Is RE-22 powder known for producing variations in velocity readings?

[gene pool]

Gentlemen,

I have a custom 6mm Remington with an 8 twist krieger barrel. After about 50 rounds I discovered that RE-22 powder produced tight groups with 105 VLD bullets.

However, I am getting some varying chronograph readings on velocity--some up to 4% difference. The bullets are very shiney so I have not yet ruled out false readings.

My question is: Is RE-22 powder known for producing variations in velocity readings from shot to shot?

Thank you,
Gene

 

[model 12 toby]

hard to tell. probably show up as vertical possibly at long range. how far was you shooting?

 

[MrMajestic]

Infrared Sky Screens? Like Toby said, vertical at distance? The Reloader's are known to be temperature sensitive but never heard of high ES's.

 

[Steve Blair]

I have a hard time getting low ES/SD with my 6mm Remingtons. They seem to have a narrow window and are pretty finicky. I've heard that the AI version is better. I've tried RL 19 & 22, IMR 7828 SSC, H4831 SC, N560 and H4350. Best results were with 115 DTAC and H4831 SC at a little lower velocity than the others.

 

[gene pool]

Thank you for your interest and replies.

I am getting .3 groups at 100 yards with mainly side to side variations from wind. At 200 yards I am getting .7-.9 groups with the same side to side variation. But when I chronograph rounds, I get variations of 75 fps...and sometimes the chronograph doesn't read at all. The sky was overcast the day I chronographed.

The chronograph is new with a fresh battery.

Gene

 

[gene pool]

I have a hard time getting low ES/SD with my 6mm Remingtons. They seem to have a narrow window and are pretty finicky. I've heard that the AI version is better. I've tried RL 19 & 22, IMR 7828 SSC, H4831 SC, N560 and H4350. Best results were with 115 DTAC and H4831 SC at a little lower velocity than the others.

sleepygator,
What does ES/SD mean? I am a little new at chronographs.

Thank you,
Gene

 

[model 12 toby]

extreme spread and standard deviation. hmmm. overcast is actually better than the bright sun. shoulda got good readings.

 

[model 12 toby]

75 is hurrific. lol. Id say that'd be hard to get unless you was trying. you weighing charges individually?

 

[jlow]

I think at relatively short ranges like 100-200 yards, you can in fact get tight groups even though your ES/SDEVs are higher. The reason is at the short ranges, the group size has more to do with how well you time when your bullets exit the barrel vs. when the harmonic wave of the barrel are at the same location. You will see the group size open up due to MV variation when you shoot at the longer ranges 600-1000 yards where velocity has more of an impact on group size.

 

[Steve Blair]

The series below was shot with 105 Hybrids, H4831 SC from 46.8 to 47.2 from a 32" Brux barrel. This is pretty typical and I am using every trick in the book to minimize variation. My 6BR and .284 Shehane both get to single digit or very low double digit ES using the same loading techniques. This has been true with several 6mm Remingtons. They can deliver fine short range accuracy but I just cannot get the velocity variation where I want it. [br]
High Low Mean ES SD
3252.20 3219.80 3235.40 32.40 13.11
3261.00 3235.30 3248.94 25.70 10.36
3279.30 3249.30 3265.50 30.00 13.46
3277.50 3248.10 3263.02 29.40 10.57
3289.40 3258.10 3270.70 31.30 14.26 [br]
First, though, you need to make sure that your chronograph is delivering good numbers. No use chasing your tail if your readings are unreliable. See if you can have a friend with a known, good load shoot over the screens and verify the readings.

 

[model 12 toby]

yeah SDs getting close to single digits are the best I've ever got. I couldn't really ask for any more.

 

[Steve Blair]

The problem is that I am competing in Long Range F-Open and F-T/R against some of the best shooters in the U.S. They are doing everything I am and more. Their equipment is at least as good as mine. Some are admittedly better shooters than me. In order to hold X-ring elevation at 1000 yards, under ideal conditions and a perfectly aimed and broken shot, My .284 Shehane can have no more than ±13 fps ES for 20 shots. But, when you consider that this is under real match conditions in which 30 rounds may be fired in 20 minutes, the load development numbers must be much better than that. It's just the way it is. The numbers above are not good enough for competition. [br]
I certainly do not go through these contortions when shooting crows.

 

[model 12 toby]

i agree. Id go with different powders and shoot groups at longer distances if possible. at least 300. I don't shoot comp. I shot 3 shot group of 3.5 inches at 770 yards and that was good for me with my 7mm mag. was getting sd's of 13 or so. shooting reloader 25. vertical and horizontal were bout equal. 6mph wind but only quarter value.

 

[Hombre0321]

Sounds like something is going on with a 75 FPS variation, either it's the powder or the chrony. I use RL 22 and do not have this wide swing you are experiancing.

The Reloader series powders at one time were noted for there temperature sensitivity. However the have been reformulated and today even on the bottle there is a note stating: "Stable At All Temperature's" this has proven true for me as I shoot in temps that range from the teen's to the 105 degree range and have no signs at all that they are sensitive.

Maybe take a good hard look at your Chrony test it with a known load and go from there.

Roland

 

[Nomad47]

The problem is that I am competing in Long Range F-Open and F-T/R against some of the best shooters in the U.S. They are doing everything I am and more. Their equipment is at least as good as mine. Some are admittedly better shooters than me. In order to hold X-ring elevation at 1000 yards, under ideal conditions and a perfectly aimed and broken shot, My .284 Shehane can have no more than ±13 fps ES for 20 shots. But, when you consider that this is under real match conditions in which 30 rounds may be fired in 20 minutes, the load development numbers must be much better than that. It's just the way it is. The numbers above are not good enough for competition. [br]
I certainly do not go through these contortions when shooting crows.

Very enlightening, Steve. Thanks.
BTW, how large is the X-ring at 1000 yards?

 

[watercam]

Getting back to the original thread, if you are not weighing individual powder charges, you should. You might consider a primer change - Wolf/Tula LR primers have smaller flashes which contributes to more consistent ignition.
Next would be Fed. 210M or CCI BR-2. I have had the best luck w/ the Wolf/Tulas.
German Salazar ran some very interesting primer tests some time back (check his blog for articles) - he did his accuracy shooting at 600 yds. and it was fascinating to see good vertical dispersion with higher ES/SD measurements.
You might consider trying to find a place to extend your range if long range accuracy is your goal. If not and you are getting accuracy you are happy with, all good! For my part I have had great luck with the Reloader powders in all of my hunting and several match loads.

 

[gene pool]

Yes, this discussion is very enlightening, especially for a semi-newby to precision shooting like me. Blessings to all of you who have commented.

The next thing I intend to do is compare readings with a pal's chronograph, sitting his and mine side by side (or maybe end to end) and both of us shoot over them.

And to one of the questions above, yes I am hand-weighing every charge. I don't think I messed up on charges, but I am not ruling out anything at this point.

Thank you again,
Gene

 

[Steve Blair]

Getting back to the original thread, if you are not weighing individual powder charges, you should. You might consider a primer change - Wolf/Tula LR primers have smaller flashes which contributes to more consistent ignition.
Next would be Fed. 210M or CCI BR-2. I have had the best luck w/ the Wolf/Tulas.
German Salazar ran some very interesting primer tests some time back (check his blog for articles) - he did his accuracy shooting at 600 yds. and it was fascinating to see good vertical dispersion with higher ES/SD measurements.
You might consider trying to find a place to extend your range if long range accuracy is your goal. If not and you are getting accuracy you are happy with, all good! For my part I have had great luck with the Reloader powders in all of my hunting and several match loads.

[br]
Mike, [br]
I found that mild primers do not perform best in my 6mm rifles with slow powders. The series above was shot with Remington 9½, usually considered pretty hot. Winchester 8½-120 also gave good results but seemingly cannot hold pressure well. [br]
If anyone has managed consistently low ES/SD with 6mm Rem, heavy bullets and slow powders, I would like to know how they did it. I weigh every charge on a Sartorious GD503, sort the brass by case wall thickness, turn necks, uniform primer pockets, deburr flash holes and sort bullets by ogive length for accurate seating depth. [br]
Gene, [br]
Has any load in that rifle displayed consistently low numbers? Another area to examine is firing pin strike. When the firing pin is not hitting the primers uniformly, ignition will suffer. [br]
Bill, [br]
The 1000 yard F-Class X-Ring is 5" diameter.