Retumbo and 25-06

[trueblue]

I am reloading for a 25-06( 24" barrel) with 59.5 gr of Retumbo, 100gr Barnes TSX, and getting 50fps velocity spreads. Using GM210 primers. Would GM215 primers make a difference, or is Retumbo to slow a powder for this set up ?

 

[Derek M.]

If you decide to go with a magnum primer, you will have to back the powder charge down and start again with tests. H1000 is a better choice in the 25.06. For me it would be a toss up b/w 1000 and 4831SC. Stick with the 210s

 

[trueblue]

Barnes doesn't list any data in their new reloading manual for H4831Sc. and the 100gr TSX. They list data for IMR4831. Could the load data for the IMR4831 be used for the H4831SC? Their burn rates are somewhat similar. I have some H4831SC on hand.

 

[Derek M.]

Barnes doesn't list any data in their new reloading manual for H4831Sc. and the 100gr TSX. They list data for IMR4831. Could the load data for the IMR4831 be used for the H4831SC? Their burn rates are somewhat similar. I have some H4831SC on hand.

Do not substitute any load data from one powder for another even if burn rates are close. You can call Barnes, and by now, I would bet they have data for the 100 grain bullet.

However, when you are in a crunch like this, you can also always reference the Hodgdon website or Stevespages.com

For that bullet weight, stevespages recommends starting at 47.0 grains of H4831 and topping out at 58.0 grains. I would also take a look at the Swift manual. Before Barnes came out with much of their data when the TSX came out, and now the TTSX, they would tell callers to reference the Swift manual since that was the only other pure copper jacket bullet maker, with a load manual, that they were aware of.

I have the Swift manual and for the 25-06, 100 grain Aframe, the charges begin at 52.1 and top out at 56.0 using H4831.

What I would do is start at about 49.0 grains. Load 3 rounds with that charge. Put 2 in your fridge so they'll be about 40 degrees. Shoot the 2 cold ones first. If no problem, shoot the one that is your current temp. If you still have no problems, that will be a good starting point for you. Call Barnes to confirm.

 

[johnnyk]

I only have Barnes #2, but I got superb accuracy from my .25-06 Sendero using 100gn TSX, 55.5gn of RL22 and Rem 9.5M primers. Never chrono'd them but they were sub .5" and NC whitetails couldn't stand "em. JohnnyK.

 

[trueblue]

Derek,
Thanks for the lead on the H4831SC charge weght. However, I am still curious what going to a GM215 primer will do for the velocity spread using 59.5 gr of Retumbo. Will this lower it due to the hotter primer ?

 

[Derek M.]

Derek,
Thanks for the lead on the H4831SC charge weght. However, I am still curious what going to a GM215 primer will do for the velocity spread using 59.5 gr of Retumbo. Will this lower it due to the hotter primer ?

Anything is possible. Retumbo is a slow powder. There are many "experts" that have written about the 270s, 280s, 25-06s, etc. and have opined that these small necked calibers with a 30.06 parent case all do well with magnum primers, especially if using slower burning powders.

Years ago when I went to Kansas for a deer hunt, I took a 270 with a generous dose of H1000 and 140 btips. These loads were ignited with WLRM primers and for a factory Ruger rifle, I was satisfied with my consistent 3/4" groups at 100 yards. Velocity was 2977, barrel was factory 22" long.

So, it is not a bad idea to use magnum primers with slow powders, just don't take a max loaded case that has used a standard primer and switch to the magnum. It may be safe, it may not be.

 

[yote bomber]

I shoot 59 grains of Retumbo behind the 115 Berger in my 24" Lilja barreled .25-06, I use WLRM primers and Winchester brass. I tried shooting the 100 TSX with Retumbo, but couldn't get enough in the case to make it worth while.

I get 3100 fps and 4" groups at 600 yards with the Retumbo/115 Berger load.