300 Ultra Mag.

ShadeTree

Handloader
Mar 6, 2017
3,523
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Word got around I guess and without intending to I've gotten a fairly steady supply of guns to work on for people. Sometimes along with working on them they want me to shoot them, so a side benefit is I get to practice with other peoples money.

This is a brand new high dollar set up. 700 Remington Sendero in a 300 Ultra with a 5-25 X 56 Swarovski, night force rail and rings. Done trigger work on it and took it apart and cleaned all the grease out. Was none too thrilled with the tooling marks I can see in the rifling and was calling Remington some names under my breath, but it shoots so that's the most important thing.

Factory Remington 180 Barnes ammo. 3 shots to get close at 50 yds then moved to 100 and it put 3 just under an inch but I knew I wasn't shooting it well yet. Yanked a called shot on the next one, then finally convinced myself that unbraked it throws things around like a P.O.'d water buffalo, but is never gonna hurt me in a sled. Put the next 3 at 1/2".



 
The weight on that sled is over 20lbs. Total weight of the sled is just over 36lbs. Didn't weigh it but the gun is probably another 11-12lbs. It would throw that weight to the rear of the sled at each shot and significantly move the sled itself. Un-braked it is a handful.

The guy dropped off a new set of dies with it and wanted me to work up some loads for it. With the way it shoots those factories, why bother? 10 minutes between each shot for cool down. Any early throat erosion isn't gonna be from me. Working up loads for that would be a time consuming nightmare.
 
That 300 RUM is one accurate cartridge. It’s amazing a case that size can be so consistent with nearly 100 grains of powder but mine has been danged good for such a cannon.
 
Scotty there's some guys I know that shoot long range with the same cartridge and I believe 208 ELD's. If they will give me their load I might be up for loading some singles up to their load checking for pressure then seeing how close it is from there. But to start from scratch experimenting with this thing being it's not my gun seems like a time consuming adventure that I'm not sure he'd want to pay for. But it is a cannon no doubt and I was impressed with it's accuracy out of the box with factory ammo.
 
Shadetree when you start working on loads the first powder I would try is rl33.
 
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