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All Springer/NP/PCP Air Gun Discussion General => Projectiles => Boolit and Pellet Casting => Topic started by: Loren on September 19, 2018, 12:18:00 AM

Title: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: Loren on September 19, 2018, 12:18:00 AM

It is a journey for sure!

Things I am learning.

1) Control the melt temp and when it is not to temperature, do not cast. 
Add sprues or an ingot....wait until the temp comes back to the set casting temp before resuming casting.  Otherwise it just adds a size/weight variable to the mix which kills accuracy.  I am considering a second pot either to premelt or pour from while temperature recovers after charging the pot. (I hate waiting)

2) Get the mold HOT first before casting.  Use a torch, a hot plate...whatever it takes, but anything cast before before and while the mold is getting up to temp is just bullets to be culled out later because they will have defects or will be off weight.

3)I am using a bottom pour lead pot.  It takes some adjustment of flow depending on how large the projectile and sprue hole is for a given mold.  I have far greater quality fills by taking a little more time with lining up the spout with the spruce hole and having a smooth flow into the cavity versus the flood method I have seen some do on youtube.  Adjust the lead flow until it is kind of "splashing" then back off until it stops and has a nice smooth flow into the cavity.  Seems all the splashing simply cools the lead and greats a bunch of turbulence that keeps the cavity from filling out completely.

4) Size your bullets.  From what I am seeing is this helps greatly reduce the diameter variable.

5)Take the time to slug your barrel.  It will provide valuable data for sizing your bullets.

6) AG's are like PB's and sometimes a gun will just not "like" a certain projectile.

Please share things you have learned In The Pursuit of Accuracy relative to making perfectly cast bullets/pellets

Loren

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: tnt76 on September 19, 2018, 01:50:50 AM

I have found I get better fill out in the smaller calibres/weights, ie. under 50gr with the mold (Alum) around 400-420f and lead at 750-770f.
And also concur with Loren, don't bother casting until mold is up to to temp.
At this stage I use a lyman ladle and when casting the pellets I tip the ladle and mold together for a pressure pour. Some others here use the same method while reporting great results too.

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: KnifeMaker on September 20, 2018, 04:10:49 AM

Yep, Pressure pouring works very well. It is even easier in a good bottom pour pot. I started with a Lee and ladle, went to a Lee bottom pour, and finally  settled on an RCBS. 


 Man, What a difference!? Quality sure can shine thru!


Knife

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: Wayne52 on September 20, 2018, 12:19:06 PM

Quote from: tnt76 on September 19, 2018, 01:50:50 AM

I have found I get better fill out in the smaller calibres/weights, ie. under 50gr with the mold (Alum) around 400-420f and lead at 750-770f.
And also concur with Loren, don't bother casting until mold is up to to temp.
At this stage I use a lyman ladle and when casting the pellets I tip the ladle and mold together for a pressure pour. Some others here use the same method while reporting great results too.

That's the only way that I've been casting since the middle 70's cause it really works good that way when using pure lead.  Hollow base Mini balls is when I started doing it this way because it filled the skirts so nicely.

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: cosmic on September 20, 2018, 03:20:08 PM

Temp controler makes it easy and don't forget to stir the pot often..

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: Sbak on September 20, 2018, 09:49:43 PM

I'll leave this here

https://www-instructables-com.cdn.ampproject.org/v/s/www.instructables.com/id/Arduino-PID-Controlled-Lee-4-20-Metal-Melting-Pot/?amp_page=true&amp_js_v=a2&amp_gsa=1&usqp=mq331AQCCAE=#referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s&ampshare=https%3A%2F%2Fwww.instructables.com%2Fid%2FArduino-PID-Controlled-Lee-4-20-Metal-Melting-Pot%2F (https://www-instructables-com.cdn.ampproject.org/v/s/www.instructables.com/id/Arduino-PID-Controlled-Lee-4-20-Metal-Melting-Pot/?amp_page=true&amp_js_v=a2&amp_gsa=1&usqp=mq331AQCCAE=#referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s&ampshare=https%3A%2F%2Fwww.instructables.com%2Fid%2FArduino-PID-Controlled-Lee-4-20-Metal-Melting-Pot%2F)

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: Loren on September 20, 2018, 11:33:39 PM

I have tried some pressure casting with my bottom pour pot.  Great fill out, but I ended up getting some pits in the base from not filling the sprue completely and had to much head pressure and had quiet a few whiskers from the vent holes.

Would need to drop the pot level and figure out how to fill the base better.  Really just need a thicker sprue plate and it would be golden!

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: KnifeMaker on September 21, 2018, 03:25:08 AM

You don't need to lower the level in the pot. Simply use the pour adjustment screw.


For complete sprue puddle, at the end of the pour, lower the mold relative to the spout at the very end of the pour. It will leave a small spru. You will want to shut off the pour a split second after lowering the mold form the spout.  This will leave a nice, small puddle.


However, you will want to leave a few large puddles  from one end of the mold to the other from time to time to help keep the top plate, (Sprue plate) hot, as pressure casting doesn't allow the required heat to be maintained.  ;) 8)


Knife

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: Loren on September 21, 2018, 06:17:11 PM

Quote from: KnifeMaker on September 21, 2018, 03:25:08 AM

You don't need to lower the level in the pot. Simply use the pour adjustment screw.


For complete sprue puddle, at the end of the pour, lower the mold relative to the spout at the very end of the pour. It will leave a small spru. You will want to shut off the pour a split second after lowering the mold form the spout.  This will leave a nice, small puddle.


However, you will want to leave a few large puddles  from one end of the mold to the other from time to time to help keep the top plate, (Sprue plate) hot, as pressure casting doesn't allow the required heat to be maintained.  ;) 8)


Knife

Yes, all about the timing...I first need to work on walking and chewing bubble gum at the same time....lol

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: Wayne52 on September 21, 2018, 08:01:55 PM

Personally I'm use to doing it with the enclosed ladle tilting both mold and ladle together simultaneously back and forth and will probably continue doing it this way ;D

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: Loren on October 06, 2018, 11:02:32 PM

Another lesson.

SIZE MATTERS... ;D

Cast .30cal 55gr EPP/UG Bullet.  All from the same casting lot, and randomly selected.  Full magazine (14 rounds) FX STX barrel.

Sized .301
(https://i.imgur.com/bGIs7Df.jpg)

Sized .300
(https://i.imgur.com/I1VFZP7.jpg)

Sized .299
(https://i.imgur.com/LCZ4V93.jpg)

Because the FX barrel has really shallow rifling I think it is very finicky about bullet size.

Another lesson

Let the sprues chill naturally.  Speeding it up with a fan tend to draw lead from the bullet base and will cause radius edges on the base even with a good pour.

Title: Re: In The Pursuit of Accuracy (Perfectly Cast Projectiles)
Post by: rintafile on October 06, 2018, 11:07:27 PM

Thats true... I ususally waite like 5-10 sec. when melted lead is freezed on top of sprue plate. And yes size really matter on casting. No reason sized that bullet on barrel :D