HELP me with my stroke! 6.5 Creedmoor super short?

[NevadaMike]

I will try to explain my process as best as I can.

1. New Hornady brass
2. Full length size with no decapping pin or ball - Pretty much no resistance while sizing - Hornady dies
3. Graphite neck lube and Sinclair expanding mandrel
4. Prime with Lyman priming tool
5. Powder via auto trickler
6. Seated 143 ELD-X with slow steady stroke with an Area 419 press - Hornady seater with 143 ELD-X stem
7. Most that seated properly were within 10 thousandths of my target of 2.820

While seating the projectiles there were varying degrees of resistance but most seated properly. I tried a slow and deliberate stroke at first hoping to seat the projectiles more consistently. I also tried a more deliberate stroke but not fast. I was thinking the problem was solved initially with the faster stroke but I still had one of the new 6.5 Super Shorts.

Questions

Do your bullets CBTO come out very uniform?
What is a normal variance CBTO to CBTO?
Is this a cheap Hornady brass thing or should I ditch the Sinclair mandrel?

 

[Pickettpuncher]

Your sizing die is way too deep. Back it out at least half a turn.

 

[Pickettpuncher]

I don’t know that a full turn would hurt anything.

 

[NevadaMike]

I don’t know that a full would hurt anything.

90 out of the 100 are fine. If it were too deep would they all have been compressed?

 

[packer58]

You may very well be borderline undersized with your mandrel creating excessive force required to seat the bullet, varying degrees of case hardening at the neck could explain away smashing a few rounds. Are you noticing any deformation of the shoulder after F/L sizing ?? If your setup allows you to cam over the ram up against the bottom of the die you can't hardly screw that up.

 

[Lawnboi]

What’s the diameter of your loaded round compared to a fully prepped round at the neck?

Couple thoughts:
- your seating die is too deep and contacting possibly
-you squeezed the piss out of the neck and have a boat load of neck tension. Just because you ran a .263 mandrel though it dosnt mean it’s .263”. If you way oversized the neck, as most standard FL dies do, you probably have way too much neck tension.

 

[jhm2023]

What size mandrel are you using? That would be the first thing I would check is excessive neck tension (interference fit). I've had great luck with .262 and .2625 mandrels to open the necks after full length resizing with Hornady dies and the decapping rod removed. Also if you seating die if way too deep and your brass is inconsistent on length can do it, but I'm leaning towards you forgot to neck expand those 10 pieces of brass.

 

[NevadaMike]

You may very well be borderline undersized with your mandrel creating excessive force required to seat the bullet, varying degrees of case hardening at the neck could explain away smashing a few rounds. Are you noticing any deformation of the shoulder after F/L sizing ?? If your setup allows you to cam over the ram up against the bottom of the die you can't hardly screw that up.

The shoulders are fine after sizing as far as I can tell. I wish at this point I had one left to measure before and after sizing to make sure the shoulders are not bumping out and I just can not see it.

 

[NevadaMike]

What size mandrel are you using? That would be the first thing I would check is excessive neck tension (interference fit). I've had great luck with .262 and .2625 mandrels to open the necks after full length resizing with Hornady dies and the decapping rod removed. Also if you seating die if way too deep and your brass is inconsistent on length can do it, but I'm leaning towards you forgot to neck expand those 10 pieces of brass.

I just measured the mandrel and it checks at .2620 everywhere I checked it.

 

[NevadaMike]

You may very well be borderline undersized with your mandrel creating excessive force required to seat the bullet, varying degrees of case hardening at the neck could explain away smashing a few rounds. Are you noticing any deformation of the shoulder after F/L sizing ?? If your setup allows you to cam over the ram up against the bottom of the die you can't hardly screw that up.

After measuring the mandrel at .2620 I am thinking you may be right here.

 

[packer58]

After measuring the mandrel at .2620 I am thinking you may be right here.

Just for grins, measure the expander button you took out of the F/L die. Another thing you can do if you have any sized brass on hand is to measure the case mouth, that will give you an idea as to how accurately your mandrel is opening up the mouth of the case.

 

[ljalberta]

I’m sorry I don’t have anything productive to contribute, but if nothing else, please know that the pictures of the 6.5 Creed Super Short gave me a solid chuckle.

Hope you get it figured out.

 

[Pickettpuncher]

90 out of the 100 are fine. If it were too deep would they all have been compressed?

Your shoulders say otherwise. You’re trying to crimp and seat at the same time which is why your shoulders are jacked up. Or those cases are too long and should have been trimmed.

 

[Pickettpuncher]

What’s the diameter of your loaded round compared to a fully prepped round at the neck?

Couple thoughts:
- your seating die is too deep and contacting possibly
-you squeezed the piss out of the neck and have a boat load of neck tension. Just because you ran a .263 mandrel though it dosnt mean it’s .263”. If you way oversized the neck, as most standard FL dies do, you probably have way too much neck tension.

I wouldn’t think too much neck tension would cause his cases to fail at the neck. At least not the amount he’s using. I used to take the expander out of my 7x57 dies and just seat a bullet without ever opening the neck back up. Just shot better that way. And we know how much dies like to choke those down.

 

[NevadaMike]

Just for grins, measure the expander button you took out of the F/L die. Another thing you can do if you have any sized brass on hand is to measure the case mouth, that will give you an idea as to how accurately your mandrel is opening up the mouth of the case.

The expander button is .2630. I am beginning to think its a neck tension problem.

 

[NevadaMike]

Your shoulders say otherwise. You’re trying to crimp and seat at the same time which is why your shoulders are jacked up. Or those cases are too long and should have been trimmed.

You may be right. My process is to put a case in and raise it all the way up in the press then thread the seating die until it contacts the case and then back it off a turn or so then lock it down.

 

[packer58]

The expander button is .2630. I am beginning to think its a neck tension problem.

Yeah, i would agree. Those 6.5 ultra shorts look pretty cool though ........ Sorry

 

[Pickettpuncher]

You may be right. My process is to put a case in and raise it all the way up in the press then thread the seating die until it contacts the case and then back it off a turn or so then lock it down.

I would measure your cases and make sure you didn’t happen to miss them when you trimmed. Back die out another half turn.

 

[packer58]

You may be right. My process is to put a case in and raise it all the way up in the press then thread the seating die until it contacts the case and then back it off a turn or so then lock it down.

That method should keep the case mouth away from the crimp ring assuming all your cases are the same length as your setup case.

 

[Pickettpuncher]

That method should keep the case mouth away from the crimp ring assuming all your cases are the same length as your setup case.

I agree. But you shouldn’t get collapsed shoulders with your neck .001 smaller than the bullet.