6.5 Creedmoor novice Load development

[dockimura]

Hello,

I'm just starting to reload 6.5 Creedmoor. I'm trying to figure out seating depth and am trying Erik Cortina's method of finding jam and then starting - 20 thousandths from there. I have a jam Case to Ogive of 2.324 and was going to start at 2.304. My concern is that I measured a Hornady 140gr ELD-M factory cartridge and its only 2.185 (I've been shooting this cartridge and have decided to try and reload with the same components). Does it seem reasonable that there would be that much jump, or is just overcompensation to make sure they are a long way from jam?

Thank you in advance!

 

[spudgun]

Welcome to the group.

I load for 2, 6.5 Creeds. As much as I hate to say your going to have to do your ladder testing to find out what you gun likes.

I use Hornady 140, HPBT match, A-MAX, and ELD's. Each one is different in my guns. Each bullet is different and has different Ogive.

What I do is find my jam point with each bullet and then work in a spread sheet.

I don't use the Ogive (I know I'll get some heat on that). I take my chamber tool shove the bullet into the lands. Insert a cleaning rod with a locking colet on the shaft. insert the rod until it touches the tip of the bullet, lock the colet against the muzzle. then remove the tool and bullet from the chamber. Reinsert the tool and then push the rod in the tool until it moves the cleaning rod. Push the rod back against the muzzle and then remove the tool and measure the OAL from base to tip.
That tells me for that bullet (each one is different) what I should set my seating die to.

I find that .040 to .050 jump gives me the best groups.

I also check these measurement after 300 rounds. This will change due to throat errosion will cause the jump to move out..

I know someone will have a different way to do it but this has worked for me over the past 4 years.

 

[Rob01]

Factory 140 ELDs are about .070" off the lands in a SAAMI freebore chamber so looks like your chamber's freebore is a little longer but not much. They load factory ammo to a spec and they do it so they will fit in every rifle's magazines whether internal or detachable so that is why they are where they are. If you can fit them in your magazines at .020" off the lands then try them there. I have shot them there and they shoot well but also does the factory ammo. The ELDs, like the AMAX, are not jump sensitive so they can jump a good ways and still be accurate.

 

[dockimura]

I went to the range and got some pretty good groups and velocities, but I am still struggling with something. I have my starting seating depth, but using my caliper and Hornady comparator tool, it was very difficult to get the same measurement every time. Is there a "standard method" to measuring CBTO? I have watched videos, and maybe its just an experience thing? Or could my caliper be off by 2-3 thousands?

 

[Kracken McGraw]

I went to the range and got some pretty good groups and velocities, but I am still struggling with something. I have my starting seating depth, but using my caliper and Hornady comparator tool, it was very difficult to get the same measurement every time. Is there a "standard method" to measuring CBTO? I have watched videos, and maybe its just an experience thing? Or could my caliper be off by 2-3 thousands?

That’s more than likely the difference in variance of the bullet measurements in your boxes of bullets.

 

[Rob01]

A couple thousandths won’t make a difference with the ELDs. I usually measure a few times with the tool and then take an average and go from there. Don’t stress it.

 

[Newhouse]

That’s more than likely the difference in variance of the bullet measurements in your boxes of bullets.

This and possible that your primers are not seated flush.

 

[nwmnbowhunter]

Make sure you can get the same repeated measurement on the SAME loaded round. This will tell you if you are measuring consistent

 

[Coyotefurharvester]

If you mean the same measurement of the same bullet, your caliper error could possibly be +,- 1 to 2 grads. If your talking different bullets/cartridges then you are seeing some stacking, bullet ogive differences, possible primer interference, caliper error, bullet lots(comparing the factory ammo to your reloading bullets lot. I would zero the caliper on the item(bullet or cartridge) you want to use for comparison and see how much variance you see. Try a whole box of factory ammo, see the range on that. I zero my caliper on the cbto measurement I want, than seat all cartridges to that by walking the seating in.

 

[wkdickinson]

I use the Alex Wheeler method to establish "touch". But really whatever method you use, it is only a "relative" index. If you always use the same tools, none of it really matters - shoot the ladder and find out what jump works best, then just measure it with the same system - there is no objective standard to measure it against.

 

[dockimura]

I appreciate all the replies. I have a new issue. It seems that on some of my rounds that the bolt has a small amount of resistance to close. I assumed this meant that the shoulders had not been bumped enough during full length sizing. I compared an unfired case that has the same brass to a sized case and there is no difference. I'm using the Hornady match grade die set. The die is all the way down to the ram, so I am not sure if there is any other way to adjust the amount of shoulder bump.

 

[lazyMlazyK]

Does your die set crimp and seat at the same time? I'm not familiar with the Hornady match grade die set.

 

[JFrank]

I appreciate all the replies. I have a new issue. It seems that on some of my rounds that the bolt has a small amount of resistance to close. I assumed this meant that the shoulders had not been bumped enough during full length sizing. I compared an unfired case that has the same brass to a sized case and there is no difference. I'm using the Hornady match grade die set. The die is all the way down to the ram, so I am not sure if there is any other way to adjust the amount of shoulder bump.

You could be feeling lug engagement or the ogive meeting the lands or the shoulder needs a touch more bump , the latter is fairly easy to increase even if a few thousandths off a shell holder is needed and easy to do with a belt sander.

 

[jepp2]

It seems that on some of my rounds that the bolt has a small amount of resistance to close.

Are you checking with a stripped bolt?

 

[dockimura]

This is a new Tikka T3X TACT A1. I believe that I have the seating depth sorted out, so I don't think that is the issue. @jepp2 why would I need to strip the bolt?

 

[bozo699]

This is a new Tikka T3X TACT A1. I believe that I have the seating depth sorted out, so I don't think that is the issue. @jepp2 why would I need to strip the bolt?

It gives you a better feel with no manipulation of the ejector or firing pin and spring. As you start sizing the case and insert it in your chamber the bolt will only fall a short ways as you continue to bump the shoulder it will eventually fall on its own with zero resistance. It’s a much more precise way of setting up your sizing die. Alex Wheeler has some excellent video on it. He pulled them off YouTube but you can find them on his site
Wayne