6 x 47 Lapua

[Peter Marum]

Barry,

Now after 30 years i see the light with tbj pumps, spent many a restless nights trying to get the best out of them'( musta been backpressure, V.B sometime has the same affect)
I jest of course, just had to replace the occasional impeller and bearing.

Peter

[AlanF]

Cameron,

Don't let all these Vic F-Std pump plumbers sabotage the thread. Give us the good oil on your 6x47 load development.

Hope to see you at the Vic Queens Tom, Barry and Peter .

Alan

[Cameron Mc]

G Day Alan

It's good to have a little humour. Better than arguments.

I have done a fair bit of testing now but the downside is the weather. High temps, lot's of wind and the ever present mirage.
Here are current loads with 6x47 and 6.5x47.
If anyone is working with these cartridges please start lower and work up.

6x47 : 40g - 2209 CCI Mag Primer 105g Scennar 3000+ fps no chrono tests yet.

6.5x47 : 39g - 2208 CCI Mag Primer 123g Scennar 3030 fps ES under 10 for five shots.

6.5x47 : 37.5g - 2208 CCI Mag Primer 139g Scennar 2880 fps ES under 10 for five shots.

I have consistant accuracy with the above 3 loads, but fine tuning is needed. They are all safe loads in my rifle with no head expansion. I have tried hotter loads but case life would be an issue. All have shot under 1.5" elevation for 10 shots at 300yds. It has been real hard to get an indication at the longer ranges because of the mirage etc.

Dave, hope to see you at CrowsNest next weekend to talk about the 6.5 you have.

Would like to hear from others trying these rounds.

Cameron

[daj]

Cameron,

Thanks for sharing your loads. Having the 139s set back in the case seems to work ok for you so I'll probably give it a try too before resorting to the throating reamer.

I still have to buy sizing and seating dies before I can start load development, so I don't think I'll be ready for Crows Nest this coming weekend.
(BTW Forster dies are the only off-the-shelf dies I could find for the 6.5x47L.)

Dave

[XCALIBRE]

Barry & Tom
My reference to back pressure stems from the need to contain the combustion of slow powder a tad longer within the case. This helps to ensure all the powder is burning before release up the barrel. It also helps to generate a high pressure where it was designed for.A heavier bullet helps to contain by it's weight as does a restrictive gas flow ie. steep shoulder angle.
The 142's launched today at 700 metres had the same point of impact on the same scope setting as the 120's. Loads were 142 Sierra : 40.0X 2209 for 2795 fps. 120 Sierra : 38.0X 2208 for 3020 fps.
Hope this helps.

[Chopper]

I know its early days but anyone had one long enough to give an approx barrel life also what about other powder use say 2213sc i have heard gives a better case capacity correct me if ime wrong but ime soon due to have aplay with the 6x47 , cases where and how much?thanks CHOP.

[Cameron Mc]

Chop, I think 2213 would be too slow in the 6/6.5x47. One load I use is 40g - 2209 in my 6x47. This is close to a compressed load. Could be worth a go with heavier projectiles in the 6.5x47.
2208 is giving me the best results so far. 6.5x47 Lapua brass is available direct from the importers, Custers in Brisbane.

Cameron

[Chopper]

thanks cameran for youre info ,i have been playing around abit with wind movements on various calibres and have been very impressed with that ,comming from 308 and 223,ihear a lot about small grouping but never about wind comparisons from various calibres this without a doubt means a very important part of our groups , a passion of mine since trainning and coaching state team, the right powder wont estimate wind but it will help and you can BUY that, i have spent the last few years in playing around and only put that into practice in the dra state fc standard teams and it has proved fine ,but again comparisons with 223 vs 308 have proved that wind selection is critial and there is nothing between both so far out to 1/ 10 minutes but with the FO calibres another story,ime not havin a go at fo but it seems you can buck the wind with various calibres and you have that choice and good luck to you if you can afford it,the most important question i have seen so far was that of , what is a good calibre to compete from 3 to 1000 and some very good answers came from that,unless you have competed in full bore, fcs , fco , theres a far bit to learn.it would be nice to hear some comments on wind from you , i will be trying some fo cals because i like to have fun and thats what its about .

[AlanF]

...with the FO calibres another story,ime not havin a go at fo but it seems you can buck the wind with various calibres and you have that choice and good luck to you if you can afford it...

Chop,

Hmmm...

I'm not taking offence, but will attempt to defend the FO position on this. Firstly, I'll agree with some of what you say.

To some degree, you can buy yourself what I'll call a "low drift" setup i.e. high BC, and high velocity. There are various financial costs to doing this, mainly high barrel wear, and you may choose to use expensive projectiles, although I believe that if you're prepared to measure and sort factory projectiles, they are just as good (for F-Open at least).

But there are other non-dollar costs which must be bourne for a low drift setup. In these I include recoil. Because there is a set weight limit, and no muzzle brakes allowed, there is a limit to the bullet weight (a major contributor to BC) and the velocity you can use while keeping your rifle well-behaved on the rests. That is why the big .30 magnums aren't generally used in FO as they are in some BR classes.

Another non-dollar cost (associated with short barrel life), is the limited number of shots you have available for load development. If your barrel has an accuracy life of around 1000 rounds, you don't want to be doing too much ladder and group testing!

I think it is great to have a class such as FO where you have a sort of free market situation where over time the ideal chamberings will emerge from the rest. Then a rule change or new idea might tip the balance in favour of something else etc.

I agree that the F-Std class is in general a better test of wind-reading skills. F-Open on the other hand gives those with other skills (e.g. advanced reloading and load development, innovation, research) another avenue to improve their competitiveness.

And remember, as in any class, you're all competing under the same rules.

Alan

[Chopper]

Thank you Allan i guess i went around a long way to ask a question no need to defend FO i find it very interesting and intend to have a go at it very shortley,as far as wind reading with fullbore and FO goes i agree with what you say but you still have to estimate the correction , fullbore you have to make bigger corrections than you would for FO but fullbore has a much bigger bull, and as ime soon to find out imagine a bit harder to keep it in that little 10 ring andas for my previous post would like to know if possible wind deflection differences , i guess some of you would have shot 308/223 to have some idea, it would be interesting.

[AlanF]

Yes I heard a whisper that you might be dipping your toe in the water with F-Open soon. With your credentials, it won't be long before you're at the sharp end I think. Despite what I said in the previous post, wind reading is still the main game. Will you be at the Vic Queens?

Alan

[Chopper]

thank you for the compliment of credentials ? i guess i have asked a question with no replies for agood reason or 2,after thinking about it what if someone asked me that in reverse,I COULD NOT ANSWER THAT, would someone come from fo to fc idont know,but i will come along SOON and have pen and paper .

[Lynn Otto]

Chopper

As I read your post, and please correct me if I'm wrong, you are asking about the difference needed in wind reading between std calibres and open calibres. I think the reason there was no answer may be because while there are people who have moved between FS and FO and like me actively shoot both, not many have thought about the differences as they impact on wind reading. I think some who have gone to FO automatically believe they have bought wind bucking ability but I think you tend to shift mental gears when you go from one to the other and I doubt any empirical data has been collected on the matter because it largely comes down to the ability of the person behind the rifle. You could not set up identical conditions to guage the difference. At the time of shooting, your concentration is solely on the job and as I tend to do my wind reading instinctively, I couldn't say how much difference I experience. Both my rifles produce very tight groups but I would never choose the 6BR over the 223 for it's wind advantage, you adjust to suit the rifle.
Sorry for the very untechnical ramble, I guess my feeling is that I wouldn't go shoot Open just because I might not have to work quite so hard on the wind reading, I like the challenge of the 223.

Lynn

[Chopper]

thanks for youre comments lynne but i still beleive wind reading is the key just as much as good equipment its just the difference in wind that will count at the end of the match, so much talk goes on about equip??ment but not in wind . ??

[AlanF]

Chop,

I can give an example of the difference between my .308 and my 6.5x284 as far as wind drift goes. This is based on the Pejsa ballistics calculator. The 6.5 has approx 70% of the wind drift of the .308. It changes with the range. At 300yd the figure is about 72% and at 1000yd the figure is about 68%. My .308 is probably slightly down on velocity compared to most (MV 2860 fps). My 6.5 would be about average velocity for that calibre (MV 2950 fps).

Compared to most Open chamberings in Australia, mine would be one of the best in relation to low wind drift, but some 7mm chamberings appearing recently are probably a few % better, if you can handle the recoil. And some of the faster 6mm chamberings e.g. 243AI, would have very similar wind bucking capability to my 6.5. The very popular 6BR would be somewhere near the middle (between 6.5x284 and .308).

Does that help?

Alan