Rifling Twist & Conical ?

[bingo1952]

What is the heaviest conical I can stabilize out of a .45 with a 1-56 twist using 80 grains of 3F. TIA

 

[rkeltner]

that's a somewhat open ended question. the short answer is it depends on your rifle, and the conical! i have a cva kentucky in .45 cal. that shoots 255 gr. lee round nosed, flat point handgun bullets (cast in pure lead, of course!) almost as well as it shoots plain round balls! i have considered getting the 300 grain gas check mold and trying it out, but it's questionable if it will shoot. the nice thing is lee molds are cheap, so if it doesn't work, there's not much loss! just for reference, the cva has a 1-in-66 twist.

 

[bingo1952]

I was thinking that 300 grains would probably be about its limit. I am putting together a what I hope will serve as a light bench gun on a H&A action. I guess I'll be experimenting with different bullet weights to see what will stabilize.

 

[paulvallandigham]

I think the 300 grainers will need a faster ROT, like about 1:34. They will work in even faster barrels, but there is a minimum. With a 1:22 standard .45-70 barrel, you can shoot them, but they are a bit fussy on the loads you use, if the bullet is cast from pure lead. I have shot jacketed 300 gr. bullets out at close to 2000 fps. in a 1:22 ROT barrel, and had excellent accuracy.

 

[Bountyhunter]

If you use the formula that calculates that, you will end up with a projectile that is just a wee bit longer than it is wide. Whatever that will weigh. It is about the length of the projectile, not the weight. Just lookin at my selection of boolits for my .45LC here, I'd guess in the area of 250 to 275 gr.

 

[Blizzard of '93]

you might try the Lee REAL slug at 250 grs with that 1-66 twist.

 

[rkeltner]

i've no reason to try the real in my 1-in-66 since i'm working well with the 255 lee handgun bullet. i can also justify the purchase of the 300 grainer because i'm in the prossess of building a 1 in 24 express rifle! (along with 350 gr, 400 gr, 450 gr.!!) also, while the real is fine in slow twist rifles, they shed velocity quickly, enough to make the difference between a 75 and a 100 yard shot! dosn't sound like a big deal untill you've got a spooky buck staring you down at 100 yds.

 

[longcruise]

What is the heaviest conical I can stabilize out of a .45 with a 1-56 twist using 80 grains of 3F. TIA

The 1/56 may not be the ideal twist for your application. However, I don't know what you plan to do with the light bench gun but assume it is competitive target work.

If you apply the greenhill formula to the question you come up with a bullet length of .542. Many BPCR shooters use the constant of 125 in the formula for the slower velocities of BP and using that constant it comes up at .452. So, pretty much as stated above, caliber length or a bit more.

Weight will depend on the configuration of the slug. You can go to Mountain Moulds web site and use their design page to calculate the weight for any design you input.

 

[bart_anastasi]

You might try calling the fellas at Parker bullets for regular conventional bullets not the hydra_cons.

They wiped me up a batch of 45 cal conicals in 525 grain and some in 400, 350 300 and 200 ish.

If you are shooting a max of 150 to 200 yards your twist rate may be enough to that distance with a stiff load for extra velocity.

Ask him for 10 of the 400 350 300 and 200 ish and give them a try just to see if they stabilize and group.

Go with 100 to 110 grains of 2f

 

[BS]

If you goto:

mountainmolds.com

You can design your own bullets, and at the bottom of the page it will tell the suggested twist. :grin:

 

[gmww]

I'm not sure if this will help you or not but you might visit
http://www.mountainmolds.com/

There is a bullet design function that might give you the answere.

 

[bingo1952]

Thanks for all the replys. It has been a big help. :thumbsup:

 

[hepburn4590]

Using "Lowe's" formula a 45cal with a 56 twist needs a bullet .477 long. Weight has little to do with it. The length has to be matched to the twist.

 

[longcruise]

Ran it through the Home Depot formula and came up with .479.

 

[windwalker_au]

What is the heaviest conical I can stabilize out of a .45 with a 1-56 twist using 80 grains of 3F. TIA

bill i have a friend that has an old numrich .45 cal with a 1in 56 twist and it shoots the lee 45 cal mini in to clover leaf this is the mould no
45 Cal. .450-294M or 45 Cal.Oversize .454-298M depending on your barrel.
bernie :thumbsup:

 

[hepburn4590]

the Home Depot.

:grin: :grin: