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VarmLR

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About VarmLR

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    http://www.referencefidelitycomponents.co.uk

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    Gloucester
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  1. VarmLR

    65 creedmoor powders

    In my Tic-Tac (as above), this is the average taken over several reloading batches: RS 62; Scenar 139 loaded 20 thou off lands; Murom KVB-223 Magnum primers; 44g RS62, Lapua SRP Brass; MV average = 2705fps; SD = 11; ES = 15 (Best was SD5; ES9: Worst was SD16; ES 30) Group average (still day 100yds): 0.3 moa Group (best) = 0.18moa Group (worst) = 0.68 moa Group best (600m) = 0.75moa Group best (900m) = 1.1 moa Haven't tried different primers but have some CCI 250s to play with. May switch to LRP Brass as loads are more economical and folk seem to be getting equivalent ES/SD with large rifle brass loads.
  2. VarmLR

    N140 vs N150 in creedmoor

    I had much the same results using RS62/140 SSTs. A good node from a 24 inch barrel was 2620fps. Haven't tried higher with that load as it's accurate and adequate for deer.
  3. VarmLR

    Velocity plateaus in load testing: Why?

    I think that he is just describing matching barrel time, except for one thing....isn't it possible to achieve similar MV's with slight variations on barrel time due to differences in pressure curve, and distance from the lands? I only know that switching powders with my .223 that I've had similar results with the same bullet and different powder so an element of that holds water. As Mark says though, this may not hold true with all bullets. Some respond better with reduced jump to the lands as they are less jump tolerant than others. I have only had success with Satterlee with jump tolerant bullets as I rarely load close to the lands. I think that the debate is healthy, as it's provoking thought into different areas of internal ballistics that we perhaps rarely discuss in detail.
  4. VarmLR

    Velocity plateaus in load testing: Why?

    I've tried Satterlee and OCW. Whilst I could achieve repeatable results using OCW, Satterlee was something of a challenge, but I finally got there (in .223 at least). To be fair to Scott Satterlee, he explains that in order to stand a snowball's chance, you need to be meticulous about brass prep, bullet and charge consistency otherwise it can be a waste of time and money. Brass should ideally be batched by volume and neck tension uniformed between cases. Bullets should be batched by mass and base to ogive measurement. Powder charge ought to be as consistently tight on tolerance as you can get it. His explanation is that unlike OCW, Satterlee concentrates on optimal bullet velocity (not charge weight, as powders will vary batch to batch) because the results are pressure dependant. Using different powders, he has achieved the same results with the same bullet provided the results are matched in velocity. In other words, even using different powders, once a node velocity is found, loading to the middle often results in tiny groups and low ES/SD. I have done this with 69TMK and 60 Vmax bullets using batched, annealed brass, and after loading have use a lee crimp die to try and uniform neck tension. For my 60vmax bullets, this resulted in an ES over 5 shots of zero at my first attempt once I'd picked the middle load. I repeated that test at that velocity (3150fps) many times now and average ES is within single figures. The 69TMK bullets showed three different velocity plateaus, the attached graphical representation is shown below for 12 different loads. I have repeated this with very similar results on velocity. Using OCW I coincidentally got a load which corresponded to load ref 6 (24.6gr RS50), so it agreed with the Satterlee results. I don't claim to fully understand why powders have these pressure insensitive regions but earlier mention of coatings behaviour may well be something to do with it. I have not had much luck replicating Satterlee results though in 6.5 CM to date. I don't know why but it's most likely something I'm not taking enough care on in the brass prep stage. The Satterlee method spat out a load which I then tried at 600m and it wasn't that good. SD for that load was quite high, as was ES so my own findings confirm that whilst there's something in the Satterlee method, test groups of the so-called central pressure insensitive load should be shot using statistically reliable 5 or 7 shot groups and repeated to determine ES. If it's unreliable, then it's back to square one. That's why I prefer to use OCW and determine the lowest ES node. Once that's found, then in spite of powder batch variations, I know that all I need do is find a load with the new powder batch that matches the velocity of the old batch and I have my node. That has been a very reliable method and here, I concur with Satterlee as he's had much success replicating the same MVs across various powders for the same bullet. It takes longer to do but at least results on paper can be corroborated between batches and the velocity is there or thereabouts each time.
  5. VarmLR

    quality mincer

    Mine seems to work perfectly. It only clogs if lots of gristle is forced through it.
  6. VarmLR

    Seating depth for .223 80gr Sierra MK?

    Michal, What load of RS52 are you using? I've had very good results with the 70gr TMKs in 1:8 .223 barrel using RS50 The smk is very jump tolerant so I suspect something else is amiss. Have you access to a chrony as this can help a lot with load dev?
  7. LoL...absolutely! It's just coming back into biking season here (at least for me) but the heated grips keep the hands nice and warm on chillier mornings. Have Spain in my sights for a tour later in the year and perhaps the West coast of Scotland. Should be lots of shooting too... Sounds like you got a load almost dialled in first attempt....LRP Brass and between 42 and 43gr H4350 at a rough guess perhaps?
  8. I did try the factory brake and it's ok but I don't have much to compare it with tbh. I guess if you didn't get on with it, it's only a one minute job to swap a mod back in, granted POI will shift between them. I've had that Zen moment more than a few times, once during a comp and swore silently, almost biting my tongue when I "missed the moment!" Weather here is picking up, enough that I actually went out and put a few miles up on the GSA today after shodding it with fresh boots!
  9. VarmLR

    Long range scope options.

    S&B PMII 5-25 is what I've been using for LR alongside a Nightforce and Bushnell DMR. All are good, the S&B is edge to edge sharp and with the fine PL4 ret, is very capable at 1300yds. I looked at the higher mag ones but factoring in mirage and keeping the sight picture steady just didn't see the need for higher mags although I can well understand why bench-rest shooters might.
  10. Congrats on your purchase Andrew. Hope you get on with the tic-tac. Must admit, I took to mine straight away. The only thing (in 6.5CM) that is sometimes irksome is the feed cycle isn't always reliable if done without slow deliberation such that the bolt comes back fully. The number of times I've squeezed the trigger on an empty chamber thinking I've cycled a round is embarrassing. Probably more my problem than the rifles, but never had this with my T3 Varmint (in .308). I tried several mods with mine when I discovered the issue. Some went on without a problem, some were pulled off axis. The ones that went on ok all had a slight distance between the mod face and the start of the thread (ie slight overbore up to the thread) hence they squared up fine.
  11. Mine wasn't threaded to the shoulder though Bradders...it ended a few mm short. Needed to extend the thread and undercut properly. None of my other rifles have this issue but yes, I appreciate that it's not only Tikka that have done this, it's others as well. At least they've recognised that for mod users, it needed addressing. It is an issue with some mods depending on how their threads are cut. Many don't have any relief or undercut of their bushings. It's then that a problem occurs as obviously, the mod can be pulled off axis at the end by enough to cause a bullet strike.
  12. Using a Sinclair F-Class front bipod and no back rest for me, as I wanted to replicate loads fired in the field. Fired about 600 rounds from this barrel and it's settled in nicely but my SD/ES has started opening up from where it was with earlier loads, so need now to re-establish an accuracy node. Reasons may be lands going back a little or powder/primer batch variation, but whatever they are, my SD is now around 15 and ES has opened up considerably to close on 30, or double what they were for the same load. Brass batch is now 5 fired but careful attention to prep observed and FL sized every time.
  13. VarmLR

    Schmidt & Bender turret markings

    2cm per click = 10cm/100m with 5 clicks so 2 = 200m at 0.4Mrads = 8cm or 3.1 inches and 3 = 300m = 1.1Mrads. That's smack on for my 139 CM load at 2700fps or .308 using 155 smks at about 2850fps. It's starting to get a bit loopy by 400m with what looks to be about 2.4Mrad drop so this isn't some flat shooting load. It dials more like a 168 or 175gr .308 load but could be any number of alternatives.
  14. That's odd because he managed to do my 26" .223 barrel! I think that the barrel was fitted back through the headstock as Bradders suggests.
  15. I think that the issues are now resolved with newer rifles Andrew. Early production runs had a few mm of the threaded area next to the shoulder left uncut which was the problem. Newer ones now appear to be undercut by all reports. Why they ever released the Tac without the thread being properly cut in the first pace beats me, as it was always going to be a potential cause of problems for mod users.
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