Speed doesn't seem right

[james6600]

New Vaquero 45 colt, I haven't had it long just thought it would be good for the daughter to drag around the farm with cb action loads in it. Her and I have put a box of Winchester cb loads, some minimum Trail Boss loads and some moderate (10gr) HS-6 loads through it (all reloads use Missouri Boolit Co 250gr rnfp #1. Today I thought I would try some tier 2 loads to see if it would shoot POA, 11gr HS-6 did it. Here is what I'm questioning, 11gr's has a thump to it that seems right but my Pro Chrono Digital (Tech that is new to me also) seems to be reading low.
6=769fps
5=741fps
4=749fps
3=785fps
2=760fps
1=744fps
AV=758
SD=16
Wouldn't you think these loads should be in the high 8 to low 900fps range? By the way the sun was west of a building so the chrono and I were in the shadow if that makes a difference.

[pipehand]

You're about 200 fps shy of what the Hodgdon manual says you should be for that much HS-6. Got anything with a known velocity to check the chrono with? Change the battery lately?

[james6600]

I didn't think about the battery as I bought it a couple months ago after I received the chrono but who knows how long it was on the store shelf. I put a couple 222 superformance through it last week and they ran 3300 +or- 20 (box claims 3341 I think). I will load up 6 more 45's tomorrow and see if it changes under different light then change the battery and see if that makes a difference. I have about an hour and a half on he chrono with maybe 50 rounds of mostly 9mm and 223 and the thing hasn't flawed yet and ran close to but under published data. So far I feel it is pretty accurate all though it could be a little slow but don't have enough data yet and I agree with your data that these 45's should be 150-200 faster. Oh and I forgot it has a 5.5" barrel and I am working up these loads as a pocket deer gun for under 50 yards when I walk the fence lines and don't want to lug a long gun around. Thanks for your help, James

[pipehand]

This past weekend, we were putting some 45ACP loads over the chrono. It's just a $99 Chrony, so the screen spacing is fixed. Anyway, we got a string of velocities that were too low to have even cycled the pistol. Turned Chrony off, unplugged battery , plugged battery back in, and turned on chrono. It then started giving believable readings at 800fps+. There is a processor in there, maybe it needs a "reboot".

[MtGun44]

Can be too close to first screen. Make a blast shield with a 2x2 hole thru it and put
it up in front of the first screen. Blast can make the speed wrong.

Or back up a few yards.

Bill

[james6600]

Ok, so I moved back 18 feet from chrono and took a shot (774fps) so then I changed the battery and took 3 more (832-757-741), still confused. Both batteries are out of the same 2 piece pack bought at the same time, are generic drugstore brand, and have a date of 03-2016 on them. I rechecked my powder charge and it's 11gr - 11.1gr, with a declining string on the last three shots I see how it still could be a battery but don't have enough experience with a chrono to know it's reaction to battery wear. Any more suggestions even if they are the same? Thanks again.

[MtGun44]

Make a piece of corrugated cardboard about 12" square, cut a 3x3" square hole in
the middle. Mount 3-6" in front of first screen. Shoot thru the hole. Make sure
that both screens are seeing sky, if one sees an awning or trees it will mess it up.

Bill

[james6600]

I went and bought two new batteries and installed one. Using 11gr HS-6, 250gr slug I'm getting 804-809-841fps. I put tape on a screen rod 4" above the sensors as I was shooting very high in my earlier post, the 841 shot was maybe an inch above the chrono so I expect it to be higher. These numbers are a little better but still low so I went and grabbed a 20ga (box says 1225fps) I got 1196fps. This has all been done on overcast/between rain days and every thing seems within reason barring this 45 colt, do you think it's really shooting this slow on 11gr HS-6.

[james6600]

Well not getting many theories to my low velocity and starting to believe the chrono is right with the 20ga only being down 29fps on a short barreled youth model. I achieved my goal of getting the NV to shoot point of aim without having to grind the front sight and it's still very pleasant to shoot. I just never heard of anything running 20% below published data that spec'ed out and this one does even though it had a .0025" barrel thread choke when new. I will build a blast shield too as it wouldn't hurt to have one just don't have the time right now.

[runfiverun]

I remember when chron'os first come out, every body said they all read wrong when they shot their 300 win mag over them..
I think after trying the loads a second time and you get the same numbers that's what you got.

[james6600]

Oops I meant .00025 not 2.5 thou. barrel choke.

[MGySgt]

There are so many variables when reloading or even factory rounds.

What is your barrel length versus the length in the book?

How is your boolit fit? Loose? Tight?

What is the seating depth versus what is in the book?

When I bought my first Chronograph a long time ago, my hunting buddy and I both had Ruger Super Blackhawks with 7.5 in barrels - same load out of both guns was a 75 FPS difference, switched loads and it was 50 FPS difference mine was fastest with one load and his was fastest with the other one.

If the load is accurate and shoots to point of aim, a 250 gr 45 at 750 is going to punch a pretty good hole in something it hits.

[L Ross]

What is your barrel/cylinder gap? A feeler gauge is an easy way to measure.

Duke

[Kull]

Agree with what MGySgt said. Take a long hard look at the book data vs your gun.

[james6600]

Lyman 49th list 10.5gr at 851fps in 7.5 barrel, Brian Pierce list 10.5gr at 893fps - 12gr at 973fps in 5.5 barrel and the 270-SAA mould, Hodgdon list 10.5gr at 946fps barrel unknown. I'm 11gr 5.5 barrel 741fps at sky screens to 841fps barely missing the top of chrono, cylinder gap is .007". That's all the HS-6 data I have.

With all the data in one place it doesn't look so bad untill you see Hodgdon's speed. Brian's wasn't done in a lab so I use it as a loose reference only. HS-6 is dirty and data is limited but it is versatile, I can load every thing with it until powder becomes more plentiful. I use Hodgdon's web site for data then double check Lyman for possible typo's. I just had a thought, all my pistols are simi autos so they have a small case, 45 colt is a large case and some powders are position sensitive (primer side vs. bullet side of case) is HS-6 one of these powders? Maybe that's where my extreme low speeds are coming from. Hodgdons web site has been accurate on all my other calibers but their 45 colt data seems too fast, they must use a 15 or 20 inch test barrel. So it seems my high speeds aren't that out of line and if my low speed is from shooting high over chronograph then I'm ok, if it's position sensitive powder then I need to back off add filler and work back up. Is HS-6 position sensitive? If so any filler advice, that's a new area for me?

[Wayne Smith]

There should be separate rifle and pistol data on the site. Are you looking at the pistol data?

[MGySgt]

James6600 - I don't know what kind of Chronograph you have but my Ohler 35 doesn't care if you shoot high or low over the sky screens - as long as you are over the sky screens and below the de-fusers the readings accurate.

I just did a test with 45acp and Unique with 3 different guns (and barrel lengths) the ES and SD's were very good. Although the velocity was higher than what I was expecting out of my 2 1911's (one 4.25 inch and a 5 inch).

[scattershot]

Just a thought, but don't those things work better in bright sunlight? maybe that's the problem.

[james6600]

Yep, pistol data and NOT the Blackhawk data, they must be using a long barrel because I think only 3 out of 12 loads look reasonable as far as speed and 6 loads are well over 900fps. I never paid much attention to speed because I never had a way to check it till this spring and since HS-6 is not the ideal powder data is somewhat limited. I did find out it is rather position sensitive and that is probably the reason I was getting declining strings of 80fps or so.

[fouronesix]

Chronographs usually don't lie. With low batteries, not resetting after use, odd interruptions, poor light conditions, direct sunlight on sensor slits, junk other than bullets flying though sensor zone, buffeting from muzzle blast... etc. they usually give really wacky readings that are either error messages or easily recognized gobbldigook- not the type you're seeing.

The Lyman data you are looking at was gathered using a Ruger Blackhawk with 7 1/2" barrel with .451 groove dia. Other variables of the powder lot, temperature, load, case, primer, bullet, lube and firearm specs could easily account for your "low" readings.

Also, HS6 is a double based ball powder. To me that raises a flag. I don't shoot double based ball powders for a reason. Probably one of the reasons you see irregular and sometimes wide velocity fluctuations

[Shooternz]

Also you could have a slow gun, I have a Colt Gold cup that is slow I have to load .5 grain more powder to get the velocity that my buddy gets with his, I load for both guns, chronographs generally work ok, if the light is not right you won't get a reading, you should try another powder if you have a suitable one could be that your gun does not like HS6, I like Unique in .45 Colts seems to shoot well either with light or heavy loads, Robert.

[9.3X62AL]

I agree with Shooter NZ's take. I have on hand two S&W revolvers in 357 Magnum--a 4" Model 686 and a 6.5" pre-27. Dimensionally, they are quite similar--with one exception--barrel/cylinder gap. The 686's gap is .004", while the pre-27's gap is .011". The net effect has been that the shorter-barrelled 686 shoots several loadings about 100 FPS faster than the longer-barrelled example. Accuracy is a dead heat, both shoot wonderfully.

In any event, that Ruger has the strength to spare to enable you to tip in more powder to get to your target velocity of 900 FPS.

[MGySgt]

Just a thought, but don't those things work better in bright sunlight? maybe that's the problem.

Not really - that is why they have plastic hood (de-fusers) to keep the bright sun light off the sensors.

[james6600]

I think on my next test I will point the barrel up between shots to settle the powder towards the primer and see if my speed is more consistant. I also think a powder change is in order but it's hard to find right now and when it is in stock its $27 a pound regardless of type.

[MtGun44]

Slow barrels DO exist, I did a LOT of chrono testing in old IPSC days - many hundreds of
guns and some 1911s will run 150 or more fps faster with same load than another bbl.

Do not ignore blast effect - no guarantee, but I have DEFINITELY seen it and needed a shield,
in a few situations.

Bill

[ironhead7544]

Some guns just dont seem to "like" certain loads. Speer did a test of six identical 6 inch 357 magnum revolvers and got as much as 200 fps variation with factory loads. I have also had start loads with high pressure signs.

I would try different powders to get what you want. For a 45 Colt load a 250 at 850 fps or so will do most anything you might want to do with a handgun IMHO.

[9.3X62AL]

For a 45 Colt load a 250 at 850 fps or so will do most anything you might want to do with a handgun IMHO.

Lotta truth in that phrase, for sure. Docile recoil combined with powerful terminal effect. Use a WFN or SWC boolit form, and the load will take care of bizness right well. Our local coyote-sized muleys and blacktails would crumple with good hits from such a loading. So would ne'er-do-well 2-legged varmints. I envied Anaheim PD's ability in the late 70s and early 80s to carry S&W Model 25-5 revolvers in 45 Colt.

[james6600]

I'm happy with 850fps I was more concerned with my extreme spread that was putting me in the low to mid 7's. I just loaded 3 more and ran them through the chrono pointing the barrel up after each shot to put the powder towards the primer and they all stayed between 845 and 855. So these are fine pratice loads but does anyone have a powder sugestion that is not tempature or posistion sensitive to use for hunting/carry, it would also be great if it metered good through my Dillon. By the way thanks again for every one's help.

[9.3X62AL]

The powder being used is clearly position-sensitive. I haven't seen this effect from WW-231, Herco, or Unique, though none of these fill the case like the 4227s would. 90% of my 45 Colt loadings use Unique or Herco. How firmly or evenly crimped are your loads? I use a moderate crimp in 45 Colt, and after my first firing I trim them all to equal length (1.285"). They hold that length for many reloads, but are uneven after first firing. I treat ALL of my rimmed revolver brass in this fashion.

[james6600]

I have been trimming the same as you and my crimp is moderate but I seat the bullet slightly shallow and crimp at the lowest part of the crimp groove that I can, loading for revolvers is new to me so I haven,t figured out if OAL makes much difference yet. I may be mistaken but isn't 4227 a long grain powder, seem's I was using it 15 or so years ago on 25-20wcf, I lost all my data from back then. I will see what is available at the local gun store Tuesday and hopefully something is in stock.

[Dale53]

Hodgdon data is gathered using solid pressure barrels. They will almost ALWAYS read high. I use the data for pressures but use my club's chronograph for real world figures with MY equipment. As an example, they read 200 fps high (.44 Magnum data) compared to my 8 3/8" barreled S&
W Model 29 and my 7 1/2" Ruger RedHawk when using H110.

Lyman often uses 4" barreled handguns (check on the first page of their data) to chronograph so that will often read lower than the longer barrels.

And so on and so forth...

Dale53

[9.3X62AL]

Velocity is what does the heavy lifting, ballistically speaking, so it is important. It is not the only element in the equation, though--you also have boolit diameter and boolit weight to rely on, and in the 45 Colt you are very blessed--relatively speaking.

I use the chronograph as much to see how consistent my velocities are running shot-to-shot as I do to see the actual velocity level. Consistency translates to accuracy potential downrange, and wide velocity dispersions can translate to exaggerated vertical stringing at longer ranges.

We can drive ourselves to distraction with some elements of this hobby field. Better to just enjoy the outcomes and not sweat the small stuff--because most of our quirky concerns really are small stuff.

[Joni Lynn]

I would suggest that the powder is position sensitive. I load Unique in my 45 Colt loads and get results like that if I don't make an effort to settle the powder to the same position in the case prior to firing. (tilt the gun up prior to firing to help the powder move back in the case)
I tried 8, 9 and 10 grains of powder as well as a few with a home made wad to keep the powder to the rear of the case. I finally found the load I like for most of my guns.