bullet seating depth

11 January 2003, 04:54

I'm currently working on a load for my 243Win (savage 111FL) and am noticing a considerable difference in bullet length between the 58g vmax and the 70g ballistic tip.

I have been currently seating the 70g bullets at .24. Now I'm a little concerned seating the 58g bullets the same. Being so much shorter there's going to be a considerable more amount of free bore before the bullet reaches the rifling. I'm concerned that there will be some barrel washing going on. Am I just picking at straws here or is this something to be concerned about?

I haven't been able to find a minimum bullet seating depth in books I've been looking at. Am I just looking in the wrong place, or is that just not documented? What would you consider a minimum bullet seating depth for such a caliber?

Incidentally the loads I am experimenting with are:
58g vmax and 40.2g IMR 3031 for about 3800fps
70g BT and 40.0g IMR 4064 for about 3500fps

Any additional advice you're willing to share would be appreciated.

11 January 2003, 05:04

trb

I think the general wisdome goes that you need .24 inch of bullet shank inside the case, but Iï¿½m sure you will do just fine with .2 or .22. I always use some bullet jump, 0,5-1,5 mm. But in some rifles I must use much more, up to 4 mm because of the magazine length. Some feel it is detrimental to accuracy, my experience is that it does not matter much. Wether some of the gas slips past the bullet does not matter, it burns the barrel the same amount wether it comes before the bullet or after, so I donï¿½t think it makes any difference concerning barrel wash out. Tron

11 January 2003, 11:11

Bigdaddytacp

quote:
Originally posted by toolyfolk:
I'm currently working on a load for my 243Win (savage 111FL) and am noticing a considerable difference in bullet length between the 58g vmax and the 70g ballistic tip.

I have been currently seating the 70g bullets at .24. Now I'm a little concerned seating the 58g bullets the same. Being so much shorter there's going to be a considerable more amount of free bore before the bullet reaches the rifling. I'm concerned that there will be some barrel washing going on. Am I just picking at straws here or is this something to be concerned about?

I haven't been able to find a minimum bullet seating depth in books I've been looking at. Am I just looking in the wrong place, or is that just not documented? What would you consider a minimum bullet seating depth for such a caliber?

Incidentally the loads I am experimenting with are:
58g vmax and 40.2g IMR 3031 for about 3800fps
70g BT and 40.0g IMR 4064 for about 3500fps

Any additional advice you're willing to share would be appreciated.

The other post has it right....just so long as the bullet will stay in the case neck and you can handle them they will be safe and it won't hurt the barrel....if you don't mind single loading them and carry them in a protective case the shallow seated bullets may shoot very well for you....the distance to the lands makes a great difference in some loads/guns as to grouping....as the other post states the "rule of thumb" is one bullet diameter.....22 for 22's and 24 for 243 ect. and if you polish the expander mandrel in your sizing die if it has one...or switch to a smaller bushing in a bushing die the tension on the bullet will be greater and hold the bullet better....according to your chamber and leade the gun might shoot the bullet seated deeper in the case just as good but for hunting loads or field loads seat them where they can stand being handled without losing the bullet or getting out of line....unless you are at the max/hot load changing the bullet depth won't change the pressure much...and generally the longer the OAL the less pressure untill you get the bullet pressed into the lands at chambering.....I haven't used any of the light weight bullets below the 80gr in my 243...the 68's and similar are popular in the 6mm PPC/BR shooters in Benchrest....good luck and good shooting!!