Makin it obturate

[smokeeter]

I've been having fits getting some of my bullets to obturate, I solved the problem with the XTP mags by cutting the bases off and they work very well with that .
I also have a pretty good supply of nosler partitian bullets that I modified and couldn't get them to obturate satisfactorily since they have a very heavy jacket. Since the base is exposed that trick wouldn't work,and I was getting the majority of these bullets key holing which indicated to me that they weren't obturating therefore weren't spinning when they came out of the barrel. Well not being able to accept that I figured I would tinker a little and this is what I came up with.
I got a box core bit , 5/8 dia, and concaved the base of the bullet then I resized it to my .4505 bore , when I shot it today the skirts opened up enough to flare the base and fill the bore to the point were at least I get the rifle striations embossed on the bullet, now with a little tweaking a load can be determined and a definite moose contender is in the making.
Here are some before and after pics of the operation.




notice the rifling on the shank of the bullet,I'm a happy camper now.

[dave d.]

:)paul nice work...

[Richard]

Nice work Paul...........Just curious, do you have a collet chuck on your lathe? And a brake so you don't have to start and stop the motor?
Richard

[smokeeter]

Just a 3 jaw chuck on the old unimat Richard, start and stop operation , no money in this production.
The bullet on the far right, I tried to cut a band in the shank to see if that would help with obturation , it does work but with much more effort.

[ET]

Smokeeter

Talk about driving the force up the hoop to get it to do what you want it to do. ;D ;D

Nice problem solving for a resolution.

Ed

[jims]

To smokeeter , I think Nosler got his start the same way you did and look at him now. Good work.

[Dave W]

Remarkable dedication and excellent work on your part Paul. Now all you have to do is get her dialed in.

[smokeeter]

Apr 22, 2009 19:54:56 GMT -5 Dave W said:

Remarkable dedication and excellent work on your part Paul. Now all you have to do is get her dialed in.

Dave it isn't so much dedication as it is stubborness.
I didn't want to get stuck with all of these noslers and not being able to use them.lol

[Richard]

Thanks for the reply Paul. At times I kind of wish I had a collet chuck for stuf like that. And, starting and stopping the lathe is a pain plus wear and tear on the motor.
Richard

[leftydeadeye]

I notice that some of the bullets were not damaged badly at the heel end of the bullet and also the rifling marks can be seen. Do you have a good idea how much obturation these bullets expanded to?
Thanks, Kent

[smokeeter]

Oct 28, 2014 22:26:45 GMT -5 leftydeadeye said:

I notice that some of the bullets were not damaged badly at the heel end of the bullet and also the rifling marks can be seen. Do you have a good idea how much obturation these bullets expanded to?
Thanks, Kent

my guess is they expanded to the bore diameter.
now that I have a full form die obturation isn't as much of a problem, even with the heavy jacketed bullets.

[Dave W]

Congrats to your son on the bull!!

[smokeeter]

thanks Dave, the boys are starting to catch up to the old man

[redpep]

Paul, are you still making any of your 300gn .457 Remington's. I shoot .50 cal and bought 200 of these from you a couple of years ago, man would they shoot.