I am building loads to test in my .22-250. I am determining over all length by using the Stoney Point OAL gauge and comparator to measure from the bullets ogive instead of the bullet tip. My question is where should I start testing off of the rifling? It has been suggested that I start at .020 off. Should I start with the bullet touching the rifling and back off in .005 increments? Should I start at .020 and go in at .005 increments? I have also heard that most .22's do a little better with some bullet jump rather than being right up to the rifling. Any help will be much appreciated.

I would seat a caliber's depth into the case, and then begin with five or six variations of powder charges.

When the powder ignites and the bullet begins to move, it obturates, which means it bulges like a soccer ball being kicked. If the bullet is so close to the lands that it actually engages the lands while in this obturated state, it can deform to a degree. The deeper seating helps the transition from case mouth to throat occur less tumultuously.

In a match grade rifle chamber, there won't be as much room for the obturating bullet to spread itself into, and on such barrels, shallow seating often works. It will even work on factory barrels if pressures are kept low enough.

But you're shooting a 22-250, and you want velocity.

I'd go with a 55 grain bullet, seat it .22" or so into the case, and use the following powder charges, loading four of each variation:

IMR 4895 (purple can)

33.4 grains
33.7 grains
34.0 grains
34.3 grains
34.6 grains (Watch for pressure signs along the way).

Shoot at five different targets, one assigned to each powder charge being tested. Shoot one 33.4 grain charge at target one, then shoot one 33.7 grain charge at target two, and continue in a "round robin" fashion until you have five three shot groups on paper. (You'll have one round of each recipe left over, which I'll mention later).

By alternating targets this way, you won't disadvantage late groups due to a fouled bore or heated barrel. Do allow time to cool, however, and it might be wise to clean half way through and shoot a couple of foulers before continuing.

After you have your targets, you're not looking for the tightest group of the five. That could easily be a fluke. You're looking for the three groups which come the *closest* to hitting the target in the same spot.
You then choose as your load the powder charge from the center of this trio.

Why do you want this? Because you want a load that can tolerate inconsistencies in brass cases, powder lots, outside temperatures, etc. The .3 grain difference in the powder charges will simulate pressure rises and drops caused by several things.

Have you ever had a really tight shooting rifle that liked to throw a flyer every now and then? While there are many causes for flyers, one cause is a pressure change in the load, caused perhaps by an odd brass case or primer variation or the like.

I call this method of load development the Optimal Charge Weight, or OCW load development method. It has worked well for every rifle I've tried it on.

When you have selected the powder charge from the center group of the three, take an additional three shots, this time all on the same target, consisting of the low, median, and high charged load. If all has gone well, you'll note that these will all three fall into a pretty tight group in spite of the .6 grain powder charge variation.

I would predict that 34.0 grains of the IMR 4895 with the 55 grain bullets will be the OCW for your rifle, as it was for mine and one other rifle we tested. You can probably skip this whole test and go right to 34.0 grains of IMR 4895 and vary seating depths and find a great load that way.

H380 is another fantastic powder for the 22-250, and you'll find a lot of good information here regarding the use of that powder in this application. If you want to use my load development method with 55 grain bullets and H380, I'd go with 35.2, 35.5, 35.8, 36.1, and 36.4, watching carefully for pressure signs along the way.

As a *final* step, you would alter seating depth to tune the group to ultimate tightness.

In my opinion, beginning with a pre-conceived OAL and altering powder charges until you get tight groups isn't the best way to go, because you may well arrive at a powder charge that will be very sensitive to cases, powder lots, temperatures, etc. The best amount of powder to have in a particular recipe is the amount which ignites and burns most consistently. For every load recipe, one powder charge (give or take about 1%) will meet this requirement. Find out what that charge is by the above method, and fine tune with OAL adjustments, and you'll have a resilient, accurate load...

Dan Newberry
green 788

Check out this article:http://home.snafu.de/l.moeller/Laddertest.htm#Loaddevelopment

Ted Sierocinski