Help with seating depth inconsistencies

[bluebie]

Hey folks,

I'm currently shooting 6.5 creed. I'm reloading using a Redding type-s full length seating die with bushing, and the matching competition seating die with mic. I trim my cases to length every time, and I'm using a hornady ogive length comparitor and mitutoyo caliper to measure ogive length. My target ogive length is 3.2055in (comparator length inclusive) for 0.010 off the lands. Let me know if you need any additional info. Anyway, on to the question:

I'm finding that approximately 5 out of every 50 rounds I press comes out out of spec with regards to the ogive length. Typically 0.001-0.003 out of spec. I i'm guessing one of the following is true:

1. The tools I'm using are simply not precise enough to expect this degree of precision and repeatability
2. The manufacturing process for the projectiles I'm using (hornady eld-m) is not precise enough, and deformation can result in measurement variations
3. Some of my brass is out of tolerance and should be tossed
4. I'm overthinking this, and should settle down and stop measuring every single cartridge I'm producing.
5. Something else??

The only reason I'm somewhat concerned about this is that my target length is so close to the lands already, and accidentally jamming a bullet into the lands would probably suck.

Thanks!

 

[spife7980]

All of the above lol I wouldnt worry about it too much.
If it does then you are in store for weight sorting bullets, then sorting by ogive length. Plus water weighing brass.

Now pull those outlier bullets and seat another bullet into the brass, did it change?
Now, put that pulled bullet into another piece of brass, did it change?
Lets you see if its the bullet or the brass or a combination of both, usually a combination of both.

 

[Ranger188]

You didn't say what brass your using.
If Hornady, then I won't use it and others don't like it. Just me
.010 off is tight. The ELD-M's don't mind a little more jump, (.02-.03) if your concerned with jamming
You don't have to trim the cases every time, with some of the other companies, just bumping
the shoulders back is enough for 4-5 firings
Some times the screw at the top of the die that holds the seater stem is loose and will give you a false reading here and their

 

[bluebie]

All of the above lol I wouldnt worry about it too much.
If it does then you are in store for weight sorting bullets, then sorting by ogive length. Plus water weighing brass.

Now pull those outlier bullets and seat another bullet into the brass, did it change?
Now, put that pulled bullet into another piece of brass, did it change?
Lets you see if its the bullet or the brass or a combination of both, usually a combination of both.

View attachment 7089512

Thanks, good idea on checking the out of spec cartridges with fresh brass/projectiles. I'll definitely do this the next time I'm at the bench.

You didn't say what brass your using.
If Hornady, then I won't use it and others don't like it. Just me
.010 off is tight. The ELD-M's don't mind a little more jump, (.02-.03) if your concerned with jamming
You don't have to trim the cases every time, with some of the other companies, just bumping
the shoulders back is enough for 4-5 firings
Some times the screw at the top of the die that holds the seater stem is loose and will give you a false reading here and their

I'm using hornady, just re-using the brass from the factory ammo I was shooting before I got into reloading. What don't you like about it? I had definitely considered seating a bit deeper to get some more cushion.

What would be involved in switching brass, and buying some virgin large primer brass from somewhere? Do I need to start the entire reloading process over again? Or can I just start running that new brass through my sizing die and business as usual?

 

[spife7980]

New brass = new load

It may be close but until you qualify its internal volumes and hardness compared to where you came from its best to start over with new brass.

 

[bluebie]

New brass = new load

It may be close but until you qualify its internal volumes and hardness compared to where you came from its best to start over with new brass.

Fuuuuuck ?

 

[Ranger188]

Hornady bullets are fine, it's their brass. It's softer than others and is less consistent than others
just takes a little more caring in your reloading process. I've seen others use it and have great results
but the majority of shooters stay away from their brass.
Yes the "other" companies that make quality brass is usually thicker and has less internal volume
so your same load would be a little hotter.
So when changing brass always start lower and work your way back to a good shooting load.

 

[spife7980]

Fuuuuuck ?

Take a group of those outliers and take a group of the inspec rounds. Then either 1) shoot them at two different dots to compare or you can 2) shoot them into the same group and see if they do anything different. If you cant tell the difference then you know it doesnt make a difference. If you want to do it at distance to really tell then you can sharpie one batch of bullets red and the others blue and then you can tell on paper without having to walk downrange to mark each shot.

 

[supercorndogs]

Hornady brass is fine. .001-.003 variation is the width of hair on the wide end. Do you notice it on target? If not carry on.

 

[bluebie]

Hornady brass is fine. .001-.003 variation is the width of hair on the wide end. Do you notice it on target? If not carry on.

Thanks for the perspective. I'm not really worried about any accuracy differential with the outliers, I'm not a bench shooter or anything. I'm just trying to be safe, which is why I was sitting there measuring each cartridge in the first place, and just happened to notice.

I think I'll just stick it out with the hornady brass until I either destroy it or burn out my barrel, at which point I'll start working with some higher quality stuff since I'll need to work up a new load anyhow.

 

[supercorndogs]

I see because you are only jumping .010 and don't want to jam. I prefer to try and find something .02 plus. Might be surprised by something in .05 jump range or even longer. You never know.

 

[bluebie]

I see because you are only jumping .010 and don't want to jam. I prefer to try and find something .02 plus. Might be surprised by something in .05 jump range or even longer. You never know.

Yeah I tested from 0.010 to 0.035 in .005 increments during development. 0.010 was the best, but not by a wide margin. 0.015 and 0.035 were almost just as good. Maybe I just go with the 0.035 and forget about it, that's plenty of margin for error IMO.

 

[_Raining]

Now pull those outlier bullets and seat another bullet into the brass, did it change?
Now, put that pulled bullet into another piece of brass, did it change?
Lets you see if its the bullet or the brass or a combination of both, usually a combination of both.

I am not sure this is a valid test, reseating a bullet multiple times can deform the area that the seater contacts the bullet. I suppose if your seater is a perfect match to the bullet then this may not happen. I do notice if I set up my seater die and I have been using the same case/bullet to slowly adjust the die down that using a fresh bullet will be slightly different then the one that has been through the die multiple times.

 

[Smithcollector]

I like chasing down these types of things as much as the next guy, but I think you will have a tough time seeing a 0.001-0.003 variation in BtO on the target. However, most of your issue here is probably variations on the bullet dimensions, so as stated above, you'll need to sort bullets to reduce the variation. I suspect most people eventually decide to pay a premium for better bullets.

 

[Ranger188]

Are you using, blems, bulk or 2 different lots of the ELD-M's?
That could cause a difference in measurements

 

[bluebie]

I like chasing down these types of things as much as the next guy, but I think you will have a tough time seeing a 0.001-0.003 variation in BtO on the target. However, most of your issue here is probably variations on the bullet dimensions, so as stated above, you'll need to sort bullets to reduce the variation. I suspect most people eventually decide to pay a premium for better bullets.

This seems reasonable. I'm not concerned with the accuracy variations, moreso with safety since I'm pretty close to the lands already, that's all.

Are you using, blems, bulk or 2 different lots of the ELD-M's?
That could cause a difference in measurements

I'm using a bulk box of 1000x 140gr hornadl eldm from Midway. They just shipped a literal cardboard box full of bullets wrapped in packing tape. It would not surprise me in the least if the shipping process deformed some of these, leading to the variations seen.

 

[FALex]

It's either variations in the dimensions of the projectiles or the neck tension on those cases was not the same as the others. Either way, I wouldn't even blink at that, and I am actually relatively anal-retentive on my reloading practices.

 

[MarinePMI]

Likely variations in the bullets. The OP can use his comparator on just the bullets and tell if that is the case. Easy way to test anyways...

One thing though, I have noticed on RDF blems that the base of the bullets are very inconsistent. Some are larger than normal, and others even have a small divot/dish in the base. The divot doesn't concern me as much as the varying diameters of the base. If the base varies, then that means the forming process has varied. If the forming process has varied, than the location of the ogive is going to vary. Which then means... you're seating depth is going to vary (since the seating stem typically indexes off the ogive).

Just something to consider...