Anyone tried casting Tin slugs ??

[Tweaker]

Considering doing this with a mold and Tin for sumatra 2500 and career airguns,  probably a overweighted slug mold so itll come out just about right using tin instead of lead. Anyone tried it? and if you noticed any observations /pitfalls?

[KnifeMaker]

Wow! I haven't see a post on this in a week or two. Mozzy on over to the Projectile section directly under PCP Darkk side. this is where you will find answers in slugs, and pellet casting!  

[tronickero]

Wow! I haven't see a post on this in a week or two. Mozzy on over to the Projectile section directly under PCP Darkk side. this is where you will find answers in slugs, and pellet casting!

Sorry for leaving the topic of the post, but your inbox is full and I cannot send a private message, how can I contact you?

Regards from Chile

Tron

[Wayne52]

I'm moving this topic to boolit and pellet casting

[Back_Roads]

 The length of the bullet may be of concern, longer bullets may be more twist rate sensitive. I have cast slugs and pellets, in .22- .50 cal. using pure tin shot them out of magnum break barrels, pumpers and PCP with great success.
 All were done using NOE airgun bullet/ pellet molds.

[Chickenthief]

length of bullet has almost all to do with twist rate, bullet weight comes a distant second!

http://www.geoffrey-kolbe.com/barrel_twist.htm

Knock yourself out!

[rsterne]

Twist rate is proportional to the square root of the density.... Changing from lead (11.3) to Tin (7.2) will require the RPM to increase by 20%.... If a slug needed a 10" twist in lead, the identical shape would need an 8" twist in tin....

Bob

[Tweaker]

Twist rate is proportional to the square root of the density.... Changing from lead (11.3) to Tin (7.2) will require the RPM to increase by 20%.... If a slug needed a 10" twist in lead, the identical shape would need an 8" twist in tin....

Bob

I recall a thread from way back regarding Tin and how it affects BC, so a rifle (with certain power restrictions) using Tin may allow for a more cylindrical slug without being too heavy. Although Im guessing even just the shape being more cylindrical needs a faster twist rate .

[UnderPressure]

Twist rate is proportional to the square root of the density.... Changing from lead (11.3) to Tin (7.2) will require the RPM to increase by 20%.... If a slug needed a 10" twist in lead, the identical shape would need an 8" twist in tin....

Bob

I recall a thread from way back regarding Tin and how it affects BC, so a rifle (with certain power restrictions) using Tin may allow for a more cylindrical slug without being too heavy. Although Im guessing even just the shape being more cylindrical needs a faster twist rate .

Yep, the slug you are describing would need a faster twist rate for two reasons:

1. Reduced density (as mentioned by rsterne)

2. Increased Projectile length.

(For X rifling twist rate the maximum length projectile you can run with tin will be less than the maximum length projectile you can run with lead.)

[UnderPressure]

The length of the bullet may be of concern, longer bullets may be more twist rate sensitive. I have cast slugs and pellets, in .22- .50 cal. using pure tin shot them out of magnum break barrels, pumpers and PCP with great success.
 All were done using NOE airgun bullet/ pellet molds.

Which molds were you using?

[Back_Roads]

The length of the bullet may be of concern, longer bullets may be more twist rate sensitive. I have cast slugs and pellets, in .22- .50 cal. using pure tin shot them out of magnum break barrels, pumpers and PCP with great success.
 All were done using NOE airgun bullet/ pellet molds.

Which molds were you using?

NOE .22 , .25 .357 I have every style air rifle pellet and slug mold they have made to date, and tried them all with tin at one time or another. The .50 was a Lee mold.

[K.O.]

Here is an example of when it could be advantageous to do so...

I have a 24" .172 Barrel blank 1:9 twist(Savage  model 24 upper barrel)... So say  I have it turned for an Mrod(or whatever)...

So what can I send out of it... well Noe Has a few molds in .172 The lightest is a .24g...

https://noebulletmolds.com/site/shop/172/172-24-fn-cd5/172-24-fn-cd5-3-cavity-pb

so I can run it at about 15g using tin by decking it to .410" long...

with lead will have a ~23g round that will want about an 11 twist barrel and should do fine in the 9 twist...

http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=.338+air&re_calculate=yes&boundary_layer=L%2FT&diameter=.172&length=.41&nose=.164&meplat=.083&drive_band=.172&base_diameter=.172&angle=0&boat_tail=0&secant_radius=&weight=15.3&density=11.4 

so that same decked mold in tin will be ~15g and want about the 9 twist of the barrel and only need   about 35 fpe to hit 1000 fps or 30 fpe to hit 950 fps...

so  30-35 fpe should not be to hard to hit with the 24" barrel using 3000 psi... so you are looking at about 825 fps with lead...

http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=.338+air&re_calculate=yes&boundary_layer=L%2FT&diameter=.172&length=.41&nose=.164&meplat=.083&drive_band=.172&base_diameter=.172&angle=0&boat_tail=0&secant_radius=&weight=24.3&density=7.2

There is a 26g mold and a 32g mold also those would be around 780 fps and 700 fps respectively... so now you look at the estimated g1 B.C. of each...

modded mold

15g is ~ .06
23g is ~ .1

non mod 24g is ~.127

26g is ~.14 and

32g is ~.13 

green 15g  red 23g   blue 26g   purple 32