Full Length Sizing FNG Question

[Choupique]

How the hell do you check the thing? I don't have a calibrated bullet launcher

 

[Fireflyfishing]

I suggest you get a comparator and measure your cases correctly.

 

[WeiserBucks]

How the hell do you check the thing? I don't have a calibrated bullet launcher

Shoot long and check data.

 

[Koda_]

How the hell do you check the thing? I don't have a calibrated bullet launcher

With another chrono. Run the bullet thru both in line.

I own another chrono so I couldn't resist the opportunity to compare them in line. They were never far enough apart to worry about it so I moved on.

 

[seand]

I’ll say it again since it was obviously missed.

Headspace is easy to check with scotch tape. Will remove all doubt and you will know where you are.

Not complicated.

 

[seand]

See if you can borrow a Magnetospeed or a garmin to check.

Years back I bought a prochrono to verify my shooting chrono. They didn’t read the same. Light chronos are a PITA. I don’t trust either of them.

If you are running faster than book max velocity (adjusted for barrel length), you almost probably over max pressure, regardless of the listed (max) charge weight.

 

[Choupique]

Headspace is easy to check with scotch tape

Copy. Will do this next time I get the rifle out.

 

[MarlinMark]

I always full length size my hunting loads. Having case/cartridge problems on a serious hunt is the last thing I want to deal with .

I reload all my hunting ammo and the trick to it is that I always make sure every round will load/chamber perfectly before the ammo goes to the field. You are correct, it is not something you want to learn in the field. So, I check them all before they get to go.

 

[MarlinMark]

Copy. Will do this next time I get the rifle out.

Or a Sharpie.

 

[Choupique]

I forgot to do that....

 

[jjohnsonElknewbie]

I watched a video the other day of probably the easiest and most repeatable way to set up your FL sizing die for bump. Get a feeler gauge from amazon or auto parts store. They typically run around $10 bucks and include a .0015 and .0025 gauge among others.

Pyrate video:

1. Remove the decapping rod from your FL sizing die
2. Extend the ram completely like normal and screw your FL die down almost all the way to the shell holder (standard SAAMI FL size).
3. Insert whatever gauge you want based on your preferred bump in between the standard shell holder and the die.
4. Resume screwing down the die until it sandwiches the gauge against the shell holder. Tighten your lock ring from there, and you should be able to slide the gauge in and out of the gap.
5. Re-install the decapping rod
6. Size a fired piece of brass and compare to an unsized and fired piece of brass. You should have the same bump for all of your brass +/- variation in the brass.

This is a low cost way to eliminate guesswork, multiple measurements, and trial/error.

Also, don't get confused about FL sizing and shoulder bump, as they're both the same process. Eric Cortina has a good video on his channel that clarifies the diffference. Essentially, bumping the shoulders .002 is still technically FL sizing as the SAAMI case specifications for any giving cartridge are more than +/- .002. Neck sizing on the other hand is completely different as it doesn't adjust the shoulder of the cartridge at all.

Cortina "Sizing brass back to SAAMI vs. 0.002" shoulder bump":

Cortina "How to easily set up your FL sizing die precisely":

 

[Vern400]

What matters is the fit of the brass to the chamber. If you have a chamber at the low end of the tolerance this makes sense. You simply need the dye to smack the shell holder on the way down to make the cartridge fit after spring back.
I have 2 rifles (same cal) that headspace 0.002 different so I have to keep the brass separate.

If your chamber happens to be at the high end of spec, or even beyond saami spec..... That's when you get in trouble pulling sizing to the bottom of the dies capability. A brass cartridge as a very high pressure gasket. You don't want to stretch it too much and make it fail. If it fails at the neck, no biggie. But a head separation would be pretty exciting in a bad way, and it might disable your gun (or you) temporarily.

I don't have fancy high dollar dies. It's a bit of a hassle to get the die set up within 0.002 in when it has a 7/8 - 14 thread.

 

[jjohnsonElknewbie]

I've never had a case failure, but I'm still pretty new to reloading. What should a guy look for to determine when brass is shot (pardon the pun)? Loose primer pockets are one indicator I've heard of, but what other signs should we be looking for when deciding what brass can no longer be sized/reloaded? I've got 3 firings on some .308 brass that I've necked down to 7-08, and so far I don't see anything suspicious. Thank you in advance!

 

[Vern400]

I've never had a case failure, but I'm still pretty new to reloading. What should a guy look for to determine when brass is shot (pardon the pun)? Loose primer pockets are one indicator I've heard of, but what other signs should we be looking for when deciding what brass can no longer be sized/reloaded? I've got 3 firings on some .308 brass that I've necked down to 7-08, and so far I don't see anything suspicious. Thank you in advance!

I've been reloading metallic cartridges since 1990. I shoot primarily 308 and 223. My end of life failure mode is split case necks. I opened a box of 50 and banged out 30 or 40 one evening shooting milk jugs. About 1/3 of them split. Zero of the missed or did anything stupid.

If you see a bright ring on the lower portion of the brass it could be stretching in that area. If you booger one up, or have one case that laid in the dirt for a month ( or a year) just cut it long ways and make sure that the brass is uniformly getting thicker as it approaches the head. If it is a thin section definitely scrap it and probably the whole lot.

Federal brass has a reputation of being a little bit soft but by and large I rarely have problems with primer pockets getting loose. I use primarily RP, LC, and Lapua brass. If you are running marginally high on pressure with high-end loads it can happen. I usually get about 6 hand loads out of a good RP case. It's pretty hard to keep everything orderly after some years of reloading. But I've never had anything that seemed like a safety problem with my brass so far. The only real safety problem I had was developing hot 308 loads with RL15 powder when it was cool, and then shooting it on a hot day. Don't do that. It won't take you long to figure it out if that happens.

 

[pbroski]

I've never had a case failure, but I'm still pretty new to reloading. What should a guy look for to determine when brass is shot (pardon the pun)? Loose primer pockets are one indicator I've heard of, but what other signs should we be looking for when deciding what brass can no longer be sized/reloaded? I've got 3 firings on some .308 brass that I've necked down to 7-08, and so far I don't see anything suspicious. Thank you in advance!

Yes, loose primer pockets is one indicator. If they start out being tight with new cases, it's an indication of over pressure loads.

Split necks is another. If that is happening, annealing can help.

Keep an eye out for case head separation. It will be hard to see at first. Barely visible in this picture, but the blue arrow is the lowest point where the sizing die sizes the case. The red arrow is a line that indicates the start of case head separation.



This is an advanced stage of separation.

 

[jjohnsonElknewbie]

@Vern400 @pbroski Thank you both for this information and I hope it helps other folks as well as myself. Every time I size I see the die marks on the cases, and now I will begin inspecting the necks and towards the base more closely. Suffice to say if I see an apparent line forming around the bottom of the case, I will proceed with caution. Most of my loads are at or near max charges, so I will make doubly sure to keep this all in mind.

Thank you again guys, you rock!

 

[TaperPin]

The head separation happens a little at a time - if you are the curious type, a bent paper clip is dragged across the area the thin ring can be felt progressing with each firing before it can be seen on the outside of the case.

Normally I reload cases until the ring is just about to split and adjust powder charge to allow at least 10 reloads and tight primers. In the photo below, if the cases lasted 10, the ring shown would be at about 7 firings, so it usually gives a warning before being so thin the case actually splits.