Should I build rounds with same COAL and vary the grains of powder at first, or
Should I find a great recipe online, then adjust COAL to find sweet spot?

I always take any online load with a helping of salt. Online is a good place to find out what would be a good selection of powders to start working with however. Just like your load books tell you if a certain powder shows up as a good powder for several different bullet weights, it would usually be a good powder to start with.
I keep reading these post about how a slight adjustment of COL turned a spray and pray into a real barn burner. Sad to say, that has not been my experience. I find the best load I can concoct and then I jim around with the COL to try to fine tune it. Sometimes it helps; sometimes it doesn't. Your mileage may vary.

I use a chronograph. I start seating depth .030" off lands (ogive measurement). Then I look for powder combinations that give lowest standard deviation (I strive for single digit standard devation). Then I adjust seating depth to optimize load.

MRAMSAY10
My load development begins with a "ladder" of powder charges. When I determine a sweet spot I will next refine with seating depth.
Hope this helps

muck

Powder, seating depth, primers or brass type... only one change at a time.

Seat the base of the bullet at the neck shoulder junction. Then up the powder charge. OAL- Bullet jump and bullet jammed into the lands are the only 2 things that make a difference. Bullet jump is almost the same pressure wise. It does not matter if its .050" or .010" off the lands,the pressure on firing remains about the same because the case volume is not greatly changed. If the bullet is jammed into the lands, there will be higher pressure, maybe as much as 10,000 PSI. The key factor in accuracy on a bottle neck round is getting the round centered in the middle of the chamber. Controling shoulder bump, bushing dies, only sizing 1/2 of the neck, and bullet jam control this. Look at the pressure curve here on firing.The OAL could make a bullet exit the muzzle at a different time cycle, catching the barrel at a certain point as it flexes. [URL= http://www.arl.army.mil/arlrep...2006/ARL-TR-3922.pdf ]Link[/URL]

Load the cartridge to the length given by the loading manual and be happy. Most bullets and barrels won't show any difference in accuracy by trying to seat close to the rifling.

Based on my loading experience w/ 17 different cartridges in more rifles than that, bullet seating depth may or may not make a difference.
I start by loading to the longest length possible for the lands and magazine of each particular rifle. Then try to get my chosen load grouping. If it groups well only then will I make the decision to play with seating depth. Some rifles are finicky a/b bullet depth, others do not care.

MRAMSAY10,

When I first joined the forum, I had thought I found a simple shortcut to finding an accurate load; the question I posted was much the same as your thread.

At that time I was doing load development for a couple of hunting rifles and had noticed how great the effect on accuracy the seating depth of the bullet had. I had some cartridges loaded up that just wouldn't shoot as accurately as when I had done the load testing and picked the load. Everything about the recipe was the same........except when I loaded the ammo after development, I paid little attention to the seating depth. I thought there was something wrong with the load or the gun.

I then took the same load and paid close attention to the seating depth. I loaded a "seating depth test" by varying the COL by .005" for some 5 shot groups starting at the lands. Well, I was disgusted through the first few test depths at the groupings I was getting that were seated close to the lands. At that time, I thought that seating closer to the lands meant better accuracy. I thought the load sucked. I continued shooting the test and the final batch of test cartridges grouped (to my surprise) at a little over an inch at 300 yards. I was blown away at how much the depth mattered to accuracy. I figured that the depth was much more important than the weight of the powder charge and set out to test the hypothesis with my other rifles.

Well, I would pick a charge weight near but below max and load test cartridges varying only the seating depth. I had decent success getting MOA accuracy in about 4 different powder/bullet/caliber tests. My luck wasn't so good on the next try. I guess the barrel didn't like the bullet.

Since then I have abandoned this method, even though HC has posted that years ago he and some folks he knew did the same thing when all they had was limited supply of components. I think it will work in a pinch but there seems to be no shortcuts unless you get lucky.

I've had better success with conventionally working up loads by charge weight at a given seating depth, then varying the depth once an accurate charge weight is identified to further tune the load.

Sounds good guys. My biggest problem is that my Browning A-bolt only allows a COAL of 2.850 to fit in the magazine. It limits me to most 180s and above if I want them anywhere close to the lands. I have 4 days left in elk season, then I will get shooting again next week and let you know what happens. Keep up the advice, it is greatly appreciated.

I had great success with seating bullets out in my .375 Ruger shooting 260 grain NAB's. It took the rifle from a good shooting rifle to a great shooting rifle. That said I would start with powders and then experiment with bullet seating.

quote:

Originally posted by MRAMSAY10:
Sounds good guys. My biggest problem is that my Browning A-bolt only allows a COAL of 2.850 to fit in the magazine.

Seating depth is the last place I tweek for accuracy. You really need to work a load up, not just grab some data off a website & go. Small changes in powder charge can greatly affect accuracy.
I start w/ a powder that gives the vel. level I want & workup from the middle of the data in 0.5gr increments for 06 size cases. I choose a OAL that fits my rifle's mag & chamber. Then go from there. When I reach a load that gives me the accuracy & vel. I want, then I will tweek the OAL to see if I can get it to shoot a bit better. Yuo only want to change one thing at a time or you'll just be chasing your tail.