[csward]

HI FRIENDS,
MY GOAL WAS TO DEVELOP A LOAD THAT WOULD PROPEL A 40 CAL. 180 GRAIN, LEAD PSP BULLET PROVIDED IN A SABOT ( THE DARK BROWN ONE ) AS SOLD BY KNIGHT, AT A VELOSITY OF 2500+ FPS..
A PERSON AT KNIGHT SAID THAT THE BROWN SABOT HAS BEEN TESTED AT 2600 FPS WITHOUT SHEDDING PLASTIC IN BARRELS. SO MUCH FOR THAT PART...
HOW ABOUT POWDER AND QUANTITY ? HODGDONS SAYS THAT 11.5 GRAINS OF clays UNIVERSAL WILL DRIVE A 260 GRAIN JACKETED BULLET AT 1300 FPS. SO, I CHOSE 11.0 GRAINS OF THAT POWDER TO TEST.
I USED WINCHESTER SMALL RIFLE MAGNUM PRIMERS. THIS SHOULD BE OK, RIGHT ?
BUT, WHAT ABOUT CHAMBER PRESSURE ? I NEED YOUR IDEAS HERE.
ALSO, WHAT KIND OF VELOSITY CAN I EXPECT ? THE PLASTIC SABOT WITH ITS .40 CAL LEAD BULLET SHOULD HAVE A LOWER COEFFICIENT OF FRICTION THAN THE KNOWN JACKETED BULLET DATA. I'M GUESSING THAT FRICTION WOULD BE SO MUCH LESS WITH THE PLASTIC SABOT, THAT I'M HOPING FOR THAT 2500 FPS GOAL I SET FOR MYSELF. DOES ANYONE HAVE ANY DATA THEY CAN PROVIDE ME ?
ACCURACY IS SOMETHING ELSE AGAIN AFTER I'M FAIRLY CONVINCED MY RSRH WILL REMAIN INTACT AND ALL MY SEMI-MATCHED BODY PARTS REMAIN ATTACHED IN THEIR CURRENT LOCATIONS. BUT CAN ANYONE GIVE AN IDEA OF WHAT SIZE OF A THREE SHOT GROUP COULD BE EXPECTED ?
ANY COMMENT, CRITICISM OR DATA THAT ANYONE CARES TO SUBMIT WILL BE ACCEPTED BY ME AS BEING "FRIENDLY" AND NOT DEROGATORY. LET YOUR MINDS FLY FREE !
CSWARD

 

[lostinVt]

I wish I could be helpful with some insight, but I can't. I must admit though that I am intrigued by the idea. I know that before I touched any one of those off, I would want to know the total weight of the sabot and bullet combined just to get an idea where to start with the powder charge. If I was doing it, I'd then go to the books and start somewhere around the minimum for that weight and work my way up.

I shoot sabots all day long in my muzzleloader, and like the idea of using them. If the sabot will stand up to 2600 fps, like stated, I can't really see it being a problem. I'd continue to check the bore for signs of fouling, the cases for signs of pressure, and the target for keyholing. I always like to go downrange after a few shots to pick up the empty sabots to look at them as well. You could see things like ripped sabots, missing petals, etc. You should start finding sabots around the 10 to 20 yd mark.

I think that I would be real careful with the crimp on the sabot. I'd try to seat the sabot/bullet into the case far enough so that when I crimped it it would get a real good grip on the bullet. Don't want to have a bullet come loose in a sabot, or a combo start to pull out with the recoil.

Just a few of the thoughts that went through my mind. Love to hear how it turns out for you. I'd be interested in what you find out...group size, velocity, which bullet you use etc. Best of luck. I can also tell you that sabots out of my muzzleloader are extremely accurate. In other words, I wouldn't give up hope on this project real quick, because I think the possibilities are there for this to work. Good Luck. LostinVt

 

[Alk8944]

csward,

Didn't we discuss this? I can't find my outgoing E-mail.

I seriously doubt that 2500+ is possible, more like 2250 seems more reasonable unless you are going to use a TC, you didn't say that I noticed.

Other than the momentum values being at best equal, assuming you do get 2500, at 100 yds the TKO value for the .40/180 @ 2250 is less than the .454/260. The difference isn't much, but it does favor the heavier bullet.

This is one of those projects we just do from time to time just to see what happens. Even if it doesn't work out I will still be interested in the results.

With the light bullet and reduced coefficient of friction I would expect you to get the best velocities with a faster powder than the customary H-110/296. I think I would try Blue Dot, Steel, Herco and others in this burning rate range. The charge weights will probably need to be still in the 28-35 gr. range due to the two primary mitigating factors. I don't have any .454 data immediately at hand, but if you can fing any for these powders and a light bullet like a 185-200 gr. I would start about halfway between starting and max. recommendations. Don't forget to include the weight of the sabot with bullet weight.

 

[lostinVt]

I do not think that he (csward) was interested as much in the TKO value of the load as he was the recoil. I think that one of his main goals is to reduce the felt recoil in a .454.

I can't imagine that I would try this load for large game. I think the bullet design would fail at that speed, unless it was for a varmint.

If my memory is correct he planned on shooting it out of a Super Red Hawk.

My personal interest, would be in a longer barrel like a Puma .454 lever action rifle.

I think that the biggest value as far as I would be concerned is the "Hey look at this," effect that it would have in a group of friends at the range.

Mr. Ward, if I misinterpreted your intent I apologize, but I sure do hope that you keep us updated on this project. Thanks. LostinVt