I'm a new reloader and have a question...

I'm using IMR 4350 and loading for my 30-06...

I ran out of powder when I discovered a load that shot really well out of my rifle...

I bought more powder from a different lot # and I worked-up some loads and found the groups to be ridiculously large...

The powder batch is the only component change...

The powder seems to give me much more pressure than the last batch because I now have a bolt-lift that is somewhat sticky...

How much consistency is there from batch to batch?

If my "ACCURATE LOAD" was at 55 grains should I find it again (+/-)within .5 grains???

Or is it a whole new ball-game?

welcome to the reloading world. Yes, from batch to batch can make a difference. Especially when you are close to the maximum load for a particular chambering. I don't know what your load is/was but I would reduce it from 5-10 % and find your accuracy load again. The stiff bolt is an obvious sign of high pressure (If everything else remains constant: primer, brass, oal, etc.) A tip is look at the lot number on the can you have now and purchase an extra can or two. This will prevent you from having to go back and keep testing and finding loads each time another pound of powder is purchased. Good Luck!

Roland, I don't know how scientific this method is, but it worked for me. I bought a Shooting Chrony for $100 or so dollars, then found out I could get a refurbished one from the factory for a little more than half that price. When I found my accuracy load I would chronograph the load with a string of 10 to 15 loads. Buying a new can of powder, I would see how close I came to the base line load and adjusted up or down from there to hit the same velosity. The new lot of powder would put me in the rough ballpark area for the load. The chronograph also allowed me to get proof positive of what my loads were doing, or not doing. I know it would be adding more $ to your reloading equation, but to me, it would be money well spent. The best to you my friend ... Tom

Now you know why I buy my powder in 8 pound jugs.
Paul B.

Roland,

good advise given above.. as Paul Said, 8lb kegs are the best way to get consistency...

however, I haven't experienced wide ranges of results from IMR powders until Hodgdon took over the name... I am wondering if they are having a different source than IMR manufacturing it...

I can see that must be frustrating.. however, if you are loading cartridges that have high capacities like an 06 ( compared to my varmint cartridges).. it probably wouldn't hurt to buy say 4lbs at a time, if you can't get a hold of an 8 lb container of it...

being a fan of the mid burn rate powders, like 4064 and Rl 15, don't ask me why, but in my experiences, there is more lot to lot consistency in the mid burn rates and the faster burn rates, than there is with the slower burn rates....

spherical powders like BLC 2, H 335 etc can also be kinda screwy when it comes to lot to lot consistency...

good luck my friend and I hope you and the family had a wonderful christmas and will enjoy a wonderful new year to follow...

all the best,
seafire
john chr.

As stated above lot to lot variations can be a PITA. What bullet and weight are you using? If you are 180gr or less, 55gr of IMR 4350 in most cases would not be over max. Have you double checked your scale for accuracy?
Also, have you given that barrel a good cleaning since your last batch of powder? If so, maybe you need to fire a few more foulers. If not, maybe a good cleaning is in order.

I use the Chrony method to adjust for annual throat erosion in Pdog rifles but over the years I've loaded IMR 4350 in several calibres and I've found IMR 4350 to be pretty consistant. To the point that I will take the last 1/8th of a can or so and dump it in a new can, roll it around to mix it and keep on reloading. I've been told this is a hugh no-no but I've been doing it for more years than I care to remember.
Have you contacted IMR with the lot number? By the way, what is the lot number?

Sure, powder lots vary. "Cannister grade" powders are reputed to be within tight tolerances, but variations like you are experiencing are not uncommon. However, the IMR line has historically been a little more consistent in this regard than some lines like the Bofors (Norma and Alliant).

I would venture that your previous lot of IMR-4350 might have been U.S.-made. IMR's are now manufactured in Canada. Regardless of what factory they came out of, lot to lot variations are a fact of life.

There are a couple of ways to minimize this inconvenience, in addition to buying eight-pounders: First, you can homogenize several 1-pound cannisters prior to starting your load development. Second, you can use the chronograph method to load to the same velocity, which may help. However, if the pressure at the same velocity is markedly different, then so will be the barrel harmonics and thus the point of impact, if not the accuracy. But that's what handloading is all about.

Thanks to all...

Now, I know to follow the rule:

Whenever a component is changed I should start from below and work up...