Retumbo, and the 300 Win Mag

[Legal-Eagle]

Are you crafting loads for the 300 WM with Retumbo? I have a Rem 700 Long Range (with 1-10 twist barrel) and hear that this powder works well. What bullets work best with this powder, and what powder charges?

 

[Offfhand]

Retumbo is .too slow to be efficient in .300 Win Mag,

 

[Varminterror]

I’m very happy with Retumbo and 208-212grn bullets in .300WM.

 

[IMtheNRA]

It is the best powder that I tried in my 700 with a 26" barrel. 74.5 grains and Berger 230-gr Hybrid Target bullets regularly print 0.5 to 0.6 five shot groups at 100 yard tests. Brass doesn't seem to make any difference in accuracy for this particular load.

 

[GooseGestapo]

I’ve used it in my .300RUM. It gives peak velocities but accuracy is mediocre.
IMO, Retumbo is a bit too slow for the .300win.
I prefer RL25 in my .300RUM. Almost the speed of Retumbo, but best accuracy.

IIRC, the US sniper round is using H1000. I’d look hard at it, RL22, RL25, H4831, and the new RL25 and IMR4451, and 7977.

 

[Legal-Eagle]

I’m very happy with Retumbo and 208-212grn bullets in .300WM.

Thanks, what is your rifling twist?

 

[Varminterror]

Thanks, what is your rifling twist?

1:10” in all of my current 300wm’s

 

[emb]

I use Retumbo with my 300 Ultra Mag Sendero with 180 and 200 grn bullets of a variety of flavors. My test range is 200 yrds. Good velocities and 1/4" accuracy-if I can shoot it. 1 in 10 twist. Every rifle is different.

 

[wildcat455]

This thread is over a month old, did you give up on the Retumbo in your 300 win mag, or did you give it a try?

I'm going to be giving it a try in 2 of my 300 win mags. I have a pound of it sitting around and it's time I do something with it.

I don't think it's too slow for the 300 win mag, but I'm not willing to argue it until I give it a try.

 

[ArchAngelCD]

I'm no expert but Retumbo is listed as generating the highest velocities in the 300 Win Mag on the Hodgdon site. If course that tells us nothing about accuracy.

I'm just thinking out loud.

 

[Legal-Eagle]

I have been in Africa for a few weeks, and so haven't done any reloading or shooting. Thanks for the info. One of my friends is using Retumbo and getting great accuracy.

Thanks for the info. I hope to start putting some loads together using heavier bullets soon.

 

[jbm]

Are you crafting loads for the 300 WM with Retumbo? I have a Rem 700 Long Range (with 1-10 twist barrel) and hear that this powder works well. What bullets work best with this powder, and what powder charges?

I use Retumbo in my .338-.416. It's a little too slow for my 300 Win Mag. I use H-1000. My choreographed load has an SD of 2.

 

[Legal-Eagle]

Update -

I finally put together some test loads with Retumbo, based on the recommendations of the friend I have who has been using it in his 300 WM with great accuracy, and went to the range.

I will try to post some pictures of the best targets I have, but suffice it to say that I was able to get one-ragged-hole groups with some bullet/powder weight combinations. I was, frankly, amazed. I was stepping-up the loads a grain at a time and found a very nice node with 190 SMK bullets. Just to be certain it wasn't a fluke, I went back again and shot some more of the identical loads some weeks later. They gave me one-ragged-hole accuracy once again at 100 yds. I had enough of them in the batch to also shoot a 500 yard target, and once I was on at that range, my balistics program could calculate the muzzle velocity. It was 2892 fps. That is respectable for a bullet of that weight.

I am going to lload up some test rounds to see how Retumbo works with some heavier bullets (200 - 220 grains). I will let you know how it goes.

 

[Legal-Eagle]

A couple of photos of my best 100 yd groups using Retumbo. I am very pleased with the performance.
The squares are one inch.



and another

 

[Legal-Eagle]

This thread is over a month old, did you give up on the Retumbo in your 300 win mag, or did you give it a try?

I'm going to be giving it a try in 2 of my 300 win mags. I have a pound of it sitting around and it's time I do something with it.

I don't think it's too slow for the 300 win mag, but I'm not willing to argue it until I give it a try.

I have just posted a couple of good 100-yd targets from my last outing to the range. The posted loads are not from the book, but are my personal work-up loads. I had no pressure signs in my loads at that level, but you might want to work-up gradually in your rifle.

 

[Legal-Eagle]

NOTICE: What loads you see posted by me above are not from any reloading manual. I don't have a book that shows any loads with Retumbo in the 300 WM. But a good friend is using it exclusively with amazing results, and he has been my guide in my work-up with this powder.

If you are going to be using this powder in the 300 WM, I strongly recommend you back off several grains from what you see as my loads listed above, and do a gradual work-up yourself. I didn't experience any excessive-pressure signs with these loads in my particular rifle, but every rifle and load is different.