.300 ultra, available powder/recipe

[mewachee]

Okay, we were discussing this elsewhere, I felt this was a better forum for it. Here is the situation:
1. 1000 yard shooting, hunting and range.*
2. Rem. Sendero .300 rum
3. Bullets - 180 to 210 grains

Here is the question. I want to use Retumbo, but it is not available locally. I have found it online, but there are the added costs for shipping. So what other options have you used with heavy bullets in the 300 ultra. I have a keg of H50bmg locally available, have any of you used this. I also see that 7828 is used with good results. Most have said that retumbo is the best.


*I am building this gun and ammo to shoot beyond my abilities. This is meant to be a thread of possible powders, availability and potential.

 

[NCsmitty]

Looking over the load charts, I have to agree that Retumbo seems to be the powder of choice, but shortages and expense can bite you.

Here's some loads from reloadersnest using H50bmg.

www.reloadersnest.com/query_pw.asp?CaliberID=62&Powder=Hodgdon H50BMG



NCsmitty

 

[GooseGestapo]

Retumbo indeed is the fastest powder, but only by a small amount.
You must find out what your rifle prefers. This may even vary between bullets.

Alliant RL25 is very good, as again, IMR7828, H50BMG (slow, though). You may find some old stocks of AA#8700 as well as Hodgdon H870. These latter two are commercial stocks of WC-860, which may be still available. I've gotten very good accuracy with the WC-860 which is a surplus military powder for the .50BMG. I bought 16lbs for $50 from Wideners about 4yrs ago. Even with load development and also buying a used Weatherby .257 and working up loads for it, I still have 12+ lbs left........ It is very temperature sensitive however. Velocities can vary between 3,050-3,300fps depending on 40-100degF. temps. Also, substituting a CCI magnum rifle primer gave a velocity loss of ~150fps and wasn't nearly as accurate as the Federals. Imagine when a near max load of powder only gave 2,900fps.... on the chrono one frosty morning!

Handloader magazine had an excellent article on loading the .300RUM about 4-5yrs ago. I suggest that you pull up that one off the archives. Also, download and save data from Alliant, and Hodgdon.

You've got a lot of loading and shooting to do..... 180-210gr bullets is a lot of choices/possibilities. I've only concentrated on the 180's. For bigger/heavier, I've got a .338/06 that is still shooting-in the barrel. After ~ 350 rounds, accuracy is still improving.....

 

[mewachee]

Thanks,

I have a 26" barrel, it should handle the slower powders.

On the bullets, I am thinking of using the 210 match and hunting VLDs from Berger.

As far as the powder goes, I am not as concerned about velocity as I am accuracy and temp sensitivity. I hunt from 90 deg. down to -10 deg.


related note: I have .270 I almost gave up on. I would go out on a different days to find my groups all over the target. I finally figured out that it was temperature. 20 degrees would move the group as much as 4 in. I switched from IMR 4350 to H4350. This all but removed the rooming. Added the Barnes TTSX bullets and that brought down the groups. I spent Hundreds, and 50% of the life of the barrel, on finding a load for the temperamental gun. I hope to find a good starting point, so I don't have to do this again with this new gun.

 

[Sidewinder72]

R 25 nad 200 A.B. works great for hunting loads. Finding Fed. 215 is another thing.

 

[SILVER-STAR]

I'm converting a Rem. 700 300 Win. Mag to a 300 Ultra Mag. with a new barrel I bought.
Now I'm seeing more Remington 300 RUM barrels coming on the market.
Does anyone know why these Remington 300 RUM barrels are being replaced?

 

[lgbloader]

I've had good luck with RE22 in my 300 RUM, 300 WBY & 338 RUM.

LGB

 

[dakotasin]

Does anyone know why these Remington 300 RUM barrels are being replaced?

probably to build customs/wildcats and all the donor parts of the rums were necessary.

some people bought a rum based on ballistics, and then realized those ballistics came at a heavy price: recoil. also, my local gunshop no longer carries anything 300 rum or bigger because they claim the 300, 338, and 375 eat scopes (i say, don't let the customer put garbage optics on).

last, some people have managed to shoot out a rum barrel.

if you're concerned about the rum becoming obsolete, don't be - maybe the 7 and 375 rum will fall by the wayside, but the rum series is indeed a fantastic series for serious shooters (not so much for casual shooters, plinkers, etc).

and as much as i like rl-25, i have found it to be just a touch fast - if you can believe that - for the rums, but makes a great back-up powder to retumbo.