Anyone load for 300UM?

[hiawatha]

Seems like I've tried every load combo for my 300 ultra. I can't get less than a 2inch group at 100yds. Anyone care to share what works for them? Maybe I can figure out what I'm doin wrong. I get 1/2inch groups with factory ammo. I load for 6mm and 30-06 with great results. Any help would be great.

[AZkiller]

Lets start with what you are doing. What have you tried?

[hiawatha]

The best results I've even come close with is 95gr of rutumbo with 150gr Hornady sst. Federal primers. Once fired brass from the same gun. I don't have a chroni so I couldn't tell you the varience in fps. I relize the ultra has to be more precise so I hand measure powder and check case length. I know I've got to be missing something.

[rossislider]

I'm just about to start loading my own 300RUM so will be interested to seeing what other suggest. I plan to start loading with Retumbo in the low 90 grain range but I will be using a much larger bullet, 210 Berger VLDs. Seems like 150 grain is pretty small for that much gun and powder. Just my opinion. Good Luck!

[WHT_MTNMAN]

A ton of 300 rum shooters use low 90s retumbo and 210 vld's.....shoots like a dream in most RUMs...i got my best accuracy with 90 grains.. most of my friends use 92..

[hiawatha]

Good to know. I've used 180 with same results. But why would 150 and 180gr factory shoot perfect? Maybe I'll go to under 90gr of powder and see what happens.

[firstcoueswas80]

Theres got to be an issue here.

 

First off, If I was you I would try matching the bullet in the factory load both the actual bullet, and the COAL as well. Second, try switching powders. Don't (and I'm assuming you are but dont know) if you have been sticking to one powder. Mix it up as well as primers and go from there.

[roninflag]

what rifle? my brother uses a heavy load of re-25 aNd a 180 accubond . we/he has used this in several different rfiles with great results.

[RHINO]

Don't base everything on 100 yards either. I was shooting one hole groups with some accubonds with my 300 um at a hundred yards but was shooting 9+inch groups with it at 400 hards. I am now shooting some 185 grain bergers with 91 grains of h1000 with federal 215 primers with a 3.660 coal. at 100 yards its right at 1". At 400 yards im shooting 1.8" 3 shot groups. I shot it yesterday with a 10 to 15 mph wind, and was able to get a 4 shot 3.75" group at 400 yards. My ultra mag seems to like h1000, but my dads likes the rl25.

[wardsoutfitters]

try 87 gns of r-25 w/ 190 sierrra match king, fereral primer

[wardsoutfitters]

give me a call if you would like I could send you a few of my loads to see how they shoot for you.

 

520-404-5114

[308Nut]

RL25 or H1000 or in some cases H50BMG under 180-200 grain pills work great. RL25 or H50BMG for 200+ grainers. The key is to watch your neck tension, seating depth and bullet runout.

 

My pet loads for 2 different 300RUMs were 92.5 H50BMG under 208 AMAXs and 90 of RL25 or 100 H50BMG under the 178 AMAX and 180 ACCUBOND. 95 H50BMG under the 200 gain ACUBOND. All were with Fed 215 match primers. Sweet spot velocities for the 180 class bullets seems to be around 3200-3250 and 3100-3150 for the 200s. Higher velocities are possible but you will pay dearly for it in other areas.

 

Factory rifles seem to prefer H1000, RL25 or RETUMBO. Tight tolerance barrels/chambers prefer those as well in less than published data and many times excel even to a higher degree with the H50BMG.

 

Whether it be H1000, RETUMBO, RL25, H50BMG etc.... shoot for a powder that offers you the velocities listed above with a fairly high or 100% load density. You should find what you are looking for.

 

Let us know how it turns out.

[ultra300mag]

I have shot a 300 RUM since they came out new. The first problem is that you cannot go with any load that anyone gives you. You need to pick your bullet and powder then shoot one round in each load that you want to try gowing one grain higher on each shot until you find your pressure max. Then go from there. Every gun likes a different powder bullet and powder combo but like I said first of all you need to find your max pressure. Then I back off three full grains and load five rounds there, go up one grain and load five rounds in that weight then five rounds just below max pressure. Pick the best group. I then load five more rounds at that weight and 1/2 grain lower then 1/2 grain higher unless the best group was at max. Shoot those five shot groups and if you are at the magic one inch mark good to go. If not sometimes just seating the best group a little deeper will make all the difference in the world. Takes some time but it is worth it. I personally shoot Barnes 168 TSX bullets with 90 grains of Retumbo. I have a Christensen Arms rifle and this combo shoots minute of angle groups all day long. Good luck and be safe. Remember don't just start with someone's load since each gun and seating depth can be different. One other thing. The hottest load is not always the most accurate load. And accuracy kills better than speed!!

[hiawatha]

Thanks everyone. Looks like I've still got alot of work to do. RUM seems more complicated than smaller calibers. I've got alot of hunts to do over the next few months then I'll be back on the range. I'll let you guys know what I come up with. Thanks again!

[hiawatha]

give me a call if you would like I could send you a few of my loads to see how they shoot for you.

 

520-404-5114

I've got your number I'll give you a call when I get a chance. My dad has an elk hunt that I would like him to use my ultra on. Just tired of spending the money on factory ammo.