COAL and the lands

[dan68]

I have a 22-250 in sako. I normally seat fairly close to the lands but am finding on this gun to be .010 off the bullet seating depth would only be in the case by roughly .085ish. I've used the same technique on several other guns but this one makes no sense to me. Also by seating out as far as I seem to dare 2.520 I'm getting pressure (flat primers) at minimum loads. Book coal calls for 2.350. Any help would be greatly appreciated.
Dan

[markm]

A couple of things....

1. What bullet are you shooting? If you're not shooting a VLD/Secant ogive bullet, depth shouldn't make a difference.

2. Are you sure the flat primers are pressure signs? I.E.... do you have hotter loads with the same primer that don't flatten out?

3. Seating close or at the lands CAN cause pressure spikes because the lack of bullet jump doesn't allow any pressure to bleed off before the bullet seals in the lands and grooves.

[dan68]

55 gr nosler ballistic tip. I have just started on this little project it's a gun for my grandfather that I've had for several years and finally put a decent scope on it to trying make a group. So as far as anything hotter no I just started at the minimum. Also had a sticky bolt on that first one after I noticed the flat primer so I backed off .5 grains and the primer was not nearly as flat

[dan68]

I should also mention I'm using CCI magnum primers trying benchmark and cfe

[Ring]

how many rounds down the tube?

[markm]

Nosler Balistic Tip certainly does not need to be seated close to the lands. I'd back the bullet up to mag length and repeat some testing.

In addition... you really need to incorporate a Chronograph to give you a complete picture of what's happening. A factory Rem 700, for example will show huge primer flow on very safe pressure loads.

It's good to watch primers and case head swipes. But a Chronograph to check against published velocities is really important.

[dan68]

Ok thanks guys. I spent a full day and a half on this. I'm lucky enough I can shoot from my deck at home and go back to the reloader in seconds. Ended up with what I though was a very respectable 5/8" 3 shot group. Tried blc2 with no luck and ended up with reloader 10x at 29.3gr federal 210 primer. I know know where near as much as I would like but more than I did four days ago. I really do need to chronograph these I know and will now that I'm satisfied at least for the time being. Three shot group all cutting each other would be better but again for now I'll take it. Now what I think the next step is not only with this rifle is to get the 21st century case trimmer. Tooooo many things to take into account. Again thank you.
Dan

[markm]

If you set your resizing die to your chamber, you'll almost never have to trim cases. I don't trim 7mag, 338WM, or 300WM ever. I do periodically trim .308 because the die is set to run 3 different bolt guns.... So my 308 brass tends to grow a little more.

I never messed with 22-250, but if you can get away with neck sizing only (or Full length sizing every 3rd or 4th firing for example), you don't have to trim.