Test target results in for 2 different H4350 lots in my 6.5 Creedmoor

[VaniB]

Ultimately, I really didn't see any difference between the two different lots of H4350 powder bought 9 months apart from two different stores. They both produced groups that were approximately the same 2" away from the point of aim, and at about the same 1 O'clock POI. I certainly can't complain about the accuracy of either group fired 3 weeks apart, especially the tighter 1/4" MOA I got yesterday.

This topic was started in a thread here a couple of weeks back on 6-6-14 for which I sought input from you guys about what I might expect with two different powder lots. Well, I finally got to the range yesterday. The 5 shot 1/4" MOA group seen in the photo which can be covered with the base of the 6.5 Creedmoor cartridge was the group fired yesterday using the new can of powder. Both of these targets are with the same rifle and 24X scope settings and with wind flags in use. The range conditions for both test targets being 3 weeks apart were about 85° vs 90° with about a 5-6 mph breeze here in humid Houston. The difference in size group , 1/4" MOA vs 1/2" MOA , is likely more of a result of my shooting and to a smaller degree the fact that the case prep was slightly different. I would not attribute the group size difference to the powder.

But no, I am not disagreeing with the accepted practice that it is better to have the same powder lots in use for any fine tuned load.


Above photo; 100 yard target fired 3 weeks ago with the first can of powder.


Bottom photo; Yesterday's range results with new powder and slightly different case prep. (....and mabe a little help from the devi on Friday the 13th? ;D )

 

[sbhooper]

Interesting. Great groups.

 

[strut64]

It was always difficult to match up powder lots when buying but in the current market - sometimes difficult to even buy powder. when you get a chance either buy several small bottles or a large bottle if your budget can take it.

 

[Judd]

You were fortunate this time...it doesn't always work out that way.

 

[VaniB]

You were fortunate this time...it doesn't always work out that way.

I did NOT chronograph the differences between the two powders. For all we know, there might be a 67 FPS difference and double the standard deviation between the two identical 42.0gr. loads from the two different powder cans. Instead of a matter of being "fortunate this time" maybe it's just that 42. grains of H4350 has a tendency to shoot 140 Amax bullets into a tight group at 100 yards that is known by Hornady to be consistant enough for them to have chosen it as their go-to factory cartridge load. (.... just maybe??)

However, now that I have confirmed that H4350 is the best powder for this rifle, my next H4350 powder purchase will likely be in a quantity that will last me a lifetime. (ie; another two or three 1lb cans.) I can't argue that using powder of the same lots is certainly preferred.

 

[Alex Wheeler]

I have a dasher barrel that shoots Varget very well. The lot was from 2010. I opened a new lot from 2013. The groups doubled in size. Velocity was the same between the lots. Started over with a complete load work up. That's the best it will shoot. I have a target alternating between the 2 lots, big, small, big, small. It wont shoot the newer stuff, something changed.

 

[Lapua40X]

... I would not attribute the group size difference to the powder...

Nor would I. There are too many other variables in the mix to rely on two five shot groups to form a powder lot difference as conclusive cause and effect. If the groups tend to remain somewhat open with the next dozen rounds I'd try a .002 - .003 change in seating depth and see if that ironed it out.