Ballistic Theory Casting, Swaging, and Ballistics ?

[rsterne]

Is it planned to have a Section on producing your own Ammo, both pellets and slugs, to include the design and development of these, and where to obtain them?.... How about the considerable amount of Ballistics Research currently being done, including the search for a better Drag Model for slugs?....



Bob

 

[Tomcat 357]

I have 2 Benjamin Bulldogs, one .357 and .457. I cast my own slugs/bullets using Lee molds and sizing dies. Thus far they have performed well. When target shooting I catch them in a trash can filled with rubber mulch then fish them out later to go back into the melting pot. Makes for very cheap shooting.

 

[rsterne]

Thanks for creating this Section on the HAM Forum, I think it will prove popular....

Bob

 

[hameditor]

Bob. It's a pleasure! We're trying hard to improve the Community all the time

 

[air hunter]

I have a question about air volume vs air pressure in a non regulated air rifle.
We are talking bigger caliber here, .35 and up.
Lets say, for easy math, you start with a fill of 4000psi and get 5 shots to end with 3000psi.
It is an average of 200 psi used each shot.
BUT... the first shot should use less air volume due to higher pressure closing the valve quicker?
Then the 5th shot should have to use more volume to push the projectile?
Not sure where I was going with this (I think the statins are fogging my brain) but maybe the question was does a Short burst of HIGH pressure give the projectile the same push as a LONG burst of LOW pressure?
Ha, sounds more like a tuning question than ballistics one!
Damn statins.

 

[rsterne]

You have it absolutely correct.... A properly tuned, unregulated PCP will have the velocity form a "bell curve", lower at the beginning and end, and slightly higher in the middle.... The first shots are less air at higher pressure, while the last shots are more air at lower pressure, giving the same velocity....

The first shots are slightly more efficient than the last ones, which is why an unregulated PCP gets louder during the shot string.... The valve is open longer, and shutting when the projectile is closer to the muzzle, resulting in a higher residual muzzle pressure, and a louder report....

Bob

 

[Tomcat 357]

I was out a few days ago with my 457 Bulldog trying some 200gr Lee REAL bullets that I had cast and found them to hold a very nice group at 25 yards. These I ran through a .457 sizing die. I was getting an average velocity of 824fps after a 3 shot string using about 200psi per shot. I then took a page from my muzzle loading experience and applied a .50 cal felt base wad to the bullets and fired another 3 shot string and got an average vel of 843fps. 20fps more and and groups that touched at 25 yards. I am now waiting for a good day to do it an again with the Lee REAL 250gr and see what I get.

 

[Loren]

I was out a few days ago with my 457 Bulldog trying some 200gr Lee REAL bullets that I had cast and found them to hold a very nice group at 25 yards. These I ran through a .457 sizing die. I was getting an average velocity of 824fps after a 3 shot string using about 200psi per shot. I then took a page from my muzzle loading experience and applied a .50 cal felt base wad to the bullets and fired another 3 shot string and got an average vel of 843fps. 20fps more and and groups that touched at 25 yards. I am now waiting for a good day to do it an again with the Lee REAL 250gr and see what I get.

Interesting!

Is the felt wad used in muzzle loading to prevent gas cutting of the bullet or is it for sealing the barrel under the bullet or a little of both?

I have tried some muzzle loading sabots in my .457 Texan with .40 cal bullets. Mixed accuracy results, but need to spend more time on it.

 

[pan60]

i shoot a decent amount of black powder i have never used wads in my riffels so i am all ears?
i have used some under the lead in my old ruger revoler but that was more for safty and help stop a chain fire reaction.
but this is just base on what i have read and as we all know you can read anything you want.

 

[Tomcat 357]

The felt base wad is to help seal the bore. The Lee R.E.A.L (Rifling Engaged At Loading) is designed with the idea of non-standard bore sizes found among muzzle loaders. The bullet is tappers from the top to the bottom.462 down to .452 and as I recall .454 at the middle ring. I ran mine through a .457 sizing die and it only shaves the top ring. I got very good groups both with and without the felt base wad. The base wad in my muzzle loaders greatly improves their accuracy. To make a batch of wads I bought a roll of 1/8” x 1”x 20’ roll of felt from Amazon and use a round 1/2” hole punch chucked up in my drill press with a block of wood under it and start cranking them out. I then use a glue stick and put a little on the base of the bullet and stick it on.

 

[Northeastbeast]

I am now trying my hand at swaging pellets. 22 caliber 22.8 grain. Its a learning curve for sure. Using a 1 ton arbor press 3/16 soft lead wire and some serious elbow grease. Ive been able to produce some good looking pellets so far. The weight is extremely accurate 99% dropping at 22.8 on the dot. Ive yet to shoot them as im in the process of building the rifle i will use them for. A new old stock bsa scorpion se. I order a few parts from huma to finish. Power plenum and reg, shroud and a airgage for the end of the tube so i can read both reg pressure and fill pressure.