I looked in the Nosler manual and modeled some of their loads in QuickLoad. They are scary high in pressure. I called them and they say they are fine, though the pulled the H380 loads out of the sixth edition, or so they said. If you have QuickLoad, try modeling 53.0g of H380 and the 55g bullet (the max H380 load in their 5th edition manual). I get predicted velocities that match theirs but the predicted pressures are way over max. Even their starting load models ~10,000 psi over max. I may be doing something wrong but I've been using QuickLoad for several years and normally get results that are within reason, often within a couple of percent in predicted muzzle velocity.

I'm using Lapua brass which, in my rifle, has a water grain capacity of 53.3g. That's a bit smaller volume than one might expect (I chambered it myself and it is a tight chamber on purpose) but it shoots well and I expect to use slightly lower charges as a result.

So before I load 5 rounds of the minimum load in 5 or 6 powders to get a chronograph reading, and establish at least a safe starting point, are there any powders that have worked well for you?

I'm hoping to get a load that will produce 1/2" groups at a muzzle velocity in the vicinity of 3700 fps or more (more is better if it groups well). I already get 1/2" groups with the 75g V-Max but would like a flatter shooting bullet for ground hogs here in PA that has a little more PBR than my .223 Remington.

Thanks
Fitch

did you mean 243win?

I've used Varget with a healthy dose in my.243 with the 55g Nosler BT. I have worked up to 4050fps out of a 24" barrel in a Rem 700 CDL without high pressure signs. The load is above book but works out great in this rifle with accuracy in the .4-.7's if I do my part.

It is devastating on rock chucks and coyotes here in Idaho but will get moved a little on longer shots with some wind. However, the speed reduces this effect down somewhat.

I've used this load very successfully on two smaller mulie bucks at ranges of 125 yards and about 275 yards with instant bang-flops.

I've found H-380 to be a problematic powder to work with. I think there may be some significant variations in lots, plus it seems to exhibit pressure spikes as opposed to the behavior of IMR powders which are pretty linear.

IMR 4895 did a good job for me when I was shooting 55 grain Nosler BT's in my .243 HB Browning Safari. They were very similar to the 70 grain bullet in accuracy, but the 70 grainer seemed to give me more "action" downrange on the target. I can't recall the exact amount of 4895 I was using, but I worked it up to about 3950 fps and called it good.

Several other powders in the 4895 burning range should do similarly well, such as IMR 4320, IMR 4064, or the new IMR 4007. I haven't tried Varget, but would think it an excellent candidate, also.

quote:

Originally posted by hivelosity:
did you mean 243win?

Oops, yes, I mean .243 Win.

Fitch

quote:

Originally posted by Stonecreek:
I've found H-380 to be a problematic powder to work with. I think there may be some significant variations in lots, plus it seems to exhibit pressure spikes as opposed to the behavior of IMR powders which are pretty linear.

I've had similar experience with H380. It is not high on my list of things to try.

quote:

IMR 4895 did a good job for me when I was shooting 55 grain Nosler BT's in my .243 HB Browning Safari. They were very similar to the 70 grain bullet in accuracy, but the 70 grainer seemed to give me more "action" downrange on the target. I can't recall the exact amount of 4895 I was using, but I worked it up to about 3950 fps and called it good.

I have some IMR4895. I'll give it a try and see what happens. It is promising that the max charge in the Nosler manual models at less than max in QL, though it is very close to max, partly because of the reduced capacity of the Lapua brass in my chamber. I'll start their minimum 40.5 and work up from there. It is such a big range, 4 grains from min to max, I'll start with 3 shot groups in half grain increments to get in the ball park, then go to 5 shot groups. If the loads start to show pressure signs the 3 round sets reduce the number of bullets to pull.

With the new barrel, the action trued, and the bedding job last winter, the rifle is very consistant - a dependable shooter. Not bench rest quality, but nice consistant groups under 1/2 MOA (about a third of the group size as it came from the factory). Just fine for a hunting rifle.

quote:

Several other powders in the 4895 burning range should do similarly well, such as IMR 4320, IMR 4064, or the new IMR 4007. I haven't tried Varget, but would think it an excellent candidate, also.

I have 4320 and 3031 both. IMR4320 looks decent in models, I may try that second. Huh? Just playing with it, IMR3031 looks even more promising than 4320 as plan B, maybe even plan A. It has a slightly slower pressure rise so it may be easier on the throat and yields predicted velocities nearly identical to IMR4895 at equivelant pressures. I'll take 3 round rough screening sets for both 4895 and 3031 to the range on day 1.

I've used the IMR4007SSC in my 9" twist .22-250. It needed really hot loads to group well with the 75g bullets but I did win a couple of factory class GH matches with it. IMR4007SSC models as having about 130 ft/sec lower MV than IMR4895 at equivelant peak pressures, and it looks hotter (faster rise time) but who knows which one might give the better group at such velocities? It did cook the throat in my .22-250 into a reasonable approximation of a dry lake bed in about 2500 rounds and those were only ~36g charges. I probably won't try it unless the first two, 4320, and Varget (as suggested by TEANCUM) don't work.

I'll report back when I have some range data.

Thanks Folks
Fitch

IMR 3031 is getting pretty fast for the .243, even with the miniscule 55 grain bullet. I've always had pretty wide velocity variations with 3031, and besides, it meters poorly. However, ya never actually know until you try it. Won't hurt to take a sample to the range.

Try about 41 grains of Varget and work up.

quote:

Originally posted by Stonecreek:
IMR 3031 is getting pretty fast for the .243, even with the miniscule 55 grain bullet.

Looking at where it is in the list, I agree with that observation. Looking at how it models, I'm a bit surprised by what I see. More on this below.

[/QUOTE]I've always had pretty wide velocity variations with 3031, and besides, it meters poorly. However, ya never actually know until you try it. Won't hurt to take a sample to the range.[/QUOTE]

There are some really interesting timing differences between IMR4895 and IMR3031. Looking at a comparison of the two powders with the 55g Nosler BT in plots of pressure and velocity vs time (instead of distance) they end up sending the bullet out of the muzzle at within a few fps of each other, but 4895 gets it to the muzzle sooner than 3031 about 0.02 milliseconds. Not having shot either one with the bullet ... YET (Come On Midway, I NEED those bullets) ... I don't know what the difference in accuracy will be, but it will be interesting to do the "experiment".

The metering won't be much of an issue, it just impacts how much I have to trickel. I weigh every charge for my rifle ammo on my older than dirt OHAUS 10-10 scale which became the RCBS 10-10 scale some time in the past. That scale settles so fast weighing the charge is not aggrivating.

That scale is also, as a happy coincidence, so much more repeatable than my Redding that the Redding was finally put away for good. For 2 months (May and June this year) I weighed all my rifle charges on both scales. When there was a difference, it was the Redding that was off. Every time, not one exception in that time period.

Fitch (Did I mention I like my Ohaus 10-10 scale?)