.40 / 1:36" ?

[GBG]

Does anyone own or have experience with a .40 and 1:36" or similar twist? I just ordered a GM .40x42x1 smoothbore and am considering having it rifled faster than the standard 1:48".

I'd like to use ~200 grain conicals for hogs in a WMA (.40 required) but still be able to use PRBs with light, quiet charges for crows and other pests in the garden.

Opinions welcome too.

 

[Rifleman1776]

No experience other than observation, reading and campfire shared wisdom.
The 1:36 twist in a .40 should work just fine.

 

[asbrown]

I put the #'s into Greenhills formula and a 1-36 twist will sufficiently stabilize a .40 cal bullet no longer than 1.75 calibres long (.7").I don't have any idea how heavy a projectile .40cal and .7" long would weigh.
bullet length divided by bullet calibre=X
150 divided by X=Y
Y x calibre=required twist
.7/.40=1.75
150/1.75=85.7
85.7x.40=34.28 1in34twist

 

[Billnpatti]

You would have to calculate the volume based on the nose shape and then multiply the volume by the density of the particular alloy you are using. Be sure to keep your units straight when making the calculations.

 

[bob308]

you mite have a problem getting a mold. as to rifle a .40 smooth bore you will end up with a .41 cal rifle.

if you did get a barrel that took a .400 bullet. a mold for a .38-40 would work. for a nice load it goes about 180 gr. if you get one with the 1-36 twist. you mite try the bullet for the .40-82 it weights 280 gr.

now you will need a false muzzle to load those bullets.

 

[Shifty]

Go to Roundballs post #1207652-under hunting

 

[GBG]

Missed Roundball's field report in a search for ".40 conical". Oldnam's mold got me interested in a more effective WMA legal .40 for hogs. I know a RB down the ear will work, but the places I hunt are so thick you seldom see a whole pig.
Thanks for the replys.

 

[Rifleman1776]

you mite have a problem getting a mold. as to rifle a .40 smooth bore you will end up with a .41 cal rifle.

if you did get a barrel that took a .400 bullet. a mold for a .38-40 would work. for a nice load it goes about 180 gr. if you get one with the 1-36 twist. you mite try the bullet for the .40-82 it weights 280 gr.

now you will need a false muzzle to load those bullets.

I had a similar thread a while back looking for a bullet mold for my wife's .40 cal. rifle so she could hunt deer with it. Someone sent me a link to a company that custom makes molds. (not Jeff Tanner) They are expensive but can do the job. A search might bring it up.

 

[nkbj]

A one turn in 36" twist is liable to be in a good range for .40 caliber.
You might want a .398", .399" or .400" sizer. If so, Tennessee Bullet Molds can provide you a sizer at a really decent price.

Altering an old .38 mold might be a path to getting exactly the right bullet. www.hollowpointmold.com is a good place to look at that possibility.

Best wishes and good luck.

 

[nkbj]

By the way, I shoot .40's with 16" and the standard GM 48" twist. Would love to have one about half way in between.

 

[Ian]

A .410" pistol bullet at .7" long will weigh approx 225gr if it has a hunting type ogive maybe 230gr. Accurate moulds will have or make anything you want and their moulds are a work of art. cheers Ian.

 

[nkbj]

Could commonly available .41 mold designs provide enough bullet to barrel contact length to work well? Sure could be a passel of fun.

 

[nkbj]

Then again, a Lee REAL is pretty short for it's diameter.