Here is the targets for your review. Temp was +30, wind was 1-2 mph at my 6, MV was between about 3200 to 3300 fps.

I tested three loads, 93, 94 and 95gr RL25 under the 178gr A-Max in the 300 Ultra at 200 yards. Scope adjustments were not touched throughout testing.

The first target, large bull was fired at with three shots of 93gr to foul the barrel good before beginning. The other two groups on the first target were fired in a round robin type afair, back and forth. The other two targets were all done in the round robin way as well.

MV and psi averages;

93gr - 3209 at 59,700 psi
94gr - 3242 at 61,600
95gr - 3263 at 62,400

MV and PSI min-max;

93gr - 3197-3228 at 58,8-62,4k psi
94gr - 3222-3265 at 59,8-63,4
95gr - 3240-3302 at 61,1-65,0

Start low and work up if you use these loads, they were fine in "my" rifle, psi here is relative, not absolute.

The dots you see that are outlined next to each group were just put there to note the impact and shot # that was being shot on the target downrange in the next group, same location. This way I could coralate the velocity or whatever to each shot if needed.

The first 94gr group that is pretty small, well I'll admit to pulling the upper right shot down low and left "into" the group by about 1/2 an inch. In other words it would have shot up and right, about 2 o'clock by another 1/2 an inch, I believe. All the other shots broke clean and were dead on the bull, this I'm possitive of, I don't do this half ass.

The last two shots of the 27 fired were the two that went high on the 94 and 95gr bulls on the 3 of 3 target. It was getting dark and I couldn't see the 2nd and 3rd shot at 94gr, the second shot may have been high on this one, the third was definately high on the last 95gr group.

Sorry if I left something out, but ask away.

The first is just a side by side of all three targets in order they were shot. The first target was shot with 9 rounds before removing and placing up the next target and so on. They were shot 93, 94, 95, 93, 94, 95 etc, etc eccept for the first target as I already explained above.









Where would you do further development at and just how would you go about it and why? I'm interested in everyones comments on this if you'll offer them. I have them seated to 3.655" OAL to fit in the mag, this is max length. All cartridges however were indexed by max runout and single fed. I would consider seating them out to the lands if needed.

Brent,

Thanks for sharing your targets...

While there is a teaser group or two there, the tendency seems toward vertical stringing, as I'm sure you've noted as well.

How long did you allow for cooling between shots? What is the configuration of this rifle (sporter barrel, medium, heavy)? Is it glass bedded and/or free floated?

If the rifle is bedded and floated, I think I would look at IMR 4350. This powder just about never fails in large charges such as you're using. It could be that the RL25 is simply not igniting consistently enough.

I know it's a lot to ask, but if you'll get some IMR 4350, and try 79.5, 80.3, 81.1, 81.9, and 82.7 grains with the 178 AMAX's, I think you'll find a more stable load in that string. The OCW would likely be 81.1, but that's a guess.

I don't know enough about the RL25 to comment further on the charge you're using. I would just say that if the rifle's integrity is in check, the load is suspect for the vertical stringing. Ignition can be a problem with powder in that amount.

Keep us informed, and perhaps others will comment as well with some ideas...

Dan

Hey Dan, thanks for the input, sometimes other perspectives are a big plus! Thanks for the suggestion on the IMR 4350 too. I just happened to have picked it out of the Nosler manual a while back and loaded the most accurate load they listed for it, 80gr I believe. It happened to be their most accurate powder too. Well, I loaded up 10 rounds at this load with the 180BT and shot a 2" ten round group at 200 yards the first try. I never have used the powder in this gun since. I bought the RL25 in an aim for a bit higher velocity than the other would "likely" produce. I never cronographed that load though. I wanted better accuracy, even though it was very promising.

The gun is bedded, accurized, and freefloated the whole length in a factory sporter countour.

I let the barrel cool like this, when the muzzle got cool to the touch, I followed it up and waited for it to get the same temp up at the forend too. It went from slight warmth to when it just started to feel cool to the touch again up at the forend. This was very consistant and took about 4 minutes in between each shot at the +30 degree temp outside. The barrel never got but barely even warm on each shot.

I see a shift from a definite left of center on the first target, to more of a center to center-right on the second target, then a fairly centered set of groups on the third. This is perplexing as well. A five or ten round group would surely not be anywhere close to just 2 MOA.

The last few shots seem to indicate the barrel needs cleaning already...maybe.

Dan, I just got a copy of Harold Vaughn's book, "Rifle Accuracy Facts" in the mail today, you'd really, really like it. It is very interesting, and harmonics are dealt with and tested in probably more detail than anything else you've likely seen or will ever see. "You" will love it! Formula I can't even begin to read and a whole lot more than most people ever think to test or much less contemplate. You are one that could appreciate the book and his work.

I'll try the 4350 again, the can is still setting there.

I see what you mean by the better velocity with the RL25...

I didn't ask, but I assume that you used a magnum primer. Which primer?

I think if you're in the OCW zone, the primer should not be much of an issue, but with that much powder, a magnum primer is likely mandatory.

An extra .005" of seating depth may help as well. The sporter barrel might be stringing those high shots with a vertical vibration whip, and once you get the ignition worked out, the stringing should stop. Since you did not see vertical stringing with the IMR 4350 load, I don't suspect the rifle at all.

One last suggestion: If you saw no pressure signs at 95 grains, you might want to see if 96 grains will bring things in tighter. Often, less than optimal charges will create inconsistent ignition and/or burn, and that could be causing the stringing. I do know that some folks are using 96 grains of the RL25 with 180 grain bullets and are reporting very good accuracy.

With the sporter barrel in this chambering, heat will be an issue, of course. It sounds like you managed the heating problem pretty well, though.

96 grains of powder, or seating an extra .005" into the case might well be worth a try.

I like to keep some "conditioning fouling" in my barrels, so I don't strip every trace of the copper out after a range session. I actually believe that more barrels are ruined from excess cleaning than from actual shooting.

With a 300 RUM, you're shooting a helluva lot of powder, and driving some heavy bullets pretty hard. That will cause fouling to accumulate about five times faster than in a .308, or so it would seem. I think if you can get 15 shots off before fouling becomes an issue, you're doing well with the factory barrel.

Take care, and keep us informed...

Dan

Dan,

I was using a 210m primer. This has been suggested as actually being hotter than the 215 in almost every test and chart I have seen.

It would be worth a try to switch and see though.

I know a few people who use the 210m in their 338 Lapua Imp, and 30/338 Lapua Imp with better results than the 215, they shoot 1000 yard BR and have tested both real well to come to this conclusion.

Have you heard about the 210's being hotter than the 215 too? I have some data from other sources, but have not tested the validity myself. I did use them down to around 0 degrees with no problems in the Ultra though.

I think I'll load some up and test velocity, psi, group size and POI shift again, this time with half 210's and half 215's. I'll do this with 4831 and RL25 both and report what I find.

Thanks for the suggestions and observations.

Brent,

I haven't heard that about the Federal primers, but I guess it's possible. I don't understand why Federal would do that...

Maybe the 215's would work better here, or perhaps CCI 250's.

You might test the 96 grain charge of RL25 if the 95 grain charge showed no pressure signs.

Keep us posted, you've got me interested now!

Dan

Hey Dan,

I'll check 94, 95 and 96 grains this go around.

I'll keep you posted and post pics of the two primer charts I have from a test that was published in Precission Shooting magazine some time back.

It is my wife and I's anniversary today, so I have to run right at the moment.

Nawwww, Brent! You can spend the evening on the internet, I mean, she'll understand, right?

(Actually, I'm surprised you got that last post in--under the wire, no doubt~!)

Happy Anniversary, hope you all have a great evening...

Dan