GC Boolit questions & advice needed

[abosely]

I'm trying to learn, for my application if Cast GC or Cast PP Boolits would better.

I don't know if this info would have a bearing on my options or not but here goes..

The rifles will be a 404 Jeffery (.423 cal) with 1 in 14" twist and 9.3x62 (.366 cal) with 1 in 12" twist.

Standard J Boolits loads are a 400 gn @ 2250-2350 fps in the 404 Jeffery and 286 gn @ 2250-2350 fps in the 9.3x62.

In the 404 I would like to use a 300 to 350 grain cast boolit at 2200-2300 fps and in the 9.3x62 a 200-230 grain cast Boolit at 2250-2350 fps.

Planning on using LBT SP molds. I'll Firelap, slug & measure the bores and make a lead throat slug so Veral can make the molds to fit each rifle.

So the questions,

If I start with a bore cleaned to bare metal and fire some J Boolits then fire some GC Boolits of the correct size and hardness at at 2250-2350 fps without cleaning the bore.

Will I get bad leading and no accuracy?

What would happen if I do the above and then switch back to some J Boolits?

The reason for not cleaning the bore is not laziness but would be in the field and not able to
clean between switching from J to GC Boolits.

Would PP Boolits work or work better for the above application?

Or, when switching from J Boolits to CG or PP Boolits or vice versa I will have to clean the bore no matter what or I'll get leading/fouling and no accuracy?

If this can be done with PP Boolits, I'll go to that forum learn about PPing.

If this can be accomplished with GC Boolits I would prefer since GC Boolits will be a little less labor intensive.

I've been reading through the old posts to try and find the answers, but have been unsuccessful
so far.

Hopefully there are not stupidly basic questions.

Allen

[MtGun44]

Your velocities will be way up around the upper limit of what is possible with cast.
Not saying it can't be done, just that this is not the easiest place to be starting.

I'd suggest getting some experience at 1400-1600 fps and then start working
your way up. You may get there and keep your accy, maybe not. If you are
lucky and diligent, I think you have a shot at making the velocities you are
looking for, esp with the large bore.

I have had decent results with a copper fouled smooth bore with cast, but others
report poor results. YMMMV. I know essentially nothing about paper patched,
other than the basic understand of what they are and how, approximately,
to make one.

Bill

[Larry Gibson]

GCs are required for your velocities if you expect any kind of accuracy. As mentioned, gain some experience at lower velocity (1700-1900 fps) and then work up refining your technique to achieve the velocities with acceptable accuracy that you desre.

Larry Gibson

[Wayne Smith]

Larry's got it. GC boolits at those velocities. I believe that copper in the bore in detrimental to lead accuracy. Lead in the bore doesn't seem to hurt condom accuracy, at least not to the level needed for hunting.

Consider your velocities. You will get more penetration at 1200-1400fps than you will at 2200fps. A hard cast boolit will effectively be a solid at those velocities. I know, it doesn't seem logical, but it's true. Check some of 44Man's posts.

[felix]

Wayne, expansion takes energy from the momentum. ... felix

[Bret4207]

As has been noted you want to go to the upper limits of cast boolit velocity. Paper patching may work fine, ask down in the paper patching section. At those velocities even a GC may not be enough.

[abosely]

Thanks Guys,

I will go to the PP forum and explore from that angle.

Allen