Load Testing...

[10mmdave]

Been having some fun (i.e. frustration) working up some new load

recipes.

Do You folks have any set way's you test new loads ?

Consistency is best (or that's what the mag scribes say anyway)

and I was wondering how others do it.

I discovered a strange variable the other day and I was wondering

if most folks single load 6-8 rnds into the cylinder or use a moon clip

while chrono testing.

Now some revo's are easier than others to not use the clip so that's

why I ask ??

[hopalong]

Dave, I use the Moons.....

I want to as closely resemble match day as possible, thus the moon clips.

I have tested without the moons and really can't say there was a difference.

but again, I want to resemble match day as close as possible.....

FWIW.

Sam

[Keith]

Has anybody else noticed that if you chrono single action only, that you get slightly lower velocities than double action? At a match recently we had to chrono and we were responsible for chronoing our own guns. ( Now the section now has to buy a new chronograph, but that's another story, and, no, it wasn't me! ) So the first 3 I did single action and the second three I did double action. The double action shots were slightly faster. Maybe 20-25 FPS consistently. I don't remember the exact numbers, but found it to be a noticable difference as did others on my squad.

Is this something I am just learning about now and the rest of you revolver shooters already know? One of the other local wheelgunners told me about this, so I had to try it.

Either way, whenever I chrono, I do it double action to simulate match day. And hope the chrono crew does it that way, too.

[Carmoney]

Gunny:

Sure it's not just the gun warming up? Every time my 625 has been shot over a match chrono this year (all double-action), the first couple shots are lower in velocity than the next couple shots. I'm shooting 4.1 gr. of Clays and a 230-gr. RNL, I just figured Clays shoots a little faster out of a warm gun.

Mike

P.S. Love the new avatar with your photo on it....

[Keith]

I would have thought it was the gun warming up, too, if my buddy hadn't put that idea in my head. I did account for the gun warming up, but, the first 3 shots were pretty consistent to each other as were the next three shots with a substantial jump in between. But, your right. It probably is just the gun warming up. Now I'm going to have to go try it DA first, then SA to see if that is the case. All in the name of science.

Not Gunny

But Gunny approved.

[George]

Hammer fall energy imparts varying levels of ignition to the primer and if it varies greatly from SA to DA it is known to cause this type of variance.

Tipping can also effect where the powder sits in the case and effect the velocity. Tip it back to pack the powder against the primer for every shot and you will get slightly more FPS.

These things do have an effect. Main point is to chrono the gun how you actually shoot it in a match, or more precisely how the chrono guy will shoot it ;-)

--

Regards

[Keith]

Hammer fall energy imparts varying levels of ignition to the primer if it varies greatly from SA to DA and is known to cause this type of variance.

Tipping can also effect where the powder sits in the case and effect the velocity. Tip it back to pack the powder against the primer for every shot and you will get slightly more FPS.

These things do have an effect. Main point is to chrono the gun how you actually shoot it in a match, or more precisely how the chrono guy will shoot it ;-)

--

Regards

<{POST_SNAPBACK}>

Tipping used to be specifically disallowed in USPSA, but I can't find it in the new rulebook. Or did I miss it somewhere?

I have seen some local shooters tip their guns very casually between shots while chronoing lately.

Sorry for the thread drift.

[George]

I'm thinking that chrono operators wouldn't mind us tipping as long as it's the full 15% of match fee! ;-)

[JohnRodriguez]

Been having some fun (i.e. frustration) working up some new load

recipes.

Do You folks have any set way's you test new loads ?

Consistency is best (or that's what the mag scribes say anyway)

and I was wondering how others do it.

I discovered a strange variable the other day and I was wondering

if most folks single load 6-8 rnds into the cylinder or use a moon clip

while chrono testing.

Now some revo's are easier than others to not use the clip so that's

why I ask ??

<{POST_SNAPBACK}>

For a given powder and bullet, i'll start at say 3.0gr and increase the weight by 0.5 gr up to 5.0gr and will load 6 or 8 (depending on the 6 or 8 shot) bullets for each charge, load them immediatly into the moonclips and place pasting tape on them with the charge weight. This will keep you from mixing up your bullets at the range. You should be able to tell if you velocity is increasing consistanty with the given powder charge. When you record your velocity in a notebook, also include if the powder burned clean or left a bunch of crap it.

[robomanusa]

Has anybody else noticed that if you chrono single action only, that you get slightly lower velocities than double action?  At a match recently we had to chrono and we were responsible for chronoing our own guns.  ( Now the section now has to buy a new chronograph, but that's another story, and, no,  it wasn't me!  ) So the first 3 I did single action and the second three I did double action.  The double action shots were slightly faster.  Maybe 20-25 FPS consistently.  I don't remember the exact numbers, but found it to be a noticable difference as did others on my squad.

Is this something I am just learning about now and the rest of you revolver shooters already know?  One of the other local wheelgunners told me about this, so I had to try it. 

Either way, whenever I chrono, I do it double action to simulate match day.  And hope the chrono crew does it that way, too.

<{POST_SNAPBACK}>

My 625 is the same way and consistently get 30fps variation, single action fire is aways lower......I realized that while working up a new load for lead bullets to shoot at the ohio section championship, so I asked the chrono guy to please fire double action across the chrono(made 175pf with 234gr LRN)

[Bubber]

Dave, The way I chrono is to set up the chrony about ten feet from me, shoot across the screens and keep shooting lower and lower until I see plastic fly, pack up my stuff and go home. Like the rest of the replys if it is a clip gun I load clips and load to capacity and record all data until plastic flys.

[Patrick Sweeney]

Three rounds each is hardly a statistically solid base. I'd say you would need to shoot 20-30 rounds in each mode, recording each velocity and the rolling average, before deciding.

Me, I load a moon clip with a test load and write the log entry number on the bases with a felt-tip marker. I then make a powder adjsutment, load, moonclip and mark. At the range I record what the marked moon clip delivers.

[ChuckS]

...  At a match recently we had to chrono and we were responsible for chronoing our own guns.  ( Now the section now has to buy a new chronograph, but that's another story, and, no,  it wasn't me!  ) ...

<{POST_SNAPBACK}>

The guy made major, didn't he?

[10mmdave]

Welp you all chrono better than me I think, actually more consistant.

The reason I started this post was what happened to me at a chrono session

a week ago.

Set up all my Chrono gear, indoors, light kit, no range lights on to mess up the

chrono, all by my lonesome so no distractions,,,,,

I typically load 5, shoot, then 5 again, no clip.

Well this time I happen to have a loaded 8 shot clip, in the gun it goes and bullets

over the skyscreens----128 pf

I then grab 8 rnds out of the same ammo and load them into the same gun with

out a moon cilp?? (I'm doing it again becuse this pf is higher than I got before)

8 rnds of no mooncliped ammo----120 pf

So then I grab another 8 rnds, snap them in a moonclip and send those over the

skyscreens ------ 128 pf

Did the moonclip/no moonclip test with the same ammo in another 8 shot and got

the same results. (well a diff of 5pf with this gun)

So kiddie's, take a cue from hopalong and test as you would if it was match day !

OH.....and never let Bubber use your chrono setup