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95gr VMAX in 6.5 Creedmoor with Tikka T3x Action and 24in Barrel  

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(@mactavish)
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Joined: 1 year  ago
Posts: 5
29/09/2017 4:21 pm  

Hi,

I've been struggling to get an accurate load with these, and that's after two OCW attempts now (admittedly limited attempts as trying not to waste too many because they're not the rifle's main diet:) Groups have been nowhere near MOA at 100 metres, whereas the rifle is actually capable of 1/4 MOA (achieved after OCW and Seating Adjustments using 140gr Berger Hybrids & 140gr Hornady ELD-Ms (the rifle's main diet).

I use Reload Swiss as I've a good supply and had great results with RS60 & RS62 with bullets between 120 & 140gr, but this little bullet, however, is proving finicky. (I'm now guessing it might be a seating depth &or neck tension &or jump to the lands issue.)

Been using RS52 so far as its properties indicate it's the performance RS option for the lightest 6.5mm bullets in a Creedmoor (backed up by QuickLoad).

Any idea where inherent accuracy nodes might exist with this bullet in 24inch barrels and perhaps also what COALs might help in my search for some consistent accuracy?


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(@fox-tales)
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Joined: 1 year  ago
Posts: 10
29/09/2017 7:33 pm  

Hi mactavish ,
Have you tried RS 62 with the 95 grain vmax.
I'm not a 6.5 shooter but when I was considering a rebarrel in 6mm creedmoor Dominik at RS sent me the wrong imfo by mistake. If you want Ill post it on here it's for 100 grain Amax using RS 60 and RS 62.
I believe general rule of thumb is to start 20 thou' off the lands . Vmax in my 243 seem to like 5 thou'.
Mark


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(@fox-tales)
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01/10/2017 8:25 am  

Imfo posted.


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(@mactavish)
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Posts: 5
03/10/2017 6:09 pm  

Hi Mark, and thanks for the suggestion.

I have considered slowing up to RS60 (or even RS62), but I'm not quite to the point where I'm giving up on the faster capability of RS52 with this bullet. I've just made up 5 at 44gr RS52, as that's the second highest node at which speeds seemed to bunch (around 3200fps) on my initial ladder test. Was going to try them out at 100m today, but it's blowing too much of a gale here to attempt a precise accuracy test. If, as hoped, they group reasonably, I'll carry out the next limited OCW between 43.5 and 44.5 and see where that leads. Really hoping for an accuracy node at or even a little over 3200fps (now I've all but given up on finding something close to where Creedmoor maxes out with this bullet (3350ish)).

As for seating depth, I've made this 5 up with the standard FL Redding die (as opposed to my preferred bushing die) to tighten the neck up to run 8 thou of neck tension for a good solid hold. This is because I've now pushed the COAL out to 2.710... this looks about as far out as looks reasonably practicable, with only about 100 thou of bullet bearing surface in contact with the neck. Believe it or not, this still leaves me 125 thou off the lands and I'm wondering if this big jump will be decisive in establishing whether this bullet will ever work quite as good as I'd like (especially given your 243's "5 thou" VMAX preference.

That, or perhaps I'm just spoilt by shooting so many 140gr match rounds into tiny little groups just lately... 🙂

Anyway, won't be out until the weekend now, but I'll let you know how I get on.

mac


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(@fox-tales)
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Posts: 10
14/12/2017 9:25 pm  

Hi Mac ,
Wondering how you got on with the accuracy testing?


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(@mactavish)
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Posts: 5
15/12/2017 4:50 pm  

Hi Mark,

Only fired one of those five mentioned in last post, before converting them to 2.600 COAL for further testing. Reckoned, all considered, they weren't a great idea (lower velocity & too delicate to store, carry & Mag (and therefore prone to poor concentricity)). After doing some small tests between 2.600 COAL up to 2.650, I found they all seemed to shoot pretty well, but perhaps a little less so towards 2.650 and I've now settled on a 2.625 COAL as a best overall compromise between speed, accuracy and consistency/concentricity. Leaves me in no doubt now that of all variables, they prefer plenty bearing surface in the neck.

So... given size, shape and now with a jump of 210 thou, these were never going to win FTR comps, but I now have them rugged, consistent, going 3400 fps (with no hint of pressure) and they're now consistently around MOA. So development's done, I'm happy, and I've made up a hundred... the odd rabbit out to 300m is more than good enough 🙂

Cheers,
mac


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(@mactavish)
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Joined: 1 year  ago
Posts: 5
16/12/2017 12:45 am  

Just realised, Mark, I hadn't mentioned all the details of that final load, so here goes...

Lapua (SR Primer)
(Bump sized 2 thou)
Murom SR Primers
45.0gr RS52
COAL: 2.625
Jump to Lands: 0.215
Neck tension: 0.002
3400fps (ES=22)
Around 1 MOA at 100m (give or take a smidge.)

= Happy 🙂

Cheers.


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(@fox-tales)
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20/12/2017 5:39 pm  

That's really flying , velocity wise .Just shows how efficient the Creedmoor case is, if you managed to push 95 grain sst to 3100 from a 243wsm , you'd be doing well.
A little tweak that might just help is a barrel damper . And yes they do work. I tried one just because I could . Richard Utting at Sharpshootinguk on youtube does an interesting review.
By the way stop showing off with your story of rabbits .I've not seen 1 on my permission in months, think they got RHD .
Straight lead to you.
Mark


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(@mactavish)
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Posts: 5
02/01/2018 11:23 am  

Yeh, I've been generally impressed with the Creedmoor's efficiency, though I was somewhat expecting it to be good given the hype of last few years. But I now also think a significant part of the impressive headline figures I'm getting (right from 95gr VMAX with RS52 at 3400fps, through to 147gr ELDM with RS70 at 2820fps (now shooting reliable sub-half MOA)), is down to these excellent Reload Swiss powders coupled with the small rifle primer Lapua brass.

I did see the dampers and thought about one for my 17HMR a wee while back. Never got round to it as it's deadly accurate for rabbits out to the the round's realistic ballistic max at 150M and I didn't really have time to go chasing what might be another vague 17HMR variable. Given a bit more experience of the 6.5CM, I could maybe revisit idea again with regard to the 6.5 95gr VMAX. Perhaps it might particularly lend itself to increasing consistency in that particular application.

Anyway, yeh, "the odd rabbit out to 300m" kinda tells we've a similar situation with rabbit populations in our neck of woods too (NE Scotland). Been mostly leaving what few alone this year. Let's hope the spring sees a return to healthier populations... 🙂

Cheers.


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(@fox-tales)
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Posts: 10
15/01/2018 8:55 pm  

Hi Mactavish ,
The rabbit thing is a little spooky, out lamping foxes 2 nights ago and not a single coney . I suspect rabbit VHD , may be part ofthe reasonfor the low fox count this year . Who knows?
Odd you mentioned the HMR , allegedly theres been a change of some sort in the manufacturing . I put some of a new batch over the chronograph and was getting a very healthy 2640fps , still awful ES .
Sorry for going off topic.
I raised a question regarding neck turning on another forum to improve neck tension consistency. Again off topic.
I'm not looking to reduce the neck, more even it out also looking at neck tension using a mandrel instead of a bushing die. I found after firing some of the necks were tighter than others . When I've some results I'll post them .
Regards


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