New Retumbo Powder

[Long Time Long Ranger]

I just tried a new keg of Retumbo using my old loading data. It was way to hot. Has this gone the way of H-1000 with the newer batches faster burn rates than the older ones? Right now this batch of Retumbo is about the same burn rate as my old H-1000. Just wondering if anyone else has experienced this.

 

[tim jurczak]

Ranger, I don't know about what speed Retumbo used to burn at but I am looking for some loads for my 6.5 STW. I have tried it a little and 77gr gave no appearant pressure with 140gr AMAX. Fine. Then 78.gr seemed pretty darned hot with 130gr Accubond. ***?. Maybe something else is going on. I would have thought based on burn speed charts I would have gotten to 82gr with 140's but that is very presumptuous.
The 6.5 STW is an odd one I'll tell you. Powders that were slow enough to gag 270 Why and 7mm STW seem fast in this cartridge. In otherwords no full/ compressed loads.
What's your story?

 

[sp6x6]

LTLR, I had a guy that did the same basic build as my Norma as far as barrel and action. He is in the gun bizz and I got reloading info from him. He had good results w/92 grn. retumbo and a 300 smk, he is now shooting a berger. I was showing pressure at 90 and a 300 berger? Dont really know if this means anything. He had done his load work earlier than me , year. Dont know his current load. But I dropped back to 87.5 @ 2725 for a accurate load, I didnt want to hot rod my rifle

 

[kaseyfied]

same thing for me with h1000.. was using 93 grains for 300 grain bergers outta my 338 lapua.. got new powder.. took me a day to get the case out.. now im shooting 88.3 grains.. at 2860 for average velocity.. before 93 got me little over 2800.. crazy

 

[hypersonic]

I just tried a new keg of Retumbo using my old loading data. It was way to hot. Has this gone the way of H-1000 with the newer batches faster burn rates than the older ones? Right now this batch of Retumbo is about the same burn rate as my old H-1000. Just wondering if anyone else has experienced this.

Still on old lots of both but not very much of either remaning. Now I am scratching my ever balding head. I can understand a bit of varation from lot to lot but what I have been reading here and other places over the last little while has gotten me just a wee bit off center. And now that I have found a load for the 7RM with the 150 Etip over Retumbo that is a screamer and rips bugholes I am going to have to rework, seemingly quite a bit more than I would expect from years past. Intrested to see your results in grain versus grain diferences from old to new. Have 20 round loaded with the 150's and probably enough Retumbo for 40 more and that **** sure ain't enough to work out to 600 this year and give me hunting ammo for next year.

 

[J E Custom]

I just tried a new keg of Retumbo using my old loading data. It was way to hot. Has this gone the way of H-1000 with the newer batches faster burn rates than the older ones? Right now this batch of Retumbo is about the same burn rate as my old H-1000. Just wondering if anyone else has experienced this.

I have had the same experience with many powders that had different batch numbers some were
hotter and some were colder/slower. So I normally start a little lower and work up to the same
velocity if pressure allows on a new batch of powder.

Powder degrades over time and will become slower but it normally takes years.

There are a few powders that become critical with only a few tenths of a grain increase and
Retumbo is one of them. other powders can be increased 1 grain at a time and pressure goes
up linear while other powders will go up linear for a while and then suddenly go off the charts.

I am not sure why this happens and I'm sure that it is not the powder manufactures wishes
because he wants all of his powders to be consistant and reliable.

J E CUSTOM

 

[5280yotes]

I thought it was me, but apparently not.. I havent had time to chrony yet due to weather but the last shooting session, POI was about 1.5 high @200yds with same load. The only diff was the lot# on the powder.

 

[JeffVN]

Agreed. For me both H1000 and Retumbo are running hotter then the older lots and my load data has changed as a result.

JeffVN

 

[Greyfox]

I have new lots of Retumbo that are definitely different from an older lot., couple of years. Using my 6.5x284, the older lot would produce 2965 FPS with 59gr. Two different new lots produce 3015 fps with the same charge. It is consistently 50-60 FPS faster. No pressure signs, and my groups are just slightly larger, by .25MOA or a little less. Though it might be my chronograph, but the difference on the readings are consistant between the old and new lots.

 

[jmden]

How recently purchased is this 'hotter' Retumbo?

I've got a keg that's nearly two years old that I need to replace soon and am wondering if I might see the same thing.

 

[Greyfox]

How recently purchased is this 'hotter' Retumbo?

I've got a keg that's nearly two years old that I need to replace soon and am wondering if I might see the same thing.

Just over the last 6 months.

 

[el si]

I noticed the change in Retumbo as well.
I had a 94.0gr load in 300 RUM that is now at 91.5gr otherwise I get stuck cases.

The old lot was 4779 bought in 2010 and the new lot is 4838 bought early 2011.

 

[Long Time Long Ranger]

The load in my 300 RUM dropped 3.5 grains to produce the same result. On the can it lists 101.5 grains for the 180 grain bullet and 98.5 is now max in my rifle. 102 was my previous accuracy load. My 200 grain AB load dropped 4 grains. Old H-870 would change 2-3 grains sometimes lot to lot and you just come to expect it but first time I have seen it in Retumbo which I have been using since it was introduced.