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Duckhammer_77
Member since Nov 2016
1665 posts

Need some reloading help with weird velocities
Testing a powder/bullet combo at the range and, for some reason, the Labradar failed to register two of the three shots at a specific powder load. The shot that did register was 3,077 fps for 77.0gr of powder. The three holes were just under 1” @ 100yds.

I go back the next weekend with two more cartridges of 77.0gr of powder to get the missing velocities (I used a beam scale b/c elec scale was out of battery). Except these cartridges registered 2,967 & 2,951. I’m thinking I messed something up – that's a drop of 100+fps from the first time. (for reference, the avg velocity steps under 77gr are: 76.6gr = 3,077 & 76.3gr = 2,957).

So, I go load three more at 77gr using the warmed-up, fresh-battery, calibrated electronic scale & checking w/ the beam scale. These velocities were 2,943; 2,943; 2,939 – SD of 2.3; 1” group.

So ignoring the first 3077 shot we have the following:
2,967; 2,951 + 2,943, 2,943, 2,939 – SD of 11.2
2,951 + 2,943, 2,943, 2,939 – SD of 5.0

Have I found a unicorn sweet spot load for this rifle? Load manuals say I should be averaging 3000+ for this load/powder...WTF...TIA

30 Nosler
Berger 180gr VLD
H4831SC
Weather was hot/humid similar all three days shooting
Barrel was not hot when fired; scrubbed clean & oiled between days at range.
This post was edited on 7/30 at 11:58 pm


Douglas Quaid
TBD Fan
Mars
Member since Mar 2010
2899 posts
 Online 

re: Need some reloading help with weird velocities
Do you fire fouling shots after cleaning your barrels before recording shots on the chrono?


Duckhammer_77
Member since Nov 2016
1665 posts

re: Need some reloading help with weird velocities
these were not the first shots fired on any of the three days. Barrel was fouled.


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saintsfan1977
West Monroe, from Cajun country
Member since Jun 2010
4809 posts

re: Need some reloading help with weird velocities
Your rifle barrel might not be fast enough to get that velocity. Or the labradar was lying. Read the entire manual and see if there are settings you might need.

But if your SD is that low, yes. Stick with the unicorn.

Load 5 and see if you get the same SD. If you do, don't worry about 100fps.



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civiltiger07
LSU Fan
Baton Rouge
Member since Dec 2011
10217 posts

re: Need some reloading help with weird velocities
What length barrel does your gun have and what length barrel does the load data you are using list?
This post was edited on 7/30 at 8:06 pm


towgunner18
LA-Lafayette Fan
Madisonville
Member since Aug 2019
82 posts

re: Need some reloading help with weird velocities
I’ve always found manuals are a guess not a set in stone should be shooting this.

I’ve found OCW tests work better than ladders and i find my node much faster. I never really got into chasing velocity but focused more on SD.

LINK

Keep in mind VLDs are jump sensitive and you’re gonna chase the throat as you shoot the barrel


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Duckhammer_77
Member since Nov 2016
1665 posts

re: Need some reloading help with weird velocities
1:10" twist, 26" carbon fiber Christensen rifle.

My next step is to load the bullets in increments up to the lands per the berger manual using this powder/wt combo and one other powder that showed a lot of promise.
This post was edited on 7/30 at 10:27 pm


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bbvdd
Alabama Fan
Memphis, TN
Member since Jun 2009
18793 posts
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re: Need some reloading help with weird velocities
Talk to me about your brass

Once fired, twice fired, how was it cleaned between firing (if it was cleaned).

Any chance the bullets were sitting in the sun the first time around?

I will say that beam scales are usually only accurate to 1 grain while most electronic scales are a fraction of a grain.


bbvdd
Alabama Fan
Memphis, TN
Member since Jun 2009
18793 posts
 Online 

re: Need some reloading help with weird velocities
Also, looking at the load data on the Hodgdon website it shows a 180 gr bullet max load of 78.1gr at 3059fps.

77gr might be around your speeds but those are with Sierra SPBT and not the VLDs
This post was edited on 7/30 at 9:50 pm


bbvdd
Alabama Fan
Memphis, TN
Member since Jun 2009
18793 posts
 Online 

re: Need some reloading help with weird velocities
Also, on your LabRadar, did you have the gr bullet set for 180gr bullets?
I know if I don’t have mine set to the proper bullet weight (like shooting 150 but have it set to read 180gr) it will throw off some incorrect speeds.

Also what’s your trigger set on?

And, I just ordered a recoil trigger for mine since I pretty much only shoot mine suppressed.

Piet recoil trigger

Not here yet, can’t wait to try it.


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TigerOnThe Hill
Springhill, LA
Member since Sep 2008
5594 posts

re: Need some reloading help with weird velocities
quote:

Load manuals say I should be averaging 3070+ for this load/powder...WTF...TIA

No, the average velocity from the loading manuals is 3070 + fps. The velocity for each load a loading manual shows is the velocity they found under the circumstance they shot that day w/ the gun they shot. That's NOT necessarily what you should expect to get. Although I've been shooting over chronographs >30 years, I don't have any personal experience w/ the Labradar. Having said that, if the Labrador is like any other chronograph, it will have variations. W/ a regular chronograph, variations for me are not unusual w/ a number of different factors. I'd put my money on loads #2-5 and consider load #1 an outlier. The question is, "What are your goals for accuracy and velocity?" Depending on what your goals are, you may've found your load (assuming chamber pressures of your load are acceptable). A properly constructed 180 gr 30 caliber bullet should put dispatch most game animals in North America w/o problems. The Nosler load data shows muzzle velocity of 3026 fps w/ 77.0 grains of 4831SC so you're pretty close. Have you chronographed other loads in this gun? If so, how did they compare? Some barrels are a little fast (velocity wise) while some a little slow. E.g. I safely get 3550 fps in my 221 Fireball riflew/ a 40 grain bullet and CFE BLK whereas Hodgdon gets 3543 fps, but w/ a barrel that's 2" longer than mine.

ETA: I'd imagine all your loads came from the same lot of powder since they were shot over a short period of time. Velocity and chamber pressures will usually very some w/ different lots of powder. Because of this, if I'm dealing w/ a gun I expect to shoot frequently, I like to buy a 5-8# keg of powder. I'd also think your loads used the same primers and brand of brass. I hate to point these out as you sound like an experience hand loader, but I don't take anything for granted anymore.
This post was edited on 7/30 at 10:57 pm


civiltiger07
LSU Fan
Baton Rouge
Member since Dec 2011
10217 posts

re: Need some reloading help with weird velocities
quote:

just ordered a recoil trigger


I have one one on the way now as well.


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DownshiftAndFloorIt
LSU Fan
Here
Member since Jan 2011
54635 posts

re: Need some reloading help with weird velocities
quote:

Talk to me about your brass


This is where the question mark is IMO


Duckhammer_77
Member since Nov 2016
1665 posts

re: Need some reloading help with weird velocities
bbvbb-

-ETA-the 3077 outlier was in once fired nosler brass - all others were in new factory nosler brass; everything prepped the same, same primers.
-bullets were not in the sun, just ambient shade temp
-Labradar set to 180gr projectile; trigger set to "trigger" level 1, not "doppler"
This post was edited on 7/30 at 10:57 pm


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Duckhammer_77
Member since Nov 2016
1665 posts

re: Need some reloading help with weird velocities
TigerOnTheHill-

-went back and checked Berger & Nos manuals - 77gr of H4831SC should average 3000-3025 for 180 gr bullet
-the circumstance they shot that day w/ the gun they shot - you are very correct
-consider load #1 an outlier - yep
-goals for accuracy and velocity - accuracy trumps speed; this is a "beanfield/powerline" gun for CPX2-3 game.
-Have you chronographed other loads in this gun? - yes, Magpro 81.6gr has a 1/2" group & SD of 12ish



Duckhammer_77
Member since Nov 2016
1665 posts

re: Need some reloading help with weird velocities
The 3077 outlier was in once fired nosler brass, all the other rounds/speeds were in new nosler factory brass. All brass fully prepped by me in the same way, CCI benchrest primers.


bbvdd
Alabama Fan
Memphis, TN
Member since Jun 2009
18793 posts
 Online 

re: Need some reloading help with weird velocities
Any chance you have that brass separated? Weigh each piece and see if you have any that stick out high or low.


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bbvdd
Alabama Fan
Memphis, TN
Member since Jun 2009
18793 posts
 Online 

re: Need some reloading help with weird velocities
quote:

The 3077 outlier was in once fired nosler brass, all the other rounds/speeds were in new nosler factory brass. All brass fully prepped by me in the same way, CCI benchrest primers.


Shoulders on it bumped .002?

The brass will stretch to fill the chamber. I’m betting this was your difference.


Duckhammer_77
Member since Nov 2016
1665 posts

re: Need some reloading help with weird velocities
the brass is separated between (now) once & twice-fired.
you got me curious now to load 77gr in once-fired brass to recreate the higher velocity and see what groups & SD look like.


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TigerOnThe Hill
Springhill, LA
Member since Sep 2008
5594 posts

re: Need some reloading help with weird velocities
DH, You're handloading the right way. I bet on a variation w/ the chronograph. W/ further loading/shooting, I bet you'll get velocities similar to loads #2-5. Will you be satisfied w/ this load? Under similar circumstances, there've been times I chased that "extra 100 fps." There've been times I settled for a load w/ 100 fps velocity. Of course, no one know how much powder and bullets you may burn chasing the extra 100 fps. Keep us updated.


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