More observations on Velocity Change with Powder Position

[earlmck]

A while back (3 weeks or so) I posted on the large velocity difference I found with 44 mag, light load of Green Dot powder, CCI LPM primer, depending on powder forward vs. powder back in the case http://www.levergunscommunity.com/viewt ... =1&t=65533. Then a few days later I did a similar trial with 30/30, Unique, CCI 200 primer http://www.levergunscommunity.com/viewt ... =1&t=65564 and found no difference at all with powder back vs. powder forward. I figured it was probably the Unique powder which made the difference, and several of you fellers made the same assumption.

Now I knew that it could also be the primer -- CCI rifle vs. CCI mag pistol, though that didn't seem likely as I doubt there is a lot of difference in their "fire power".

But I figured I'd better run some more tests to be sure we had this properly nailed down.

For this I used th 44/40 case since it handles the slightly taller rifle primer. 7.1 Grains Green Dot, 205 grain Lee RNFP plain base bullet.
CCI 200 rifle primer: powder forward -- 1148 +/- 25 fps. Powder back: 1221 +/- 13 fps.
CCI 350 LPM primer: powder forward -- 1142 +/- 30 fps. Powder back: 1238 +/- 24 fps.

We expected this, didn't we? Green Dot powder is the culprit, primer makes no difference.

So I go to the trusty Unique powder, 8 grains of it since it is a bit slower powder. This gives the same fill % as the Green Dot (about 45% full at my COAL). I just shot the CCI 200 rifle primer load. Powder forward: 1168 +/- 10 fps. Powder back: 1246 +/-13 fps.

I had some 44 mag loaded with that same 8 grains Unique, CCI 350 primer
forward: 1168 +/-22 fps. Powder back: 1236 +/-25 fps.

Oh poo! Unique powder doesn't work its miracles in the 44 cases. So it looks like the magic ingredient for making loads that are not sensitive to powder position is to use a 30/30 style case. 44 mag or 44/40 are sensitive to powder position of small powder charges not matter whether Unique or Green Dot.

Oh yeah, group size consistently was a bit better for the powder forward.

So it looks like I am back to the drawing board.

[J Miller]

I guess I'm just not good enough a shot to see those differences on the target that these powder charges make. I've shot Unique since ...... well I was barely shaving. I've shot it in every handgun caliber I've ever loaded. And I've shot Bullseye, 231, 700x, and other fast burning, small charge full power loads in the .45 Colt with great results.

That said, I've never used fast burning pistol powders in any rifle cartridges, never got into cast for those.

Now, I'll tell a wee story and ask a question.

Many summers ago I picked up a box of REM-UMC smokeless balloon head .45 Colt cartridges. Being curious I took one apart. The powder was 5 grs of something that looked like Bullseye with a thin cardboard disk holding the powder against the case head. Lots of empty case between the disk and bullet base.

Since a factory loaded ammo with a disk to hold the powder charge against the primer flash hole, why can't we? Seems it would be a solution to small charges of fast powder in big cases?

Just curious.

Joe

[earlmck]

I guess I'm just not good enough a shot to see those differences on the target that these powder charges make. I've shot Unique since ...... well I was barely shaving. I've shot it in every handgun caliber I've ever loaded. And I've shot Bullseye, 231, 700x, and other fast burning, small charge full power loads in the .45 Colt with great results.

Since a factory loaded ammo with a disk to hold the powder charge against the primer flash hole, why can't we? Seems it would be a solution to small charges of fast powder in big cases?

Just curious. Joe

Coupla' things, Joe. First is that when we are just shooting and not thinking of powder position generally we end up with the powder fairly close to "powder back" position most of the time. So our loads are reasonably consistent that way just by accident. Most of us only get "powder forward" when doing something unusual, although I have a friend who would be the reverse of that because he points the gun down toward the ground to work the lever and then brings it back up (yeah, he is slooow and not a cowboy action shooter).

Second is that we can and some of us do a variety of things to hold the powder back against the rear of the case. I can't think of anybody I know who uses the cardboard disk, but some folks use a folded piece of toilet paper, some use a tuft of dacron or similar "pillow stuffing" and some use plastic shot buffer. But it is an extra step, and a rather time-consuming step so we don't go to it lightly. There are also warnings out there that doing this can result in a "ringed" barrel though I have never seen such, and I have done a modest amount of both the dacron thing and the shot buffer thing.

[AJMD429]

If using a less-than 60% (or so) fill, I tend to want to charge all the cases, then peer into them with a flashlight, or use a 'tamper' to probe them, to be sure I didn't double-charge or even over-charge any of them significantly, so at that stage it wouldn't be all that much extra 'work' to insert a wad of toilet paper or cardboard disk.

I can't imagine any 'ringing' of a barrel would happen unless the 'filler' was something fairly substantial, though I suppose if a big bunch of powder slipped in front of the 'filler', and was prevented from initial ignition, it could ignite later when distributed down the bore. Still, I'd be surprised if that would be an issue - the bullet has already started moving very fast, and 'lubricity' is probably great by then.

I suppose someone who really wanted to know these things could experiment with 'partitioned' loads, where half the charge was behind the 'filler', and the other half intentionally placed on top of the filler...

[w30wcf]

A few things come to mind.
1.) Pressure - in your .30-30 test it is higher which perhaps = more complete combustion
2.) Case Shape - the .30-30 has more of a venturi effect.
3.) Sectional Density (bullet) - the .30-30 has close to double the amount which = more resistance which relates to 1.)

w30wcf

[CowboyTutt]

I have generally always been against using fillers as McPherson has seen some chamber ringing using them as a gunsmith. Things might go fine for many, many rounds, then something goes wrong. So I have avoided fillers. Therefore I was truly surprised when McPherson of "Metallic Cartridge Handloading" fame recommended using floral foam as a filler a few years ago to me. It works, and seems to be safe enough even for McPherson.

Meanwhile been using about 11 grains of Blue Dot in my huge 43 Mauser cases with a 485 grain lead bullet. A fast burning pistol powder can be more consistent in a large, mostly empty case and less sensitive to position.

Regards,

-Tutt

[earlmck]

I have generally always been against using fillers as McPherson has seen some chamber ringing using them as a gunsmith. Things might go fine for many, many rounds, then something goes wrong. So I have avoided fillers. Therefore I was truly surprised when McPherson of "Metallic Cartridge Handloading" fame recommended using floral foam as a filler a few years ago to me. It works, and seems to be safe enough even for McPherson.

Meanwhile been using about 11 grains of Blue Dot in my huge 43 Mauser cases with a 485 grain lead bullet. A fast burning pistol powder can be more consistent in a large, mostly empty case and less sensitive to position.

Regards,

-Tutt

So what is "floral foam"? That's not one I've ever heard of.

And your Blue Dot load -- have you tested that one out to see that it isn't position sensitive, Tutt? I'd be a little worried you might leave a bullet stuck in the barrel with that one fired in a "powder forward" position.

[CowboyTutt]

Floral foam is the green foam stuff that comes with your flowers. As to my Blue Dot load, it has been tested.

http://www.gunblast.com/AndyTuttle_FOBD.htm

Regards,

-Tutt

[CowboyTutt]

Old information but maybe still relevant.....

http://www.levergunscommunity.com/viewt ... f=1&t=8936

[hayabusa]

Guys it is probably hard to imagine, but I ran a floral foam company in Vivian, La for about 18 months and then we moved it to Jefferson, Texas for about a year before I went to work for GM in Shreveport, La.
I used to give cases of the foam to my SIL who owned a Florist Shop in S'port, LA., but I have only used filler in case forming. Maybe I should have kept a few cases of floral foam. We also made the Pink foam that the Podiatrists use for Feet imprints. That is so soft compared to floral foam. The pink stuff would probably be better for powder position control.

Hope this was not a thread hijack.

hayabusa

[earlmck]

A few things come to mind.
1.) Pressure - in your .30-30 test it is higher which perhaps = more complete combustion
2.) Case Shape - the .30-30 has more of a venturi effect.
3.) Sectional Density (bullet) - the .30-30 has close to double the amount which = more resistance which relates to 1.) w30wcf

It shouldn't be any venturi effect because I used the 30/30 case initially because I didn't have a 38/55 to duplicate the original test which showed no position sensitivity. No venturi effect in the 38/55.

Maybe your #3, the sectional density is the key. Look at Cowboy Tutt's load that he reports is not position sensitive -- very low pressure (QL thinks about 6k psi) but a high sectional density bullet. And the 38/55 load that was reported to be non-sensitive would have been a 250 grain bullet, so also pretty high sectional density.

All my position sensitive loads have been in pistol cases with low sectional density bullets. This may give me hints for a direction for further exploration.

[Tycer]

A few things come to mind.
1.) Pressure - in your .30-30 test it is higher which perhaps = more complete combustion
2.) Case Shape - the .30-30 has more of a venturi effect.
3.) Sectional Density (bullet) - the .30-30 has close to double the amount which = more resistance which relates to 1.) w30wcf

It shouldn't be any venturi effect because I used the 30/30 case initially because I didn't have a 38/55 to duplicate the original test which showed no position sensitivity. No venturi effect in the 38/55.

Maybe your #3, the sectional density is the key. Look at Cowboy Tutt's load that he reports is not position sensitive -- very low pressure (QL thinks about 6k psi) but a high sectional density bullet. And the 38/55 load that was reported to be non-sensitive would have been a 250 grain bullet, so also pretty high sectional density.

All my position sensitive loads have been in pistol cases with low sectional density bullets. This may give me hints for a direction for further exploration.

Cool.

[CowboyTutt]

I just wanted to clarify that the reason Blue Dot probably works as a smokeless load in a 43 Mauser is not just it's fast burning rate but because it is a very easy powder to ignite in terms of chemical composition and granule shape. I did see significant fluctuation when I tried a load that was below 1100 fps with my 500 grain lubed bullet. Once I got to 1150 fps things seemed to work well with very low SD's and ES's. So even Blue Dot needs some pressure to work right and without it, it can be erratic.

We haven't really discussed temperature variance and how much that can affect velocity too with some powders. That's why I really like Hodgdon Powders as they have many formulations that are more resistant to large temperature changes.

Earl, how is that Quick Load Program working for you? My friend McPherson actually did a lot of the data collection for that program years ago. He never got paid for it. Mic still uses the program though as no one has come out with anything better yet.

But a sore subject for my friend for sure.

Thanks,

-Tutt

[CowboyTutt]

I should probably report that my Mauser loads are not roll crimped either, just a slight taper crimp to chamber and shoot single shot 1 at a time. When roll crimped, accuracy went south but what I would do if shooting in repeater mode in a 71/84 Mauser. How tight your crimp is, how close to the rifling you bullet is seated, how hard the bullet, all these factors can affect pressure quite a bit. Everything has to be really consistent to get an idea of what is happening with a particular load.

I am by no means an expert here, I'm just blessed to be the friend of one after many years.

Regards,

-Tutt

Earl, keep up the good work!

[earlmck]

Earl, how is that Quick Load Program working for you? My friend McPherson actually did a lot of the data collection for that program years ago. He never got paid for it. Mic still uses the program though as no one has come out with anything better yet.

But a sore subject for my friend for sure.

Oooh, that would leave a bad taste in a fellow's mouth about the QuickLoad. Here I have been wishing they would update their powder data base because there are so many that are not on it (LVR for one, and anything else from any powder company introduced in the past 5 years). Maybe that's why no update: they can't get anybody to work for nothing anymore.

Mostly QuickLoad works out amazingly close for me. By far the biggest exception being for your 43 Mauser load, Tutt. QL says your 11 grain Blue Dot/485 grain bullet should be about 840 fps and 6K psi. I had to up the charge to 17.5 grains to get it to show your actual 1150 fps at a reasonable 13K psi.

[CowboyTutt]

Hi Earl, I screwed up. I just pulled out my reloading logs for my Mauser. My memory is faulty.

485 grain bullet (realy 500 grains lubed)
18 grains Blue Dot
CCI BR-2 Primer
3.185 COL no crimp

1174 fouling shot
1169
1164
1165
1160
1177
1174
1169
1171
1177
1176

HI 1177
Low 1160
Ave 1170
ES 17
SD 5

These were measured on a RCBS Digital Powder Drop before it failed.

Only very slight taper crimp.

Maybe this will make more sense. Sorry for the bad data. My bad.

-Regards,

-Tutt

[earlmck]

Hi Earl, I screwed up. I just pulled out my reloading logs for my Mauser. My memory is faulty.

485 grain bullet (realy 500 grains lubed)
18 grains Blue Dot
CCI BR-2 Primer
3.185 COL no crimp

HI 1177
Low 1160
Ave 1170
ES 17
SD 5

-Tutt

Well that makes old QL look pretty good again, Tutt. Thanks for the correction. And wow what a beautifully consistent load!