Perhaps I should start several threads with these questions but I will list them all here anyway.

My favorite load for ground squirrels is 22.2 gr. 4198 IMR (Manufactured by IMR Powder Company in Canada), 40gr. Hornady V-Max, Winchester WSR primer, O.L. 2.26", chronos at 3400 fps in with a Ruger #1 Varmint rifle with 2" Unertl 15X. Load consistantly holds .50" and has done .25" at 100 Yards.

Question #1: I ran out of that batch of 4198 and have some 4198 IMR (Manufactured by E. I. Du Pont in Wilmington, Delaware). The color is slightly paler and it throws at least 1/2 gr. lighter from the powder measure prior to trickling on the scale, than the Canadian 4198. Have any of you experienced this powder difference and what loading suggestions do you have for each version? How different are these powders?

Question #2: Obama's statements have caused a panic of hoarding loading componets by shooters. The most recent gun show in Reno was a zoo as literally thousands of people stampeded to buy any components they could find. Primers for small rifle soared from $35 a brick in Reno to $100 a brick at the Puyallup WA show the following week. I was nearly out of small rifle primers and found 2 bricks for $40 each (ouch). They are CCI No, 21 primer for 5.56 ammunition (stated on box). I have been since told these are hotter than normal small rifle primers. What are your thoughts on this primer and are they really hotter? How would they fair with my current loading data?

Fishydr

I don't use that powder but I find that changing primers seldom has an impact upon accuracy but will have one on groups.....depends upon a lot of factors but in the end, each rifle is unique. I find that I get best results from my Ruger 77 stainless with A2230C under a 50 grain Sierra #1450 BlitzKing. This bullet does not perform well in my 22-250 however. It likes Varget and the 55 Grain Nosler Ballistic tip. Both like to go fast but I keep my loads a half grain to a grain below listed max. I use a Sinclair overall length tool and comparator to set the bullet .001 off the land and grooves. The results are amazing.

Du Pont spun off its powder making, renamed it IMR, and moved it to Canada a long time ago. So your can of DuPont is likely a lot older. It may have dried out and lost a ½ grain of solvent ( e.g. acetone ) for the given volume you use. Or, the inert materials may have changed, changing the density a fraction. Or, the grain size may be a little different.

You're right at the top load for this powder / bullet. So, load 5 ea. dropping back 2 gr, 1 gr, & 0.5 gr on the powder, and try them out. If all's ok, try your original load. This would be your routine to try the new primers, too.

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Liberals are like Slinkies - Not really good for anything, but they bring a smile to your face when pushed down the staris.

Those CCI primers (the mil-spec ones) are CCI's normal small rifle magnum primer mix in a slightly harder cup designed for military use. They'll work fine; you'll just be using a magnum primer when you use them. Might back off your charge a touch the first time you try them.

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DuPont powders were made with cotton linters and IMR (Canada) are made with wood pulp as the source of cellulose. This resulted in a bit faster burning rate according to C.E. (Ed) Harris. So back off a bit for the magnum primers and a bit more for the old powder. You might end up back where you were, or you might not.

Bye
Jack

Good info. Actually those comments were my thoughts exactly. The validation is comforting. BTW Hornday's .224 VMax 35 gr. at 3600 fps are terrific on squeaks (sage rats) and my Ruger #1 will shoot them through a 1/2" hole at 100 yards. Thanks again.
Fishydr