Reloading Trouble I'm 340Wby and TSX/TTSX

[PDub]

Hey guys,

Would sure appreciate some help here! I live up in Alberta, Canada.  Last year, I bought a RC Accumark in 340 Wby. Range Certified target had a cluster of 3 shots overlapping each other using the 225g TSX and IMR 7828. I've tried multiple combinations (3 shot groups) from 88.5 to 92g in 0.5g increments with the only common result being 2 shots touching and the 3rd 1.0" to 1.25" away(several targets). A couple groups were 0.6" - 0.7" clusters, but not the 3 shot touching like the Range Certified target.

I've been reloading and shooting for many years with much success, so I'm confident in my reloading practices and my shooting techniques.

Another question: how much run from the lands should I give my bullet?

Any help is GREATLY appreciated.

-PDub

[Blackbear3]

PDub, I'm sure your probably letting your rifle cool all the way down while trying to shot your groups? The Range Certified models are shot indoors in a controlled environment, not sure how long they take to shot them. If you look half ways down the page I have a post on my new Arroyo 340, no plans on reloading for it until next year.

[valkyrie]

PDub, I have the same rifle and my Range Certified target identifies the load as "B340225TTSX" which is the product code for Weatherby factory ammo using Barnes 225 grain TTSX bullets.  I doubt that Weatherby factory ammo uses IMR 7828 powder or that the factory hand loads their test rounds so my first question would be why do you believe that IMR 7828 was the powder used in the test rounds for your rifle?  If something other than IMR 7828 was used in the test rounds for your rifle, then your load development efforts have served to demonstrate that IMR 7828 will not produce the same results as Weatherby factory ammo.  (I do not believe the powder used in Weatherby factory ammo is available commercially.)

With regards to how far off the lands you should seat the bullet, the Weatherby FAQ identifies the freebore on the 340 Mark V as 0.373 inch so you're not going to be able (and shouldn't attempt) to get anywhere close to the lands.  As I understand it, the large freebore is necessary to maintain safe pressure levels.  The Barnes web site identifies acceptable cartridge overall length which I would think would be a good starting point.

Good luck!

[eford]

I agree with the barrel temperature as the likely reason the third impact point being father away from the others. Since the first two are close, I think you're OK as far as hunting accuracy goes.

For cartridge length, my 257 and 300 Weatherby's have their best accuracy with bullets seated out as far as the magazine allows, regardless of bullet weight.

Good luck and keep us posted.

[zonie]

unless something has changed powders used in  factory Wby brand cartridges are blended and not for sale to the public ?  Measure  the same factory ammo that was tested in your rifle, and see what the coal is and start from there.  Powder  you might look at RL22 maybe MRP ,  can't say if Norma Wby ammo uses Federal primers ? Worst case scenario you could call or e-mail Norma and ask what the closest on the shelf powder for that particular factory ammo,  they might say it's in between x or y,  then do your load work up .  Keep in mind rifles can change with age and environment,  stock torque values may change a little  along with other factors. 

[7mmweatherby]

PDub I had a experience with a 30-378 almost exactly what you mentioned

I wasn't giving enough time between shots was having different barrel temps once I discovered the problem letting completely cool off groups tighten up

I have to say  was one of the worst caliber I had for doing that then again burning a lot  of retumbo hope you find your problem lot good info posted here

Enjoy your day Mike

[eford]

I remember reading that MRP was very close to the blended powder used in Weatherby's factory loads.

With RL-26 and 180gn Hornady Interlocks I was able to get a decent shot group with MagnetoSpeed measured velocities @ 3224fps in my 300 Wby. That's close to the factory ammo listed @ 3250fps.

[zonie]

maybe I'm reading your original post a little wrong.  are you saying your rc rifle came with a test target using 7828 powder OR was this your load ?  I doubt Wby techs are letting the barrel cool down I suspect they are shooting the test load one right after the other with a little time in between to scribble things down or other tasks if needed.  throwing one flyer in pretty common it could be something as simple as the bullet seated cockeyed  a little out of round, run it on a concentricity / bullet run out tool such as  hornady  then straighten bullet as needed on the tool,  it's a possibility,  I'm a firm believer in straightening bullet run out.

[catskinner]

like the others, i'm curious about the test target using 7828, I thought they only used factory ammo for their testing.

BTW, welcome to the nation. Which part of Alberta you in? I'm in the Lloydminster area. 

Rob

[PDub]

Sorry guys,

Haven't been able to reply until today. Thanks for the feedback, a lot of information to play with. I'll try to address each question, so bear with me as i'd like to hear your feedback on my reply.

BlackBear3 - I'm pretty careful on letting the barrel cool, that being said, I'll fire 2 consecutive shots (or 3 on a lighter caliber or barrel) and let the barrel cool (to ambient) before continuing with load development.

Valkyrie - Sorry, my error on the 7828. I was loading with 7828 because the Barnes Manual calls 7828 the most accurate for the 340 Wby using the 225g TSX, my 300Wby and 300 Win absolutely LOVE the 7828. I was loading to the mag length, but will check where the lands engage the 225g TSX and refer back to the manual.

eford - It's not always the 3rd shot that is the stray, sometimes the 2nd (only shoot 3 shot groups for load development). I had this problem with my 7 STW built on a Mark V action; haven't solved that one yet.

zonie - my mistake, i was only loading with the 7828. I did buy a box of the 250g Wby factory ammo to use to break in my RC. Very disappointed as it shot 1.5" - 2.0" groups on break in.
        - nope, you read it right; I wrote it wrong. 7828 is NOT listed on the RC paperwork. I do check concentricity of all my reloads, and will straighten all that measure 0.003" or greater. I'm a firm believer as well, especially when there is considerable freebore.

7mmweatherby - I HAVEN'T tried cooling to ambient after each shot. I'm careful to never let the barrel get hotter than "warm" on load development (2 consecutive shots, maybe 3 on a light caliber). Did you let each shot cool to ambient? I'll give that a try.

catskinner - Um, ya, no. My error, 7828 was my choice of reloading powder. I'm over here in Calgary. PM me, as I'm curious on your choices for 257 wby, 300 wby, 340 wby and 378 wby. I've no problem trading reload data.

I've attached a few of my targets I reference back at my bench. You'll see where 2 shots are close (or same hole) and the 3rd is 1.25" away. A couple others are closer, but for a RC i expected better and according to the Barnes Manual, the velocities are not as high as expected. I reference the Barnes Manual as I don't have a crony or magneto to measure velocity and it was Bang on with my 300 Wby and the 180g TSX (which I did crony a while back). 

Thanks for the info guys and please comment back on anything you think I'm overlooking!

-PW

[wyominghunter]

There are a lot of possibilities and I hate to even speculate. You might use a search term in Google called "two grouping" or "double grouping". You should find some things to try or look at that way.

[oregonmarkv]

Pdub, from a lot of reloading with 340 wbys the IMR7828 will work well at least with 200g bt and 250g partitions from my experience.

[.257]

I have noticed when you have one flyer like that, it is seating depth, I would take your best load and adjust seating depth. After that I would look at primers, although with magnum loads you don't have a lot of choices there

Good luck

[catskinner]

I would start playing with the seating depth's also and see what happens, maybe some one around here has some factory 225 tsx ammo that can give you the COAL of it, so you can use it as a baseline, or if you can get a box of factory 225 tsx ammo, you can see how it shoots for you in the rifle.

I have used a lot of 7828 over the years, and had pretty good results in most weatherby caliber's over the years. the last few years, I been using mostly H450 in most of my weatherby's, I got 24 pounds of it, in an estate auction, a few years back cheap, and my Scottish blood has worked up decent loads using it   

Rob

[Fotis]

Hey guys,

Would sure appreciate some help here! I live up in Alberta, Canada.  Last year, I bought a RC Accumark in 340 Wby. Range Certified target had a cluster of 3 shots overlapping each other using the 225g TSX and IMR 7828. I've tried multiple combinations (3 shot groups) from 88.5 to 92g in 0.5g increments with the only common result being 2 shots touching and the 3rd 1.0" to 1.25" away(several targets). A couple groups were 0.6" - 0.7" clusters, but not the 3 shot touching like the Range Certified target.

I've been reloading and shooting for many years with much success, so I'm confident in my reloading practices and my shooting techniques.

Another question: how much run from the lands should I give my bullet?

Any help is GREATLY appreciated.

-PDub

What is your COAL?