FL sizing

[farrier]

To those who know more.
I'm new to reloading (>1200 rnds) and I think I am over-resizing my brass. I use a RCBS comp die set and following the instructions, I raised the press ram and screwed the FL die down to where it touched the ram. The resultant rounds were tight with two out of ten not allowing me to close the bolt. I went back to the press and started turning down the die 1/8 turn at a time and trying to chamber the brass. I got to the point where the bolt closes easily but wonder if I went to far and am overworking my brass. I'm talking about a .308 in a Rem 700 sps. Any thoughts?
Thanks, Mike

 

[Gene Poole]

Re: FL sizing

Do you mean threading the whole die deeper into the press? I fail to see how that would change anything if the shell plate already makes contact with the die base.

FWIW, in my stock Rem700 .308 chamber, a FL dies gives me the same results (1 or so in 10 not chambering or chambering too tight). I went with a small base die and all is well.

 

[crewchef]

Re: FL sizing

You really need a comparator tool to accurately measured fired/sized cases. I use the one from Hornady but there are several. Measure a group of fired cases and write down measurement. I usually measure 10 when first setting up a die for new rifle. Set up die as per instructions and then back it out about 1/2 turn. Size a case and measure the shoulder set back. You're looking for .001. If it's not getting bumped adjust the die in just a little and try again. Use small changes, doesn't take much to go too far.

If you're die has an expander ball make sure you've smoothed it and it's adjusted properly in the die. Also make sure that you're getting some case lube inside the necks. Expander pulling back up through the neck can give you issues with shoulder and overall length of case.

 

[TexIndian]

Re: FL sizing

Hmmmm I used both basic and comp RBCS resizing dies for years and never had a problem with cases that wouldn't go into a gun. They typically give you too much headspace when screwed down till they hit the shellholder rather than not enough. I agree with Gene Pool about not getting any benefit by screwing then down farther once they are hitting the shellholder. I never used the small-base dies except for semi-autos, but I have heard several folks say it made a difference in other guns.

Are you putting any crimp on your rounds? Sometimes the taper crimp built into seating dies can cause problems chambering. If you get just a tiny bit too much, it can cause swelling at the base of the shoulder which is almost impossible to spot with the naked eye but will keep a round from chambering completely. If a few cases are just a tad longer than the others, they will be affected more by the crimping action. After pulling apart 400 rounds once many years ago because of this problem, I haven't crimped a bottleneck case since. To make sure this isn't the problem, just back your seating die out farther and set the seating stem lower to get the same OAL without any crimp.

I agree with Crewchef that a rough expander can yank the shoulders back out after the die has set them. But it has to be a really rough yanking job to make things so bad the rounds won't chamber, except maybe in a tight chamber.

 

[targaflorio]

Re: FL sizing

<span style="font-style: italic">SCBS Step-By-Step Reloading
From the RCBS Website
Step 5 - Install the Sizer Die

Thread the sizer die into the press until the die touches the shell holder when the ram is at the top of the press stroke. Raise the press handle and turn the die down another one-eigth to one-quarter of a turn and set the large lock ring. If you're using a carbide sizer die, make slight contact with the bottom of the die and the shell holder.</span>
Is all of your brass the same headstamp, length and condition (fired/unfired?) If your brass is all the same and you are getting different results, something is off. You should never have a problem where some of your rounds don't chamber and think that's normal. If fired brass does not chamber it is probably headspace. I suggest a headspace gauge is a small investment for safety and accuracy. I recommend the RCBS Precision Mic. Be careful how you lube. Lube can affect the resultant size of the brass. I prefer imperial.

 

[FLIGHT762]

Re: FL sizing

The only way to tell if you're over sizing the brass is to accurately measure it. There are several tools out on the market to do this. My personal favorite is the Sinclair (first choice) or the Hornady (second choice) shoulder bump gauges. These are used with a digital set of calipers, which lets you see the numbers.

http://www.youtube.com/watch?v=-n_l-bYxbg0

The Sinclair bump gauges are a good value. About $16.00 for the body and $10.00 for the shoulder insert. The insert is good for a family of cartridges. In .308 Win. it's good for .243 Win, .260 Rem. 7-08.

 

[armorpl8chikn]

Re: FL sizing

Here is a method(below) I used for 30 years....and still do. I have NEVER owned a headspace guage and I have NEVER had a casehead seperation.
I can't believe anyone that would offer advice would be stumped by the fact that screwing it in further past shellholder contact resulted in more sizing. Seriously guys? Its called camover, and if you don't know what it is you should probably do more reading than posting.
Mike if you went real slow until it chambered up you are likely well and truly safe. Make sure you lube the necks as your expander button can pull the neck back up a bit and give you a false reading.
Nothing wrong with headspace measuring tools and if I were to buy some they would be Sinclair, but you don't need them.

FL die setup using smoke:Smoke the neck of the lubed case lightly on one side. Put your sizing die into the press and screw down to shellholder and back out a full turn. Now take the smoked LUBED (never forget the lube)case and run full into the die and back out. What do you see? How close are you to the shoulder? Using this method you can set up to lightly bump the shoulder or almost bump the shoulder and all points in between. There is nothing you can't do to a case with a FL die. If you set one up correctly it is all the resizing die you need to make brass last just as long as the primer pocket will hold a primer.

These are the old school methods that I have used for years and my brass lasts as long as anyone using a neck die. I trim very seldom. This is the third time I have posted this info. Set up a FL die in this manner and you don't need a neck die.

Use a candle for smoke.

 

[crewchef]

Re: FL sizing

I appreciate the fact that some of the "old school" methods work great but when it comes to things that can be measured precisely, why not do it. Several tools available and none of them are all that expensive. I think there are a lot of new items on the market that catch the fisherman and not the fish but accurate headspace tools are something I wouldn't load without.

Just my .02 and since everybody has one (an opinion) that's about what it's worth.

 

[farrier]

Re: FL sizing

Thanks for the replies/info. I'm loading up another hundred on Friday and will back off the die and adjust down a little more carefully and see what happens. I'll polish my expander before I start as well as lube case necks inside with a little more attention.
Mike

 

[Fuzzball]

Re: FL sizing

Die adjustment instructions get us in the ball park but that's all. No way doing something by rote can accomidate the variations in brass, shell holder, die, press spring.

A die moves almost 72 thou per turn. The normal full range of headspace tolerance is about 6 thou; you do the math for how much of a turn will go from minimum to maximum for that.