Well , Im shooting a Kimber montana in 300 WSM.
150 TTSX (this time) Every three shot gouup I get a oddball round , Ex: today my three shots were - 3189 - 3228 - 3228 FPS
Naturaly the two rounds at 3228 fps were about .5moa apart , with the first shot at 3189 fps about 1.2 moa away opening the whole group up . Now I shot two foulers , and let the rifle completely cool while rotating rifles .Its not always the first round of the group that is the oddball either .

I weigh my cases , triple check my charges with two scales , sort my bullets by weight seat and crimp (lightly) all in the same manner .
No extreme temp variations between shots ect...
I can always tell on paper which round was the oddball ,
Whats next ? What am I forgetting ?

Any help is greatly appreciated.

While your shots show chronographic consistency, the barrel harmonics aren't liking the load. More or less powder, or a different powder for a different velocity which will eliminate the fliers.

Sorry Sako , I punched in the wrong numbers , the velocities are correct now -

More than why my barrel might not like that load , why is that one round so far off in velocity ?
Im willing to guess if the first round was closer to 3228 that my group would have been alot smaller .

quote:

Im willing to guess if the first round was closer to 3228 that my group would have been alot smaller .

I wouldn't bet on it!!!!!...

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3189 - 3228 - 3228 FPS

In fact these are quite consistant numbers and I seriously doubt that this variance has any effect at all on your groups.....nor are you likely to improve on this variation unless you change powders......and then it may get worse!

It's also conceivable that you might improve variation in velocity and the groups get worse.

Throw away the chronograph and just measure the groups.....if they aren't good enough then try something different.....

I see way too many folks trying to correlate things to velocity.....and in most cases there is no association!

Your extreme spread is 39 fps which isn't much at all and certainly isn't the cause of your group opening up. I've seen plenty of loads that have all three touching that had much larger velocity spreads than that. To a certain extent velocity and accuracy aren't very closely related. It's much more critical to have a very uniform velocity when shooting long range like 1000 yd matches, but at normal distances it doesn't matter that much. You need to search out another source for your accuracy problems, it's not the velocities.

Thanks guys , This is a constant learning experience , I appreciate the help .
Im gonna run another batch of the same load and shoot at a more "formal" range .

Mercula, Taking a different approach... perhaps it isn't the ammunition nor the rifle, but you the shooter. Now hold with me a minute on this. You mention shooting different rifles while the 300 cools, so you are changing your body position and the rest is being moved around. This all has something to do with group size. The more energy is being released with any given shot the more the need to maintain absolute consistency with the hold and contact of the rifle. Your cheek pressure, the way you grip the rifle, it all adds up.

So try to slow down and sit down one one leasurely group and maybe it will tighten up!

Yea , thats exactly what I was thinking , my setup that day wasnt ideal for precision ,
I also didnt think an ES of 39fps was that good ,I thought it shold be less than that.
thanks again everybody .

boltman is right, that kind of consitancy is quite good. If you are throwing the same shot each time, then you might be able to blame something on the rifle/round (ie, cold bbl. shot, hot bbl. shot, etc.) If you are throwing a shot wild anywhere in the string, it may be your rest &/or technique. Good bench shooting is an art that & unfortunatley have never mastered.

Something to think about.....

I'd be willing to bet that 90% of all the folks talking about their 1/2" groups on the internet would be unable to show you a real 1.25" group for five shots if challenged to do so!

Make your expectations match your game.....if you're really a benchrest shooter then you need to change a lot of things.....there's forums just for those folks.....and a few of them post here but it's mostly hunters here! If you're insisting on your hunting rifle shooting real 1/2" groups then you're in for a lot of frustration.....and you may actually make it.... but I'd not bet on that either....I'm cheering for you either way.

No , this is a hunting rifle and I am by no means a benchrest shooter , But after so much time is spent I keep looking for improvment , that to me is what handloading is all about . If it wasnt , then factory ammo would be good enough. (financial reasons excluded)

I was just looking for some advice to improve the quality of my rounds . Ive learned alot already just in this thread .
thanks again .