Guys, the quality of your observations will raise the bar for future competitors and ensure FO is a competition truly designated as formula one. It has great spinoffs for other classes and to get a gong in the future will have tremendous value as the class builds in number. By sharing and analysing results it is surely contributing to the respect and fellowship and pleasure we get from shooting. I don’t see these processes being about one-upmanship but one of objectivity. But a healthy stir occasionally adds a bit of colour.
If I was taking a line through Cam’s scores with a 60.9 at nine hundred, then a 60.3 at one thousand, it demonstrates to me, the managing of a larger group with a rifle fully in tune by a master pilot. As Raven has pointed out, he just held the 6 ring, so something in the conditions opened his group. I feel it was not a tune problem. At the same time Tony, who had a tuned rifle too, going by his 900 performances did not have a pleasing score at 1000. Tony was operating at a lower accuracy node than Cam shooting close to Cam at the same time I understand. Tony’s strategies for dealing with conditions will grow as he develops his understanding. Relative to Cam’s time in the game, Tony’s is very short but loaded with talent.
While it may seem a bit harsh, VarmintAl on another site has a saying displayed in his workshop:
“The person who learns to do a job well will always have work but the person that learns why will always be their boss”.
It seems to me that more gun was a positive in the frontal conditions dealing with compressed air layers above the mounds; and if you were squadded in a position to be poking your trajectory out of the compressed layers into the turbulent parts of the atmosphere, then a better nose shape and better still, one that had a greater radius in the body would marginally assist you to get an edge.
The other edge is not experience, but learning from experience through observation and analysis.
Rod’s observation of shooters is very significant. He saw a trend of rising shots, then a trend of falling shots. I felt he was describing the atmospheric pulse I mentioned earlier. His solution to maximise his score was similar to the sacrificial lamb used in team shooting or a number of single sighters used from various shooters at different times to tell the coaches what was happening. Brilliant. While some others who had lesser scores, could say you can’t help bad luck, Rod obviously had a strategy. By playing the percentages your turn will come.
If you did the best you can under the conditions you can be proud.
Hopefully this discussion has had a lot of positives to improve your performance for your next trip to Belmont. David
Hello David Would you care to comment on the advantages / disadvantages of a couple of loads I have used at 1000? Which would be the best for the conditions encountered at 1000 yards? 155 Hybrid at 3100fps MV and 215 Hybrid at 2680fps? Previous experience with both have exhibited X ring waterline. My 215 load at 1000 handed me a high and low 5. It had been doing similar things at the shorter ranges however so I suspect another problem. Shane
Shane, I haven't proofed this piece so there may be a few blues or rambling as I am a bit knackered typing all this stuff recently. But I am sure you get the gist of it. There is never a simple answer. To be successful in F class you certainly have to pay attention to detail.
I cannot see your rifle to check for any mechanical issue in the setup or look at your position with regards the rifle fulcrum point and weight of the base of the stock in the rear bag even though you shoot with a bipod. I would expect that to be top notch with your buddies overseeing this work.
With regards to your technique, I know you use free recoil. There are occasions you have to adapt your style to wring every bit of muzzle energy out of your gear in certain environmental conditions like the headwinds over high mounds where managing a larger group is more important than precision. Using free recoil can sap some of that muzzle energy. By shouldering the rifle in such conditions you may pick up 30 fps in your 30 cal.
As a hunter who has used a Harris bipod with a lot of different gear, I always got my best hits by leaning into the bipod. For me that is a natural style that can be translated to target shooting for the very situation we are discussing.
However, you would not use that shouldered rifle unless you have done short range tuning for it or mastered the technique. What I am saying, you can’t expect to have the same group or elevation for a free recoil rifle then suddenly changing to full shoulder, and firm grip contact to expect it to hit in the same place and perform as well. This means you probably require different loads for different techniques.
The free recoil will serve you wonderfully in all other situations and be magnificent in crosswinds that are not sufficient to buffet you.
Could I say, and Tony and Craig might confirm, that your groups patterns in short range testing should hold, albeit sometimes bigger at long range. The shapes of your groups will tell you if the harmonics are crook due to extraneous problems such as tension released on say scope fittings, or crook lugs etc. or stock shape when firing, upsetting the natural flow of the harmonics. You have to check the alignment of the takedown screws, that there is only contact on the rear of the recoil plate or lug etc. Craig’s early group shape had me puzzled but I found out he was using an offset stock as I queried the direction of bullet fall, not that they were not good, but I wondered why they were different.
Normally niggling vertical needs more powder or change to a hotter primer or playing with the neck tension to ensure an efficient burn. Anyway they are off topic a bit and are tune issues. To cut to the chase, the tune can be done at short range with long range shooting in mind. If you are outside the normal tune expectations at short range it won’t perform at long range. So I assume DaveMc would have briefed you there.
That means if the long range tune is not performing something else is happening. The first thing to do is have someone else shoot your gear with free recoil. That would give us an idea if the balance of the kit was upset. Not only should, fore and aft balance be checked, so should the sideways balance because this can be a sneaky bastard in combination with a barrel torque even when the barrel is fitted in the vertical, if it pitches off centre with a bias as per the video Aaron once posted in our discussion of torque effects. Again short range grouping picks this up and you re-index the barrel in a worse case scenario or use counterweights on your stock and or barrel.
In regard to the external ballistics, these can normally be accommodated with changes of powder, primer, barrel weight or tuner, or reduced barrel length or profile change, ignition issues etc. which I believe you have accommodated for a normal tune.
Teasing out the issues further, the BC of hybrid 215 will assist you in compressed layers or denser air that is pounding you laterally if the denser atmosphere is sufficiently deep and the projectile does not penetrate a turbulent interface with better air. But equally the high velocity of the 155 hybrid takes less time to reach the target, so therefore is not affected by as many regular anomalies of the atmosphere when you consider that it is travelling at 3100 fps compared to 2600fps. That’s roughly 1.3 seconds compared to 1.7 seconds in the air. Its a bit like a lock time comparison.
When doing the test work for project Penumbra, using the older, tangent ogive Sierra 155, they were doing their best grouping at 2975 -3000 fps. This is also a common velocity for many projectiles that perform their best grouping across calibres. So I would not be surprised that formal testing would reveal the 215 gn projectile would perform well at that velocity, except to say its drag characteristics maybe designed to accommodate a lower velocity.
There are some other techniques to raise this velocity that I have briefly mentioned to DaveMc that remain confidential in view of international competition. They all read these blogs. So what I say is common knowledge.
The two bullets have the same diameter, so no big advantage is gained by either in the turbulence of compressed frontal air meeting clear laminar flowing air, except for the greater mass of the 215 grn. Which is also a factor determining its torque. The benefits of this greater mass often cause havoc with pressures and popping primers. Getting the right harmonics and having to reduce velocities to cope with turbulent air unless you play with the chamber is more difficult for the 215 grn compared to using the 155 grn.
Therefore, the much greater velocity obtained by the 155 scores better by punching through turbulence we have been focussing on.
In stable conditions, with high winds, the high BC wins because it saves you doping the wind, because it will shoot inside the lesser BC projectile. Then you look at the group size each will produce at short range for a long range tune, to see if any BC advantage is outweighed. Remember the BC advantage is not there if the strength does not fluctuate or you can read it because BC is not necessarily a function of group size. That’s why TR shooters who know their projectile can shoot amazing scores.
With the normal pulse of frontal or rear winds, we expect to have elevation fluctuation but usually a very tight tune or a compensation tune at long range can improve that further. But with high mounds, the pulse is accompanied with sections of compressed air layers and I think any elevation fluctuation will be exacerbated by projectiles travelling slower on the whole, because the compared bullets share the same diameter and share a similar hybrid shape. That would put the 155 on steroids in front for the turbulent condition in my opinion.
The is a bullet sort of pulse characteristic that may be greater with the 215 grn, that is like a wobble of a javelin in flight. Its called nutation. Its a bit like a porpoise swimming, but maintaining direction. With the smaller targets its a possibility at short range, but a remote one, that this can be expressed as elevation hits.
However, if you can think strategically like Rod, by observing the trends in the up and down pulse of other shooters as determined by the wind, it may improve your score. This means your skill base has to improve if you wish to use the 215 grn. We all look for the lateral trends upwind of other shooters. The 215 grn will take care of that lateral wind push better, but not the elevation variables associated with significant pulse combined with turbulent flow as well at those lower velocities. Its the elevation variables we are trying to reduce.
If on balance, your rifle groups significantly better with a certain pill, that is your best call. Normally, like Keith’s sound advice, you run with the pill that produces the tightest tune. It may well be on a low velocity, but you have to adapt to the conditions as per Belmont to get the edge, and to manage a larger group like Cam.
In closing I would say, don’t use the bullets interchangeably in the same barrel. You end up screwing the throat profile and harmonics by different wear patterns of the bullets. Not only that, if you are mixing powder by shooting a single base powder for lighter bullets and then a double base slower powder for heavy bullets you will interfere with the barrel work hardening processes when it is new because of different chemical reactions in the micro fissures determining hardness and wearing down the barrel to get over a usual speed hump when its new. You only have a window of 700 rounds of perfection for big events.
The other thing you do is create a different fouling profile with different powders and if not sufficiently cleaned can skew results in short range load development.
David, thanks for the considered reply. We will check the scope this week. I was speaking with our Team coach yesterday and he said the plot from the 1000 was 2/3 X ring. I lent it to another Team member for the last 900 and 1000 ranges where it certainly picked up some points for us.
Maybe I am simply past the magic round count - approx 1000 rounds now. I had built this rifle for 900 + 1000 only but have been forced to use it for 3 Queens and lead ups! I have on your advice only used the 215 Hybrids and one powder in this barrel.
Will bore scope as well the rifle balance seems very good - tracks back on target 80- 90 % of the time.
Agree on Harris - they require forward loading - i think because of the retractable springs? I have had my Joypad modified for a very secure fit onto the stock. It has shot well free recoil without requiring any loading. I found i couldn't replicate identical shoulder pressure to give flat waterline at 1000. I have heard shoulder pressure will increase velocity. BTW 215 will exceed the Belmont limit at 2708fps?! My loads are mindful of this. I have no pressure problems and have established a wide node. Free recoil compared to mild shoulder = 1 moa impact difference for me at 1000.
Shane, it would be interesting to try the 155 at the higher velocity before you re-chamber. It could be your gear is not stiff enough to withstand the force of the thrust in the vertical or give a little under different mound shapes with the heavy pill. David.
Sure looks like Belmont is a range specific setup. Steep mounds and bloody speed limits. Of course when we had that previous discussion Shane some time ago, I was not aware speed limits were going to be introduced. C'est la vie.
There may be other venues where you can use the 215 with more grunt or places where the combination of steep mounds with the the frontal or rear wind are not present and you could use your slower velocity.
Hello again David It would need a rechamber to run 155 in this barrel due to custom throat. The previous throats could interchange 185 and 155 but due to length required for 215??? I would have a serious amount of jump.
With the longer throat I can exceed the Belmont limit.
Interesting discussion. I shoot f standard and was seduced by the higher bc's of the Berger Hybrids. I have found they don't hold up as well as the 155.5 Fullbore for longer ranges. Why this is I am not sure, but perhaps the greater overturning moment of these pills leads to greater instability in crosswinds that change 3 or more times encountered on my home range. The 155.5 Fullbores just seem to have a considerable edge in long range stability. Both were driven at 3000fps in a 1:12 5R Bartlein.
One factor is the twist rate. From personal experience the Hybrids 155 were as accurate as anything I have seen. In a 1/11 twist and this is the reccomended twist from Bryan Litz also for these pills.
Shane I take your point. But sometimes we can learn something about the barrel. A few months before I had that brain tumour out, I carried the wife's bags to Sydney and decided to have a ping but wasn't expecting anything due to health issues. I had a Border barrel that would not shoot. I took the throat out about 80 thousandths of an inch. I also went for the doctor and loaded it with 45 grains of 2206 using Sierras. It shot like a train and earned a few gongs. What I do know, the throat had a tight diameter. I can guarantee it had no pressure spikes with that long throat.
Sometimes this game leaves you scratching your head, but by playing, and I am fortunate to be able to do that at home I discovered something new for myself.
If you decide to re-chamber it, could you shoot a 155 first, then lengthen the throat, clean it thoroughly with perhaps a minor lap and have another ping with the 215 gn ? Then chamber up a new barrel based on your results? Just food for thought. David.
Last edited by williada on Sun Aug 23, 2015 11:11 pm, edited 1 time in total.
Too many things on the go but keeps life interesting, David. We only got home Friday lunchtime and will try and forensic the problem next week? Certainly could do that experiment as we have a throating reamer. Also have a 1/9 Bartlein sitting about from Craig which we both are intrigued as to how it will shoot the 215 Hybrids? Needs to be chambered and fitted - plus a couple of Krieger 1/10 HP have finally turned up also.
Biggest hassle here at the moment is no pills available? I bought everything Q Store had late last year in 215 and seemingly not much since? Just about out now - all there seems to be available is 155?
See the UK; USA and Canada are way ahead of us - they just shot a Teams [combined FO + F/TR] at the Canadian Nationals. This is something I have been suggesting for quite awhile here. It is the only way we can give coaches practise at dual coached teams on current numbers. this is what let the F/TR Team down in Raton - no dual coach practise with poor communication as a result. Definitely cost us a place medal
Quote: I had a Border barrel that would not shoot. I took the throat out about 80 thousandths of an inch. I also went for the doctor and loaded it with 45 grains of 2206 using Dyer 155's. It shot like a train and earned a few gongs. What I do know, the throat had a tight diameter. I can guarantee it had no pressure spikes with that long throat.
David, any idea of what jump that long throat would have given you, and, also velocity? I am assuming that is the Dyer HBC that you used? not the original Dyer? I am using two M892 chambers(different reamer brand, standard throat), 12 twist barrel, and if I use the new Sierra 2156 155's they are only sitting in the case 45th even with a 20th jump!!! Ray.
G'day Ray, How did the bedding of that Mauser turn out with the Araldite?
I'm glad you asked the question about the Dyer's. The wife just told me I was using 155 Sierras in Sydney. Sorry about that, because I ran both out of that barrel successfully, and as it wore I turned to Dyers in its later life going for more bearing surface for gas seal. That seemed to stick in my head as I typed. A bit tired. I had been jumping the old Sierras .010" in a Palma Chamber but used a PTG Universal reamer and just kept chewing out throat until the 3 shot groups tightened on a 100 yard short test range at that time, until I got the right fall of the shots, slow on top of fast in a tight group that was positively compensating. So the actual order of the jump was about .090" from the ogive. I think I posted a test barrel result on the forum before from a presentation to the Australian Palma Team in 2003, demonstrating the group shapes in .010" graduations out to .100" a while back from the actual data of project Penumbra tests. I cannot be sure of the exact figure of the chrono, it was so long ago, but it would have been running about 3000+ fps.
You can't get these jumps with a standard ream Ray. You have to use a universal throat reamer which is registered in .005" increments or a standard throat reamer. I think I ran with 1 1/4 degree leed angle. Throat diameter was probably .3084" not .3085", just a tad tighter.
As an aside note, I found good jumps for the Dyer between .005" and .008"; and about .015" in Kreiger barrels.
Longranger, I think you have identified a critical area of the trajectory that needs further investigation for a comparison between projectiles because winds are often faster at that height. I was hoping someone would have responded to your question for a bit more anecdotal evidence.
But to keep on topic, the compressed air at Belmont over the steep mounds would have a bigger effect early. For other Australian ranges, Longranger’s point is very valid.
Coming back to Shane’s issue with the heavy pill, and casting aside the turbulence issue because he felt he saw similar issues at shorter ranges; and also given the lighter setup of F/TR there are two further areas to explore given he had someone else shoot it with good results and I have had more time to think about this.
Firstly, a slight ignition problem may exist if there is an air gap in the case. Maybe trying to reduce velocity? Powder can move forward on different mound angles and the burn efficiency may suffer. It is very marginal and normally a high density of powder is desired to keep rattling the super centre. If the group just opens a tad, then rough conditions will add to group size enough to pop you out for the odd one or two shots.
If you know the powder case combination is great on full density and the bloody speed limit prevents you from achieving this, then the solution is to keep cutting the muzzle back and shortening the barrel to the artificial maximum velocity. This presents two other problems. The pill exit timing and group shape. To alter the exit timing, to satisfy this you need to play with the throat. In doing so, you also reduce velocity. You need to know for every say .010” you take out of the throat how much velocity is reduced before you go lopping sections from the muzzle. If you have barrels of similar dimensions the ballpark figures are close enough, but each barrel is different.
The other major point I make is in relation to the heavy whip on barrels these heavy pills impart. Unless the mound setup is spot on, I can envisage the odd tracking issue. Shane indicated it tracks well 80-90% of the time. That could be two or one suspect releases every ten shots. It’s a possibility given the recoil in F/TR usually moves the front bipod from what I have seen it is re-positioned for each shot. The new joystick bipods for which I have no experience might not be so bad.
By reducing the length of the barrel, the whip can be reduced too. That means the use of say a bedding block is out of the question to stiffen the setup due to weight limits of the class, to make it less responsive to whip on dicky mounds. The other way to reduce the whip is to place upward pressure on it with a forend bed. But if the rifle stock is inclined to move, you have to be constantly at it to keep it in shape.
These heavy pills just might group better with gain twist rifling with reduced rotational inertia to dampen vibrations. Just food for thought.
Couple of more comments David The load is about 100.5% as there is the mildest compression at final seat felt on arbor press. OAL stay stable - not compressed as such. I have a heavy tuner on the muzzle helping tame the whip. The rifle was shooting beautifully for me over 2 Queens and lead up. Then I put one of our Team on it for the 900 and 1000. Still holding great waterline - just later on in Queens started to play up with high and low? All using same plates front and rear as for Nationals as well. At least one per range and more often than not two! I hope I can forensic the situation - too busy back at work to bore scope as yet. I should have had one with me! This game is seriously frustrating at times! Shane
Longranger wrote:Interesting discussion. I shoot f standard and was seduced by the higher bc's of the Berger Hybrids. I have found they don't hold up as well as the 155.5 Fullbore for longer ranges. Why this is I am not sure, but perhaps the greater overturning moment of these pills leads to greater instability in crosswinds that change 3 or more times encountered on my home range. The 155.5 Fullbores just seem to have a considerable edge in long range stability. Both were driven at 3000fps in a 1:12 5R Bartlein.
Anyone else found this with the Hybrids?
Hi Mate , I had the same opinion as u did. My Son earlier this year shot a possible 90.7 at 800 yes with ful bores and some say they get a higher x count . However I think every barel is different and for whatever reasons some barrels don't like hybreds. My win at 1000 yds in June Nats were hybreds at a slow 2980 fps . Had beautiful waterline and only dropped shots out to the side .was also the same tune for the 60.6 at 600 yds. My barrel is a lilja 1:12. My load I tuned in warmer conditions for Bundy opm and was getting 3040 fps. The drop in velocity was due to ambient temp drop. Ambient temp tuning is something I'm just starting to get my head around. As there can be 30 fps or more difference between hot and cold. Still and always learning , when u think u have masterd this sport , it soon proves me wrong and humbles me!
I've also had troubles with vertical as it has been mentioned . Mine was defiantly me to do with shoulder pressure and not seating the heal of the stock in the bags. On the weekend I purposely moved my body closer and increased shoulder pressure and vertical went away. At Ipswich opm I had 4 shots dropped to vertical , cost a podium . It's very annoying, one can live with dropping them out to the side but when they are all exactly 12 o'clock exactly halfway into the 5 ring , it's frustrating!
Another cause of vertical that I've found and scratched my head over on it was . Happened especially 600 yds or more , the rifle water lined beautifully for 4 or 5 shots, then would go haywire after that ( was hybreds too, so I blamed that). Was always in very tough conditions too when I was taking my time . Until I think it was mr Sutton or mr Tillick can't remember now , told me not to chamber the round until you are about to shoot. Otherwise you'll cook the round and gain 30 odd fps more speed thus a high shot. If u didn't know any better one would dial back down and this would work for the next shot because it was cooked too. Then a quick shot would see it go low . Adjust again , then another cooked bullet would go high again . By now I would be thinking my load was out or the barrel was gone! Ever since then I haven't had that sort of vertical problems. Just technique problems! Not to mention lack of skill problems! Lol! Kind regards Graham Sells.
As Raven has pointed out, he just held the 6 ring, so something in the conditions opened his group. I feel it was not a tune problem. At the same time Tony, who had a tuned rifle too, going by his 900 performances did not have a pleasing score at 1000. Tony was operating at a lower accuracy node than Cam shooting close to Cam at the same time I understand. Tony’s strategies for dealing with conditions will grow as he develops his understanding. Relative to Cam’s time in the game, Tony’s is very short but loaded with talent.
David.
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