which is inherently more accurate?

[Oklahoma Rebel]

http://www.accuratemolds.com/img/bullets/catalogue/37-290XR.png this style,( except I designed one with a gas check) or a bore rider, like another I designed, the 37-286c ? I know it all comes down to boolit fit to the throat, bore and groove, but surely some of you have shot both types enough to have a good, valid opinion? my main concern with the 37-286C is not wether it is a good boolit or not, it is just how much has to fit just so for it to shoot well, and I have also heard they are not as accurate at higher velocities. my goal is 2100-maybe 2200 fps max. so if you have experience with these, please share your opinion. it would be appreciated! have a good'un-Travis

[Thumbcocker]

Maybe a call to the maker would be in order?

[Oklahoma Rebel]

I might e mail him, tom doesn't like to talk on the phone ( hearing problems)

[RogerDat]

Not any sort of authority but I have had good luck with bore rider designs in a couple of cases. The Lee 8mm surprised me at how well it shot. Forget the other one but am thinking it was 303 Brit sample from another member.

[Oklahoma Rebel]

is it really as much of a pain as I am making it out to be?

[oldblinddog]

I would get the one you linked.

[Oklahoma Rebel]

what do you mean by linked?

[Oklahoma Rebel]

oh, the 286C? that's the one I modified from 37-285C, the crimp is further back, the meplat is wider, and the front drive band is longer by half, at least.

[Oklahoma Rebel]

oh, nvm, you meant the 290 xr, I want a gas check, and the other boolit I designed from scratch on auto cad is very similar, except it has one grease groove, the crimp groove is farther back, and now has a recessed part for the gas check. I am trying to see if someone will turn one on a lathe so I can see first if it will fit. the message is in the projects forum

[Oklahoma Rebel]

what would you call that type of boolit, since it isn't considered a bore rider? (37-290xr)

[white eagle]

no such thing as inherently accurate

[Oklahoma Rebel]

yeah, I am just asking for opinions, I know fit is king and all that

[Larry Gibson]

"I have also heard they are not as accurate at higher velocities. my goal is 2100-maybe 2200 fps max. so if you have experience with these, please share your opinion. it would be appreciated!"

Whether or not a bore rider is "accurate at HV" is dependent on the quality of the cast, the actual design of the bullet, the fit of the nose to the bore and, mostly, the RPM at which they are launched.

With your bullet in your 14" twist barrel if you cast quality bullets, use a correct powder and load correctly should give very useable accuracy upwards of 2400 +/- fps.

[Oklahoma Rebel]

ok, thanks, I have a pretty good alloy of 3.5%/3.5%/.3-.4% copper, I think its about 15bhn a/c, and not sure, but over 20 h/t'ed

[Oklahoma Rebel]

people make it sound like the sizing has to be perfect down to the .0001 to get them to run right,kinda worried me, maybe i'll get a combo mold of that one and the one my father and I designed, in the cheapest alum. block, then see what works best.

[runfiverun]

see my SIG line.
IME bore riders are very accurate.
they just aren't under high stress situations since they rely on the nose so much.

[Oklahoma Rebel]

I am planning to use imr4064 but thinking about going slower with imr4350, which would you choose?

[Larry Gibson]

Any flavor of 4350.

[Oklahoma Rebel]

any flavor? lol I think imr is the faster of the 2-3, and usually a couple bucks cheaper, besides, since I started casting, imr is all ive used

[cainttype]

Might wanna try cutting that alloy 50/50 with Pb just to see if you need those concentrations of Sn, Sb, and Cu to accomplish your goals.
More is not always better, or even necessary... It’s easy enough to try.

[Larry Gibson]

In velocity/pressure testing all three 4350s I've found the burn rate of each is more relative to the cartridge, bullet weight and primer used.

[Oklahoma Rebel]

well, I am planning on going 2100-2200fps with this boolit,so we will see. it will soften a bit when I combine the alloy with another, almost the same, but softer alloy, I was gonna throw in some lead pipe alloy with some copper added. that way I wont dilute the CU while I am softening it