Guys,

Dad and I just spent yesterday at the range testing loads for my 340Wby for an upcoming plains game hunt to Namibia. I've settled on the 225gr Nosler Accubond as my bullet of choice. We'd loaded up some testers using IMR7828SSC (we bought 8lbs of it, why not?). The loads were promising in the velocity department, with upper end velocities right around 3050fps. The groups weren't what I'd call bad, but they hovered around the 1 3/4" - 2" range for three shots @ 100yds. I KNOW this rifle can shoot better than this because Weatherby factory ammo gives me much smaller groups.

I want to load another powder to get this load shooting correctly in the rifle (an Accumark). I want 3000fps out of the load and I'm looking for 1.5" or smaller groups. I know Weatherby factory fodder is loaded with MRP which is essentially RL22. Should I give RL22 or RL25 a try next? I've heard a lot of good things about both, moreso for RL22.

Your thoughts, please. Thanks!

What nosler says are most accurate.....

Powder: RL-19
Charge Weight (in grains) Muzzle Velocity (fps) Load Density
83.0* 2942 fps 90%
81.0 2866 fps 88%
79.0 2790 fps 86%

Powder: IMR7828
Charge Weight (in grains) Muzzle Velocity (fps) Load Density
87.5* 2942 fps 95%
85.5 2871 fps 93%
83.5 2800 fps 91%

Powder: Viht N165
Charge Weight (in grains) Muzzle Velocity (fps) Load Density
86.0 2953 fps 93%
84.0 2884 fps 91%
82.0* 2816 fps 89%

I guess we can nix 7828 off your list...got any re19 or Imr 4831 on hand....I'd give them a try next as maybe a faster powder will work better?
ALSO--you may want to try some longer range shooting. One of my best 180 grain 300 wby loads shoots 1.5-1.75" at 100 but settles down to nice round 3"/300 groups which I can definately live with.

Powder is only one accuracy factor. If you are getting good velocity with low standard deviation, then I would first try adjusting the seating depth. You may also wish to try a different primer. See what results these changes have before rushing off to try a new powder. Even with a new powder, you'll have to search for the best seating depth, etc.

Just looked again at your velocities. You might throttle back a grain or two and see what that does for your accuracy.

By the way, your bullet should be a great one for Namibian plains game. I used a .338 Win with Nosler 225 Partitions on a trip there in 2007 and was very pleased. I have since worked up the same load in that rifle with the 225 Accubond and will use it on my next trip. There's no Namibian plains game that a .30-06 won't handle just fine, but the .338 or .340 gives you some margin, so long as you can shoot it well. Good luck, you'll have a great time!

Thanks for the replies.

Stonecreek, I had actually thought about varying the seating depth a little. Since it's impossible to reach the lands in the factory chamber, we've seated the bullets as long as possible so they'll still fit in the magazine. We had actually thought about making the rounds a little shorter in the OAL, as I've heard that shorter may actually be better in factory chambers.

As for velocity, the minimum load shot reasonably well (~1.5"), but still on the wild side for a hunting load. That, and they were only moving about 2800fps.

What's funny is I also tested 225 Partitions with the exact same load data and got pretty much the same accuracy as the Accubonds, but they were moving about 100fps slower. The slippery Accubond really does make a difference! I've got great expectations for it on plains game; it's good to hear of your positive experience w/ the 225's.

I'm not too picky, as this is a hunting load, but it needs to be tighter than this.

quote:

225 Partitions with the exact same load data and got pretty much the same accuracy as the Accubonds, but they were moving about 100fps slower. The slippery Accubond really does make a difference!

What you gotta understand here is the partition is the "slippery one" in comparison to the accubond. The accubond is no doubt making more pressure and thus the higher velocity. BUT it is interesting there is that much difference.

I'm not sure I understand what you mean, kraky. I was referring to the higher BC of the Accubond, but I think you're talking about something else. Can you shed some light for me?

While we're at it, how does everyone else determine OAL for Weatherby cartridges?

I'm assuming your chrono was set close to the gun....although a few people do put them down range....say 200 yds...to check bc. When you said the slippery accubonds make a difference right after saying they were 100fps faster I assumed you meant they were slipperier going down the barrel and that is why they were 100 fps faster.
My point was that a "slippery" bullet goes down the barrel slower than one with more resistance and that if anything the partition is the slippery bullet of the two (going down the barrel).

Clayman, I use 7828 in my 338-378 with 225 grain pills. You might be finding that your rifle likes a powder that is a bit faster. IMR 4831 and H 4831 are some other loads that I have seen that work well in the 340. Which ever powder you use, take into consideration the temperatures you are working up the loads compared to the temperatures in Namibia . Hodgdon seems to be less temperature sensitive then IMR.

Ken....

Heat,

I've read some of your posts before and knew you had good luck with 7828. I can't honestly believe it's the powder, as I know a lot of people have had excellent results when shooting it out of Weatherby rounds. I'm thinking I might vary the seating depth with my previous loads to see if that does anything. Like I said before, I'm not looking for the world, but better than 2" groups....

quote:

Originally posted by Clayman:
Thanks for the replies.

Stonecreek, I had actually thought about varying the seating depth a little. Since it's impossible to reach the lands in the factory chamber, we've seated the bullets as long as possible so they'll still fit in the magazine. We had actually thought about making the rounds a little shorter in the OAL, as I've heard that shorter may actually be better in factory chambers.

As for velocity, the minimum load shot reasonably well (~1.5"), but still on the wild side for a hunting load. That, and they were only moving about 2800fps.

Yeah, the freebore in the Weatherby chamber makes seating depth something of a crapshoot. I would suggest that you try seating to approximately the same overall length as a factory round to see if that makes a difference.

I would try loading to around 3000 fps with this bullet and cartridge. That is plenty of velocity and should come at a reasonbly moderate pressure.

I don't think you mentioned the primer you're using. Generally speaking, slightly milder primers promote better accuracy. Moving down from a Fed 215 to something like a CCI 250 or Winchester WLR might help. In fact, if you do find a favorable difference in primers, don't hesitate to use any standard LR primer, even one as mild as a CCI 200. IMR 7828 isn't that hard to light, and the volume of the case is irrelevant. Besides, you won't have any sub-zero temperatures to contend with in Namibia. But seating depth is more likely to influence accuracy than the primer you're using.

You don't mention the accuracy of any other hand loads in this rifle. Have you used others that equaled the factory loads? If not, then you might look at your loading techniques: My recommendations would be to (1) partial FL resize, (2) make sure your brass is trimmed to the proper and consistent length, (3) properly chamfer your case mouths, and (4) make sure that your seating die is backed off of the shellholder head enough that you are not hitting the case mouth with the crimping ring when you seat the bullet.

Stonecreek,

Seating to OAL of a factory round was my next thought. It's difficult to determine this, as they don't load the 225 AB, so our comparator won't exactly work. I might be able to get an idea using standard calipers, which appears to be the best option right now.

The primer in the loads is Federal 215, and we've had excellent luck with them in other Weatherby calibers in the past. I'll look to seating depth before chaning them out.

The other handloads in this rifle, including the same 250gr Hornady PSP Weatherby loads in factory ammo, will group under an inch with 7828SSC. We're not crimping the mouths, brass has been PFLR'd and meticulously chamfered and trimmed to length, and we're getting total bullet runout in the 3-4 ten thousandths range, so consistency is very good.

The more everyone helps me dig into this, the more I'm thinking OAL is the main issue. Hell, I've got 6 more pounds of 7828 to use; I gotta make this work!

Sounds like you're doing everything right. Sometimes a particular gun just doesn't like a particular bullet, even when both of them are top quality items. However, I wouldn't give up on the Accubond until you jigger a little with seating depth.

If you should give up on the 7828, send the rest to me. The new IMR 7828 SSC is about as close to the fine old 4831 Surplus powder as I've found, and it meters SOOO much better!

FWIW--my 340 accumark has a preference for 250 partitions over anything else I've tried. I have never tried the accubond but would like to. Lighter (200 grain and under) don't shoot well in this gun.
My gun does like the hornady 250 also but really likes the 250 partition. It's hard to argue with a 250 part flying around at 2900 fps.

kraky-- Indeed! Mine loves the 250gr Hornady softs, which is my only other handload for this rifle at the moment. I've got a 250gr Partition Gold loaded to test, but that takes a back seat to the Africa load until next summer.

Thanks, everyone, for the advise. I'll goof around with the seating depth and get back to you - hopefully with nice, tight, little groups!

Call me old school but I've had 3 340s, IMR4831 is the ticket. Speed and accuracy.

Yeah Clayman I have had good luck with the 7828 in my boomer as well as my 257. It's more temperature sensitive then I would like but it does work for me. I noticed Stonecreek brought up the "factory overall length" which is what I do. Even if it's not the same bullet. I match up at approximately the ogive so the overall length will change a bit but the results have been good so far. You might find that this particular bullet likes more or less jump to the lands to be at it's best.

Ken....