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About Laurie

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  • Birthday 10/05/1949

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    F-Class, BR, and any form of target shooting that involves a scoped rifle, but doesn't require shooting offhand

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  1. Ha! Ha! I always said our Leslie is a jammy Geordie b*gg*r!
  2. Laurie

    Starting loads...useless?

    There are starting loads and starting loads depending on the source. A generation ago, Hodgdon only gave maximum charges with the instruction to subtract 6% to get a starting load, an exception being H110 where only 3% should be deducted. Over many years, I've concluded Hodgdon got that pretty well right so a 46gn maximum 308 Win load should start around 43.2gn and a 24.5gn 223 max would be ~23.0gn. This approach was apparently too technically demanding for some customers and/or the lawyers didn't like it, so Hodgdon now quotes staring loads in grains like everbody else. Taking some of its 168gn 308 Win loads at random its current starting loads run from 5 to 9% below the stated maximum depe3nding on the powder grade. Look at Hornady's manuals though and you get a very different approach. The lowest loads quoted are much more than a 10% reduction. Its 7th edition (sticking with 308 and 168gn bullets) lists H. Varget from 32.6gn to 44.0gn - a difference of around 23% which I find ludicrous. Apart from taking forever and wasting a lot of barrel life in working a load up by 11.4gn, the lowest charges will be grossly inefficient and most likely inconsistent as they are running at well below the powder's 'happy' pressure band. Other manufacturers / sources quote ranges anything in between these extremes. The original Hodgdon advice remains pretty valid. Unless the bullet or powder manufacturer says otherwise in relation to a particular cartridge-powder combination, something in the 6-10% band below maximum is usually a suitable reduction. There are exceptions either because the powder is very low-pressure intolerant and/or it is a high volume case design as in many over bore capacity magnums being loaded with very slow burning propellants. In such cases the quoted starting charge is also the minimum charge and must not be reduced further. Doing so risks very inconsistent results and in extreme cases a dangerous one that sees charge detonation instead of burn and pressures that will destroy the firearm. Sierra Bullets whose people know more about safe load development than most say that charges should be worked up in step sizes that are c.1% of the quoted maximum, so 0.4-0.5gn for max loads of say 46-49gn, 0.2-0.3gn for 223 Rem size charges. On approaching maximum loads, reduce that further to say 0.2-0.3gn for 308 Win size charges, 0.2gn for 223 size. On precision, traditionally it was said that maximum loads / pressures rarely or never gave the best groups and this has become a handloading 'rule'. This was largely down to the poor quality of most mass manufactured rifles after WW2 where locking lugs didn't bear evenly on the receiver, or in many twin lug Mauser type actions, one lug didn't touch the receiver at all until pressures approached maximum, then it would touch randomly producing fliers. This condition shouldn't apply to modern factory rifles hopefully and certainly not at all to custom stuff built on small production volume actions. Often such rifles group very well indeed somewhere near maximum loads and MV extreme spreads are generally smaller with higher charges. However, any individual rifle's best precision occurs in a series of charge / pressure / MV 'nodes' or bands as charge weights rise, usually 1-1.5gn apart in a 308 size cartridge / charge weight. So a starting load may or may not be right on a 'node' and could give superb groups. As charges rise, groups open up until the next node appears. Often the very highest allowable charges / pressures fall between nodes, so a lower charge weight gives best results. That's what on-range load development is about / for - ie finding precision and small MV spreads at an optimum velocity for the firearm and the application. As One on Top of Two says, the reason for quoting starting charges and working loads up from them is primarily about safety as individual barrels / chambers and cartridge component choice other than the powder can see considerable pressure and hence usable / safe maximum charge variation between individual rifles. Only a fool starts with the maximum - but there are fools out there sadly.
  3. There are two factors / ways forward here. One is that you actually need very little shank seated in the neck for single-loading range shooting. I've many times used less than a half-calibre seating depth and got good results. However, for a semi-auto/straight-pull with pretty violent bolt pick-up and feed or a tactical / sporting bolt-action set-up in magazine use and rapid bolt operation, I'd prefer a full calibre depth of seating. With barely seated bullets transport, handle and chamber the ammunition with care to keep the bullet concentric. If this is acceptable, a mere tenth of an inch shank held in the neck is adequate for 30-calibre. Second is the bullet design and how jump tolerant that makes it. The 155.5gn Berger is a very jump tolerant design indeed and if you simply seat it at 2.800" COAL or (if appropriate) whatever COAL the magazine will handle and still feed reliably, the odds are that you will see good results despite horrendous amounts of jump. With any given charge weight, you do lose a bit of MV though. Partially related to this, I've just started load development of 260 Rem in a rebarreled (opriginally 308 Win) FN SPR with a lot of freebore designed to see 140gn VLDs seated optimally. One bullet I'll try is the Berger 6.5mm 130gn AR-Hybrid designed for AR-10 type rifles (or AR-15s in 6.5 Grendel) and which allegedly is very jump tolerant in long-throated (or worn barrel) versions of same. The COAL at around 20 thou' off the lands is 2.927" in this 260 Rem chamber in newly cut form. The rifle's magazine won't hold/feed rounds at the 308's 2.800" COAL, max being something in the high 2.7s (bit remiss for a police / LEA repeating rifle I'd have thought, although the original US FBI spec was for use with Federal 168gn GMM which is under 2.8"). I'll work a load up for the full 2.927" COAL to see what it's capable of then try it again at whatever the magazine accepts and see what that does to groups, MVs and spreads. That'll be around 160 thou' jump - a good test for Berger's claims for this rather (!!) pricey model. As I normally single-feed rounds in this rifle, COAL and magazine OAL mismatches aren't normally an issue for me.
  4. If you're getting 2,700 fps with the 175 SMK and good groups, that really is an excellent factory load. Handloading will allow improvements, but not the large step change often associated with an upgrade from off the shelf ammo. Everything I hear about GGG suggests they produce good stuff - a far remove from RG 155gn 'Bisley Match'!
  5. Laurie

    1 in 12 twist .223 Savage

    The 52gn Hornady match is a good choice for 1:12 twist 223s. The BVSS is an excellent platform too to build an F/TR rifle on should you decide to rebarrel it in the future either in fast-twist 223 or 308 Win (requiring a bolt-head swap - a cheap conversion and 5 minutes work taking the bolt apart and reassembling it). I'd also do a cleaning rod and tight patch check-the-rifling-pitch test on the rifle as it now stands as many BVSSs were supplied with 1:9 twist barrels letting you load 70gn match bullets. Both VarGet and N140 will work with 52s, but are a bit slow burning. (Note too that you'll have trouble getting a replacement supply of VarGet should you like the results as its importation into Europe has been banned since last June, thanks to the EU and its Reach regulations.) In the days when I shot thousands of its AMax predecessor in a 12 twist Remy VS I found that a step faster burning powders, particularly Viht N133, gave me the best results.
  6. Assuming that the 175gn GGG uses the Sierra MK of that weight (as the NRA match 155 does), I'm not too surprised. At modest MVs, the old 175 often gives amazingly good good groups and is very barrel / chamber / velocity tolerant, at least until you try to drive it fast. I shot one of my smallest ever 100 yard 5-shot groups with an IMR-4064 handload with this bullet in 308 Win, moreover in a factory rifle, an early FN SPR tactical / sniper 24-inch barrel job. It was a genuine 0.1-inch and the rifle/handload shot very well at 300 yards too in the benched winter series 'Precision Rifle' matches we used to shoot at Diggle. For short / mid-range use, if you can get factory ammunition with this bullet to perform as well as that, it becomes difficult to justify handloading at times. Unfortunately, the old 175 with its modest 0.243 average G7 BC and the likely modest MVs from the GGG version isn't competitive these days in F/TR at 500/600 (unless shooting in a flat calm) even in club level competition and is ballistically hopeless beyond 800 yards. I quickly found this with my 175 SMK / 4064 handloads, the Catch 22 being that the tight groups came with ballistically sub-optimal low MVs in the 2,600s and the higher MV loads that met the external ballistics requirement wouldn't produce groups under 0.75-MOA. With a good 155 such as the 155.5gn Berger LRBT Fullbore the better long-range bullets up to and including the 185gn Juggernaut, a good F/TR rifle will average under 0.3-MOA at 100. Note the word average as <0.3-MOA means the best individual groups will be under 0.2-inches. My Osprey Rifles (now GS Precision) built Stolle Atlas will still shoot 0.15-Inch groups with the 155.5gn Berger at an MV that has dropped to through throat wear to 3,027 fps (32-inch barrel) despite it having seen nearly 3,000 rounds down the barrel. The average though will be about 0.3. These bullets at suitable velocities will hold under half-MOA elevation at 1,000 yards, most of a 20-round string in quarter-MOA or thereabouts, unless on a range where wind effects also have an elevation component as in Diggle and Blair Atholl when the wind comes from some directions. The heavier 30-cal bullets in the 200/210gn bracket don't usually group quite as tightly or hold as good elevations at long ranges but buck the wind better and so tend to give better L-R scores over a season. Even so, I've seen those 101RC guys who shoot national level F/TR and who generally like and still stick with the old 210gn Berger BT put five shots into ragged holes in loads testing at 100 at Diggle off the bench despite using not at all optimal bipod front-support.
  7. Laurie

    65 creedmoor powders

    That's the sort of SD range I'd expect. I got bit higher but still very reasonable values with Norma large primer brass and the SP Brass will usually give a decent ES/SD reduction. On MVs, bearing in mind that the SP / small flash-hole Lapua brass (which I've no experience of in this cartridge, but do in 308 and 7-08) needs anything between 0.5 and 1.5gn more powder to achieve large primer velocities and there is a report somwehere on UKV in another topic that gives figures from somebody with direct experience that supports that in this cartridge. Given One on Top of Two's SP case MVs are pretty well what you're getting with the more potently primed cases again suggests your recorded MVs are lower than they should be for some reason. Of course, no two rifles even from the same maker produce identical MVs, but even so.
  8. Laurie

    65 creedmoor powders

    Hmmmm .... there's something not right there, especially when accompanied by such good groups. Have you tried this load out to a decent distance, say 600 yards? If it still shoots well at that, it again points to something 'funny' in the reported MVs. The MagnetoSpeed is very good, but I'd do a battery condition check. I'm reliably told the chronograph gives inaccurate / variable results at particular level of battery condition and that's reached long before the battery fails. I don't know what that level is, but in the days when I used these devices I found the battery check pretty quickly showed voltage dropping from 9V to 8.3/8.4V with a new battery where it seemed to stabilise and determined I'd replace it once it dropped below 8.3V. Otherwise, try different primers in the Hornady cases. I got good ES values with the CCI-BR2 in the Creedmoor with RS62 in both Norma and Hornady brass. Lapua brass would be well worth trying, but at 44.3gn, I suspect you'll need to replace the Hornady cases pretty quickly anyway. There is an anomoly there in any event in that 44.3gn is a pretty stout load and you should be getting higher MVs than c.2,710 fps. QuickLOAD predicts ~60,000 psi and 2,830 fps. Even though QL tends to overstimate RS62 performance in the cartridge, that's a large discrepancy. So again, either your measured MVs have a reliability issue or there is a primer performance issue. (A decent firing pin strike on every primer?) Unless your battery was new, I'd try that avenue first, and if no change to the results swap primers - but drop the charge and work up again.
  9. Laurie

    65 creedmoor powders

    Trying different primers may solve it or at least reduce the spread. The CCI-250 is a magnum grade and a fairly 'warm' one at that, not needed for low 40s gn of this powder. Another possible factor is chronograph reliability - many optical models are very sensitive to a change in light level and/or accurate set-up in relation to bullet path so the large ES may not be real. What sort of pattern are you getting in the whatever number of shots in the group? Spread all over or four reasonable and one far outlier? If the latter have a good look at that case. Hornady 6.5 Creedmoor brass was frankly rubbish in its early days. It's reportedly improved since, but 300 cases I bought maybe five years ago when we could first get this brass here were poor. For a start they came in two distinct and very different weight bands with a 0.3gn difference between them in fireformed water capacity, more than enough to affect performance. Also ... and this may just be an issue with your cases ...... they had the worst internal burrs frrom flash-hole punching I've seen in any make of case or cartridge model. Two had large 'twists' of metal still ahead of the flash-hole attached to its side at one end and partially blocking it, one as a near quarter inch long figure 8 and the other a bit shorter as a 6 or 9 shape. Flash-hole deburring of most older makes of US brass (Peterson and other new arrivals are much, much better) is usually the one case-prep step that is virtually guaranteed to make a real-life improvement. Tool cost is modest and it's an easy one-off job.
  10. Laurie

    Velocity plateaus in load testing: Why?

    I just kept working up until I couldn't get any more powder into the case. 'Normal' loads had all the indications of over-light ball powder charges such as huge muzzle flash and poor obturation. I'll stress the barrel in this rifle was an extreme example - I reckon the bullet was getting on for a half inch out of the case-neck before it hit the lands. Despite all logic, it actually shot pretty well for about 18 months, then half way through a 3-distance comp it just stopped performing literally between two shots - would hardly hold the old NRA target's 'black' at 500 yards. (Not that this is extreme. I saw something online last year in The Firearm Blog or somewhere about two milspec M4 or M16 type rifles, one of which had seen 14,000 rounds through it and the other if memory serves 23,000. The barrels had been sectioned and the higher round one was were pretty well smoothbore for three-quarters of its length. I agree on chronographs. Good and reasonably affordable ones are one of the big steps forward. Back then none of us had a clue what our ammo was doing. It wasn't all bad - in the absence of any pressure guides other than case / primer condition and case life, you had to be cautious with your loads on the better safe than sorry principle. (Not that this stopped the few stupidos you get in any activity who took the highest recommended maximum load they could find and used it as a starting load.)
  11. Laurie

    Velocity plateaus in load testing: Why?

    Seating the bullet deeper in rifle cartridges usually has this effect. Intial reductions in COAL may make no change or even a small increase, then a significant MV reduction occurs at a certain point. This used to be mentioned in many loading manuals at one time but has now disappeared. Somewhere I have a manual which memory says is Viht's original edition or an early Lapua one (they only ever did two) where there were results of a test series on a 308 Win cartridge loaded with a lapua manufactured standard 7.62 Nato bullet to roughly 7.62 standard pressures and 2,800 fps MV where the bullets were seated deeper in 10 or 15 thou' steps. When the jump became significant the MV dropped noticeably and stayed at the new level through further COAL reductions. This was quoted as a result of larger jump into the lands gives the bullet 'a run at them' and as it's travelling faster on reaching them gets less of a check and resumes accerating down the barrel quicker than with a short jump. I saw this effect recently in a 284 with Sierra's new 183gn 'Uber-VLD'. Seating it 'in' as one does with VLDs didn't work - vertical stringing even at 100, so I went to steadily increasing jumps, six of them from just out to 40 thou'. The first five COAL reductions saw no change in MV (but an effect on ES), then at 40 'out', MVs dropped and ES reduced. This is the opposite of what most people now believe for two or three reasons. First, in small capacity pistol cartridges such as 9mm emp[oying very fast burning powders with near 100% fill-ratios, COAL reduction does increase pressures, potentially dangerously so loading manuals warn against reduced COALs as general advice; second, some powder types if already compressed, particualrly small grain ball powders can see funny / undesirable ignition/burn effects; three QuickLOAD which has a simple equation here that says reduced COAL = reduced initial combustion chamber volume = higher pressure. What many QL users don't understand is that this is based on the assumption that the COAL used sees the bullet ogive close to the lands and there isn't a COAL - chamber mismatch. In the days when many of us started prone shooting with clapped out first gen 7.62 TR rifles whose barrels had seen many thousands of rounds through them and had massively eroded (but fortunately smooth) throats in the chrome-moly barrels these rifles came with, we soon realised that maximum manual charges were meaningless and MVs were substandard because of the large jumps involved. I bought a Mauser '98 action Schultz & Larsen sometime around 1990 from a guy who'd bought it new in 1968 and had used it regularly since in club and regional competition for 22 seasons on its original barrel. I ended up using the old Lapua 185gn D46 FMJBT seated out with hardly any shank in the neck (still nowhere near the lands) and as much Hodgdon B-LC(2) as I could get in the case which was something like 5gn above book max. It was still a modest pressure load.
  12. Laurie

    Velocity plateaus in load testing: Why?

    Absolutely! A verfy useful modelling tool to compare options and tool to get starting points for load development, but that's as far as it goes. ........ and there are 'issues' with some propellant default values. Actual load developoment and a good chronograph on the range then tells you what works at what charge and MV levels. So far as the issue of plateauing goes, there are two issues as already pointed out in previous posts. One is that charge weight / pressure / MV is not a straight-line curve. Many but not all powders peak in MV terms at a given charge weight and produce minimal MV increases after that. You can find references to this back in early postwar days when handloading really got going and authorities like Jack O' Connor, Warren Page, P O Ackley, George C Nonte Jnr and others mention it. All agreed you are already at a too high a charge level when this happens and charges should be backed off not increased. Excessive pressure signs such as hard bolt lift may occur at this point too. This occurrence seems most common with plain single-based extruded types such as traditional IMR grades. Thne other is the issue of rising charge weights which tend again not to be linear. If going up in 0.5gn steps and a full grain increases MV by 60 fps across batches covering say 3gn, a half grain should see a 30 fps increase, it's common - I'd go further and say normal - to get results like 30, 15, 45, 25, 30 and so on. Where there is a large average change, it's often associated with an equally large change in ES/SD and this distorts the average on what are small samples. (ES values in a series might see values like 10, 35, 15, 8, 17, 25 lacking consistency although many combinations tend to see larger ES values with low-pressure loads and produce a decreasing trend as charges and pressures rise and the powder gets into its most efficient pressure bracket. The top end load that produces hardly any additional velocity often sees an abrupt move to a very large ES, but again no guarantee.) Rerun the series and as said in an earlier post 9 times out of 10 you get a different detailed result although the trend and the overall average change repeats. In terms of charge weight accuracy, my early test load batches are all check-weighed on a lab quality electronic scale and I work with plus or minus 0.04gn variations. When I get to fine-tuning, I'll go to the accuracy of the scale limit of 0.02gn. This is accurate enough to see MV changes in series that are loaded in 0.1gn steps which I occasionaly use although I much prefer cartridges and load combinations that aren't finicky and perform well across a fair size charge weight band - not always an option though! I take Browndog's point about variable (separate) charge artillery and mortar ammunition and the direct charge weight to MV correlation. Sadly, results here aren't entirely applicable to rifle calibre ammunition. As a development engineer who'd been involved in this field once told me, artillery piece and ammunition design is full of predictable results and the vast computing power now available to designers means they do more development in an office than on the range. To use the jargon cause and effect are mostly 'linear' - change factor A by B% and and you get result C multiplied by a constant. As he put it though, smallarms weapons and ammunition are absolutely bedevilled by an interracting mix of linear and non-linear effects that makes prediction very difficult and on-range and pressure barrel validation essential.
  13. ........... as a special order line only. Having shot a variety of the commonly available off the shelf deer rounds some years back in an ex-police Parker-Hale M87, results were so-so at 300 and poor at 500/600 yards. The only half decent performer was some very cheap and elderly SAKO 90gn FMJs in the old 1970s orange and white cartons that York Guns had acquired from somewhere - probably ex-police - and when they were gone, they were gone. (Not just me who has found this. Many years back a northern police force re-equipped with AI rifles at great cost, but unfortunately specified 243 as that had been what they and most other police firearms teams had used with the previous generation of rifles. They were very disappointed indeed with the results and the error of their ways became apparent with a side by side test against a decent but not custom 308 Win rifle on Diggle Ranges. The upshot was that the entire inventory was rebarreled to 308.) 260 Rem and 7mm-08 aren't the obvious solutions they might seem. Loadings available have relatively light expanding bullets as they're mostly seen as light deer cartridges, availability in the UK is dire, and prices for 20-round boxes are frightening if you do find a stockist. Neither has factory match ammo available here and the 260 is very poorly supported nowadays by the ammunition factories, not even Remington doing much at all with it. Unfortunately we don't have the range of specialist suppliers and boutique loaders that the US has such as Prime Ammo and Hunting Shack both of whom do excellent 260 Rem loads at attractive prices including 130 or 142gn match loads. HPS (which makes good stuff) is our only such supplier and will certainly do match rounds for the 260, don't know about 7-08, but to special order. As already noted, 6.5 Creedmoor and 6.5X55 are the obvious sub 30 cal choices where a simple barrel swap is on offer for the SSG3000. Both have good factory ammo available including match bullet loads. Only Lapua manufactures 6.5X47mm and I'm pretty sure prices will be punishing. (HPS availability again too.) However for a limited amount of range use and not beyond 600 yards, whatever's wrong with the existing cartridge - ie 308 Win? It's perfectly adequate for this purpose, is pleasnat to shoot, and there is a lot of good quality and reasonably priced suitable ammunition around including of course the GGG stuff from the NRA Armoury at Bisley.
  14. Laurie

    7mm LRM

    If you're happy with the 7RM's external ballistics, you have various non-belted alternatives. Perhaps the two most obvious and simplest are the American short magnums, viz SAUM and 7WSM (or one of the minor wildcats that F-Class shooters use and are designed to get brass and case-neck benefits such as 7/270 or 7/300WSM). You may not want to go downwards on performance, but the SAUM doesn't lose much over the Rem Magnum. With a 12% smaller capacity case, that equates to a 3% reduction in MV for the same barrel length and PMax, or around 85 fps for a 2,800 fps loading. It's done OK for Paul Hill here and taken a lot of US matches. (In fact, there are many more 284 Wins and improved variants such as the Shehane and KMR taking 1,000 yard US matches than anything else.) http://bulletin.accurateshooter.com/?s=Paul+Hill&submit=Search The 7mm Blaser case has near identical capacity to the RM so is a ballistics swap. Some of the European 'Effers' use this cartridge presumably because reamers and good brass are readily available. The WSM in its various forms has near identical capacity and peformance to the Rem Mag and Blaser and is a known success in this country with lots of experience. (In the US with a combination of big temperature variations and very fast 'string shooting' in F-Class producing serioulsy high barrel temperatures few use the WSM and the SAUM is the natural upper size limit for the sevens. The 300WSM has more than a few adherents though particularly in the Southern states with their windy desert ranges and copes well with the temperature issues as well as giving good barrel life). Moving up to the next case size bracket, the 7mm BooBoo wildcat and 28 Nosler have 10-12% greater capacity. Given that the WSM / Blaser / WSM are pretty heavily over bore capacity for 7mm, this pair are seriously 'over-bore' and the gains from the extra charge size reduce accordingly whilst an already poor barrel life will likely be halved in range use shooting multiple shots.
  15. Laurie

    6.5 creedmoor and RS62 temperatures

    RS60 is Alliant Reloder 17 under another name. American experience says this is one of the most temperature affected powders on the market and many competitive US shooters have dropped it for this reason. It will potentially give very velocities in this cartridge, but if loaded to maximum pressure / MV it will accelarate barrel wear significantly compared to RS62 or other non high-energy grades.

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