Home Forums Hunting & Shooting Long Range Hunting 300 RUM +220gr Modded 220gr MK's

I had a tack driver Sendero 300 RUM 220 Sierra Match King load (4-shot <0.5 MOA 100yds), but could not find a good 220 gr boat tail hunting bullet. Hornady ELD's are too long & don't stabilize with its 1:10 twist. I'd seen some claims of guys drilling the Match Kings, and as I'm a machinist, I thought I'd try.

I indicated a #3 center clamped in a v-block with a Bridgeport within 0.0002" then used a 5 /16 (0.3125) volley to clamp the bullet. Prior to machining, I sorted and filed the metplats to within 0.001" all the same length so I could touch off once chucked up. I touched off & drilled 0.250" deep, feeding the knee up. The pilot of the center drill is 0.125" . After drilling, I left the bullet chucked, dropped the mill in backbeat and used a mill file to deburr the tip while still chucked.

This yielded a 216gr hollow point, and among 10 bullets I weighed 0.2gr different, as good or better than unmolested 220's. With a load of 92.5gr of 24N41 2890fps, I fired into some very tough high density foam a buddy had who works at a mild shop. It traveled 18" deep & we recovered the projectiles. Perfect uniform mushroom expansion 0 .765" dia.

We've tested Sierra 6.5 140 Game Changers in 6.5-300 Wby, 130 ELD Match in 6.5 PRC, and 120gr Barnes TTSX in 264 WM, and the RUM 220 Sierras by far are the best. The Barnes immediately ripped the petals off and went straight through like an FMJ.

Forgot to mention, I shot the hollow points and accuracy at 100yrs was unchanged, still <0.5 MOA.

Have you ever thought about trying the 215g Berger hybrid. ?

Of you shoot a 300 RUM with them, and have a good load, I'm game to try them. Other than a 243 Ackley Improved with 65gr flat base bullets, I've had limited luck with Bergers in my 264 WM. Thanks!

I've killed several elk with unmolested 264/140 smk's.....I can't imagine the 308 variety will put up more fight.

Ive killed several elk with the 200.20x and 215hybrid and now a couple with the 225eldm......all very much as expected results.

If you're worried about performance......don't.

a machinist can make it work!

I'm surprised the 220 Horn ELDx didn't work for you. I'm just starting shooting that in a 300 Win 1:10. So far, excellent out to 400.