quick question on seating depth

[skankpile]

I'm a new reloader.. so I'm somewhat scared of working up loads. I've been following the nosler manual for my .243 with 95gr molly bst bullet with the IMR4350.

,nosler recommends a max imr4350 of 41.5gr)

My process so far:
1) seating factory depth of some other bst & 39.5gr IMR4350
-I was unimpressed

2) same factory seating depth and 40gr IMR4350
-still unimpressed but groups did shrink, less wind bucking, but still short in my opinion

3) I now have loaded up a few to try at 41gr & set the bullets to .010" outside the lands

Im thinking that #3 will show the most promise, but I'm questioning changing both seating depth and charge at the same time. I read that many people here don't worry about it until they start seating inside the lands, and I'm still short of the lands by .010" & off max charge by 0.5gr.. so am I on the right trak?

 

[boogershooter]

To add to this question,I'd also like to ask :Whats the best method to find the lands ie measuring device etc.

 

[RichAllen]

Hi "boogershooter"?

I will take a stab at your post.

You need to buy the Hornady OAL gauge.,formerly stoney point)
Along with the gauge you need buy the proper case guage for your caliber rifle.
I just used mine tonight for the first time and it took all of four minutes to find out the OAL of my chamber.
It's overpriced for what it is but it works effectively and you can use it over again.

My standard COAL has been 2.798, the tool showed me that I could be tight against the lands using a COAL of 2.897.

When I first started reloading,couple months ago) i went to Sinclairs and bought about ever measuring tool they made. I use most of them regularly.

Hope this helped a little.

Rich

 

[billmo]

skankpile, you will fare much better to only change one varible at the time. I guess the shortest route is to seat your bullet in the lands about .010 and start with the low loads in your Nosler guide and work up in small increments. .03 to .05 of a grain at the time til you see pressure or think you have found a sweet spot. Then work with your bullet seating depth at .005 deeper per try after that to try and improve your groups. I think you will find your best accuracy sooner this way unless you just stumble upon it by chance and that don't happen very often. I hope this helps. Bill

 

[skankpile]

you mean take my OAL + 0.010 into the lands, back my load down to say 39grain.. and then go harder into the lands instead of working up to them..

seems opposite of what I was thinking..I'll pull the rounds and try it your way.

just ordered an RCBS charge master.. this beam and shake for the IMR4350 is driving me nuts..

 

[billmo]

you mean take my OAL + 0.010 into the lands, back my load down to say 39grain.. and then go harder into the lands instead of working up to them..

seems opposite of what I was thinking..I'll pull the rounds and try it your way.

just ordered an RCBS charge master.. this beam and shake for the IMR4350 is driving me nuts..

Yes sir, except don't go harder into the lands. Don't bother changing the bullet seating depth until you have found the most accurate load by adjusting powder charges. Then, test different bullet seating depths at app. .005 per increment deeper into the case. Shorten your OAL. That way you are only changing one thing at the time and should burn up less components, barrel, and time.
Bill

 

[skankpile]

billmo.. you got me on the right track now.

I loaded up a bunch of rounds 39,39.5,40,40.5, & 41gr...I actually stopped at 40.5 as the gun started jumping more than usual and I noticed the primers pushing back into the pin..

funny thing is that right on the lands the lowest charge is the most accurate, but I liked the 39.5 the best...so now I've loaded up another 20 rounds and am spacing back in 0.003 increments back from 0.000 to 0.010 off the lands and will see what happens next.

My question is that once I find the jump sweet spot for the bullets, should I vary the powder charge again?

 

[billmo]

You may play around with .01 gr. at a time back and forth high and low and see what happens. Glad it is coming together for you. Keep up the good work and shoot straight. Bill