Too much powder? Beginner needs some help!!

[ru1234]

I've got a Weatherby 30-378 Accumark and am shooting a 180 Barnes TSX. I came up with some loads using Retumbo powder based upon Hogdon's website that shows a 113grn max for a 180gr bullet. The load that worked great for me was 110grn of Retumbo that averaged 3415fps. I then checked Barnes website and they show the max to be 105gr of Retumbo.

I haven't had any over-pressure signs like sticky bolt or flattened primer, but if I look very, very closely I can see an ever so slight ejector mark. Half the time I cannot even see it unless the light is just right.

I also checked Weatherby's website and they show their factory ammo with the Barnes 180 going 3420 at the muzzle.

Soooo..I'm thinking I'm okay with this load, but I want to make sure.

Opinions?

 

[britz]

I am not familiar w/ the 30-378 wby mag, but here is some general advice. Better safe than sorry. Just because Wby pushes their bullet faster doesn't mean the you can match these speeds. Wby may use a different powder that will produce more acceptable chamber pressures with that particular bullet. I cannot give you any reasurement on increasing your powder level. However, I generally look at the primer to tell if the powder level is too high. However, I would be vary concerned about the discrepencies in the powder levels!

 

[auton]

Reloader 25

I beleve Reloader 25 will fit the bill!

 

[NYLES]

Here is what Barnes vol 4 will say....

.30-378 WEATHERBY MAGNUM

180 TSX

MIN MAX FPS
H4831 91.0 97.5 3277 87%
MAGPRO 93.0 98.0 3220 79%
RL 22* 91.0 97.5 3256 87%
7828SSC 89.0 97.0 3209 83%
AA870 112.5 118.5 3286 96%
H1000 95.0 102.5 3191 91%
MAGNUM 98.5 106.5 3278 87%
RETUMBO 97.0 105.0 3242 95%
US869 112.5 119.5 3318 96%
H50BMG 108.5 116.5 3270 104%


Your 5 grs over with no signs....I dont see a problem with that. I ve loaded alot 5 grs over with no signs. Also Ive noticed vol 4 seems to be more conservative than vol 2 or 3, I just wish it was published so we could have TSX load data and not be playing these guessing games without spending $50 to access the info on the net.

 

[kraky]

I've played with retumbo a quite a bit in 30-378, 300 wby and 300 win mag. I can tell you that in the 30-378 hodgdons data is strong and Barnes is weak. That being said I think you are at the max. You don't want to shoot in significantly warmer weather than you have done your testing and you don't want to let the bore of the gun get overly fouled. Personally if you could find a load down at 3350 that shot really good I think you would be better off when you get out in the field hunting. Moisture, dust, crap that can get into barrels after days of hunting can jump the pressure a bit. I found this out in Alaska with my 340 wby after 3 days of solid rain. Even though I had the barrel taped moisture had gotten in.
If you have a hand held primer you will "feel" in 2-3 loadings if those loads are too hot as your primer pockets will most likely be getting loose. Weatherby brass is a bit soft and will tell you pretty quick if your loads are hot by expanding the primer pockets.
These are my opinions...others may try and tell you different.

 

[CAM]

ru1234

1+ for what Kraky said!!

This fire breathing demon is very tempermental.

CAM

 

[ru1234]

Thanks for the replies gentlemen. Anyone else?

 

[ru1234]

Anyone know if the discrepancy between Hogdon's and Barnes would have to do with the type of bullet tested? Hogdon's used a Speer not a Barnes. I thought that since they were the same weight bullet they would take close to the same charge.

 

[James H]

I am loading 111gr. Retumbo in my 30-378 using either Barnes 180TSX or Hornady 180IB both get just over 3400fps in a 26" tube(barrel is really too short for this overbore ctg).
Anything more and bolt starts to get sticky and primer pockets swell.

 

[kraky]

The diff's are probably more in the barrels they tested them in. HOdgdon might have actually tested in a barrel with freebore. There are alot of people having custom guns made up nowadays. Some people are having them made without freebore and this TOTALLY changes the volatility of weatherby cartridges. It would be my opinion that Barnes is showing low data trying to protect themselves from one of these types of guns or a situation ike that. It's very important that you not just trust one source of data for your reloads....especially in a bad boy like the 30-378. It is critical that you cross reference as much material as you can.
By the way sometimes powder manufacturers change their minds big time after publishing data. When Retumbo came out they said 84 grains was a max load under a 200 grainer in 300 win mag. A little while later they published data for the 200 accubond at 78 grains.....that is a BIG change of heart there!!

 

[ru1234]

[ QUOTE ]
The diff's are probably more in the barrels they tested them in. HOdgdon might have actually tested in a barrel with freebore. There are alot of people having custom guns made up nowadays. Some people are having them made without freebore and this TOTALLY changes the volatility of weatherby cartridges. It would be my opinion that Barnes is showing low data trying to protect themselves from one of these types of guns or a situation ike that. It's very important that you not just trust one source of data for your reloads....especially in a bad boy like the 30-378. It is critical that you cross reference as much material as you can.
By the way sometimes powder manufacturers change their minds big time after publishing data. When Retumbo came out they said 84 grains was a max load under a 200 grainer in 300 win mag. A little while later they published data for the 200 accubond at 78 grains.....that is a BIG change of heart there!!

[/ QUOTE ]

Kraky- I'm assuming more freebore equals less pressure than one without much or any freed bore? Sorry for such a newbie question.

 

[kraky]

YUP..you got it right. Last fall I did some reloading for a friends guns. He had two custom weatherbies made by the same guy. He wanted to try the 200 accubond. I started halfway between min and max loads with RE25. We started with virgin 300 wby brass. The one gun just loved it and had no signs of pressure. All excited he fed the same recipe and batch of ammo to his other gun and it blew 2 primers and almost froze a bolt. WE came to find out later that the last gun was built without freebore as my friend told the builder he wanted accuracy as a major criteria.
That was a real eyeopener and I told my friend I was all done reloading for him unless he bought a chrono and chrono'd all my loads.

 

[ru1234]

James I sent you a PM

 

[ru1234]

Kraky- thanks for the information.

And thanks to everyone else on this site for being so helpful.