I know there are a couple of you guys out there that have performed extensive research and reloading on this cartridge and I've been loading this cartridge for about two years now. A friend of mine and feloow AR poster suggested and with good reason, that some of my loads might be to hot, so I solicit your opinion on the following:

Weatherby has waxed and waned on their advertise velocity for the 250gr offering throughout the years. Originally, they touted an MV of 2850 fps at about 50k PSI. This data was published in their old 'Weatherby Guides'.

Ove the last few years however, they've bumped up their advertised velocity to an even 3000 fps with their factory loadings. When I bought my Accumark, I started loading using their recommended 84.9gr of MRP at an advertised 2850 fps and about 49,600 average breech pressure. I also tested their factory offerings and they produced velocities in the mid 2900s and very accurate.
Well my stated loads above came in at a SCREAMING 3022 plus FPS with great standard deviation and zero pressure sign that I could tell, other than velocity of course which is an indicator of pressure of course if the speeds are too high. Barrel is a 26" Krieger factory.

So, my question is this, given the fact that Weatherby advertises 3000 fps and my loads show no visible pressure signs (loose primer pockets start at about the 5th or sixth reload), is the aforementioned load too hot? thanks, jorge

Jorge,
From what you say the load is probably ok.

It may in fact be over SAAMI spec but we don't know that. Velocity is indeed a pressure sign but used alone it's nearly meaningless.

I now use the primer pocket test as my primary test criteria. I used to use CHE but others here have convinced me that it's not as useful as I thought it was.

If it was me in your shoes, I'd back off one grain and go hunting. That's still an awesome amount of power.

I have no hands on with the 340Wby. But using Loadtech to arrive at your load I need to set the bullet out to a COL of 3.6 and run pressure to the 67,000 range and I can 3020+/-. Longer throats on Wby, case capacity etc will vary this data.

Like vapodog said if it were mine I would back off just a touch. A gror even two should only drop you 20-50FPS. How dead does he need to be. Those two grs drop pressure 3-5000psi

Well gents, I couldn't stand the suspense so I pulled some bullets apart. Yup, you guessed it, they were hot-loaded to 87.1gr. Guess my balance beam scale was off that day. Max load according to Weatherby is 88grs, so I should be ok now as the rest of my reloads were clocking around the mid 2900s right in line with factory. jorge

My last one had a 24" tube and my 250 load went just over 2900 with good case life. I would consider 5-6 loadings decent, I generally chuck my brass after this many loadings anyway.

If the primer pockets are tight for five or six loadings,you shouldn't have any problems.

By the way,this was taken from the kreiger website

quote:

Q: Why is there some confusion that we might do button rifling?

A: In 1999, we started another barrel company Criterion Barrels that manufactures button rifled barrels for the O.E.M. market. These barrels are not directly for sale to the general public. Recently there have been some magazine articles written regarding this company which has caused some confusion. Be assured that when you order a Krieger Barrel, you are getting a single-point cut-rifled Krieger Barrel.

The barrels on the factory weatherby rifles are the Criterion barrels according to the weatherby site.The criterion company is owned by Kreiger as the above quote states,but the barrels that are factory installed on the weathery rifles are not the actual Kreiger barrels as many people mistakenly assume.

I realize this is picking fly-shit out of pepper, but the quote below is from Weatherby's website:
Kriegerâ„¢ Criterionâ„¢ #2 contour button-rifled steel barrel. Krieger Criterion barrels are known for their quality and ability to maintain excellent accuracy.

Maybe the land sharks can weigh in, but I think calling it a Krieger is within the "spirit" of the above statement. Bottom line, who gives a shit, the rifle is a tack driver out of the box. jorge

Just returbed from the range gents, where the temperature was 80 deg & sunny. I hate Florida,,,Anyhow, I carefully loaded a new batch, ensuring 84.9gr of MRP and my loads are a comfortable 2958,56 & 60. That's more like it I guess, although deep down I think I was ok with the 87.2 and 3050 fps. Thanks to al for the help. jorge

Find some of Bob Hagel's writings -- Handloader and Rifle magazines back in the 1970s and '80s and several books including Game Loads and Practical Ballistics for the American Hunter.

Hagel used the 340 Weatherby and wrote extensively on it.

His loads were considered hot by some, but were tested at both Speer and Nosler. He used them for years without difficulty. I have used Hagel's loads for over 30 years without difficulty.

Hammer

quote:

His loads were considered hot by some, but were tested at both Speer and Nosler

Yet for some reason nosler is extremely conservative with the weatherby and ultramag cartridges.Their data is so conservative that they are producing less velocity with a 165gr bullet out of a 300wby mag with a 26" barrel than with the same bullet out of a 300winmag with a 24" barrel.They also have the 30-378 with 180gr bullets producing more than 200fps less than factory loads.

I own the 338 RUM and I usually shoot my 250 gr bullets at 2970 fps. I think thats fast enought.
I mean dead is dead.

Jorge,

No offence but any 340 pushing a 250gr at 3022fps is way over max pressure. With the same bullet and 115 grains of Retumbo the 338-378 will max out at just under 3100fps. There is no black science here just heat, expanding gas, and pressure.

The serious question is how does your 340 match the speed of a case that has 30 grains more powder to expand?

Weatherby gets 2950fps or so by using some form of high energy powder...Not by using MRP. Weatherby has bumped their advertised velocity not the load data.

I have been shooting the 340 since the late '70's and back then the only powders (odd balls aside) that worked properly were MRP and H-4831. To this day (give or take a grain or so) I use the same loads.

2900fps is plenty hot in the 340. 2850fps is a safer bet.

I'm not here to pee on your 340 fun parade….just trying to keep you safe.
Take care Jorge.

Jamie

Xman: your post is exactly the kind of info I was looking for and I thank you. The load I am using is right out of the old Weatherby guide and it is not their max load of 88gr MRP.

Current factory loads give me the mid 2900s and so does the 84.9gr MRP I am using. Maybe I have a "fast" barrel in my Accumark? I've been keeping careful track of the brass and expansion is not excessive and primer pockets are fine until about the 5th or 6th reload. I've shot it in temps exceeding 90 degs with no problems, What I do find vexing is how Weatherby, trhoughout the years has moved the velocity of this cartridge up and down more than any of their other calibers. I don't like to hot rod my reloads at all, I just picked this load BECAUSE it was below max and it turned out very accurate. In fact, since MRP is no longer available here in the US, I've converted all my other Weatherbys to other powders, but I've hoarded my last 3lb of MRP just because the load is so accurate and had shown no signs of pressure. At least to my untrained eye anyway. Any other suggestions would be appreciated. jorge

quote:

Originally posted by stubblejumper:

quote:

His loads were considered hot by some, but were tested at both Speer and Nosler

Yet for some reason nosler is extremely conservative with the weatherby and ultramag cartridges.Their data is so conservative that they are producing less velocity with a 165gr bullet out of a 300wby mag with a 26" barrel than with the same bullet out of a 300winmag with a 24" barrel.They also have the 30-378 with 180gr bullets producing more than 200fps less than factory loads.

Sorry Jorge did not mean to but since it was brought up...

I spoke with Nosler in regards to their load data on the 300 and 30-378 weatherby...They told me their data was based on Weatherby's own pressure specs...go figure...

That's about the time I started using other bullets for big game...Barnes TSX, North Forks, and Woodleigh that's all I use now....

Jim: I'm in the preocess of switching over wholesale to the TSXs in every caliber I won. jorge

The tsx bullets seem to produce slightly more velocity than most other bullets without seeing pressure signs,at least in my rifles.Usually 40fps or so.

quote:

Weatherby gets 2950fps or so by using some form of high energy powder...Not by using MRP. Weatherby has bumped their advertised velocity not the load data.

I'm not so sure Wby uses "enhanced" powders... I think they load standard powders but load hot.

I chron'd a friends custom 340 (26" HS bbl.) some years back (wtih Wby freebored chamber). The ammo was Wby factory 250's from the late 1980's. It chrono'd right at 3,020 fps average velocity.

Would I load that hot? Nope. Personally I'd load right around 2,900 (or in that neigborhood, wherever it shot best up to 2,950) and call it good.

Jorge of all people needs no admonition's about "old vs bold pilot's" of that I'm sure!

Brad: I'm off to Pensacola for my "twilight tour" and I'll get to dust off my wings and get to do some intructor flying, so THAT will qualify me for "old AND bold!" Regarding this 340, I'm just going to "hold what I got" with the aforementioned load in the mid 2900s and call it a day. I think 2850 is not taking advantage of the round's full potential. Hell, I can get 2780 with 70.1gr of RL-19 in my 24" barreled 338 Model 70 and 250 Partitions.

Incidentally, in my experience, Weatherby DID load their ammo hotter in years past. I just shot some early 80s 139gr 7mm Weatherby that clocked right at 3500. I got to thinking I might have an optimistic chrono, but my friend was there with his chrono and they both recorded the same velosity. Temperature was in the Mid-80s. Incidentally, the higher velocities with TSXs in all calibers has been my experience as well. jorge

Jorge, best wishes to you on the tour! Naval carrier piolts are the best and you have my highest admiration that's for darn sure!

Yeah, sorta forgot "bold" and "carrier pilot" are one and the same ...

The thought comes from being raised by an old Air Force, Bush and Airline Pilot!

Take Care...

PS, totally agree... I'd run the 340 right where you've got it. I'll bet it's just fine.

Weatherby certainly has loaded some ammunition very hot over the years.My 257wby produced 3555fps,exactly as advertised,but every round showed extrusion marks,and when I reloaded the brass the primer pockets were noticeably looser than with new brass.My 300wby brass showed .0025" expansion at the belt after firing,again very hot.

Jorge ---- I have shot two .340 Wby's extensively, at present I have only one, an old Sporter Model that has been through hell and high water with me from Colorado, New Mexico and Alaska. The second .340, a Sako became a Browning skeet shotgun. In looking at all my charts, (I chart every shot I have fired as to load, temp, accuracy, chrony reading, etc.), I find the following. One barrel liked 225, 240 and 250 grain bullets, this is the one I kept. The other liked 225 grain bullets only. When I say liked, I mean I could achieve one hole groups with those weight bullets with that barrel, when all things were right with the rifle and myself. 2000 plus rounds have told me RL-19 was my best powder from 85 to 88 grains with 250 grain and 240 grain North Fork bullets and 250 grain Nosler Partition Gold bullets were 2950 to 3018 fps. The 225 grain bullets with Swift A-Frame, Sierra, North Fork, Nosler, Barnes x and XLC and TSX, would do 3100 to 3150 fps. These loads showed no signs of pressure. I tried several powders but only RL-22 was a distant second in accuracy to the RL-19, Fed 215M primers only. If you have not tried RL-19 in your rifle you might look at it. Are my loads too hot, only a strain gauge would tell, maybe that is next on my list. Good shooting.

Thanks, Pat. This thread might turn out to be a "Reference Standard" thread for all us 340 shooters. I like the cartridge more and more each time I shoot it. Even thinking of buying aother 340, a standard MKV Deluxe to take too AFrica and leave my Accumark for my future moose & bear hunts. jorge

Jorge:

What do you define as "loose" primer pockets? My cases never feel as tight as when they are virgin (ha ha) but if the primer doesn't stay seated after 5 loadings, it chews up the brass too much for tastes.

I consider primer pockets loose when the primers offer very little resistance when being seated.I have seen the primer pockets so loose after only two firings that some of them would move in the case if you tapped the rim of the brass on the reloading table.

Az: It varies with brand names, it's rather subjective, but I define soft as when resistance is almot imperceptible. When I get that, I "wrap" the cartridge on it's edge to see if it starts to come out. I've never had tht happen, but when I do get an easy fir, I discard the case after tht last loading. Sorry I can't give you a more definitive answer. jorge

Jorge, been following this a bit...having no experience with the .340, but picking up some tidbits here and about. Fella named Darryl Cassell used to hang out at LRH that was shooting a .338/.416 'cat. He used his brass three times, max. Pressures in the 70kpsi range and he knew it, but don't think he had loose primer pockets at that level. May be recalling this incorrectly about Cassel FWIW, but in my limited experience if your pockets are loose after 5 loadings you're kinda hot...it is iffy to guage your loads on that index. Even Elmer Keith went to a similar wildcat to beat 3000 fps with a 250 grain bullet...safely. Also, for the record, that Cassell fella was shooting 300 gr SMK's at around 3100+ fps. 40" barrel.

A little late here... But I average right aroung 2940 fps out of my Mk V SS in .340. This is with a 250 gr. partition and 86 grs. of RL22 which is for practical purposes the identical twin of MRP. This is a running average over more than 1500 recorded rounds shot.

The factory fodder with the same bullet reaches spec out of my rifle right at 2960 fps. My .340 has made me lazy as Rl22 has given me such exceptional results from the get go it is the only powder and the Partition is the only bullet I have tried and used in the ten years I've had the rifle. Though the new 250 gr. TSX and 240 gr. NorthFork are tempting.

I forgot to add this is using Weatherby headstamped brass and Win. large rifle primers. With my current lot of brass I'm on the seventh full power loading and the primer pockets are still acceptably tight. So I predict that the pressure in my rifle-load combo is within operating spec.

Good info Dave. Since I'm using 85gr of MRP and getting about the same velocities, I think we're fine. Max book load for MRP is 88gr. Only difference is I use Fed 215M primers. thanks, jorge