300 rum to 6.5x284 conversion

[Cwhitney]

I currently have a 300 rum sendero, my family has owned several of them and have done extremely well with them with numerous 1000+ yard kills. Unfortunately, the sendero I have now tracks bullets at a 45 degree angle with every shot as the barrel gets warmer. After several attempts to fix the problem with no success, I have decided to start a project and convert it to a 6.5x284. I understand that I'm losing the knockdown power for 1000+ yard shots and I'm ok with that. My goal here is to obtain a dead accurate 800 yard shooter capable of .25 moa at 100. I've ordered a 26" bartlein barrel with a #13 contour and will be ordering a pt&g long action standard bolt, along with a jewel or Timney trigger. I'm going to have a smith blueprint my 700 action and swap the barrels. So the reason I've came here is to ask what problems I may run into along the way, get your guys' opinions or concerns on the conversion. And also as I'll be 100% new to the 6.5 I'm curious what kind of information I can get on loads. As of now I plan on using 140 grain Berger hunting vld's. This gun will be used for blacktail deer. Please, let me know what you think, any help at all will be appreciated.

 

[ZSteinle]

about the only issue I could see would be feeding issues but that could be fixed with a detachable box. I think with the RUM the bolt slides are really wide so when you put a 6.5x284 case in the magazine it might just pop right out. other than that you will like the 6.5x284. took mine to africa with 140 vld for plains game with great sucsess.

 

[Engineering101]

A thought - if you go 26 Nosler instead you won't have to change the bolt and the ammo will fit in the mag since the Nosler is based on the RUM family. Also the 26 will get you to 1,000 yards for deer sized game. If it is a pure hunting rifle barrel burnout should not be a big issue.

 

[Cwhitney]

Interesting thought. Do you know what the barrel twist would need to be? The bartlein I ordered has a 1:8.5 twist.

 

[Engineering101]

I'm running an 8.5 twist Krieger, 5R.

 

[Cwhitney]

Okay thanks. What kind of accuracy are you getting out of that 26? And is obtaining brass an issue?

 

[Cwhitney]

Zstein- thanks for the input, I do plan on adding a detachable box on a manners stock, but that will have to wait til next year. I'm kinda pressed for time on this project because our season opens in October.

 

[AZShooter]

I have said this before on this site.....the reamer is a very important part of your new custom. Have you consulted with your gunsmith on the 6.5-284? The specifications are critical to the performance you will want. Throat length and angle, does it have a no turn neck? What bullet release clearance? What brass will you use? If it were my custom I would order a reamer after reading a bit and talking with the reamer maker. I have used Pacific Tool and Gauge repeatedly and am very happy with their reamers.

Good information here:

6.5-284 Cartridge Guide within AccurateShooter.com

 

[Engineering101]

I don't yet know what kind of accuracy I'm getting as when I last shot it the rifle was not bedded. It grouped .75" at 100 yards in that condition. That testing was to get the velocity of my chosen load verified. Now it is bedded and I'm going back to the range in 1 hour. I will cut back the bedding 1/4" at a time until my load groups 0.5 MOA or better. I'm running the 127 grain LRX at 3,450 fps. I have a couple boxes of 140 Bergers but figure they are too soft to be running at 3,400 fps - meat damage being the concern. No big issue there as my 1,000 yard dial up with the LRX is only 16 MOA which is less than one revolution on the VX-6 turret.

I bought two boxes of brass and the RCBS reloading dies off Midway USA and then saw two more boxes on the shelves at my local Sportsman's. I didn't buy those as I figure 100 pieces is enough for a hunting rifle which this is.

 

[Ben Hall]

6.5 284 ammo rifle theres some ammo and the smith should be able to negate any feed issue .

 

[ukdeadcentre]

I have found my 6.5-284 to be exceptionally accurate, RPA Quadlite action with a 32 inch 1 in 8 twist barrel. With Berger long range 140grain target bullets and H4350 it will put 3 shots at 100 yards into the same hole (0.2 inch centres), muzzle velocity 3,110 ft/sec. It is also accurate out to 1000 yards even with a 20mph cross wind. I used the Sierra Infinity software for ballistic calculations.

I am now looking at the relative merits of the different 300 magnums for 1,200 plus yards. Going the opposite way to you.

 

[Ben Hall]

sounds like a .300 wm will do what your after and also 26 nosler sounds interesting

 

[MudRunner2005]

Being that you have a .300 RUM rifle already, and you want to swap to a 6.5 caliber, then the .264 WinMag would work good for you, since you already have a magnum bolt face and magnum magazine follower.

A 6.5-284 will require your gunsmith to do alot of work, or spend alot of your money... You will either have to have your bolt face filled in, re-cut, etc... to accomodate the smaller bolt face of the 6.5-284. Or buy a new PTG bolt body, which will run you about $250-300.

I honestly don't think I'd use that rifle for a 6.5-284 build. I'd keep it a magnum caliber. And then buy a cheap used 700 in .270 or .30-06 and use that for your action to build off of.

 

[Deleted member 46119]

I'm with Mud and others. IMO stick with a magnum case the would feed from the existing mag and feed lip configuration. Cost to convert would be so high it would be more economic to purchase a complete rifle or action for the project.