how much more velocity?

[tayhot]

currently shooting 93 grains of H1000 in 338 RUM and velocity is 2961 fps. How much more can be anticipated if I load up to 93.5?

[Tumbleweed]

Not sure what bullets you're using, barrel length or if this is close to your max load. Something I have noted in the past: I rifle's barrel can only burn so much powder. I have worked up a couple of loads in my 300RUM where you get close to max load or even a tad above and you stop gaining velocity even with more powder. The pressure signs seem to increase on the case but you can get to a point that the rifle will not produce more velocity even with a grain or two more powder. In this case I have backed down the powder charge until the velocity just starts to fall off. So to answer your question, in your big case chances are you won't notice a difference with .5 grains unless you've got very tight ES with our current load. Hope this helps. Of course, watch for too much pressure!

[Long Time Long Ranger]

I assume the 300 grain bullet since that is a very popular load you listed there for the 300 grain in either 338 RUM or 338-300 RUM. You are at the top end with that load and is max in most rifles. It is a load I used back in 2001 when the 338 RUM first came out and I was comparing it to the 338-300 RUM I had been doing for a couple years back then. As you go higher even in 1/2 grain increments you can get into pressure spikes with severe but inconsistant velocity increases. If you are getting low extreme spreads where you are I would stay there. You can kill about anything in north america as far as you can hit it with that load. You don't need any more if this load is accurate.

[Fiftydriver]

I would agree, if your getting 2960 fps with a 300 gr SMK, your FAR over where I would be comfortable with most 338 RUMs. I would not go any higher in powder. Do not get sucked into the "Grass is always Greener" disease!!! OR that dangerous "Tinkeritis" condition.

If your load shoots well and is consistant, I would get off load development and move to practical field shooting practice. Personally, I would drop 75 fps off your velocity if your using a 300 gr bullet personally.

[tayhot]

Not 300 gr it's 265gr ttsx. I will load a couple and see what happens

[Fiftydriver]

That makes a big difference. 3000 fps should be pretty comfortable at least. Possibly even a bit more depending on your barrel length.

[Long Time Long Ranger]

Ok, I feel better now to. That would be scary pushing a 300 grainr like that in the 338 RUM particularly if it is the new H-1000. My load was with the old powder and although I am still using it and have not shot the new I hear you will not load 93 grains with the 300 any more. That sounds like a good load for the 265 and you could go up 1/2 grain at a time there and see what you get. I have got some very good results with that bullet.