Thread: Trying something, Eric Cortina method of load development

Seating depth ladder all sorted....now just need the weather to play ball

Good on ya Danny. I am shooting charge weights and recording velocities tomorrow as I have had to change bullets for my 243 Comp rifle. Then will shoot the best ES load with reducing load lengths on Tuesday so I am hoping to have a new load in the next few days. Erik makes a convincing argument with very little ego involved.

Originally Posted by Dermastor

Good on ya Danny. I am shooting charge weights and recording velocities tomorrow as I have had to change bullets for my 243 Comp rifle. Then will shoot the best ES load with reducing load lengths on Tuesday so I am hoping to have a new load in the next few days. Erik makes a convincing argument with very little ego involved.

It's been a bit of a saga getting this sorted, I desperately need a new press as the thread on my Lee where the die screws in is flogged out and allows slop.
It makes it incredibly difficult to seat with any degree of accuracy, I am literally having to hold the die steady with my left hand whilst pulling the leaver with my right.....then back the seating stem out 1/4 turn and start again with the next projectile slowly winding it back in (if I don't follow this procedure the seating depths are all over the show with no 2 the same).
Unfortunately with birthdays, wedding anniversary, Christmas and then more birthdays funds are not likely to be directed at the lead shed till February

can you pack it with thread tape and sort of bind the bugga in place???

also MAYBE worth a crack...can you pinch ring off 2nd set of dies and thread it on UNDERNEATH and work your two rings against each other sandwiching press in between.....the two rings pulling towards each other sort of makes the press thread redundant....

I know when Im seating my 170grn round nose speers I have to back the die waay back up or seating stem wont go high enough to seat correctly.....so the depth of die itself isnt criticle for projectile seating.its distance from seating stem to base that matters.

Originally Posted by Micky Duck

also MAYBE worth a crack...can you pinch ring off 2nd set of dies and thread it on UNDERNEATH and work your two rings against each other sandwiching press in between.....the two rings pulling towards each other sort of makes the press thread redundant....

That might just work.....

Originally Posted by Micky Duck

also MAYBE worth a crack...can you pinch ring off 2nd set of dies and thread it on UNDERNEATH and work your two rings against each other sandwiching press in between.....the two rings pulling towards each other sort of makes the press thread redundant....

Thats a cleaver idea MD. Danny I have a spare ring here that you can have, yours for the asking

Originally Posted by Moa Hunter

Thats a cleaver idea MD. Danny I have a spare ring here that you can have, yours for the asking

Pretty sure I have a spare, but thanks for the offer I'll try it tomorrow.

Originally Posted by dannyb

What is interesting is that some of the loads with a higher E.S actually shot tighter groups,

Or the Chrono is having a bad day and you already have a real nice load but the high ES on the day leads you down the garden path

That's why lot's of data is king - and I partly disagree with Eric.
While doing a ladder test, you are already clocking up load # on the brass, using primer, burning powder, sending down lead and investing time so you may as well use the additional information of group size for your load development. Doesn't mean you trust the first good group OR the first low ES you come across but you rather go back to confirm and form a clearer picture over time on a ladder.

Bottom line for me is, I don't trust my performance on the day + I don't trust the chrono so I use repetition to filter out background noise.

Originally Posted by JaSa

Or the Chrono is having a bad day and you already have a real nice load but the high ES on the day leads you down the garden path

That's why lot's of data is king - and I partly disagree with Eric.
While doing a ladder test, you are already clocking up load # on the brass, using primer, burning powder, sending down lead and investing time so you may as well use the additional information of group size for your load development. Doesn't mean you trust the first good group OR the first low ES you come across but you rather go back to confirm and form a clearer picture over time on a ladder.

Bottom line for me is, I don't trust my performance on the day + I don't trust the chrono so I use repetition to filter out background noise.

I see where your coming from, and yes if I was just testing 1 load and not a ladder I would be inclined to agree, however all the velocities I recorded were consistent with the increase in powder which tends to suggest that the chono (magnetospeed) was not having a bad day.
Like you said lots of data and repetition filter out any misgivings, I did shoot my charge weight ladder at paper so I do have a baseline of data to work from.
My seating depth ladder includes 3 rounds at the original seating depth of 15thou off my jam measurement just in case, this should show if the speed recorded was consistent and accurate.
Thanks for your feedback.

Originally Posted by Micky Duck

also MAYBE worth a crack...can you pinch ring off 2nd set of dies and thread it on UNDERNEATH and work your two rings against each other sandwiching press in between.....the two rings pulling towards each other sort of makes the press thread redundant....

Well seems like it will work @Micky Duck, feels rock solid compared to without, there is enough room to get the bullet in and there is enough travel in the stem to seat them where I need to.
I'll post results next time I'm seating projectiles.

stoked.....

Originally Posted by dannyb

Up to 63gn they all shot pretty much the same, they started to open up at 63.5gn and I started to get pressure at 64gn so settled on 63gn
Aldo anything over 63gn was compressed so I'd rather stay away from that if I can.

With the Partition load, I am wondering if the best charge weight might actually be at around 62.8 ish and not 63 ? Going from 63 to 63.5 'they started to open up' well 'they' might have started to open up at 63.1 or .2 on the first days tests and at 63 yesterday. Without any load tests it is just guessing. 63 might be right on the upper edge of the good spot ??

Originally Posted by Moa Hunter

With the Partition load, I am wondering if the best charge weight might actually be at around 62.8 ish and not 63 ? Going from 63 to 63.5 'they started to open up' well 'they' might have started to open up at 63.1 or .2 on the first days tests and at 63 yesterday. Without any load tests it is just guessing. 63 might be right on the upper edge of the good spot ??

Probably need to revisit the 62gn load to be fair....I kind of fell into the speed trap and looked for the fastest best group but shit even doing 2900 fps thats plenty of hurt on reds out to plenty far. I'll get the berger load sorted then I'll come back to sort the partitions.