Author Topic: reduced charge accuracy load folo  (Read 4715 times)

caliber45

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reduced charge accuracy load folo
« on: February 03, 2009, 03:42:44 AM »
Gents -- A brief folo to my recent post about a reduced-charge accuracy load (.40-cal.; 21-inch "carbine barrel -- scratch-built Hawken style; .395 ball; pillow ticking; spit; 25 grains 3F Triple Seven powder): At 25 yards, it produced a three-shot group of sub-half-inch.  Was advised by some of you kind folks to check it at 50 yards. Did so today. Bad news: 12 rounds fired grouped at 6 1/4 inches. Better news: 10 of those 12 were in 3 1/4 inches; eight of them were in 2 1/2 inches; five in 1 1/2 inches. All of the eight were in the 3-inch bullseye. Not a tack driver (yet: still need to play with patch thickness, etc.), but I'm pleased to see they are at least trying to "hang together." For what it's worth . . . - paul

Daryl

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Re: reduced charge accuracy load folo
« Reply #1 on: February 03, 2009, 05:44:15 PM »
For such a  short sight radius, 3 1/4" for 10 out of 12 isn't too bad at all.  The 21" .50 cal. barrel originally on my canoe gun would hold around 2" to 2 1/2" and that's the best it would do at 50 yards.  An oblong hole at 25 yards was normal for that barrel with almost charge. To shoot tighter at 50 yards, I had to go to 80gr. 3F, which only chronographed 1,440fps.  Even a drop to 70gr. opened groups to double and threw in flyers. No flyers from 80gr. to 110gr. of 3F.  What this testing showed me was that the 21" .50 barrel duplicated Taylor's 44" .50 for velocity with the same powder charge weight - his using 2F, mine using 3F.

I've never shot T7 -  I bought a couple pounds for ctg. gun shooting, but not sure I'll ever use it in them. Real BP has shown better ctg. gun accuracy and consistency than the other 'fakes' when I did test such powders years ago.
« Last Edit: February 03, 2009, 05:45:05 PM by Daryl »

BrownBear

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Re: reduced charge accuracy load folo
« Reply #2 on: February 03, 2009, 06:06:23 PM »
Have you chronographed light loads with 777, or heavy heavy one for that matter, Caliber45?  Anyone else?

Your results sound a whole lot like what my shooting pard is getting in an array of calibers, and it's making us both a little nuts.  I suppose I could break out my own chronograph, but it's easier to type than work.

You make me really wonder if 777 just needs larger charges for consitent burns and velocities. 

caliber45

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Re: reduced charge accuracy load folo
« Reply #3 on: February 04, 2009, 02:41:34 AM »
Thanks for the comments, guys. Daryl, I guess sight-radius is a critical factor in this case (plus my own shortcomings as a marksman). As I said, I'm glad it's "trying." I haven't gone on upward in charge experimenting because economy (weight of the carbine, caliber and powder charges) was my goal. One of these times, when I get bored, I'll try a few heavier loads to see how she likes them.  When my supply of Triple 7 is exhausted, I'll give BP a try to see if there's any improvement. BrownBear, sorry to say I haven't chronographed any of my loads, being too cheap to spend my limited "building" funds for a chronograph. I do know that with the 25-grain loads, the balls are flattened but not noticeably expanded or otherwise deformed. With 50 grains, of course, they are inverted concave at the rear and distinctly mushroomed, as expected. Maybe someone else on the forum has clocked the velocities. - paul

BrownBear

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Re: reduced charge accuracy load folo
« Reply #4 on: February 04, 2009, 08:16:18 AM »
The only reason I'm interested in velocity is the question of consistency.  Lots of variation in velocity would sure add up to larger groups as the range stretched, even if it gave small groups at 25 yards.  Just brainstorming.  Not worth buying a chronograph for, but worth getting near someone who has already bought.  The heavier loads might well overcome the potential issue altogether.

Daryl

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Re: reduced charge accuracy load folo
« Reply #5 on: February 04, 2009, 08:12:39 PM »
Most of the phoney powders require considerably compression to burn correctly.  Loading from the muzzle makes it difficult to get the correct compression - each and every time - which is mandatory for accuracy with the stuff. Consistancy is important no matter what powder is used.
« Last Edit: February 04, 2009, 08:13:56 PM by Daryl »

BrownBear

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Re: reduced charge accuracy load folo
« Reply #6 on: February 04, 2009, 10:07:47 PM »
Good point Daryl.  We've learned to be as consistent as possible in seating pressure with the subs.  I'm still wondering about peak pressure and velocity consistency with light loads, associated with their general difficulty in ignition.  Guess the only way to check on it is to dig out the chronograph.  Dang it.

northmn

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Re: reduced charge accuracy load folo
« Reply #7 on: February 04, 2009, 10:46:27 PM »
I chronographed some 777 loads in a 45-70 with a Gould HP and got something like 1600 fps with a 70 grain equivalent.  I used a measure set at 70 grains and weighed three or four measures of 777 at that setting and took an average so I could weigh it in the case to get consistancy.  Don't remember the actual weight of the 777.  Does OK for hunting loads.  My trouble is that if I use the phoney powder I feel like I might as well shoot smokeless in a BPC. 
As to the reduced loads.  I used to shoot 40 grains out of a 45 at squirrels.  Shot good enough at squirrel ranges, some of which may have been closer to 25 feet than 25 yards.  I use a 45 ACP case for my 40, and again it works up close.  If you are shooting at ground squirrels at longer ranges then the fine tuning is needed.  Minute of squirrel head or rabbit head can be reached with light loads up close.

DP

Daryl

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Re: reduced charge accuracy load folo
« Reply #8 on: February 05, 2009, 05:05:08 AM »
I had better luck with Black Mag 3 in BP ctg. loads than with Pyro - haven't tried T7 - heard of some pressure excursions with T7 - needs grubbing out, I guess - don't like shooting subs, but sometimes had to when no BP could be found up here.

Len, Brad and I are going to use the smoke-poles for our workaround guns this coming spring gopher shoot.  Ranges will be whatever we can see them at- depending on the light and foliage.  My summer load is spit patch and 55 to 60gr. 2F  with .400" in the .40.  I need to find a load for the .40 with LHV for summer shooting. Too, the shortening of the .40 barrel along with it no longer being held in a full stock may change it's demands.

  I need to do more load testing and would like to find a light, rat load for out to 50 yards that gives the kind of accuracy I need. So far, 40 through 50gr. shoots bug holes at 25 yards but spreads to over 2" and over with fliers at 50yards.  Not good enough.  I wonder if this has anything to do with the 48" twist, which should be lots for a .40 cal.
« Last Edit: February 05, 2009, 10:34:32 PM by Daryl »