Thursday, June 11, 2015

Got a question about the light/very light/mouse fart loads

want to cover:
On a more serious note: 5 gr. of powder in a '06 case is almost nothing. Do you use some stuffing, like a bit of cotton fluff or paper on top of the powder to hold it against the primer for consistent ignition? Or does it just not matter in your application?
And, do you find that if you reduce powder charges too much, you get incomplete ignition resulting in a squib? Honestly, I have never seen anyone going down in velocity to such a degree, but you seem to have a reason for it, and it does get you out to the range. And that is reason enough
.
Covering this in some detail,
You're right on 'almost nothing'.  The standard M2 Ball load in .30-06 is a 150-grain jacketed bullet over (originally as I recall) 48.0 grains of IMR4895 powder for a velocity of ~2800 feet per second.  Compared to that 5.0 grains is tiny.  And this uses a fast-burning pistol powder which takes up less space than 5.0 of 4895 would*.  I've read a lot over time of people using something as a filler with small powder charges to keep it in place near the base of the case for consistent ignition(from "You must use'" to "Don't be stupid, don't do it!"); not just on tiny charges like this, but reduced charges like you'd use in a Garand using cast bullets.  Some cartridges/propellants it's not argued, you need to do so; some propellants will not ignite and burn consistently if you don't.  Some it's optional unless you're going for maximum accuracy, it can make a difference.  And for some, doesn't matter(one reason for The Load for many cartridges being 16.0 2400 under a cast bullet 150 to 180 grains; 2400 isn't position sensitive so no filler needed).  Bullseye(or Unique or several others) seem to ignite and burn quite well without being so confined, and serve the purpose well loose in the case.  Also, that's one reason a lot of people recommend drilling the flash hole out**, to make sure ignition will be as good as consistent and even as possible.

One of the warnings in some of the Cast Boolit threads on the subject was 'Yeah, if you want to try taking it as far down as possible, be sure to take a range rod with you 'cause sure as hell you will get one stuck in the barrel at some point.'  In the spirit of "Just how slow can I take this?" I might try that sometime, but right now I was looking at, in no particular order,
quiet,
low recoil,
at least decent accuracy,
not having to beat something out of the bore.
Partly out of "This sounds neat, I'm gonna try it!", partly "How would this work for cheap practice/pest control out of a centerfire rifle?"   And I've got answers; with a bullet your rifle likes, you can get pretty good accuracy out to 50 yards with low-to-nonexistent recoil and much-reduced noise.

Also, so far I've seen no evidence of unburned powder granules, and the bores have stayed nice & clean, no sign of lead fouling.




*Don't EVEN think of using that small an amount of such propellant.  Ever.  Just don't.
**Remember, you should mark and keep the cases for these loads separate from what you use for full-power loads.  ESPECIALLY if you drill out the flash hole, NEVER use those for anything but the very light loads.

4 comments:

Pawpaw said...

Good advise, but you have to realize that you're in basically un-charted territory, so proceed cautiosly.

One note. You cannot get a load that will leave the bullet half-in/half-out the muzzle. Believe me,I've tried. It will either stick in the bore, or it will fly downrange about 30 yards and flop in the grass. It will not stick right at the muzzle. Go figure.

Oe other note: I thought THE LOAD was 13.0 grains of Red Dot.
http://members.shaw.ca/cronhelm/TheLoad.html

Firehand said...

True enough. Did a lot of reading before I tried it.

I'll happily take your word on that.

Bitch, bitch bitch. I haven't seen any Red Dot in the wild for at least a year, more like two, so I can only speak of 2400. At least until I do find some to try.

Arthur said...

Any time I modify a parent case I take a triangle file and put a series of small notches in the back of the rim. Doesn't affect extraction, but it makes a nice visual and tactile indicator that something isn't quite 'right' with the case.

BTW, I love anything that confirms my biases. In this case the bias you're confirming is 'Unique tends to *not* blow up my sh*t'.

Firehand said...

General advice I read was to do something like that for any case, drilled-out flash hole or not, used for these light loads, due to the shoulder possibly being set back. And that's exactly what I do, though it's one big notch instead of several.

Thinking about it, several would be a good idea, though.