Hypothetical Load?

[Josh Smith]

Hello,

Hypothetically, let's say that I'm working on a wildcat load.

Please assume the load was originally developed with a powder with a similar burn rate to BE.

The original specs are thus:

40gn lead bullet, BC about .132
.224 caliber, seated depth only .10-.13"
3.1gn water capacity
1.5gn fast (BE-like) powder charge, small pistol primer
COL of .985" +/- .005"
Claimed velocity of 1230fps

Firearm is a rifle, 21" barrel.

Now, let's say that the load were worked up to the same specs, except that the powder charge was 2.0gn of W231 to take advantage of the longer burn time afforded by the longer barrel.

What would you expect from such a load? Velocity, etc?

Thank you,

Josh

[35remington]

How do you know, for a fact, that the original powder was of a burn rate similar to Bullseye? Did the manufacturer of the ammunition tell you this was so, or are you relying on an unsubstantiated source?

The assumption part is the problem. I presume you're talking about your long rifle reloading, and assumption is a heck of a thing to go on. I would not expect a great difference in MV between "Bullseye speed" and "W231 speed" in a rifle length barrel, as both powders peak close to the chamber, and bullets are slowed by friction and the rapid drop off of pressures long before the bullet is reaching the muzzle.

Despite what the burn rate charts imply, there isn't much real difference between the two powders you are referencing, and in no pistol or straight walled cartridge can I find loading data that allows a one third heavier charge of W231 as compared to BE. For example, in the 45 ACP with a 230 grain bullet, around 5 grains BE is standard maximum or thereabouts. This would suggest that 6.7 grains W231 is an appropriate charge (one third more).

It is not. No charge of W231 is listed at that weight; it's at least a full grain lower or more, or about 12 to 16 percent.

Extrapolation is risky, and so is the assumption. Start low, work up, is the usual advice. It applies here as well.

I would expect the W231 charge would reach the same velocity with only a few tenths of a grain more powder. As in 1.7 versus 1.5 grains. At this velocity I would expect little difference in pressure between it and Bullseye when producing the same speed. As I said, for a rifle length barrel, there is little difference between the two. Both are quite fast.

Overloads with a thin rimfire case are especially undesirable.

For a blowback type action, powder speed toward the slow end can produce case head rupturing.

[Josh Smith]

Hello,

Thanks.

Josh

[missionary5155]

Good morning
I may have missed it but a fast burner in a long barrel is counterproductive... You will experience less velocity.
Optimum barrel length in the .22 rimfire is about 18"... longer barrels cause more drag than they give acceleration with the average .22 rimfire round.

[MakeMineA10mm]

Hello,

Hypothetically, let's say that I'm working on a wildcat load.

Please assume the load was originally developed with a powder with a similar burn rate to BE.

The original specs are thus:

40gn lead bullet, BC about .132
.224 caliber, seated depth only .10-.13"
3.1gn water capacity
1.5gn fast (BE-like) powder charge, small pistol primer
COL of .985" +/- .005"
Claimed velocity of 1230fps

Firearm is a rifle, 21" barrel.

Now, let's say that the load were worked up to the same specs, except that the powder charge was 2.0gn of W231 to take advantage of the longer burn time afforded by the longer barrel.

What would you expect from such a load? Velocity, etc?

Thank you,

Josh

Insufficient information, too many variables, and big assumption are all present here. Is this a straight-walled or bottle-necked case? (Makes a difference.)

Maybe I've not seen what you are doing here, but I see others are referrencing you making a 22 long-rifle style wildcat? There are a couple on the market already - I believe one is the 22 Cooper Centerfire Magnum, IIRC. (Have to pull out my wildcat books.) Assuming it is Bullseye-burning speed in a 22lr is very dangerous. In fact, a common powder for 22s in europe is VV 3N37, which is a VERY, VERY slow powder compared to Bullseye or W231.