High velocity readings for Ruger Only .45 Colt Loads??????

[Gus McCrae]

Start these loads slow and work your way up..... I thought I was.

I'm trying to figure out what is going on and would like some advice. I'm shooting a 5.5" Ruger Bisley in .45 Colt.


Beartooth 265 grain Keith type bullets of .452" diameter (throats of Ruger measure .451" diameter)
23.5 grains of H110, carefully measured using a Dillon Balance Scale
CCI300 Large Pistol Primers
Starline Brass
Heavy Crimp Using a Lee Factory Crimp Die right at the crimp groove of the bullet
I take my time and carefully load 20 rounds


I started at 23.5 grains as this is what Hodgdon had listed for a 260 grain cast lead bullet. I'm using a different bullet, but I didn't figure the difference to be that significant as long as I was starting on the low end of the scale.

F1 Chrony gave me some oddball high readings with some other loads (10 grains Unique with same bullet) and some that were in the ballpark of what I expected (around 1050 fps). Some of the readings were as high as 3000.

When I stared with the heavy loads, I shot six rounds. Two were in the what I expected range 1350-1360 fps , one was in the over 2000 fps range, three were in the 1770-1820 fps range. These readings were not in any particular order, but the after the real high reading, I decide to move the Chrony out from 10, to 15 feet and started getting the 1770-1820 fps readings. Each shot sounded and felt about the same and recoil was strong, but surprisingly comfortable. I decided to trust my instrumentation and not push my luck for the rest of that shooting session.

The day was bright and clear which I've read can cause erroneously high readings and "Err" readings. I did have the diffusers installed. We tried some .22 LR and got some believable readings and some not so believable. Still I worry that something in my load isn't right (afterall, I'm not really interested in blowing myself or the new gun up). The throats do need to be reamed/honed, but I'm not sure that that difference will cause what I'm seeing. If all of my high readings were way high, I'd probably not be so concerned, but the few that were 400 fps high make me question my loads.

Me, My loads, my chrony, something else? Was I not holding my mouth right or what?

[fouronesix]

With readings like that- no way they reflect what is actually going on with the load so proceed accordingly.
This time of year or early morning or late afternoon (even with the screens installed) there is a chance that direct sunlight is hitting the sensor slits. Try taping some card stock on the sides to shade the slits from the direct sunlight. And, make sure the battery is good.

[Southpaw 72]

+1 on a good battery. Mine will give some pretty strange results when the battery starts to run down.

[Grump]

Direction of the light can make a HUGE difference.

My .357 Mags were suddenly over 2,000 fps until I realized that the shadow of either the gas cloud or the shock wave was falling over the stop screen before the bullet was direct vertical over it. Sun was at my back at a low angle.

Safely turned my direction of fire 90° so the sun was coming in sideways and the velocities were just as suddenly reasonable and within expectations.

[Gus McCrae]

Oh, the battery was new.

[Gus McCrae]

It was around 1:30 PM and the sun was behind me when shooting.

[paul h]

The shooting chrony will give wierd readings when it doesn't like the lighting.

[Gus McCrae]

Anyone find any reason to be worried about the load?

[frnkeore]

Not at all, I shoot 23.0 gr of 296 behind my resized Lee 340 gr bullet (336 gr 2% tin/WW) in my 7 1/2" long barreled BH.

Frank

[Zymurgy50]

Try using a black permanent marker on the lead before you shoot it over the screens. Chronographs are trying to "see" a dark object moving against a light background.

[cbrick]

At the Los Angeles Silhouette Club where I did most of my load work and chrono testing before I moved I finally smartened up and stopped using the Oehler chrono completely in winter. The sun was so low in the southern sky there was no way to get reliable readings, all testing was nothing more than a waste of ammo. The rest of the year was simply a matter of shading the screens from direct sunlight.

Rick

[TXGunNut]

I get the most consistent chrono results on overcast days. On sunny days I'll disregard an out-of-line reading. As mentioned above skyscreens work best when the sun is directly overhead, mine stay in the box where they're safe. ;-)

[Gus McCrae]

Thanks all.

[Kull]

Me, My loads, my chrony, something else? Was I not holding my mouth right or what?

The chrony I bet. I experienced similar errors and finicky behavior with the shooting chrony I had.

[Lefty SRH]

Shoot some .22lr over it to check it, some that is of a known Velocity

[BABore]

Move your screens on farther. The muzzle blast is likely causing you grief. I have it happen all the time shooting over a Pact chrono with my 480 Ruger and hot 45 colt loads.

[454PB]

Usually I have the chrono 15 feet from the muzzle as you finally did, and anything closer will give erratic readings like you got when shooting guns with a lot of muzzle blast. My .454 Casulls are especially bad for that, and I sometimes have the chrono even further away. I sometimes wonder if boolit lube screws up the readings, because I find it plastered all over the front of the chrono. Sounds to me like it's either muzzle blast or bad light angles messing up your readings.

[Gus McCrae]

Thanks, I'll try out all of the above. Now, I'm not so scared of my loads. :)

[Gus McCrae]

Well guess what. I tried again on a cloudy day. Got stable readings of 1120 F PS with 23.5 grains H110 under a 265 grain Keith.

I feel better now.

[TXGunNut]

Good! Sounds like a pretty good loads. How was the ES and accuracy?

[Gus McCrae]

ES?

Dunno about accuracy yet. Got to tinker a little more.

[ironhead7544]

I have had that problem before. Used a spare target frame to block the direct sunlight. Cured the problem.

[TXGunNut]

ES=Extreme Spread of velocity readings; highest to lowest. Good measure of consistency. Standard Deviation (SD) is another measure sometimes used. It's a tool I use to evaluate combustion efficiency. If I have a load that isn't working like it should and it has good ES (and/or SD) I know I need to look at the boolit for areas to improve. If I find a large ES I suspect the problem lies with the powder, primer or possibly crimp.

[cbrick]

ES=Extreme Spread of velocity readings; highest to lowest. Good measure of consistency. Standard Deviation (SD) is another measure sometimes used. It's a tool I use to evaluate combustion efficiency. If I have a load that isn't working like it should and it has good ES (and/or SD) I know I need to look at the boolit for areas to improve. If I find a large ES I suspect the problem lies with the powder, primer or possibly crimp.

Not so much crimp if the boolit isn't moving regardless of chrono readings. I would look closer at boolit/neck tension as being inconsistent. You'll find crimp has less to do with powder burn consistency than many think. Neck tension however has a great deal to do with it.

While the following test results are for the 357 the same will result in the 45 Colt. Check out the various crimps from none to hard and the resulting chrono results. What they do all have in common is consistent neck tension.

FA 357 Mag 9”
RCBS 180 GC Silhouette @ 192 gr. (WW HT @ 18 BHN)
16.0 gr. H-110
Winchester brass
CCI 550 primer
Temp 70 Humidity 38%

All chrono tests 10 shots

1> My normal profile crimp, second firing of WW brass, Carbide die sized
E.S. 30
A.V. 1518
S.D. 9

2> Roll crimp, second firing of WW brass, Carbide die sized
E.S. 30
A.V. 1520
S.D. 9

3> No crimp, second firing of WW brass, Carbide die sized, very slight bell
E.S. 30
A.V. 1528
S.D. 9

4> Light profile crimp, virgin WW brass, not sized, not expanded, slight bell only
E.S. 26
A.V. 1532
S.D. 8

5> My normal profile crimp, virgin WW brass, not sized, not expanded, slight bell only
E.S. 26
A.V. 1536
S.D. 8

Hope this helps,

Rick

[TXGunNut]

You'll find crimp has less to do with powder burn consistency than many think. Neck tension however has a great deal to do with it.-cbrick

That's why I qualified it with "possibly". I've only run into it once and it struck me as odd, wasn't with a pistol cartridge anyway so not relevant to the thread. I agree about neck tension, no crimping technique will ever make up for improper neck tension.
I don't use my Chrony much, mine just came back from a 20+ year vacation. It's come in quite handy lately but checking speeds on some BP loads was a real eye-opener, lower ES than any smokeless load I've tried.