308 rounds fail case gauge

[skullbox]

I'm new to loading .308 but have been reloading other calibers for almost 10 years. I'm full length re-sizing and they gauge just fine. I'm chauffeuring and deburing the mouths. No crimp. I checked a batch of 50 before seating bullets and they all gauged just perfectly. I seated the bullets (no crimp) and it seems about 10% of them don't gauge once the bullets are seated. I mean not even close. They do however chamber and fire in my bolt gun. I've noticed most of them seem to be scraping the copper jacket when seated. What am I doing wrong?

Gear:

Mixed brass but mostly LC
Redding Dies
RCBS single stage press
Nosler custom competition 168gr
44.3 gr of Varget
Don't know my OAL length without going into the shop to check, but they fit in PMAGs.

 

[SanPatHogger]

I loaded a few rounds a couple weeks ago and noticed I was scraping bullet jacket when seating. I chamfered and deburred but still scraped bullet jacket. Ive also has some pressure signs at timed pushing max loads with 4451 and 65 gr bullets in the .243. I decided to anneal the brass and trim it. I loaded a few and did not scrape bullet jacket and pressure signs disappeared.

Try annealing. It cant hurt anything. And good luck.

 

[winniedonkey]

How much neck tension are you running with?

 

[skullbox]

So I just played with this a little using some TMK bullets. I thought about the neck tension and checked with the Ballistic tools gauge which appears to .305 after using the neck sizing die. That almost eliminated the copper shavings. It seemed to fix my gauge problem. I'm guessing that using my FL sizing die wasn't opening the the neck enough. Maybe it was shaving just enough copper to make the case mouth even thicker and that's why they would no longer gauge.

I don't think I should need to FL and neck size correct? Does this mean my FL die isn't set correctly? I did the usual lower it down the case holder then back out 1/4 turn.

 

[FLIGHT762]

So I just played with this a little using some TMK bullets. I thought about the neck tension and checked with the Ballistic tools gauge which appears to .305 after using the neck sizing die. That almost eliminated the copper shavings. It seemed to fix my gauge problem. I'm guessing that using my FL sizing die wasn't opening the the neck enough. Maybe it was shaving just enough copper to make the case mouth even thicker and that's why they would no longer gauge.

I don't think I should need to FL and neck size correct? Does this mean my FL die isn't set correctly? I did the usual lower it down the case holder then back out 1/4 turn.

Your F/L die setting for precise shoulder bumping has nothing to do with your neck tension. Your neck tension is set by the expander ball size on the the F/L die decapping stem when you pull the expander ball through the neck on the down stroke of the press ram. You gauged your case mouth @ .305" after sizing. That is fine @ .003" neck tension.

You do not need to F/l size and then neck size separately. YourF/L die does both at the same time. From what you posted, your die is working fine.

You are going through a learning process. There's going to be some trial and errors until you figure out how this process works.

If you need more "Chamfer" on the inside of the case mouth to avoid some bullet shaving, use a VLD style chamfer tool.

 

[skullbox]

Try annealing. It cant hurt anything. And good luck.

Should I do that after doing all the case prep right before I seat bullets, or before I trim/chamfer/debur? I'm using the RCBS trim mate prep center. To my knowledge, the chamfering/deburing tools are universal size so I shouldn't need to swap them out between 223 and 308.

 

[FLIGHT762]

Jesus Christ, Don't get too far ahead of yourself. Get the basics figured out (un fucked) before you go on to something else you know nothing about. Simmer down.

 

[winniedonkey]

I'll catch some poop for this but I FL size, non bushing, and use an expander mandrel to open it back up. I do it on my gas and bolt guns. A bushing die set properly would work the neck much less but it's a decision I live with....I forgot to expand once and loaded a few gas gun 308s up and had some serious shavings. Lesson learned.

 

[FLIGHT762]

I'll catch some poop for this but I FL size, non bushing, and use an expander mandrel to open it back up. I do it on my gas and bolt guns. A bushing die set properly would work the neck much less but it's a decision I live with....I forgot to expand once and loaded a few gas gun 308s up and had some serious shavings. Lesson learned.

^^^Haah Haah This ^^^^ is exactly what I was talking about, now someone is talking about "Mandrels". O/P can't get his basic Redding F/L die un fucked and now "Mandrels" that the O/P probably doesn't understand (Expander mandrel or tim mandrel? What size?)

Annealing, Mandrels, Bushings, Collet N/O dies, Body Dies, Bump dies, Arbor presses, in line seating dies, runout , SD,ES and you guys know the rest.

Can we start with the O/P setting his die up to bump the shoulder .002" from his fired cases and getting his bullets seated?

O/P what case gauge are you using to check your loaded ammo?

 

[skullbox]

I'm using this one:

Search results for: 'ammo chamber checker 308 7 hole'

www.egwguns.com