300 Weatherby mag Handload

[poplarking]

I have been handloading for me 30-378 with Retumbo powder. I would like to use this powder for developing a good load for my brothers 300 Weatherby Mag. We are loading 180gr Accubond, weatherby brass, Fed 215 primers. I was thinking of starting off with about 80gr and checking the speed with my Chronograph. Any ideas or experiance with retumbo and a 180gr Accubond in the 300 Wb mag.?

 

[kraky2]

I found retumbo to work great in my very fussy 300 ultrlight. As a matter of fact I was just about to spring for a new re-barrel. I found that it loved 200 grain accubonds at 86 grains and 180 tsx's at 88. The 88 grain load is doing about 3250 and that's with hornady brass which doesn't have the same capacity as wby. Wby brass does about 3210 in my gun. Retumbo is slower than H1000 but just a tad bit. I would recomend that you start with H1000 data and work up an extra grain or two with the retumbo. Starting way down at 80 grains would be a big waste with a 180 and retumbo.....I'd say load up 3 loads at 85, 86, 87 ea and go to the range and see what they do. Good luck....I hope it shoots as well for you as it did for me. Also, I did play with temp's with the retumbo a bit. It shot the same velocity at 20 degrees as it did at 65 degrees. (Not huge extremes but that's pretty much what I would hunt in 95% of the time.)

 

[MagnumManiac]

poplarking,
I think you may find Retumbo to be a tad too slow for 180gr bullets,I'm getting awesome speed with either H1000 or RE25,both on or above 3200,depending on how hot you load 'em.In a 28" barrel!I don't load 'em real hot,I like my brass to last a while.(it's very expensive over here!)
Another thing you will find is that the Accubonds get higher velocity with lower pressures than other bullets,this is why I recommend H1000 or RE25.
H1000 start load 83gr-max load 88.5gr.
RE25 start load 83gr-max load 88.5gr.
I use Federal Gold Medal Match Magnum primers for all loads in this cartridge.
Good Luck!
MagnumManiac
gun)

 

[kraky2]

Magnum...not trying to start an argument but I don't understand your post. The guy wants to try retumbo and is looking for someon who's used it. I post that it worked great accuracy wise and got me 3250 fps with a 180. You come on with apparently no experience trying it and tell the guy you think he'll find it's too slow a powder?
One last question...can you explain your comment about how accubonds get higher velocity at lower pressure than other bullets??

 

[MagnumManiac]

Magnum...not trying to start an argument but I don't understand your post. The guy wants to try retumbo and is looking for someon who's used it. I post that it worked great accuracy wise and got me 3250 fps with a 180. You come on with apparently no experience trying it and tell the guy you think he'll find it's too slow a powder?
One last question...can you explain your comment about how accubonds get higher velocity at lower pressure than other bullets??[/quote
Kraky1,
To explain how Accubonds get higher velocity with less pressure would take a book!
Here's a simple explanation.
If you have used Accubonds or Ballistic Tips a lot,you would have noticed that for a long bullet,which they are longer than other bullets of the same weight,they have less shank that engraves the rifling,which means,as my tests over my chronograph have proved,they get higher velocities with less powder than other 'conventional' style bullets of the same weight.
Less powder means less pressure.

Now for your other comment,you stated,Retumbo worked GREAT,and got 3250.
I shoot a 300 Weatherby!
I have found Retumbo to be TOO SLOW for this catrridge with 180gr Accubonds for the above reasons.Which means that you can get very high velocities without the need for ULTRA SLOW powders.
You quoted using Barnes tsx 180gr bullets,which anybody that has reloaded for more than 5 minutes knows they produce HIGHER pressure than anyhting else,therefore needing a SLOWER powder to get published velocities.
Hope this answers your question.
MagnumManiac
gun)

 

[kraky2]

Actually..what I think you are trying to say is that accubonds make more pressure with less powder. Because that is what is actually happening. ANY time you have a longer bullet with more bearing area it makes more pressure....not less. Just like moly coating makes the bullet slipperier and people have to actually add powder to get the pressure and velocity back up again.
As far as a big difference between the accubond and the tsx.....maybe one grain...maybe not. I've played with lots of both and find them to be so close to one another that I would never say that one powder could work for one and not the other.

 

[MagnumManiac]

Actually..what I think you are trying to say is that accubonds make more pressure with less powder. Because that is what is actually happening. ANY time you have a longer bullet with more bearing area it makes more pressure....not less. Just like moly coating makes the bullet slipperier and people have to actually add powder to get the pressure and velocity back up again.
As far as a big difference between the accubond and the tsx.....maybe one grain...maybe not. I've played with lots of both and find them to be so close to one another that I would never say that one powder could work for one and not the other.

I think you better read my post a little more closely,I stated that accubonds have less bearing surface than TSX bullets,and most others,which gives LESS pressure.The Accubonds do not give higher pressure with less powder,because how would I be able to load above listed max loads and still be in the SAFE level of pressure.The Accubonds and Ballistic Tips are what you would call 'powder efficient' bullets,because as I stated they get higher velocity with LESS powder.It is not the pressure of the cartridge that moves the projectile,it is the GASES produced,in this case the bullets move easier through the bore at lower PRESSURE.
Pressure has very little effect on velocity,a 10% reduction in pressure may only give a 2% reduction in velocity!FACT!
You have contradicted yourself with the bit about moly coating,it DECREASES pressure so you can use more powder to get higher than normal velocity.You cannot compare the two,because a 'normal' bullet isn't 'slippery' like moly is,but you can compare Barnes bullets to others,they ALWAYS produce higher pressure with LESS powder,as much as 5grs less powder for max loads!
I have done extensive testing on this subject,comparing bullets of different length,shape,hardness and construction,and they all vary in how much velocity they will get with a certain powder charge (the control charge).Accubonds and Ballistic Tips have ALWAYS given the highest velocities in these tests,regardless of calibre or weight.
MagnumManiac
gun)

 

[kraky2]

Someone please chime in and help this guy! BTW--Just measured a 180 accubond and a 180 tsx for bearing area with a bullet comparator and caliper. REsult....Accubond has .559 shank to engrave the rifling...tsx .447. In all honesty I thought the tsx would be less (But it is still 20% less). And I should amend my statement about long shank bullets making more pressure to say....any time you compare two bullets of like alloy and lead hardness....the longer shank WILL ALWAYS MAKE MORE PRESSURE.

 

[Dknox]

What issues would I have working up some loads with Retumbo and 185 VLD's......I have a ton of supplies for this combo...I'm trying to help a Buddie out...please any info ..Thx ,Don

 

[Long Time Long Ranger]

The problem you will run into using retumbo with the 180 grain and lighter bullets in the 300 wby is you run out of case capacity and will have a very compressed load. A faster powder would be better. Something in the h4831, re22, imr 7828 range. Retumbo will work you will just have a very compressed load with a very full case. Your 80 grain load of retumbo is way to light a load for the 300 wby with 86-88 grains being a good load but you will be crunching powder.

 

[Lefty7mmstw]

Put a strain guage on that thing or you don't have a clue what the pressure is. I had one on my last 7stw and it was an eye opener. Many things I thought were true suddenly weren't.

As far as retumbo in the 300 wby, go for it. I do like rl25, but if single base floats your boat, that's one of the best for that cal. Use the hodgdon website for charge weights. If data is available, I use it. We were using Retumbo in a 300 win and getting top speeds, so the wby with its 10% more capacity will not be a problem at all.

 

[Dknox]

Thanks fellas ....can I pull the bullet out a bit,even though its a free bore?as long as they fit in magazine well?...that should take care of crushing powder right?? . Thank you soo much for your imput .Dongun)

 

[gerryb]

I find I can load more powder with the TSX bullets as they have the bands. In about 30 of my rifles the powder charge with the TSX is either equal to or a little more than my accubonds loads. I like both bullets and get good velocity with both but the accubonds have a higher bc and out past 400 yards there is a difference. I would try 7828 also and retumbo may shoot the best in your gun , if you had some MRP powder it really gets good velocity in the weatherby rounds. Heck try them all and see which one gives speed and accuracy.

 

[alaska]

The best powder I have used in my 300 weatherby with 180gr Part or GrandSlam is

26" barrel is best to get the most VEL

Reloader 22 @ 84.0
fed 215GM primer in WBY cases