300 rum

[raven1776]

Hey all. I am sure this subject has been touched in before but there are hundreds of pages here to go
Through. I bought a Remington sps in a 300 Rum and am looking to build a load for it. Right now I use remington9 1/2 M mag primers, Remington brass, 89.6g of retumbo powder and 210g Berger vld's. What powder weight increments are best when moving up and down to find what your gun likes?
Also, the Remington mag well will not allow me to make the COAL fit the chamber so I am stuck with near factory seating depth.
Currently I am getting just above 1" at 100 yards but not consistently.
Thank you for the help.

 

[Lefty7mmstw]

I found retumbo doesn't shoot as well in some 30 rums as rl 25 does. I'm shooting 1 to 1.25" at 200 with mine with rl25 and 180 hornady bullets at 3300 fps. It also likes 225 hornady pills with either rl33 or rl50. Both my bdl and my brother's sendero had indegestion on retumbo and thrived with rl powder.

 

[raven1776]

Thanks for the info! Do you have the specs for your reloads? Case, primer, powder starting weight?

 

[Lefty7mmstw]

Thanks for the info! Do you have the specs for your reloads? Case, primer, powder starting weight?

I use the 180 hornady sp flat base for one load at 93 grain-94 grain rl25 with rem brass and a 215. 3.60" oal.. That load will do 3280 fps at 93 grain(just over 3300 fps at 94 grain) and shoots 1 to 1.25" at 200 yards in two rifles.
The 225 hornady hpbt is in rem brass with a 215 at 3.65" oal and if using rl50 you need as much as you can get in the case, or about 100-102 grain. 102 will net 3000 fps and 98 will net 2870 fps. With rl33 I got to 95 grains as top load with the hornady 225, but didn't get a chrono reading (to windy-didn't set it up). Both powders are 1/2 to 2/3" at 100.

 

[MTBULLET]

I had the best results with H-1000
NOTE: HAD, my SPS bbl. was worthless after 272 rounds, 2nd bbl. (douglas) lasted 630ish rounds, 3rd. bbl (pac-nor)was toast at 830ish, shooting in the 3400 fps range with 168vld. 3300 range with 180's, but shot the 168 MUCH better.

 

[raven1776]

When working up a load with a new powder what is the best increment to move, .1g, .2g, .5g?
Thank you for all the info!!

 

[raven1776]

I guess what I am really worried about is spending all this time working up a load just as the barrel burns out!

 

[BEEMAN]

I moved up in .5 gr increments. I am shooting 91 gr H-1000 and a 215 Berger Hybrid. COAL is 3.843 so it is a single shot. Will shoot one ragged hole at 100 and 200 yds. Best ive done at 400 is 1.25". I would try the 215 Hybrid. It really was easy to load for in my rifle. Tried all different seating depths from 130 off to 8 thou off and they all shot at 1" or under at 100 yds.

 

[Forrest Ebert]

I shoot the 300 RUM using a load of 95.0 grains of Retumbo, CCI 250 primer Rem. brass full length sized and a 211 grain Bob Cauterucio custom bullet col is 3.679" which is maximum mag. length and I get 3150 fps along with .313" groups. I use Retumbo for the simple reason that it is not temp sensitive like the RL powders but you might wnat to try IMR 7828 & H1000 as well in your rifle. I hope that this info will help you .

 

[raven1776]

Thank you very much everybody! I will put all this info to work and hopefully get to the range tonight or tomorrow! I will keep you all informed as to how it all works for my gun!
gun)

 

[Lefty7mmstw]

When working up a load with a new powder what is the best increment to move, .1g, .2g, .5g?
Thank you for all the info!!

In a big case like this I move 2 grains at a time for the most part when working up loads. As to the rl being temp sensitive, I've seen hodgdon vary 100 fps with their extreme powders(h4895 in a 25wssm). Rl usually isn't any worse and is usually better.

 

[highridge1]

Yeh I would use RL25 over H1000, H1000 is very inconsistent lot to lot.

 

[raven1776]

Seen this in another post somewhere and it got me thinking, how important is it for each casing to weight close to the same for accuracy? If it really makes a difference, how big of a spread would you give each group of casings? I have 7 different weights of the same brand casings. There is about a grain between each group.
Just wondering if it makes that big a difference.

 

[cohunter1]

Just tuned in, I have a pet load for my 300 rum sendero, Rem brass, Barnes TSX 180 gr,Fed 215 primers, 92.9 gr Retumbo, ragged one hole group. Start at 50 in lbs torque on bedding screws, and go from there. Have to check my notes for seating depth if your interested.


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