Getting Back To Basics

[truck driver]

Been working with my 300wm and RL26 powder. All I can say is the stuff is amazing if you want speed above normal factory velocities.
After looking at my chronographed velocities I found I was in 300Weatherby territory with velocities or just nipping on the heals. Accuracy has not been what I was expecting and this got me to thinking, bad ju ju when I start thinking but I decided to revisit some old reloading manuals and see what the top velocities for a given bullet weight was and in my case it's the 180gr.
Hornady's second edition shows max velocities at 3100fps. I'm well past that and then some with no signs of pressure.
Now I'm wondering if I have surpassed the original manufactures limitations for this cartridge design and if it's the reason for the accuracy to be other then what I expected.
The newer high energy powders could be causing the bullet to destabilize. If you drop the powder charge down to reduce velocity then you are below 90% case fill.
When comparing the old standard powders with long cut grains that fill the case to 95-100% capacity the velocity is slower in the 3050fps range which is where the older manuals show the most accurate loads.
I realize that not all rifles are the same and the chamber size has a lot to do with velocity and pressure, a tight chamber will produce higher pressure and velocity. Some cases have smaller H2O capacity and made from thicker brass which can cause higher pressure and different velocity from other brass and that's why we weigh them and get a H2O capacity .
Depending on who makes a given lot of brass for Nosler will have a different H2O cap.
My 338 brass is lighter and thinner than some others have and the H2O capacity in my brass is higher. These are all variables we have to consider and adjust our loads to.
After I shoot what I have already loaded with RL 26 and if I don't see any improvement in accuracy that I can tweak I think my next recourse is to step back and look at other powders.

 

[Anonymous]

I tried some Superformance in my .300WSM with 165gr bullets. The velocities were simply amazing but accuracy was indifferent at best and minute of barndoor at worst.

The older I get, the more I realize that velocity isn't all it's cracked up to be.

I went back to my piddling loads of 180s at 2925 that shoots bug holes.

 

[TackDriver284]

I have seen great accuracy in my 300 WM with 180 grain bullets, RL-22, around 3150 to 3200 fps. I seen accuracy fade over 3225 fps. which is out of my node. I have gone as high as 3,260 fps when i saw pressure, the ejector hole mark on my brass head.

 

[Nimrod84]

TD, I agree with your suspicion. But given the title of this thread, I will add that in my humble opinion bullet design (and rifle twist rate) limitations are just as big if not bigger than the the limitations in a given cartridge case.

Small imperfections or design weaknesses in bullets dramatically open up groups as velocity and thus rotational forces increases. Above 3100 fps, I think you have to buy well crafted bullets to get great accuracy. A lot of twist rates are optimized for the light for caliber bullets (150 gr in 30 cal, or 140 gr in 7mm) and for the historical velocities. This causes over stabilization at the higher velocities or a mismatch when shooting heavier bullets at higher than historical velocities.

I'm not sure what bullets you are trying, but you might want to try something different before giving up on the RL-26. SMK come to mind just to rule out the bullets as the limiting factor, but I wouldn't suggest hunting with them...

 

[BretN]

TD,. I think you're on the right track. I only have one gun that consistently shoots well at book max, the rest all shoot better somewhat below that to closer to starting load. I usually use the most accurate load even if it's slower.

My 280 shoots wonderful groups with RL19 and 140 gr AB's, but just above a starting load. RL19 is also one of the highest velocity powders listed by Nosler, so a mild load of that is closer to a max velocity load in other powders. It took me a lot of load development with that bullet to finally listen to what my gun was trying to tell me and be happy with that as the answer. I had just about given up on the AB and RL19 though, and sometimes you do need to do that too. Good luck with it.

 

[truck driver]

Thanks for the comments fellows. Believe it or not I'm loading Nosler AB seconds which have always shot well for me. I loaded up a bunch for accuracy tweak and progressively seated them deeper and the far I jumped them the worse they shot I started at .050" off and jumped .010" up to .090" and gave up since they went from just under a inch to almost 3" with three shot groups.
I've never had this happen with ABs before.
The load was setting on a node and I was expecting great things not the opposite.

 

[ShadeTree]

TD, I can't argue the basics point. It's how I approach every load if possible. I start out seated to the base of the neck regardless of long bullet jump in some rifles. I pick a powder that will be somewhere around 90% case fill or above at a mid range load, and run up the scale. Good ole 4350 works well for a lot of my needs.

A lot of my rifles seem to really like either mid range loads, or around a grain below max. Once I verify the best group, I might try seating .020 both directions if I feel it has room for improvement.

I know it's way more involved than that to find consistent long range tack driving loads, but sticking to the simple basics is the quickest way I'll find a trustworthy sub MOA load for a rifle.

 

[SJB358]

I do my load work the same way a few others do on here, find where the bullet wants to shoot, find a flat spot and shoot paper, find what seems consistent over a few groups and call it. I love seeing the bug hole groups, but I have largely gone away from a bench lately and been much better at my shooting. It doesn't offer the perfect scenario to shoot bug holes, I get them now and again, but not as much as I did off the bench.

I will say it was awesome to see my little brother work his loads just about the same way, found an accurate load in his little 270, shoot it for consistency then just practiced out to 500 yards with it. When it came time to shoot at nearly 250 yards, he executed the shot like he'd been doing all summer... The load chrono'ed a decent 2910 Avg with a 140 Tipped TBBC.. Crushed the elk and couldn't or wouldn't have been better if he'd been pushing it 100 or even 300 FPS faster. I still love speed, but it is something to behold when stuff is kept simple... Was good for me..

 

[Richracer1]

I like the statement that JD338 has in his signature, "Speed sells but Accuracy Kills".

That statement is basically how I do my load development. Start with a powder that has the higher listed velocities for that caliber/bullet combo, then work for accuracy.