6.5x47 OCW Results

[Big Al]

I was asked to develop the load for a rifle I recently built and this was todays OCW test, I seem to be building quite a few 6.5x47's at the minute and the more of them Im doing the more I promise myself one. They all seem to shoot really well

 

The obvious flyer at 37.0gr was exactly that, the trigger broke just a bit sooner than I was expecting on the second shot of the round robin and I felt it immediately. Considering the third shot went where the first had and taking into consideration the quality of the other charge weights I think in this instance its a fair call as a flyer.

 

[Tuck]

Very tidy Al, do you always use RL15? Is that your go to powder?

[Big Al]

Very tidy Al, do you always use RL15? Is that your go to powder?

 

 

Ive only used H4350 or RL15

 

Laurie mentioned something a while ago about sometimes a barrel in 6.5x47 likes either the faster or the slower type of powder, I saw this for myself not long ago.

 

After building one rifle that shot 120/123gr bullets really well with H4350 the next one didn't like it at all and the POI of the OCW groups was all over the clock face. I then changed over to RL15 and the groups halved with the POI being far more stable. This is the third rifle in this caliber recently so I just started where I left off with RL15. I think being the faster powder I will now stick with it for the 120/123 weight bullets until one wont shoot, then hopefully H4350 will fix it.

 

My friend had had good results with Varget and the lighter class of bullet.

[simonl]

Some lovely groups, but which of those do you choose?

[Big Al]

Some lovely groups, but which of those do you choose?

 

 

36.7gr would be a good bet as its between two very stable POI's so should remain stable, it will be a little on the slower side for that bullet but accuracy beats speed most days. If it was my own rifle I would also look a bit further up at 37.6gr and 37.8gr as there will most likely be something tasty up there waiting to be found, assuming there are no pressure issues. I will leave that for the new owner to find if he wants, considering its a foxer/stalking rife he may well be happy with what Ive already got.

[Dorset Winmag]

Good combo the 123 & RL15

 

My rifle has its "sweet spot" at 37.5 grains

[gunner]

Some very tidy groups , what magnification were you on ? Im assuming you didn't have a problem with heat haze ! cheers bud.........

[Big Al]

Some very tidy groups , what magnification were you on ? Im assuming you didn't have a problem with heat haze ! cheers bud.........

 

 

It was damp and a bit chilly were I was yesterday afternoon, no fear of heat haze!

 

Scope was an NXS 8-32 with NP2DD ret, it was on full power and shot rested from a makeshift bench.

 

Disregard the rifle, that was another build I was testing at the same time but thats the bench set up, crude but effective!

[gunner]

Hey the setup works thats what matters

[Swarovski1]

Very nice groups.ive got some 123gr amaxs but no rel 15.ive not done any load load testing with the 123s but I did have a 300yds mcqueens pb using them over n540 I had I was using up.any predictions on the 37.4gr load.

[Swarovski1]

My barrel is new.it only seen 200 odd down the barrel.my coal is 2.667 with 140gr amax.i think the 123s were the same give or take a thousandth.can I assume your loads were touching the lands.

[lapua]

surely ocw instructions say that you choose the one closest to the poa, therefore you should ignore group size and pick 37.2?

[Big Al]

My barrel is new.it only seen 200 odd down the barrel.my coal is 2.667 with 140gr amax.i think the 123s were the same give or take a thousandth.can I assume your loads were touching the lands.

 

 

I was 0.20" off - the throat is not standard.

[Big Al]

surely ocw instructions say that you choose the one closest to the poa, therefore you should ignore group size and pick 37.2?

 

 

I dont think they say that at all.

 

I look for the three groups with the most stable POI and then fine tune the middle one of these with a seating depth test.

[lapua]

I dont think they say that at all.

 

I look for the three groups with the most stable POI and then fine tune the middle one of these with a seating depth test.

You are correct, i just re-read the instructions!

[Swarovski1]

Going for a group with the best poa doesn't make sense because you have to have some kind of zero anyway.not sure on moving seating depth either at the mo as what I've read the 6.5x47 doesn't seem to be fussy.I've just loaded everything I've tried so far has been seated 10 thousandths off have all shot well.not all as good as the groups big Al has shot are really good.doesnt really make any difference on powder amount from his targets either by the looks of things

[Big Al]

Duplicate post.

[Big Al]

Going for a group with the best poa doesn't make sense because you have to have some kind of zero anyway.not sure on moving seating depth either at the mo as what I've read the 6.5x47 doesn't seem to be fussy.I've just loaded everything I've tried so far has been seated 10 thousandths off have all shot well.not all as good as the groups big Al has shot are really good.doesnt really make any difference on powder amount from his targets either by the looks of things

 

 

I set every bullet 0.020" off for an OCW test just so there is a constant, after all you have to start somewhere.

 

If once Ive established the OCW I have groups as good as I want then thats the seating depth sorted as well. Sometimes even though the groups are consistent they still need to be made smaller. I then do the same style of round robin test by using the OCW and then work longer and shorter (either side of 0.020" off) until I find the improvement Im expecting.

 

So far with the 6.5x47 and a number of different bullets Ive found 0.020" off has worked well, even with Berger VLD's which have a reputation for being fussy. I do think the powder amount matters, even though these are great groups you can see a very clear trend of them opening as charge weight increases and also POI shifts, this is due to charge weight. As I said earlier, if it were my own rifle I would continue this test starting at 37.4gr and working upwards until the first signs of pressure, I would hope to see the groups starting to shrink again as another node was revealed.

[gbal]

Al,as you know I'm not into max velocity per se (see below).

I'd load ten minimum at 36.7 and see how they shoot...with two 3 shot groups either side by .1g,each under .2,and very similar POI,

I'd be asking "What else would anyone want?" though I'd like to see a 5 shot group-not that many need to shoot 5 shots....if the first one is accurate!

(Assumes the 36.7g gives decent velocity-whatever the velocity,zeroing will be needed,and clickups for more distance. Accuracy/precision is more important,though both velocity and precision,once a decent level is reached-are secondary to the rest of the raft of facrors-headed by wind reading skill....so much harder to master than ever more 'load development"... Each to their foibles,of course,but it helps to be aware of the fuller picture,and allocate your resources/efforts accordingly.

 

So "enough velocity"-I mean that most applications are not uber velocity sensitive....and velocity brings diminishing returns (may even degrade precision) - as you will have to dial in anyhow,and most shooting is not pushing the limits of the cartridge (because hit % just drops...)...Competitive target shooters are maybe on slightly better grounds by looking for an equal precision,with more velocity (slightly less drift-as wind error is reduced-so accuracy is improved -but it's unlikely to be great,and has costs.)

One alternative take is more aimed at normal field shooters (or informal gongs) at distances within the cartridges comfort envelope (that's often 300y for small vermin, even less for fox....and at much longer range-moa fractions are not the key to success (as above).

If wanting to shoot really effectively at real distance,get a cartridge that is more suitable-or accept velocity that is near max,not way above it-wearing out the barrel.Somewher near sane saami max velocity will also be 'adequate' in terminal performance,another few fps won't make it any better....if it does,a better cartridge is indicated.

 

Very,very few rifles can shoot sub .2 consistently 'even' at 100y...BUT it is nice to see one that can!

 

 

"if they are all going through the same hole,pretty fast,who cares about more velocity?"

 

If this is heresy to some,try putting the argued case for more velocity (subject to above uses)

 

"More is less" Mies van der Rohe (admitedly, a revolution in architectural design,not shooting) :-)

 

gbal

[lapua]

Just use 38gn varget, job done!

[Chris-NZ]

Pretty much what I've found too

[Swarovski1]

I've shot alot of small holed groups.apart from one flier that's benchrest standard.one off line shot out of 15 shots is really great shooting.probaly better than 5 consecutive groups I've shot in the past.maybe you could give me some lessons

[Swarovski1]

Just use 38gn varget, job done!

I happen to have some varget.what jump on this load.

[Swarovski1]

OCW.....?

[Swarovski1]

This was the last group I shot.i bought new trigger from bradders.scope came off.once put back on first 2 shots cut and were 3/4 left 1/2 low.adjusted and shot this 3 shot group.140gr amaxs over 39grs of rs60