Test Seating Depth With Each Powder?

[Tiny Tim]

When you try another powder with a bullet you have been using, do you go through the complete seating depth process? Or have you found that the seating depth remains fairly consistent independent of powder? With powder availability issues like never before, I find myself having to make some changes/ substitutions.

 

[archangel485]

I sure don't but I wouldn't swear that's the best way to do it, haha. Cal Zant has a really interesting article on PRB, I know there are many who like to get that bullet right up by the lands and chase them as they wear down, but I like this approach better. Basically, have them a ways off the lands, you may shoot slightly larger 100 yard groups, but you're not likely to have to re-tune it every 100 rounds and for me the simplicity resonates, so this is how I do it.

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[jimbires]

for a few years now I have been testing for best seating at a minimum powder charge , first . so far I have been able to change powders , or powder amounts and my best seating has stayed the same . by finding best seating first , it seems to be all about barrel and bullet . I might tweak seating a little , but nothing major .

 

[Rick Richard]

My experience is if you find an optimal seating depth for a barrel, then that depth will be about the same for other powder loads.

 

[rsmithsr]

wow, people happy also ran results.
basically anytime you change a part of a load you start over.
with a new powder, a new ladder test which might be smaller as you know the velocity the rifle likes. the fine tune powder, then fine tune depth

 

[Savage 12BVSS]

My experience is if you find an optimal seating depth for a barrel, then that depth will be about the same for other powder loads.

This has pretty much been my experience also, once you hit the node it only changes slightly if at all with a similar burn rate powder.

 

[Mikecr]

Best seating for a particular bullet and barrel, while off the lands (OTL), does not change for the accurate life of the bore.
It doesn't change with different powders either.

This is because seating is not tuning.
Finding and using best seating is simply resolving a condition worse otherwise.
Same with primer testing.

 

[aushunter1]

Different powder, different burn rate, different pressure, different CBTO.

You be the judge, work up the new powder at the same CBTO & see what happens.

Let us know if it works!

 

[Dirtrax]

Different powder, different burn rate, different pressure, different CBTO.

You be the judge, work up the new powder at the same CBTO & see what happens.

Let us know if it works!

Ok...it works. Not just with differing powders or charges, but with bullets of different weights but of the same design from the same manufacturer (Berger VLD). I've tried to sneak different seating depths past my barrel but it won't have it. YMMV

 

[Tiny Tim]

Ok...it works. Not just with differing powders or charges, but with bullets of different weights but of the same design from the same manufacturer (Berger VLD). I've tried to sneak different seating depths past my barrel but it won't have it. YMMV

Interesting concept. Issue of scaling perhaps?

 

[Dirtrax]

I can't say other than I have experienced it.

 

[Mikecr]

Picture ping pong balls interfacing with a vacuum tube at the top of a lotto tank.
Some zip right into the bore & others enter with a rattle..

Now tighten everything from throat to bore in precise tubing. Add an offset center of gravity to the balls. Then launch them to & through the bore tube from a set distance. You may see some balls correct themselves from distortion and mis-balance on release of the bore tube (it's muzzle). Some will release in true harmony, while others go off in abstract directions.
One day it's discovered that by changing the set distance to bore tube (the launch point), resultant dispersion amplitude changes. This, with launch points that are NEAR the bore tube, with further launch distances having less and less affect. So with a bore tube that molds(erodes) further away and potentially to more optimum shape with each launch, the affect of this matter becomes less and less.
It's also noticed that the launch gas composition and pressure for this test makes no difference.
But ball and bore radius matters. Change either, you change everything.

Now when you build a ping pong gun, with a new bore tube, you can test for best result launch points for chosen balls, and never mess with it again for the life of that bore tube. You just log that launch point and always set it there.

 

[J E Custom]

Everyone will have a different take on seating depth that works for them. I was loading lots of ammo trying to find that "best" load for many years until I started resolving one issue at a time. I consider seating depth as a different issue than load efficiency/accuracy so I now work up the load changing only one thing at a time (All seated at the same length). Then when a good load is found, I start adjusting seating depth.

Seating depth appears to be more of a bullet barrel relationship and once the seating depth is found for a particular bullet O jive and weight I have not noticed any real change as long as the seating depth is based on bullet o jive.

Normally when I get to this stage I am finished with load development and just want to see if a seating depth change will make an improvement. Most of the time it will. So If I have a load with good SD.s , and the barrel likes the bullet shape, weight and velocity, Seating depth is the frosting on the cake.

This is just my method and just the way I do load testing to minimize load count in working up to the final load. what ever works best for each is good.

J E CUSTOM

 

[BrentM]

I don't change depth with a known good depth. For example, I have been successful running 6.5 ELD's, ALL OF THEM, at .020 off the lands and messing with many powders and found all shot very well. Well, enough a tweak wasn't warranted. Take that same scenario and add it to 5 different barrels. Same results. I did the same with berger 140 and 144's. Same depth, different powders and barrels, all similar results.