300 RUM issues any thoughts?

[djtjr]

Guys for thousand of you loading for the 300 rum or other hot overbore cartridges I have some questions. I built up a load settled on 93.5 gm of retumbo under a 200 accubond in rem brass and a 215m primer with the bullet seated to mag depth. A few weeks ago I built up in .5 gn increments from 90 to as high as 97 before starting to see pressure signs ejector marks flat trimers etc. I settled on the low node and took it out yesterday just to chrono it for a upcoming hunt to start building my click chart. In similar temp weather as the last excursion I blew the first 3 primer clear out of the case with some other signs of presure but not much. It was only the 2 nd or 3rd firing on that brass so would it be customary to get loose primer pockets after 1 firing any other thoughts? Is there a better brass option? How many firings are you getting out of your mag brass. Any other thoughts welcome.
Thanks
Don

 

[JRS]

I bought one thinking it would be the "end all". It sure proved to me to be just that, but from both ends. I averaged 2 firings from each case. Another concern is barrel life when loaded too hot.

 

[robbor]

they are a nice round but obviously brass is iffy. Brass is avail from federal, nosler and rem. I sure wish someone had done a standardized version of the 338 lapua in 30 for real quality brass. I have been considering trying a primer pocket tightener but press mounted. 21st century said he had made one for 7mmmag. Im hoping to talk to him more when i get some fun money and seeing what he can do. I have only use federal that i got a long time ago but i dont shoot much. They guys over at longrangehunting have more experience with rum brass. They were saying nosler was goodor better than rem as i recall.

 

[40X Guy]

I have a custom .300 RUM based on a Rem 700 LA and Brux 28 inch Heavy barrel. I had rifle built just over a year ago and immediately bought 2 boxes of Nosler brass as it is thicker and definately better than factory offering's and that is limited to Remington brass as far as unloaded brass. The neck in my chamber is .340 and I have to turn necks to a loaded diameter of .337 with the Nosler brass. But rifle is pretty much the ultimate hammer with my load of 208 A-Max and a hot load of Retumbo which I will not list here. If you are worrying about how many times your Rem brass will hang in there, go out and order some Nosler brass and have no worries. One serious cartridge that will whack most anything in North America!

Frank

 

[338Lapua]

I don’t have a 300 RUM I have a 300 win mag.
I am using Norma brass and have 11 recorded reload through 20 pieces of brass, I neck sizing and anneal necks, and its probably got 1 or two reloads left in it before primer pocket are toast. high pressure will destroy your brass every time, its just the way it is.

 

[ebb]

I thought i was lossing my mind when may 338 lap was having presure with an old load i knew to be good. We had to come way down read 8 grains to not get flat primers. When i got home my friend had the same problem with his 300. Its the Retumbo i belive. Try a different powder.