Full length sizing

[Drewdemon]

New reloader, I haven’t make my first round yet and I’m getting frustrated. I’m full length resizing and resizing from 1.556 to 1.554. I’ve adjusted my full-length sizing die ~50 times and I don’t get consistent results. For example, I’ll run 5 through and get 1.554, then lock the ring and it goes to 1.553 or 1.552. Then I’ve locked the ring with the results I want but after resizing 10 cases it goes back to 1.553 or 1.552. I’ve made sure the ring is (snugged/cranked) locked down. I’ve meticulously held everything in place to make sure the lock ring does not move when I tighten down the ring.

What am I doing wrong/missing or should I expect a .001, .002, .003, etc variance when sizing?

I’m reloading 6.5 creedmore for a bolt gun
Forster full length die and forster co-ax press
Hornady brass (6.5CM 140g ELD-M)

Thanks

 

[Juggerxxx]

What are these dimensions actually measuring? Shoulder bump?

 

[Sheldon N]

Consistency of case lube helps with consistency of shoulder bump. Not sure which lube you're using but I've had best results with home made alcohol/lanolin mix.

For die setup, try making your adjustments on the lock ring by moving it against a reference point on the die. A very tiny movement results in a lot of change in shoulder bump. I use the edge of the gap in the lock ring, then a reference point on the die body. Lock the ring, size several cases to see the result. If you need more or less then loosen the ring, move it slightly against the reference point, then lock it again and size more cases to see the result. If you're trying to size cases with a loose ring then locking it down that can cause inconsistency.

 

[Geno C.]

Cases that don't all spring back the same after sizing can also cause this. Annealing helps with that. Also measuring can cause a variation on .001" easily. A little more or less pressure on the caliper, case just off centered a hair. All kinds of things. Get it when you want it after you lock it down and run it. Would be my opinion. Unless you're after tiny groups on paper, I haven't seen a extra .001" bump cause problems on steel shooting.

Also, if your measuring tool is only readying to the .000" then you can get that variance also without it really being that far off

 

[mdmp5]

Inconsistencies are caused by all of the above, but it is also difficult to get consistent anything with the press without a slight cam over.

 

[Timo Turl]

Don’t over think it especially if you are getting low SD / ES. Fairly normal and I find it’s often down to me and my use of the calipers.

 

[1J04]

Welcome to reloading..........

You'll be fine and are already doing just fine, you just need to know that. Listen to what's already above and you'll be golden. You're using good equipment so run it.

 

[Drewdemon]

I anneal before i resize.
I'm using Hornady lock and load comparator tool with a Mituyoyo caliper
Hornady one shot lube

I'm measuring all cases from the datum line before sizing w/out primers.

The premise, from everything I've read is to resize the shoulder (and body) back .001-.002 for a bolt gun. I expected once i dialed in the correct settings with the die and press it would be repeatable, every time. Is that correct?

Should i be saturating the cases with lube?

 

[MtnCreek]

If your die has an expander ball, that probably the cause of a lot of it. Remove the ball and see how your measurements look.

 

[spife7980]

Have you measured what they were before sizing and seeing if it scales proportionally? Mine rarely are all the same exact size to start with. I like to measure 10-15 cases to find the most common length and then adjust to that length. If I have my die set up to bump a 1.554 back to 1.552 then a 1.555 will still get bumped back to 1.552. But if Im bumping back a 1.553 it can end up 1.551. Then some that are 1.554 will only bump back to 1.553. I figure thats due to the differences in hardness/material thickness/spring back and then the shoulder angle as well. What you want to do is measure a sample population larger than 1.

I like to saturate the cases and then roll the around in a cardboard box. It acts as a lube pad of sorts, it will lick off excess lube but allow it to stay plenty wet.

 

[Drewdemon]

Have you measured what they were before sizing and seeing if it scales proportionally? Mine rarely are all the same exact size to start with. I like to measure 10-15 cases to find the most common length and then adjust to that length. If I have my die set up to bump a 1.554 back to 1.552 then a 1.555 will still get bumped back to 1.552. But if Im bumping back a 1.553 it can end up 1.551. Then some that are 1.554 will only bump back to 1.553. I figure thats due to the differences in hardness/material thickness/spring back and then the shoulder angle as well. What you want to do is measure a sample population larger than 1.

I like to saturate the cases and then roll the around in a cardboard box. It acts as a lube pad of sorts, it will lick off excess lube but allow it to stay plenty wet.

I've measure roughly 150 cases (pre sizing) at this point. I premeasured and sperated based on size. I had a group of 1.556 that i "attempted" to bump back .002. I figured once i trusted the measurements i could scale back.

 

[spife7980]

I've measure roughly 150 cases (pre sizing) at this point. I premeasured and sperated based on size. I had a group of 1.556 that i "attempted" to bump back .002. I figured once i trusted the measurements i could scale back.

If those that are measuring 1.556 before sizing are going to 1.554 then thats fine. If those that measure 1.554 before are getting bumped back to 1.552 after then thats fine. I wouldnt get too caught up in it. Just find your longest, take it back .002 and check to make sure it chambers. If it does thats good and test one of your short cases and see just in case. In this situation than a few thousandths of variance is expected.

BUT if those that measure 1.556 get taken back to 1.554 and then the next 1.556 gets taken back to 1.552 then I would say you are not lubing enough/evenly or your press stroke isnt the same/you arent going until the handle hits those red bumps on it on the press body.

Also, make sure that these are the same lots of brass. I thought all one manufacturer would be close enough and mixed in 50 of one lot into my other lot of 100. I have now separated them out and its easy because they dont measure the same.

Oh, one more thing. Make sure you are using the correct side of the jaws.

 

[Drewdemon]

If those that are measuring 1.556 before sizing are going to 1.554 then thats fine. If those that measure 1.554 before are getting bumped back to 1.552 after then thats fine. I wouldnt get too caught up in it. Just find your longest, take it back .002 and check to make sure it chambers. If it does thats good and test one of your short cases and see just in case. In this situation than a few thousandths of variance is expected.

BUT if those that measure 1.556 get taken back to 1.554 and then the next 1.556 gets taken back to 1.552 then I would say you are not lubing enough/evenly or your press stroke isnt the same/you arent going until the handle hits those red bumps on it on the press body.

Also, make sure that these are the same lots of brass. I thought all one manufacturer would be close enough and mixed in 50 of one lot into my other lot of 100. I have now separated them out and its easy because they dont measure the same.

Oh, one more thing. Make sure you are using the correct side of the jaws.

jaws? caliper jaws or something else?

 

[CharlieNC]

When the handle on your press is in the down position, how long do you hold it there? Variable time = variable bump. Measure a few brass with increasing dwell time, and by running the same brass a few times through the die while its in the shell holder. One of these will provide more consistent results.

 

[spife7980]

jaws? caliper jaws or something else?

The forster jaws, what works in place of a the shell holder. I tried to do some 223 in the large side and got some post sizing variance in my measurements, I assume from the variance in the extractor groove and its fit within the jaws. I doubt this is your issue but its a simple variable to eliminate.

 

[Gibble888]

I had the same thing happen to my 458 socom and almost drove me nuts.....clean the inside of the case necks with alcohol and test.
I also use one shot and never had a problem with other rounds.
D

 

[Drewdemon]

I will try all of the above [thanks everyone]. I had two containers of ammo (same lot #). With everyone's suggestions i manged to get consistency after a while with the first one. Then i switched to the second batch and i had to readjust the die again. After a few rounds it was consistent again. Im not sure why that's happening yet but i feel comfortable with the consistency enough to move forward.

For trim length, i went with the books's (Hornady's) "Case Trime Length" of 1.910. I hope that's correct or i just wasted 2 hours. Reloading is not a quick process...

 

[spife7980]

If I remember correctly the spec is 1.920-.020 so 1.910 is right in the middle. That’s the same way I do mine. Sure I can let it grow a little bit if I cant trim in between loadings for some reason but trimming to the middle spec is a a safe option and the benefits of pushing a longer case neck aren’t worth it to me.

 

[Drewdemon]

If I remember correctly the spec is 1.920-.020 so 1.910 is right in the middle. That’s the same way I do mine. Sure I can let it grow a little bit if I cant trim in between loadings for some reason but trimming to the middle spec is a a safe option and the benefits of pushing a longer case neck aren’t worth it to me.

Where could i find that spec your referencing? There seems to be a lot of opinions but i could not find any facts.

 

[spife7980]

Where could i find that spec your referencing? There seems to be a lot of opinions but i could not find any facts.

Your particular reamer may vary, but this is saami spec, aka the baseline standard.
http://www.saami.org/specifications_and_information/index.cfm
http://saami.org/specifications_and...ns/download/Z299-4_ANSI-SAAMI_CFR.pdf#page=51

 

[Drewdemon]

Your particular reamer may vary, but this is saami spec, aka the baseline standard.
http://www.saami.org/specifications_and_information/index.cfm
http://saami.org/specifications_and...ns/download/Z299-4_ANSI-SAAMI_CFR.pdf#page=51

View attachment 6904134

This is great.. thanks