View Full Version : 38-55 RB problems

05-30-2010, 07:23 PM
38-55 RB problems

I am at 30 feet and shooting into a 22 cal steel trap (Otters)
84 grain .380 soft lead ball

Both loads are shooting less than 1-inch groups with open sights if I do my part
Both loads left a little (less than a dozen flakes) unburned powder in the bore

How my fps do you think will not harm the trap? ( I was thinking 800-900 Fps)

Not sure why I had the very low fps shots, all balls are crimp with Lee factory crimp die.
Not sure why there is unburned powder in bore.

1.7 grains of 700x real Quiet (My dogs dont mind it ,or the neighbors)

Good cat sneeze or gallery load?

448 fps

237 it was a flyer also 3 inches left

I then load 700x 2.1 grain (darn dogs hate it)

529 fps

Thanks for any help

05-31-2010, 03:23 AM
............Sounds like you're having fun, :-) Lets see someone buy loads like THESE someplace :D Your problem probably has to do with the relatively large case volumn. I'd suspect that the primer probably had enough umph to start the light ball moving forward. Straight cases have close to a 1:1 expansion ratio, meaning when the ball has moved forward about 2" the volumn (case and barrel) has effectively doubled. So it's either the powder doesn't see enough pressure to completly burn, or the primer ignites starting the ball forward and at the same time blowing the powder around. Some of it follows the ball without igniting. Just my 2 theories.

An example is when I first began working with cast in the 223. I have a Savage M112 with a 26" barrel. Wanting to play with some very light loads under a 55gr slug, I started out with 1.5grs of Bullseye IIRC (too lazy to go check my data). Regardless, the important part is if I simply loaded a round and fired it, the slug would not exit the barrel, but would plug the bore and the action would hiss for awile as the pressure leaked back around the case.

Once I flipped the bolt handle up while it was hissing. The bolt slid back and the case made a POP! as it came out of the chamber to ly there in the loading tray of the action (it's a single shot). Now if I loaded the cartridge and then elevated the muzzle straight up to place the powder against the primer the slugs not only cleared the barrel but tripped the chronograph at almost 500 fps. Very simple proof that powder orientation is very important in loads like this.


05-31-2010, 11:21 AM
Those .22 traps are made to take 40 grains at around 1,000fps. A steady diet of 1,200fps .22rf will bend the back plates in them. I found that out the hard way. I think that you are pushing your luck with 84 grains @ 800fps. I think that eventually, you will bend the trap.

If you put a 1 foot square cardboard box full of crumb rubber in front of that trap, it should be able to eat up the energy in that little round ball. I use a 1 foot cube with a 1/8" steel back plate as a stop for .38 specials. They just about make it to the back of the box. You can real all about my adventures building traps here - http://castboolits.gunloads.com/showthread.php?t=26627