Resizing inconsistency - Am I missing something

Reloading for 6.5 Creedmoor using Redding Match grade Bushing Die and Redding Press

Once fired Hornady brass all measuring 1.561” on my digital calipers. Have set up the full length die to bump shoulder back .002” with a .290 bushing. All case necks are measuring exactly as they should and most cases are coming out at 1.5575-1.559” but I’m getting random cases at 1.555-1.556”??

Process is to lube cases, resize in press then rotate 180deg then press again. I’m measuring each case as I’m a bit obsessive 😂

Have kept those cases that are over sizing aside but I’d like to know if anyone else gets this inconsistency? Is it normal or is there something I’m missing?

Are you trimmimg mate? That's what will give you a consistent OAL.

Sent from my SM-G975F using Tapatalk

I assume you're talking about the shoulder comparator measurement not OAL.

I've been trying to work this out too. On my 6.5x55 I try to size to 1.765" but usually get 1.764-1.766" and a few outliers at 1.767" and 1.763".

I've tried different lubes and techniques, and it seems to be par for the course. From what I've read if you anneal the cases correctly then they should all size the same.

I’ve found the most accurate way to control shoulder bump/ headspace is using the competition shell holder set from Redding,

Quote:

---

Originally Posted by Gerardo

Are you trimmimg mate? That's what will give you a consistent OAL.

Sent from my SM-G975F using Tapatalk

---

Sorry mate I should’ve said I mean base to shoulder not OAL, thanks though!

Quote:

---

Originally Posted by Magnetite

I assume you're talking about the shoulder comparator measurement not OAL.

I've been trying to work this out too. On my 6.5x55 I try to size to 1.765" but usually get 1.764-1.766" and a few outliers at 1.767" and 1.763".

I've tried different lubes and techniques, and it seems to be par for the course. From what I've read if you anneal the cases correctly then they should all size the same.

---

Thanks mate glad it’s not just me 😂 I’m assuming it could also be the degree of accuracy that my calipers can achieve, I’m confident that each case is being sized repeatedly in the same way so hopefully they’re consistent enough to produce results.

Just remember if you measure lots, i.e every case (i've been known to as well) it's not necessarily a bad thing but be prepared for tiny inconsistencies as you describe which can be attributed to many factors. This is not always useful information and sometimes it's best not to get bogged down in the detail and stick to results.

Just remember brass get work hardened with firing and with each firing it'll have more and more springback. One of the main reasons people anneal with a AMP annealer is to get the most consistent anneal, thus the brass will have the same level of springback = consistent neck tension and this is true for shoulder bump as well. You can have the best dies, press etc, but if your brass isn't consistently annealed (or not annealed at all) you will have inconsistency in your sizing process. It might not happen in the start of your brass life but will show itself later after multiple firings.

Just another variable to consider. There are quite a few youtube vids about annealing and sizing consistency

Sent from my SM-G780F using Tapatalk

^ +1

Sometimes I think that a 2 to 3 thou inconsistency in measurements is largely unavoidable. Given the machinery involved and the the measuring devices we use.
I've experienced the same "flyers" with shoulder bump (headspace) and also seating depths. With seating depths you can use the same die in the same press, same brass and same projectile batch, same force on the ram, and still end up with a 1 to 3 thou difference in a batch of ammo.
Maybe these variables are able to be totally eliminated but I've tried to no avail, and have settled for the consistently accurate ammo I produce within the variances.
Thats pretty much all that matters because there are a raft of other variables that come into play once the ammo is in the chamber and the crosshairs are on the meaty brown bit

What I've learnt is measure everything when setting up the dies, bullet seating or whatever the process is and measure until you are happy to begin reloading. The only measurement I take after that is the group size, like others have said thats all that matters.

Quote:

---

Originally Posted by Magnetite

I assume you're talking about the shoulder comparator measurement not OAL.

I've been trying to work this out too. On my 6.5x55 I try to size to 1.765" but usually get 1.764-1.766" and a few outliers at 1.767" and 1.763".

I've tried different lubes and techniques, and it seems to be par for the course. From what I've read if you anneal the cases correctly then they should all size the same.

---

With your 1.767 what was the measurement before sizing.

The only time I get a case discrepancy and it's always oversized is when I forget to clean inside my FLS die before starting. After each use I spray a shot of CRC Longlife into the die. CCR Longlife leaves a coating inside. This along with the lube on the case is enough to upset things but not to degree posted in this thread.

Quote:

---

Originally Posted by Magnetite

I assume you're talking about the shoulder comparator measurement not OAL.

I've been trying to work this out too. On my 6.5x55 I try to size to 1.765" but usually get 1.764-1.766" and a few outliers at 1.767" and 1.763".

I've tried different lubes and techniques, and it seems to be par for the course. From what I've read if you anneal the cases correctly then they should all size the same.

---

With your 1.767 what was the measurement before sizing.

The only time I get a case discrepancy and it's always oversized is when I forget to clean inside my FLS die before starting. After each use I spray a shot of CRC Longlife into the die. CCR Longlife leaves a coating inside. This along with the lube on the case is enough to upset things but not to degree posted in this thread.

Quote:

---

Originally Posted by zimmer

With your 1.767 what was the measurement before sizing.

---

I should probably be a bit clearer.

Fired cases are usually 1.766-1.768"
Zero clearance is 1.767"
I'm aiming for 1.765±0.001".
When sizing I usually get 0.004" of variance, depending on how I have the die set e.g 1.763-1.766 or 1.764-1.767.
Every now and then there will be cases which do strange things, but I've also changed lube recently.

However I haven't measured how much difference the case volume makes to velocity. It maybe inconsequential. I do know it affects bullet jump but In my case the change is irrelevant.

I've never measured my case so can't tell you if it's normal or not.
Set aside the "shorter" cases and load them up as usual and see if there is any real world difference on target.

If you are chasing tiny groups for F Class or Benchrest then maybe worry, otherwise don't sweat it.
It's easy to get caught up getting everything perfect but 9/10 if the loads are performing as they should down range then don't worry about it.

Quote:

---

Originally Posted by Hg1990

Reloading for 6.5 Creedmoor using Redding Match grade Bushing Die and Redding Press

Once fired Hornady brass all measuring 1.561” on my digital calipers. Have set up the full length die to bump shoulder back .002” with a .290 bushing. All case necks are measuring exactly as they should and most cases are coming out at 1.5575-1.559” but I’m getting random cases at 1.555-1.556”??

Process is to lube cases, resize in press then rotate 180deg then press again. I’m measuring each case as I’m a bit obsessive ��

Have kept those cases that are over sizing aside but I’d like to know if anyone else gets this inconsistency? Is it normal or is there something I’m missing?

---

I have had a few beers so hopefully this makes sense!

As some have said I find it best to always measure head space using shoulder comparator measurement not OA

To do this properly you need to discover your 'feel' head space and your 'no feel' head space. The difference between these two lengths should be exactly 1 thou.

I always set up my FL dies to bump the shoulder 2thou past my 'no feel' head space. This allows for a bit of dirt/water and shit to enter the chamber and not over chooch the cartridge.

Ultimately it's like seating bullets, it's very hard to get them exactly consistent due to the variation in brass tension/play in press etc which is why we seat them over length, measure them and then adjust a micro seater die accordingly to achieve this consistency.

A thou or two on a headspace measurement isn't the end of the world at all providing that it's under your 'feel head space'.

Bullet seating depth is much more important to get exact IMO especially if you are seating to 'just touch'

I wouldn't bother sizing them, rotating them and resizing them again. I very much doubt that you would notice any difference on paper from doing this.

Quote:

---

Originally Posted by Pete_D

Just remember if you measure lots, i.e every case (i've been known to as well) it's not necessarily a bad thing but be prepared for tiny inconsistencies as you describe which can be attributed to many factors. This is not always useful information and sometimes it's best not to get bogged down in the detail and stick to results.

---

Thanks mate I figured this was the case 😂🤦🏼*♂️

Quote:

---

Originally Posted by dirkvanvuuren

Just remember brass get work hardened with firing and with each firing it'll have more and more springback. One of the main reasons people anneal with a AMP annealer is to get the most consistent anneal, thus the brass will have the same level of springback = consistent neck tension and this is true for shoulder bump as well. You can have the best dies, press etc, but if your brass isn't consistently annealed (or not annealed at all) you will have inconsistency in your sizing process. It might not happen in the start of your brass life but will show itself later after multiple firings.

Just another variable to consider. There are quite a few youtube vids about annealing and sizing consistency

Sent from my SM-G780F using Tapatalk

---

Thanks mate I thought that may be a factor, been looking into the AMP Annealer but can’t afford one atm. I’ve watched just about every video Erik Cortina and F-Class John post so am definitely all the way down the precision rabbit hole 😂

Quote:

---

Originally Posted by Tui4Me

I have had a few beers so hopefully this makes sense!

As some have said I find it best to always measure head space using shoulder comparator measurement not OA

To do this properly you need to discover your 'feel' head space and your 'no feel' head space. The difference between these two lengths should be exactly 1 thou.

I always set up my FL dies to bump the shoulder 2thou past my 'no feel' head space. This allows for a bit of dirt/water and shit to enter the chamber and not over chooch the cartridge.

Ultimately it's like seating bullets, it's very hard to get them exactly consistent due to the variation in brass tension/play in press etc which is why we seat them over length, measure them and then adjust a micro seater die accordingly to achieve this consistency.

A thou or two on a headspace measurement isn't the end of the world at all providing that it's under your 'feel head space'.

Bullet seating depth is much more important to get exact IMO especially if you are seating to 'just touch'

I wouldn't bother sizing them, rotating them and resizing them again. I very much doubt that you would notice any difference on paper from doing this.

---

Definitely makes sense, thanks for the info mate. Have been putting the smaller brass aside so at least I’ll have consistent batches, who knows they may even perform better !

Quote:

---

Originally Posted by Hg1990

Thanks mate I thought that may be a factor, been looking into the AMP Annealer but can’t afford one atm. I’ve watched just about every video Erik Cortina and F-Class John post so am definitely all the way down the precision rabbit hole [emoji23]

---

Honestly, there are a lot of guys offering the service of annealing your brass for say $25/100cases or less. I'd rather just go that route in the mean time until you get the funds together.

Sent from my SM-G780F using Tapatalk

Quote:

---

Originally Posted by dirkvanvuuren

Honestly, there are a lot of guys offering the service of annealing your brass for say $25/100cases or less. I'd rather just go that route in the mean time until you get the funds together.

Sent from my SM-G780F using Tapatalk

---

Will have to see if I can find any near me! Thanks again mate

Can't speak from experience brass wise, but know F class shooters who hate Hornady brass. Tend to stick to Laupa or Norma but in saying that I've had Winchester and ADI brass that shot really well.

Quote:

---

Originally Posted by flock

Can't speak from experience brass wise, but know F class shooters who hate Hornady brass. Tend to stick to Laupa or Norma but in saying that I've had Winchester and ADI brass that shot really well.

---

100% agree. Quality brass will save you a lot of headaches and it lasts longer too.

Sent from my SM-G780F using Tapatalk

Quote:

---

Originally Posted by flock

Can't speak from experience brass wise, but know F class shooters who hate Hornady brass. Tend to stick to Laupa or Norma but in saying that I've had Winchester and ADI brass that shot really well.

---

Don't know about hating Hornady brass. Just never in my mind to use other than Lapua or Peterson.

I'm like you and can't help but to measure all cases :oh noes: Though the more I'm loading the less I'm measuring these days as I just don't need that perfection for my intended level of shooting. 900m steel, 600m deer and up to 300m headshots on meat animals if carrying out whole(conditions permitting) .
I found the same thing as you with the shoulder bump varying slightly. The main causes for me where not cleaning the die out if sizing dirty brass while using Imperial sizing die wax, not lubing the inside & outside of case neck enough (standard F/L dies and graphite) and the biggest issue was not annealing. I also double run in the F/L die to get a more consistent sizing, Probably because of the button expander, 2nd stroke up just feels smoother too. :yaeh am not durnk:
I anneal every firing with a gas torch and twirl the case by hand for 4-5 seconds and put it down fast! :on fire: Might not be amp annealer accurate but bloody makes a difference to the brass sizing consistency (never have to readjust dies either) and case life.

Are you using a single-stage press? I may be doing it all wrong but years ago i was getting inconsistencies with .308 brass so after months of pulling hair i opted for buying a total of three rockchucker single stage presses and put each die in its own press. it meant i didn't have to ever adjust the dies and all the brass turned out the same (more or less). also i find it best to use a already sized case that you are happy with to set your die. same with seating and crimp.

Quote:

---

Originally Posted by Tirau

I’ve found the most accurate way to control shoulder bump/ headspace is using the competition shell holder set from Redding,

---

What Tirau says!

Sent from my SM-A025F using Tapatalk

Quote:

---

Originally Posted by Roarless20

I'm like you and can't help but to measure all cases :oh noes: Though the more I'm loading the less I'm measuring these days as I just don't need that perfection for my intended level of shooting. 900m steel, 600m deer and up to 300m headshots on meat animals if carrying out whole(conditions permitting) .
I found the same thing as you with the shoulder bump varying slightly. The main causes for me where not cleaning the die out if sizing dirty brass while using Imperial sizing die wax, not lubing the inside & outside of case neck enough (standard F/L dies and graphite) and the biggest issue was not annealing. I also double run in the F/L die to get a more consistent sizing, Probably because of the button expander, 2nd stroke up just feels smoother too. :yaeh am not durnk:
I anneal every firing with a gas torch and twirl the case by hand for 4-5 seconds and put it down fast! :on fire: Might not be amp annealer accurate but bloody makes a difference to the brass sizing consistency (never have to readjust dies either) and case life.

---

Thanks mate, great info. I clean the die every time I resize plus all the brass is cleaned before resizing. I think looking at yours and a few other posts the main issue will be annealing, will have to look into who can anneal for me!

Yep I double run as from F Class Reloaders I’d seen online you can get better concentricity.

Thanks again mate

Quote:

---

Originally Posted by nowool

Are you using a single-stage press? I may be doing it all wrong but years ago i was getting inconsistencies with .308 brass so after months of pulling hair i opted for buying a total of three rockchucker single stage presses and put each die in its own press. it meant i didn't have to ever adjust the dies and all the brass turned out the same (more or less). also i find it best to use a already sized case that you are happy with to set your die. same with seating and crimp.

---

Thanks mate yep using a Redding big boss press and have the die set with a witness mark and don’t adjust the lock ring between sizings.

I am new to reloading.

Have watched and read a lot of information and it gets confusing.

Have "invested" in a press, dies, scales, calipers, brass, powders, projectiles, comparators etc and then read that someone using a Lee Loader set and a hammer held the world record for smallest group for 7 years. So, I bought some of those as well.

Accurate shooting seems to me to be a bit like fly fishing and playing guitars, the more you try to learn the more difficult it seems to become.

In am wondering what things are the most important in learning to shoot more accurately.

Is it the ammo, the gun or a lot more consistent practice?

Quote:

---

Originally Posted by Delta Variant

more consistent practice?

---

that's most of it. imo.

Are you sure it's not a measurement issue? If you mark a vertical line on case shoulders with a sharpie and also mark the shoulder insert thingy as well. Measure a case with the marks lined up then size and measure again with the marks lined up. Try a few cases are you still seeing the same variation? when you sit the case in the callipers/gauge wriggle the base of the case side to side along the axis of the blade of the calliper to seat it, while applying gentle pressure. I found one of these really tightened up my measurements https://benchrite.com/davidson-seati...-checker-base/ I got it from Sinclairs

I also agree with beetroot, as long as you check for imminent case head separation with a hook-shaped probe inside the case and they are all good and they all chamber, eject cleanly after firing and shoot ok then I wouldn't worry.

So I think I've solved the mystery. I thought is was just my non-annealed cases so I got them annealed and the inconsistencies persisted. My next thought was it must be the play in the press turret, a nice new single stage didn't help (no, I didn't buy one). Then at some point I stumbled across several references to this video. All my cases with the exception of 1 came out with a variance of 0.001". I'll check it over some more resizing, but I'm getting ready to hang up the calipers.

180deg? try 90deg, then maybe 90deg again. Works well with neck sizing, may work with full resizing and shoulder bumping?

Guys... just a small trick on using calipers...

There is always a little slack along the green line pictured below.... varies from one to the other.

First, ensure the springs along the green line are in good nick and keep the bottom slide of the car body firm against the bottom of the rail.

Then instead of using the thumb wheel or thumb on the position in the black circle.... just exert a little light pressure to "hold" the case, either side of the lower jaw adjacent to the case... red arrows... this prevents the spring(s) on the slide at the green line from compressing which in turn results in more consistent readings.


Attachment 189506