Your best plinking load?

[Siringo]

In the book 'Flight of the Bullet" by Mann (old book during the transition from Black Powder to Smokeless) he made mention that very smooth bores and shallow rifling are detrimental to accuracy with lead bullets. I wonder if we can have this problem with the chrome plated bores/

[BD1]

Only time will tell. The bore looks a lot like a 1911 to me, and all my 1911s love cast boolits.
BD

[Siringo]

Has a lot to do with the bullet speed and twist.

Also, I had tried using 45 caliber muzzleloading sabots w/40 caliber bullets. Groups were terrible. I looked at the spent sabots and each one of them had a 1/2 round divot out of the skirt. Same size as the port for the gas system. With a lead bullet w/o a gas check -- a tiny bit of the rear base may get blown away into the gas tube or gas cut and when the bullet leaves the muzzle, that little bit removed may kick the bullet all over.

I have used 405's and 335's and had fairly good results, of course using gas checks. Groups were not great, but usually under 3 inches easy, some less than 2 inches.

[slash2]

Add 230 gr. Zero Hollow Points with 41 grs. of Lil'gun to my list. I haven't chrony'd them yet but they print the same as the 275 gr. Barnes with 34.5 grs. of Lil'gun @ 100 yrds.

[Siringo]

I will keep this in the current running thread here.

I want to develop a load using the 230 grain jacketed round nose that moves along around 1500 to 1600 fps. I don't want fast -- I want slow.

There was a recent article about using IMR Trail Boss for reduced loadings in rifle cartridges. This powder was developed for Cowboy Action Shooting. The way the article described how to load -- find where the base of the bullet sits in the case and fill the powder to that point. That is the maximum load. Take 75% of that amount -- that is your starting load. Well I did this using 284 cases and Montana 230 gr round nose bullets seated to 2.10 inches. The amount of powder was 14.4 grains.

I shot 5 of these to see if the action would stay open and it did not -- meaning not enough pressure. I have no idea on the velocity. Since that bullet is .4505 diameter, I am going to try with true .452's to see if they makes any pressure difference and try 450B cases because they hold one more grain of powder.

Developing---------------

[Hoot]

I've used it to load .300 Win Mags down. How clean did it burn for you? Any worse than the other popular powders for this caliber you've used? I'd like to venture more in the direction of hollow points than round nose, only for one reason. The less weight in the tip, the longer the bullet can be for the same weight, the more surface area in the neck for tension, the less critical the crimp requirements. Maybe that's the tail, wagging the dog...

Hoot

[BD1]

You can't just look at the peak pressure of the load, you need to look at the "curve" and what the pressure level is when the bullet goes past the gas port. The faster powders will develope their pressure peak earlier in the bullets travel and then drop off fast. The pressure may be too low to work the action by the time the bullet passes the port. Slower powders are still increasing the pressure as the bullet travels down the barrel and the opposite end of the spectrum is a "too slow" powder in a gas/op rod gun, like the garand, that bends the op rod when the pressure is still building as the op rod starts moving. In a direct impingement gas gun like the AR, this can show up as case rims being torn off when the slow powder/heavy bullet balance exceeds the parameters causing the action to start opening while the pressure is still so high that the case hasn't let go of the chamber walls.

There needs to be enough gas pressure at the port to operate the action, but not too much, and enough time before the bullet leaves the barrel to maintain that pressure while the action opens. This "balance" is what determines the size of the port and how far down the barrel it's located based on the load the barrel is designed for. If you stray too far from the powder speed/bullet weight balance the designers used to set the port size and location, you'll have some issues.

I've done some thinking about putting a second port in my barrel closer to the chamber to allow the use of faster powders. My objective is suppressed loads, but this would allow "plinking" loads as well. The issue is the ease of changing between the ports.
BD