284 Win in competition

[ecomeat]

I went out to Goondiwindi OPM on the weekend to (a) fireform 60 newly prepped Lapua cases for NSW Queens & (2) test between CCI BR2 and Fed 210 GM primers, looking for variations.
I shot two ranges on Saturday with a MagnetoSpeed chrony on, and then swapped the order and did the same again the following day. So 10-12 shots at each range would be meaningful statistics.
Both days started "coolish"......maybe 20 degrees when we started and by mid to late morning would have been 26 or 28 degrees, headed to 30 as a Max.
Loads were identical, except for Primers : newly match prepped Lapua cases, 55.7 gr of 2213sc and 180gr Berger VLDs jammed 0.010" I was looking for approx 2830 fps on the MagnetoSpeed to equal the accepted "node" of 2820 measured at 12-15 feet from the muzzle as is normally done with conventional chronys.

Day 1
CCI BR2 primers shot first approx 9-00 am
AVG 2825 fps. ES 48, SD= 14

FED 210GM primers shot approx 11-00am
AVG 2846 fps. ES 27, SD=10

I was thinking that a clear picture has emerged here. ES and SD still nowhere near good enough, but Fed primers well in front. Then.......

Day2
Fed 210GM primers shot first at 8-15am
AVG 2826 fps. ES 31, SD = 10

CCI BR2 primers shot approx 11-00am
AVG 2842 fps. ES 27, SD=8

So early morning shots averaged 2825 fps and 2826 fps
Late morning shots averaged 2846 fps and 2842 fps. Pretty damned close, and that would be really good, except it was two different primers in each group, which now has me really scratching my head .
Is a 15-20 fps change in velocity between an "early" shoot and a late morning shoot........i am thinking 6 to 8 degrees lift in temperature , completely normal ?
Its probably meaningless, but on both days my score was higher on the mid morning shoot, but like most days, the winds were very variable. Waterline was really tight, except for the 5th shot in the first shoot (2825 fps Avg) when 2797 just gave me a 5 at "6 Oclock" at 300 metres.
Does anyone load a lighter/slower load specifically for first up ranges, or am i fretting about nothing ? From the many comments and questions on the firing line, I am guessing that not many people have shot an OPM with a chrony on, so perhaps the velocity change is happening to everybody as the day wears on, but you didnt know it ?
Thanks for any comments.
Tony

[bruce moulds]

tony,
was your barrel cleaned at night then shot all day.
increasing fouling can increase vel and pressure during the day.
might help, might hinder accuracy and s.d.
in real terms, there is no difference between an s.d of 10 and 14. this can often reverse if repeated.
keep safe,
bruce.

[ecomeat]

Bruce, after a really thorough cleaning following the QRA Queens, i actually put 6 x foulers thru it at home the day before, and sighted it in for approx 600 metres.
Then went to Goondiwindi and shot 3 ranges (2 with the MagnetoSpeed on) on the Saturday. I didnt chrony the 3rd range.
Looked at it with my borescope at the end of the day and it was surprisingly clean.
Shot the first two ranges with the chrony on for the data, and the final 600 metre range without it.
I know 15-20 fps isnt "that much", but I cant get it out of my head that with 284 Win and 2213sc thats about 0.3 or 0.4 of a gr. So if that much "doesnt matter", why arent we all just measuring our powder with teaspoons instead of using superbly accurate digital scales etc ?

It cleaned up as good , if not better than ever, when i cleaned it on Monday morning. 2 x wet patches followed by a iosso nylon brush with KG1 Carbon remover, shellite to clean, followed by simple Sweets regime (2 wet patches, iosso nylon brush, wait 5 mins then good scrub with Sweets on a bronze brush. Shellite on 2-3 patches, dry patch it) and it was perfectly clean. Barrel is a Bartlein 5R .....a "full brother" to the one Alan Fraser shot so well with in Raton.
It had shot some 75 rounds by the Monday morning when i cleaned it and there was nothing wrong with its accuracy (that couldnt be fixed by changing the trigger puller)
Tony

[Norm]

Tony,
Give standard CCI 200 LR primers a go and see how your ES goes.

[DenisA]

G'day Tony,

I can confidently say that when I chrony loads at the short range when shooting groups with a known good load, the MV is a little slower with a cold barrel (even if its fouled) and takes a few groups of 5 to consistantly reach its reputed MV level. That said, the POI isn't any lower on the slower speeds which may come back to a compensation effect.

I've been doing a little reading lately on ES and SD. My understanding is still poor at best, but I think I can make some sence of the results.


GP Ave MV SD low MV hi MV

Day1
1 2825 14 2811 2839
2 2846 10 2836 2856

Day2
3 2826 10 2816 2836
4 2842 8 2834 2850


From what I understand of the 'rule of thumb' theory of SD, your results show a fairly gentle increase on each day.
I suspect that the second groups will be a tuer ES than the first as the barrel has warmed.
The high velocity of the first groups fall within the velocity variation of the second groups.
That means that somewhere within the first 12 shots, you had reached the MV variation of the second group.
The lower speeds creating the lower first group average may have only been 5 shots to get heat into the barrel.
ES and mean MV are an abrupt figure and statistically vague.

It would have been great to get those 3rd groups chronied.

I think we need to remember that even statistics are subject to variables such as barrel temp, fouling and ambient temp.
As we all know, results are statistically more accurate with more inputs.

May be you should do the same test, but share the 2 primer types 50/50 in each detail and alternate them keeping track of where they are. Maybe mark the cases.

I suspect we'll find theres little difference between primers.

Please dont take this as me telling anyone anything. I'm a 1st year compared to you guys and I'm just thinking out load. Hopefully someone can correct me where needed or tell me shut up.

[AlanF]

Just a few comments about my recent experiences. Lewis Reynolds kindly lent me his Magnetospeed at the FCWC, and I used it mainly to compare speeds using Australian and US powder batches. Once that relationship was established (N165 almost identical actually), I did some further testing to check velocity variation with some loads. The results lead me to believe that, as with conventional chronies, the Magnetospeed figures seem reliable within a session, but you can't necessarily compare one session with another. For example I had an approximately 40fps difference in velocity for the same load on different days - approx same temp and same barrel condition. I suspect its to do with the distance of the "bayonet" from the path of the bullet - change this, and velocity will change.

FWIW I was getting velocity SD of about 12fps in the load I adopted which was 57.5gn N165 with BR-2s and molyed 180 VLDs. Depending on which testing session I believed, velocity was somewhere between 2900 and 2950fps - I suspect closer to the lower figure because the primer pockets survived several firings. I still lost a few to vertical but that could have been partly the conditions.

Tony I wouldn't get too serious with testing until you have at least 200 rounds up. My Bartlein did come up approx 50 fps in velocity at about that round count, and this is a commonly observed phenomenum with most barrel brands. I want to thank you again for persisting with the Bartlein importation - I've always regarded barrels as one of the items most critical to success in this game, and this one went very well. I also took a very good True-Flite as an "emergency" but it was not needed.

Alan

[ecomeat]

Thanks for the input.
Looking at the timing on the last post, it seems someone might have a bit of jet lag ! Welcome home, World Champion.
I actually went past/thru the 200 round mark while at Goodiwindi. That was one of the main reasons that I went for the 4 hr drive. I started the weekend at about 175 shots thru it, and finished at close to 250. I know that Rod Davies, yourself Alan, and others had cautioned about barrels speeding up at around the 200 shot mark so was keen to get well past that before the NSW Queens. Plus, the 6 ranges over two days was ideal to fireform some more cases for Sydney.
My own gut feel from limited experience is that Denis is close to the money about the requirement of a barrel to heat up enough before its mv figures become reliable. This new 1.25" straight cylinder 32" barrel certainly takes a few more shots to heat up, but then seems to hold the heat longer as well.
Like Alan I have suspected from Day one that the Magneto speed would show variable results if not placed in exactly the same position of "overhang". I consciously try to place it with the same 3/4" overhang every single time I use it. I had some experience trying to use the Version 1 on a barrel that was over 1.0" thick and kept getting erratic results......trying to use it in a situation that the makers didn't recommend. So I got the Version2 bayonet as soon as it was released, which saves me from having to alter tiny grub screw settings if someone needs to borrow it. The V2 fits a thick barrel perfectly and doesn't get adjusted, whilst the V1 can be made to fit anything 1" in diameter, or less.
I will try CCI200 and PMC primers this weekend at our Club day and see what changes I can identify,if any.
If the man who was "World Champion" on Day 2 at Raton happily shot it with an SD of 12, then I can probably stop stressing over SD's of 8 - 14 !!
Alan how often did you clean over there, once you got into the serious competition end of the trip ?

[AlanF]

Tony,

You got it right with about the jet lag. Currently I can't keep awake past 8pm, so wake up about 2am .

Regarding cleaning, it was daily, and as well as the normal powder solvent then Sweets, I used a smidgeon of Iosso paste just in the throat.

One very sensible concession throughout the US Nationals and FCWC is that a short period for blow-off shots from the mound was provided every morning even during the teams shoots. This is something I'm going to put to the NRAA to see if it can somehow be incorporated into our competition shoots.

I also got to use an empty chamber indicator (ECI) for the first time. Our system is slightly safer, but only because we have a requirement for both scorer and check scorer to inspect and verbally announce "clear!". If the ECI was incorporated into our check routine then it would be fine, whilst making it much quicker for some stock/action designs.

Alan

[lewis reynolds]

Alan plus 1 for the blow off period. I am just rethinking my cleaning technique for the nsw queens. With no opertatunity to pre foul a barrel. I would like to see a one minute blow off on the first range of the day. Before prize shoots I would do this in my paddock the morning or night before but at malabar with no zero range and a multi day event it would be beneficial for me. Just my 2 cents

[ecomeat]

Tony,
Give standard CCI 200 LR primers a go and see how your ES goes.

Norm, sorry meant to post this before the NSW Queens.
I recorded 3 x strings of 10-12 shots at our Club day two weeks ago, using different Primers in each string. We started approx 11:30 and shot till 1:30 so conditions certainly very similar.
All shot in 284 Win using Lapua cases , 180 gr Berger VLDs and 55.7 gr 2213sc
FED 210 GM Primers : Avg 2823 fps, ES 36 and SD 9
PMC Primers : Avg 2798, ES 27 and SD 7
CCI 200's : Avg 2819, ES 46 and SD 14.

FED and PMC primers both scored very well. CCI 200's very unacceptable !
FED 210's scored 59-6/60 @ 600 yards
PMCs scored 65-3/66 @ 600 yards
CCI 200s scored 58-2/66 @ 600 yards

This was in the Bartlein barrel that I then had some success with at the NSW Queens. I went home from our Club day, and loaded up for Sydney using the Federal 210 GM Primers.
Just for fun, at the North Arm OPM that is coming up, I will use the MagnetoSpeed and shoot the first morning range each day with Fed 210s and then use PMC for after the day warms up...............and they "should" end up being pretty close to the same velocity (although i wont be using the Bartlein, but another pretty good Maddco instead)
Rgds
Tony

[Norm]

Tony,
Interesting results with the CCI200 primers. The cooler primers sure seem to do a better job with AR2213sc.
I use a slower powder and that may be why I am getting good results with the CCI200 primer, it may need the extra ommpf that the 200 provides?

[bsouthernau]

This thread started off (as I recall) comparing CCI BR2 to Federal GM210M and then expanded to early morning and cold barrel etc etc. There have been a few sets of data provided but no tests of the statistical significance between any performed. I'd suggest Student's t as a good starting point.

Barry

[ecomeat]

This thread started off (as I recall) comparing CCI BR2 to Federal GM210M and then expanded to early morning and cold barrel etc etc. There have been a few sets of data provided but no tests of the statistical significance between any performed. I'd suggest Student's t as a good starting point.

Barry

My brain doesnt function well enough these days work out that probability, Barry.
I would be happy to cooperate to the fullest possible extent if anyone IS up to speed with a working brain or scientific calculator.
I have just been relating/sharing some recent experiences and data, and hoping that someone on this forum might be able to help me decipher it.
Tony

[bsouthernau]

Afraid I'm just a cookbook statistician myself Tony. You can do quite a lot of this stuff in Microsoft Excel - I might have a look later in the week if I get my loading for SA finished.

Barry