Hammer
Its nice to cut down on the case prep. I would measure the cases and if they don't need to be trimmed... don't trim them. I would though, but it probably won't be necessary for most of those cases.
For bullits,I like v-max's or bt's if money is no object. If it is...like VG stated. The speer 52 hp is hard to beat, or the 50 tnt. You almost have to do something dumb to have a ricochet with any of these bullits...and again...like VG mentioned...you don't want too tough a bullit for obvious reasons and all cattle should be left standing.
For powder. Ball powder meters well if your guns like it. Short cut cyl. powder will be fine though. I like aa2015 or varget to name a few.
Looks like you like to reload so you'll enjoy the homework. If you ever are in a really big hurry or the shootins really good and you run out of ammo. AAAHHH! Try some Black Hills ammo. Its a good way to accumulate somemore brass.
I use benchrest primers. Rem, or fed. I have'nt noticed in my testing if it helps, but I use it anyway. Mayse I just can't shoot good enough to make the diff.
25gr. AA2015, 40GR NBT REM 71/2 BR
24gr. AA2015, 50TNT REM 71/2 BR
These loads have served me well in the .223
For the 22-250...34gr. RL15. 55 v-max, and fed 210M.
Good luck in your testing.
You might need more ammo.

Will soon be loading about 3,000+ rounds of 223 Remington for use interchangeably in various rifles including Remington, Savage, and Winchester. Ammo will be loaded on a Dillon and in 2,000 once-fired-in-these-same-various-rifles cases and a 1,000 new WW cases. Ammo will not be separated by rifle but in a communial bag. (This is not a commercial operation, but a group of friends making an annual sorte for Montana prairie dogs.)

What standard load would ya'll recommend ?

Since it will be loaded on a Dillon and individual powder charges will not be weighed, would a ball powder be best ?

What dos and don'ts, such as "should the new brass be trimmed?"

Also taking a half-dozen 22/250s. Standard load ?

Hammer

I use serria 52 gr match with wcc 844 at 3200 fps in all my 223s. Who knows how many p dogs that load has acounted for.

P dog shooter: Please do not use the wonderfully accurate Sierra 52 gr. bullets on Varmints, especially on Prairie Dogs! Those bullets are the most ricochet prone bullet I have ever fired (other than some types of military FMJ ammo)! I quit using them decades ago!

You are simply sending ricochet after ricochet far down range whether you have hit the Varmint or missed the Varmint! This is compounded by the relatively low speed of 3,200 FPS you are shooting them at. You are simply going to get a lot of ricochets not 100% ricochets but I will bet 25% of those shots have a pass through and ricochet. Maybe more.

Please use a frangible bullet while Varminting especially in flat country where the Colony Varmints live! One of these days I fear something bad will happen if you keep sending those extremely hard projectiles down range!

Please do not take this criticism as a personal attack! It is not meant as one.

I have used and seen those bullets used and they are simply the most dangerous bullet you can fire in flat country!

Let me relay just this one incident to you! I was Hunting Rock Chucks out west here in flat country. Lots of small dairies in this particular area. The ranchers wanted the Chucks killed to save grass and danger to the Beef and Dairy Cattle. I showed up at a place I had Hunted for many years and my friend the rancher greeted us with glee. Then he said by the way I want you guys to be extra careful and let me show you why. He took us to his corral and there was an adult dairy cow with a festering wound in her high hip area. He was awaiting the butchering truck to come and kill the cow and take it away that very day! Well the next day I get by again to do some more Hunting and the owner showed me the projectile that came out of that now dead cows wound! It was, I am sure, a Sierra 52 gr. HP/BT Match bullet! It had a slight bend in it and a slightly blunted tip. I wanted the bullet to take home and confirm its identity but the man needed it for demonstration purposes from then on to visiting Varminters!

I have seen 52 gr. Sierras pass right through (and kill!) Varmints of various sizes then whine away into the distance or skip across the prairie putting up puffs of dust as they travel away.

With the popularity of Varminting and especially Prairie Doggin recently it is now even more important to use a frangible bullet! Sierra 52's (and 53's) are not reliably frangible what so ever. The Sierra company even advises against their use for Varminting.

I simply will not Hunt anymore with anyone using Sierra 52's in flat country! The danger factor and liability are just not acceptable to me! Other brands of 52 gr. HP bullets I have seen used are much more frangible than the Sierras. I hope you can find one that is safer to use. I used the wonderful Speer 52 HP/Flat Base bullets in my new 220 Swift last year for Prairie Dogs and Rock Chucks. Very explosive and accurate this bullet is!

Hold into the wind

VarmintGuy

Hammer: Please consider and try this load for your 223's. I had it recommended to me many years ago and I have passed it along to many people and it has been virtually universally accurate and lethal on Varmints for all of us.
The fellow that recommended it to me used a Dillon progressive press to make his loads using this recipe and it worked well for him in both his AR-15 like Varminter and his bolt guns. I use it in a couple of my 223's to this day.
223 Remington: Sierra 50 gr. Blitz bullet with Federal 205M primers and 26.5 grs. of H4895. I used this loading to make some very small groups in my Remington 700 Police Sniper Special. It is a superb loading for Prairie Dogs and Rock Chucks. Not only that, the Sierra 50 gr. Blitz bullets (#1340) are very economical! The primers are a penny more apiece but I think well worth it! These bullets are also very frangible and will not ricochet.
Good luck with this load and the upcoming season!
Hold into the wind
VarmintGuy

I load on a dillon,my load is 26 gr win 748
fed or lc brass,rem 55 gr hp,cci 450 primer
this is an accurate load in 3 thompsons 3 different ar-15's
and a mini 14.

I second that recomadition of win748. That is what I use with all of my 223 ammo no matter what the weight of the bullet is. I also agree with the what is said about match bullets. If your going out after animals use hollow points, speer points, or balsitic tips. The last ones are great. I do not recomond anything smaller than 50gr on yotes though. My 2 cents worth.

Ray

I use a Dillon RL550 too.

In a slow twist Barrel:
Hornady 55gr SX 26gr WC844 or WC846
or
Hornady Vmax 55gr same powder charge

I use once fired military brass ... LC 79 is my current
lot.

I have been very satisfied with these loads. I shoot these loads in my heavy barrel AR15, Savage mod 12. My AR has a 1-12 Shilen barrel. I don't know what the twist is on the Savage.

You have some good responses here, but I guess I will throw in my two cents worth.

A couple of "standard" loads that keep showing up year after year are as follows:

For the .223 Remington a great prairie dog load is one that the guys at Hodgdon have been recommending for a long time.
This is any good 40 grain bullet propelled by 28 grains of H 335. I have shot lots of varmints with that load and it works in most .223's that I have shot.

And for as close as you will find to a "standard" load in the 22-250 try a good 55 grain bullet over 35.5 grains of H 4895. I have had great success with this in a number of 22-250 rifles. Having said that, some 22-250's are little more accurate with 50 grain bullets. I use 36 grains of H 4895 behind the 50 grainers.

Have fun on your prairie dog hunt.

R F

Shot a cardbord box filled with wet news paper today. It was at 400 yrds with a 223. I was using 50gr sierra spitzer in front of 26gr of win748 and federal bench primers. The recovered bullet was .6537 in dimater and weighed a little over 13grains. That was all that I could find. The jacket had no lead on it. I did find small chuncks of lead that I weighed with the cooper. Just thought that this would be of interest.

Ray