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View Full Version : 187 BIB's in a 1-13" twist .307" Palma barrel



WAMBO
04-20-2008, 10:52 PM
After reading about the 187 BIB's in Lynn's thread I was thinking about maybe trying them in my 300 RUM.
It's built using a rechamber Kreiger Palma barrel that has a 1-13" twist and has a bore and groove diameter that's .298" x.307".
Do you think these will work in this barrel or would I be wasting my time.
TIA,
Wayne aka WAMBO

Charles E
04-21-2008, 07:43 AM
The bullets will be stable. "Work" depends on what you are shooting. These are target bullets only. Be aware that the ballistic coefficient is about .520 as measured by doplar radar, or about .550 calculated with a method similar to the one Berger uses. By in large, people who use a case like the .300 RUM are after different things, and find arguments in favor of high B.C. bullets.

Those of us who tire of the varying quality of VLDs like the BIBs, and they've chalked up a number of impressive wins.

Dave Tooley
04-21-2008, 07:54 AM
One thing Charles did not mention is velocity. There is an upper limit in speed/RPM's that you will reach very quickly with RUM case. Depending on the condition of your barrel you may have some disappearing bullets once you get past 3250 FPS. Coupling speed with your tight bore may lead to problems. Keep me informed as to what you find. I would like to know they worked and how they didn't work if that happens.

Dave

J. Pendergraft
04-21-2008, 11:30 AM
I'd be scared of the tight bore. I don't think you will be able to get max velocity without blowing them up. The 187 BIBs has a long bearing surface that you will be swaging down in that tight bore. The tight bores are used almost exclusively for the Palma bullets are they not?

WAMBO
04-21-2008, 09:10 PM
Thank you for your reply's.
I use this 300 RUM for informal long range target shooting and hunting.
I was worried that the tight bore might be a problem with the 187's but wasn't sure.
The rifle shoots the 190 SMK's pretty good, have shot a 3 shot 4" group and several sub moa 5 shot groups at 1K, some around .75 moa.
The load for the 190's is a mild one around 3100fps using 82grs of H4831.
I mainly shot it prone off a bipod at steel targets, it's in a HS PSS stock but it handles real well in the bags off a rest.
I guess I'll just have to give it a try and see how it does.
When I gitter done I'll post the results.
Thanks again,
Wayne aka WAMBO