Picked up my first Lee collet die set yesterday and will be putting some loads together with it today.....anyone use these?

Don`t have a 7mm Mag but I do use one for my 223, 260 Rem, 7-08 Rem, and 30-06.

I like `em!

I use one for .375 loads -- only to crimp at cannelure so bullet won't move under repeated recoil while stacked in the magazine.

I use them for my 7 RM very accurate but you will have to use a Full length die after a few loads to move the shoulder back a little so you can close the bolt.

I have one in 22-250, 222, 6.5 rem mag, 270, 280, 7 mag, 30-06, 300 WSM, 300 WM and 338 WM.

There is a little bit of a learning curve. The first thing I do is to adjust the lock nut all the way to the top of the threads which inserts the die down as far as possible. That's because the Lee Collet resizes by downward pressure on the ram handle not by camming over like a regular die. Adjusting the lock nut all the way up will put the handle in the most horizontal position possible


Makes it easier to put the 25# of downward pressure on the arm and be consistant. Don't expect to feel any sizing going on. Just get a bullet and try to insert it in the neck and you will see that it did in fact resize the neck.

Don't expect a lot of bullet grip. Lee sizes their mandrel .001" to .002" below caliber and the reason they told me was that in their development they found that sizing the neck smaller also created more runout. That's why the Lee Factory Crimp that BNagel was actually talking about, makes a good companion die. Also the Redding Body Die for pushing the shoulder back without touching the neck.

I get a Lee Collet Neck Sizer for any cartridge I'm trying to wring the last bit of accuracy from, including my son in law's 7 mag., love them. But, as the fellow above mentions, there is a learning curve. We can't just follow a set of rules, 1-2-3, and get best results. We have to use them enough to understand them and use them correctly. If you won't do that, you need to find another neck die. Some thoughts -

First, never push the ram up against the base of the die "dry", if you do the collet will likely seize and not spring back down when you lower the ram. You can only fix that by removing the top cap and other innerds from the die.

Second, keep a light coat of high pressure grease on the collet's working angled surface, that is the cone at the top, so it can slide up and back down easily. In fact, some of those cones are machined a bit rough, inside the body and outside of the collet. If so, they will benefit from a bit of owner polishing to smooth them a little.

That die top cap thing is fairly soft aluminmum so it can serve as a "fuse" to blow out if you put too much pressure on the die. If strips out Lee will only need to provide you with a new cap, not the whole die! Just use a bit of judgement when leaning on the press lever, don't stand on it and you should be alright.

Don't expect as much bullet tension as you usually get with a conventional die. it's not likely nor is it neccessary. However, a seated bullet should not be moveable due to hand pressure. If it does you will likely need to reduce the diameter of the sizer mandral a thousant (no more) with sand paper and an electric drill motor.

I had a chambering problem probably caused by not applying enough pressure to close the collet and ended up pulling a bunch to FL resize and set the shoulder back.

I just bought a couple of chamber gauges to keep on my bench to make sure it won't happen again.

You are getting some very good advice.