Testing .40 Patches & Velocities

[Herb]

In this test of a .40 Vincent I built, I used .400 balls from Eddie May and .020 OxYoke patches with 40 grains of Goex 3F.  Having only three balls left, I used .010 OxYoke patches and they went 222 fps faster and cut the group size by one-fourth.  I always wondered if that result would repeat.

Today I tested those patches again, shooting from rest at 50 yards.  My ".400 Rush Creek" cast balls are really only about .395 and weigh 95.5 grains, very uniform.  The .020 OxYoke patching measured .019 and the .010 OxYoke patching really was .010.  I used spit for lube and did not wipe between shots nor between targets.  40 grains of Goex 3F. (On an IBM computer you can enlarge the photo by holding down the Control and hitting the Plus sign.  Minus makes smaller.  Control zero (0), back to normal.

The caplock Thomas Oldham Bedford I built has a 7/8" x 42" Green Mountain barrel.  I used CCI 11 caps.   The flint Jacob Wigle (Westmoreland Co., PA) rifle I built with a 15/16" x 44" Green Mountain (IIRC) barrel.  I could not start an .020 patched ball into the bore, so went with ".015 OxYoke" precut round patches, which really mike .011 to .012.  And then .010 on Target 4.  Notice that Target 3 shows a 1.9" group with the same velocity and wide spread as Target 1.  Then on Target 4, I used .010 OxYoke and the group went to six inches. There was radio interference preventing further chronographing, so I got only one velocity, 1599 fps.  So I shot four more ".015" OxYoke, same as on Target 3, and the accuracy returned.  I did not find any torn patches.  Just some of the variables out there!

[roundball]

Having only three balls left, I used .010 OxYoke patches and they went 222 fps faster and cut the group size by one-fourth.

That's interesting...in some chronograph tests I've run, thicker tighter fitting patches gave me slightly higher velocities, not lower.  And a difference of 222 fps is huge.

[Maven]

"On an IBM computer you can enlarge the photo by holding down the Control and hitting the Plus sign.  Minus makes smaller.  Control zero (0), back to normal."

Herb, That also works on other PC's, my Dell (Windows XP) for example.

[Herb]

Thanks, Maven.   I should have said "IBM type", mine is also a Dell with Windows Vista.  Don't know if this works on an Apple.  Another way to enlarge is to go to the bar at the top of the screen and click on the gear-shaped icon and then "zoom" to change image size.  There may be other ways, if anyone knows, please tell us.  It often helps to see larger images.

I got a new Sony Cyber-shot camera and loaded the disc on my computer. There is now a new program that is changing my photos and I haven't figured out how to keep the photos in my Windows program, nor how to crop or enlarge in this program.

[Herb]

This was the crown on my Wigle rifle.  The barrel is a 15/16 x 44 round bottom Rice.  This sharp crown would not allow seating the .395 ball in an .020 patch without a hammer (literally).

So I crowned it, following Daryl's procedure.  The bore is lightly coned, but I can seat a .395 ball in an .010 patch only half way into the bore.  The new crown permits seating the .020 patch with a good whack on the short starter.

The two targets on the left were pictured above.  Shown for comparison.  The top center target was shot with .020 OxYoke patches (really about .019) and the results were about the same, low velocity and a wide spread, not very accurate.  Target 2 (top right) was with some new JoAnn Fabric linen I found in Salt Lake City, very white, loose weave, measures about .014.  I did not expect much of it, but it held together.
Target 3 (center bottom) with .010 OxYoke shot tightest and fastest.  Target 4 was with 70 grains of Goex 3F and the .010 patch.  No blown patches today.  Don't know why the fliers, it was not the wind, blown patch, or my holding.  The crooked nose cap came when I riveted it on.  I'll take it off and refit it.   

[Daryl]

Not sure what to say after that flurry of activity, Herb. I've not found that large spread of velocities before. Wide spreads mean large variations is pressure - which shows up in speed. This usually has a detrimnential effect on accuracy.
This picture freeked me out!


 Guess I should perhaps post after the fortified wine wears off. Yikes again!

[Daryl]

Herb- when I chronographed my .40, I was using the accuracy loads of 65gr. 3f and 75gr. of 2f - both GOEX.  I used 10ounce Denim which measures .0225" on my calipers- squeezing the tines tightly bewteen finger and thumb.  the rifle game be excellent accuracy, and almost identical velocity for the loads in the .42" bl.  Both were just over 2,200fps. This was out of my Goodioen barrel, with square rifling, every narrow lands, wide grooves and 48" of twist.

If this current mild weather holds, I'll see if I can get out and try it again, now that it's only 36" long and on a different stock.

[Herb]

Daryl, that crown that freeked you out was the way Rice made it.  I  had him do a "deep crown" once when he gave me the option, but don't remember what barrel that was.  This 40 grains of Goex 3F load gave poor accuracy and wide velocity variation in these three .40 calibers I built, and probably more if I looked at all my records.  I respect your experience and will try your loads when I can get to my range again.  I have used Swiss 2F with good results in a .40, but probably should try at least 50-60 grains.  I also have Swiss 3F but don't remember trying it in a .40.

[smylee grouch]

Herb: I have had several GM 40 cal and all shot great but I always got my best groups with 60+ grs. of 3f Swiss and tight patch, 395 or 400 balls. Out of 6 40 cal GM the best grouping one put five shots into .6 inch outside measure at 50 yds. This was with my old eyes so I think you need more powder and a tighter patch. Best wishes and good shooting.    Smylee

[Candle Snuffer]

Did I miss it, or did you mention what the twist was, Herb?

[Herb]

The barrel is stamped 1*48.  Thanks to all for their accurate loads.  I'll work on this rifle when the weather allows. 

[Daryl]

Herb, what actually freeked me out, was the distorton in the picture - looks like the hole is WAY off centre, side to side as well as top to bottom - optical illusion I expect.

When I first got my .40 barrel, I asked here what the chunk shooters were using for loads in their rifles.  I knew they only shot at more meaningful ranges of 50 yards or further in their accuracy games. The overriding trend was for the heavier charges- 55gr. Swiss to 65gr. Swiss and GOEX, which is about what I'd expected. 

My own barrel showed a preference for over 60gr. when using LehighValley Lube - a very slick lube.  65 was the best with 3f and 75 with 2F- identical accuracy - I was pleased. Later on, in more testing, I found it would shoot as well, with as little as 55gr. 3F OR 2F, if I was using a water based, WWWF/oil-type lube- or spit - pretty much identical results. 

The same 'trend' held sway in my .45 barrel (same rifle) as well, ie: 10gr. MORE powder if using really slippery lubes.  I now have a sample of Shenendoah lube and expect the same results as I had with LHV as they are so close to each other.

I am absolutely convinced that with more testing, Herb will be making tiny groups with all of his lovely rifles.

[Herb]

Yes, it was camera distortion on that muzzle, I am looking down on it a little.  Unfortunately, the crooked nose cap is not.  Will refit that.

[Daryl]

In looking over the targets again, Herb, I got to thinking about my own grouping in regards to aiming point.

I found a round 4" (5" max) black bull to be one of the best targets to shoot at, with either a bead or blade front sight, and holding 6 o'clock.

 It appears your aiming point is about 4" wide, but only an inch tall. Does that give you a really good sight picture?  I find sight picture is so very closely tied with group size, no matter what sights are being used.  I find the bull or aiming point size and shape to be quite critical - even with a scope it can make a substancial difference, but even more so iron sights.

I guess the reason I was thinking along this line, is I believe your overall grouping should be better and I think perhaps sight picture could be a reason why.

To a point, the smallest aiming point you can see well, will give the best groups with any load.

[Herb]

All you need is a vertical and horizontal reference.  I can shoot a sheet of blank paper and don't even need an aiming bull.  You just hold the same each time, from memory.  A big bull loses shots in the black, that is, they are hard to see.  These big groups are due to the load, not the bull, my holding, the wind, or how I hold the rifle.  I always considered 40 grains of 3F a standard .40 caliber load, but it is really not very accurate in my rifles.   I kept using it here as a standard of that Vincent rifle.

[Daryl]

OK - we all have our favourite shapes. That shows at a chunk shoot.

[Herb]

In the July, 2010 issue of Muzzle Blasts, Clark Frazier listed some Bench Rifle loads showing bullet weight and powder weight.  He divided the weight of each caliber ball by the weight of the powder charge to get a Ratio, which averaged 1.454 for four calibers.  To figure what it would be for your caliber, divide the ball weight, such as 95 grains for a .40, by 1.454 to get the powder weight, 65 grains here.  That is the charge weight for a presumed accurate bench rifle load.  So I tried it in my .40 Wigle flintlock.

I used ".020" Ox Yoke, really .015, with .395 balls and 70 grains of each powder, fired at 50 yards.  Top Right, 70 grains of Goex 3F went 2010 fps.  Next, Top Left, 70 grains of Goex 2F went 1809 fps, no wiping.  Cleaned the bore now.  Target 3, Middle Left, was 70 grains of Swiss 3F at 2169 fps.  Target 4, Middle Right, 70 grains of Swiss 2F went  2047 fps, radio interference on chronograph.  Target 5, Bottom Left, 70 grains of Swiss 1 1/2 went 1950 fps.  No wiping for last three targets.  I aimed at the center of each page and at least this gives relative velocities for these five powders.

[Daryl]

Interesting Herb.  For small calibres it might be just fine.

 
The formula fails quickly though, with increased bore size due to the exponentially heavier ball weight with increase in size.

 

[Daryl]

I found some of my own .40 cal. targets.  All shooting at a measured 50 yards off a rest.

The top target.  

 This one has 4 groups with a bench-rest 5 shot group on the centre bull with balls from my .395" SC Lyman mould and the same load on the top left bull, offhand same ball, load of 55gr. 2F and .0215 patch, but with 8 shots fired.  Due to running short on pre-lubed patches, I used spit for lube for the offhand group.  I've found it shoots virtually identially to the WWW and a bit of oil added.  I have since accurately measured these .395" mould balls and they are .398" X .397" - just about round - and for this barrel, exactly bore size less .001" one way. It has a .398" bore.

I then shot the top right target from the bench with the oblong balls from my DC mould. These were obviously oblong so I measured them at .392" X .400".  The other cavity went .400X.400.  Do you know what a pain it is to cast only one cavity form an iron DC mould?  This bull was also off the bench, same powder charge and patch and then used the oblong balls on the bottom right target, same load only fired the 5 shtos, offhand.

The reason for this test, was due to some fellas here thinking it didn't matter what the actual accuracy of a load was "because I'm only shooting offhand".  These two simple targets show how a less accurate load effects your offhand accuracy as well.  Note the 1/2" group on the middle bull, compared to the 1 1/2" group on the top left target. That's bench then offhand.  Then, with a less accurate load of 1 1/2" top right bull vs the offhand 3" bottom right target group.  If the load is not accurate off the bench, it is even less accurate when fired offhand.

Now, truth be known, it takes training to shoot well off a bench just as it takes training to shoot well offhand. Taylor is a prime example of someone who used to shoot better offhand than off a bench- really.  Now, he's learning to shoot better from a rest and able to take advantage of it's benefits towards load development.



This target (sorry .45 GM bl. 60" twist) was shot to test various charges with LehighValley lube as Leehigh Valley lube's accuracy failed with the lighter charge capable of being used with water based lubes.  Normal prior to this was 62gr. 3F with spit or WWWF.

 I had already found that heavier powder charges were necessary with this very slippery lube.  During this day's shooting, the bore was cleaned, not just wiped, before the top right and bottom bull was shot.  By the second dirty shot I could usually see the hole developing.

As you can see by the sight drawing, I was trying a slightly different rear sight shape. The 4" bull sat quite nicely in the wide part of the V, but I sould see light on each side of the blade, below the bull. Seemed to work, but with those dang fliers!

In cleaning the bore after the first 15 shots, I used 3 wet patches then 5 drying ones. This was only the second time I'd tried LHV in this barrel and wasn't sure how it was doing, but it seemed quite consistant. This was the changed "new OxYoke formula".  I did have a fliers on 4 out of 5 groups, but that quite possibly could have been me.

This test showed me that LHV was quite accurate, as accurate as spit lube, but required 10gr. or more powder to get that accuracy.  Dropping the powder charge with LHV by 10gr., to 60, more than doubled group sizes - consistantly.

[smylee grouch]

I hope my picture shows up but I wanted to show how the old adage of aim small-miss small hold true. When I try to aim for center of black on any size bull my groups are real big but when I hold on a smaller spot,the center of black at 6-o-clock my groups shrink considerably. If my photo comes through you can see the 5 shot group right above the bottom of the black and the three flyers a half hr. latter when the sun came out from behind the clouds.  40 cal GM barrel with only 55 gr 3f swiss 20/1000 spit lube ticking at 50 yds. My old eyes just couldnt get my gun to shoot worth a hoot aiming at a large aiming spot. I think the diferenting point from black to white is alot easyer to see and aim at.     Smylee

[smylee grouch]

OK so my pics didnt show up but I will try again.

[smylee grouch]

[Daryl]

It's amazing what lighting change does even when you are shooting from under a roof. Having the sun come out on the sights can really cause problems.

When bench shooting out in the sun as on the primitive range, I try to remember to use shaders, if I have them with me.

[Herb]

Thanks for the input, Daryl and smylee.  I had the sun to my back and I shaded the sights, but there was a lot of difference in light on the sights during this test.  Also, I might have shot better with a reference spot to hold on, maybe the size of a quarter.  I could see the holes when they cut together to make a bigger spot, but wasn't holding on them.  From these five targets, the first and last groups seemed to be best, at velocities about 1950 to 2000 fps.  I'll shoot these again when the weather is good, and that  55 grains of Swiss 3F load and 55 grains of Goex 2F.  Target 3, 70 grains of Swiss 3F, was big with the clean bore, but I don't think that made the difference.  It may have been that velocity.  When the radio interference started, I had to time my shots between when the chronograph was running because of those radio signals, and that made for some fast shooting until I couldn't win.

[smylee grouch]

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           I have made alot of shaders which help to keep a consistant sight picture especialy in the sunshine. This one was made using an old practice engraving plate, cant just throw stuff away ya know.