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Laurie

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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. Laurie

    Neck size, or full length: has the jury decided?

    As VarmLR says a couple of posts back, neck tension and 'headspace' consistency are the key items. I'd add working the brass as little as possible. Many people will tell you that 'headspace' is a technical term relating to the firearm chamber dimensions alone. Whilst certainly true for a gunsmith chambering a barrel or checking a firearm with gauges, in the wider sense and as I undertand VarmLR means - and I also do here - we're talking case fit in the chamber, specifically case shoulder position in relation to the matching section of the chamber. (Technically speaking, rimmed and belted designs headspace on the rim or belt at the rear end of the chamber, but sized case shoulder position is important here too for various reasons not least case life. I used neck sizing alone for many years in standard SAAMI sporter and military rifle chambers. The main reason for this was using a Lee Hand Press, not a more powerful bench job, saw the Lee Collet die save a helluva lot of wear & tear on the upper arms, shoulders and chest muscles. It worked fine too. BUT ......! These were invariably mild loads that probably generated not much more than 50,000 psi pressures (for historic military arms, more likely 40,000 psi). As a result, there was very little shoulder movement. Neck size cartridges for a modern rifle using loads that generate pressures equivalent to those in factory catridges (generally ~2,000 psi below SAAMI / CIP MAP celings and you'll soon find NS alone very unsatisfactory. Working up 260 Rem loads the other year, I did a box with the Collet die alone as I might have once done out of interest using once fired - in the same rilfe - cases. Around proved hard to chamber through generating resistance to final bolt closure because the case had become a mild crush fit in the chamber without any shoulder bump. Those that showed any resistance to chambering, invariably proved even harder to eject after firing, the bolt being very tight on upward movement and through obtaining primary extraction - no issue after that point as the tightness in the chamber wasn't through lower case body expansion (as in very high or over-pressure firing), but through turning the bolt against a case jammed into the front of the chamber length-wise. Other giveaways are witness marks on the shoulder and depending on the bolt-face design and protruding features, it scoring circular marks on the case-head. (These are sometimes wrongly diagnosed as an excess pressure sign.) As well as being inherently undesirable, having half your rounds a crush fit, even if initially only slight, and the other half chambering easily without resistance breaks one of the key tenets of precsion loading - consistency. Why don't all cases exhibit the same fit or degree of tightness? Simply because smallarms cartridges generate considerable pressure ranges even when every care is taken in handloading, so shoulder movement varies from case to case on firing. (That's why SAAMI and CIP use Maximum Average Pressure limits.) I've also read that the case fit changes firing pressure produced - don't ask me how, but it's apparently so. The 'tighter' the round in the chamber, the greater the pressure generated on an average basis. Another cause of discrepancy. The ideal situation is 0.001" clearance as based on measuring fired cases, and for every case to have that or something close, ie 0.001-2". This requires shoulder bump on resizing and moreover some canny equipment purchases and press use. Modern presses, brass, and good quality dies with the better case lubes will provide that degree of consistency. A generation or two back, handloaders who started measuring shoulder position after sizing found that getting better than a 5-thou' sized range was really difficult. As well as providing the potential for better results proper shoulder control improves case life and reduces trimming frequency. This applies particularly to those types that don't headspace on the shoulder, rimmed or belted. Because the rifle manufacturer usually puts in much more shoulder area clearance than is acceptable in rimless set-ups, the 'standard' setting on a full-length die in the press, bottoming hard on the shellholder, can really push shoulders back far too much for the chamber's actual dimensions. The case fireforms back to the chamber size and is pushed back again on the next resize - do this a few times and you have an incipient case separation even with mild loads. I used a Hornady 'headspace gauge' (more accurately case gauge) on 7.62X54R cases I was loading for a Nagant M1891/30 sniper rifle I had until a few years ago and found I wasn't 'bumping' shoulders one or two thou',or even a few, but 20 thou' plus with the die on the default setting. Add in the use of a bushing sizer, mandrel expansion, and annealing and brass will last a long time unless the pressures your loads generate expand the case-head and hence primer pockets. You can't do anything about the amount of neck expansion on firing seen in a sloppy factory or military chamber and hence the amount of sizing down needed, but you can often reduce overall brass movement here by getting on for half by abandoning a standard fixed neck diameter / expander ball type die for either a collet or bushing type. (it has become popular in some circles in North America with some cartridges to neck-size with the Lee Collet which really does do a good job especially if tweaked a little then to seperately body-size using a FL bushing sizer without any bushing fitted or a specialist body die that is a FL sizer but which doesn't touch the neck area.) There is a half-way house, that I've tried, really like a lot, but which doesn't seem to have caught on much - the 'bushing-bump' type sizer die. These were available from custom diemakers such as Neil Jone only for a long time, but Forster now makes them for a limited range of cartridges and they're usually available off the shelf at Hannams Reloading. This is a bushing neck-sizer die but which also touches the shoulder area only of the case-body bumping it as in a standard FL sizer according to how it is set in the press. I ran a 308 Win F/TR rifle for some years using this die alone and getting multiple sizings / firings with easy chambering throughout despite using loads that QuickLOAD says are on or marginally above SAAMI peak pressure limits for the cartridge. (In the very strong small primer Lapua 'Palma' case.) So ... going back to the beginning, if your loads are truly mild, the Lee Collet die used alone will usually give excellent results. Otherwise, neck-shoulder bump / FL size every time. If using any form of die that moves the shoulder, fired / resized case measurement and appropriate 'bump control' are very good ideas, essential for the precsion shooter. Likewise, only a fool will NS brass for dangerous game shooting, or for that matter not check that each and every loaded round chambers and extracts easily. The same applies albeit with less risk to life and limb maybe but to avoid injury to pride and wallet for those loading ammunition for expensive stalking holidays or important target competitions, especially those involving rapid fire such as CSR. I'm not so sure about 338 LM as this large and high pressure cartridges has its own 'rules'. I suspect those with experience of it will advise FL sizing every time.
  2. Laurie

    Bullet seating, are we doing it wrong?

    I see what Fox Tales is getting at, and it's inherently correct - but the claimed effect is exaggerated. 10 thou' difference in case-head to shoulder datum points between new brass and fireformed then properly resized fired cases is huge, at least in modern rimless commercial cartridges and firearms. (Early 20th century rimmed military designs such as 303 and 7.62X54R as werll as belted magnums deliberately ran with large amounts of case to chamber clearance at the shoulder, but they don't headspace on this point.) 10 thou' clearance is in effect 'excess headspace'. it means the first fireforming use risks thinning the case walls just above the web. Oddly enough, I've just seen something similar with new brass for a particular cartridge desdigned mainly for use in AR type rifles and it caused me some vexation and head scratching when shot in a turnbolt rifle until I twigged what was going on during fireforming. The difference between a good quality new case and one fired / resized in a decent chamber is much smaller usually, under 5 thou' and often at around 3. Of course, the modified case used in the OAL gauge tool might produce such a variation. This tool is a boon, but it's nothing like as precise as many believe - hence the very sound advice that unless very precise measuring methods are employed, jump shouldn't be set at 5 thou' or less and 10 is a lot better. This avoids the possibility of an over-measurement producing a COAL that is right on the lands but only just - not in itself necessarily undesirable, but what is to be avoided is the situation where small variances in bullet ogive positions may see one round with its bullet a thou' or two 'in' and the next a similar amount 'out', a set-up that usually produces fliers.
  3. We'd better not tell them then. A bit of the Nelson blind eye touch maybe. Serious point though - it'll leave many 303 shooting MoD range users wondering if they can take their pieces of British and British Empire history to an MoD range. When people make 'technical' regulations, sometimes common sense is allowed to be applied to their interpretation, but that can't be taken for granted.
  4. A bit hard on 7.92 Mauser shooters in historic arms rifles. Does it affect 303 too (it is a larger calibre even if only just than 7.62/308)? If so the MoD has banned the cartridge most of its ranges were built for and its own regular and reserve troops used for 70 years, the cadets a few more years longer.
  5. The basic Russian Murom LR primer works very well in the 284 Bruce - that's the KVB-7. I've also used the so-called Magnum version of this model successfully in 284 and Shehane, the KVB-7M. The 7 and even the 7M are very 'mild' models and that's generally what works best in this cartridge even with charge weights in the mid to high 50s grains. Before anything else though, try the CCI-BR2s you have. This is a mild and very consistent model. Avoid the Rem 9 1/2 and 9 1/2M, both very 'hot', also the Federal 215 LR magnum and its 215M 'match' version. Exceptionally 'hot' and in a cartridge the size of the 284 tend to produce large MV spreads. (Might suit a mid winter 600 fixture with temps at minus 10 though! ) I'm assuming you're using a realtively easy to ignite powder such as Viht N165 or the now lost H4831'shortcut'.
  6. Laurie

    6.5 creedmoor and RS62 temperatures

    Yes, I have Hunter and have used it in a few things over the last few years. It'll be one of those tried in the 260. It flows too well for the RCBS Chargemaster even with David, Shooting Shed, Bonwick's thingie used, so it (and other Ramshots) sees my old Hornady 'Competition' volumetric measure recalled to use. In this tool, the Ramshot grades produce remarkably consistent weights.
  7. Laurie

    6.5 creedmoor and RS62 temperatures

    I agree RS52 is very different to N550, but VarmLR says he was using RS62, very similar burn rate to the 4350s, N150/550, and N204 but single-based of course. It's interesting (and encouraging) that you find N204 so close to H4350. I intend to do some comparative tests in 260 Rem next winter looking for alternatives to IMR and Hodgdon H4350. RS62, Norma N204 and URP, Viht N550, Alliant Re16, and Lovex SO65 look the most likely possibilities. In the US, Re16 is being quoted as a very close match to H4350, very temperature tolerant - allegedly as good as the best of the Hodgdon / ADI 'Extreme' grades, and giving somewhat higher MVs than H4350 in suitable cartridges. It is of course double-based like all Alliant and Norma powders and I haven't seen a % value anywhere as yet, so may be hard on barrels if loaded up fully. Like the Norma grades, Re16 is manufactured by Bofors in Sweden, but has Bofors / Alliant's new 'TZ' treatment technology to reduce temperature change effects. It is finally available here and I've bought a couple of pounds to try. Norma powders have always had a reputation for being very temperature affected. I certainly found that with Alliant Re15 (same thing as Norma 203-B) in 223 some years ago even in our climate. Whether the newer grades such as URP are better I don't know, likewise whether Bofors / Norma are respecifying existing grades or improvements are restricted to the new ones only available under the Alliant brand name with 'TZ' (Re16 and 23 so far). Even if they've not said so, most propellant manufacturers are looking to reduce the temperature sensitivity of their ranges. Vihtavuori is allegedly in the process of doing so for all of its rifle powders whether N100 or 500 series. So far the only one they're admitting to is the new N565, but rumours say other older grades have been 'done' too. The company is keeping very tight on this and will only announce it if and when the entire range has been modified. Whether any such change affects other characteristics is an interesting (and important) question given that Viht has a reputation for lot to lot consistency so no need until now to check if a new lot needs any load adjustment. Returning to N204 it is one of the lower nitroglycerin content Norma grades at 4.5% by weight, so should give a small performance boost but without significant extra wear and tear. The new(ish) URP is one of the three 'hottest' Bofors/Norma grades at 10.5% alongside 217 and slightly less than MRP's 11.5%. URP is stated by Norma to be slightly faster burning than 204, and its applications are similar looking at Norma's No.2 manual published last year. In some applications, it gives little or no MV increase over 204 at Norma's listed maximum loads; in others, MV is significantly higher. Lovex SO70 (being the old Accurate-4350) would seem the most likely 4350 alternative from that source, but was always known to be the slowest burning of the 4350 trio. I've never found it as satisfactory as the IMR and H versions perhaps partly for this reason. SO65 though looks interesting. Explosia's burn rate chart shows it on the same horizontal line as H. VarGet which is clearly nonsence. It makes a very poor VarGet replacement in cartridges like 308 Win and superficial digging in Explosia's Lovex loads data tables shows it's much more at home in higher case capacity to bore ratio cartridges like 7X64 and 7X57mm. I've used it for some time in a long-throat 7mm-08 F-Open rifle with very good results indeed with the 150gn Lapua Scenar-L as a short-distance load. I note with some interest that Shooters World in the US which is now distributing Lovex powders under US-orientated SW brand names (SO65 becomes 'SW Long Rifle' for instance) raves about it for use in the 6.5mm Creedmoor .... https://shootersworldpowder.com/long-rifle/ .......... the classic H4350 application. One problem is that Explosia's own loads data omits many cartridges people here might want to try it in, 260 Rem and 6.5mm Creedmoor for instance. Shooters World is building up its own pressure-tested data-sets https://shootersworldpowder.com/wp-content/uploads/shooters-world-manual.pdf which fills some gaps. There's a good selection of Creedmoor load combinations.
  8. Laurie

    6.5 creedmoor and RS62 temperatures

    Yes, all Alliant 'Reloder' series rifle powders are 'double-based' Most come from the Bofors, Karlskoga, Sweden plant and a smaller number from Nitrochemie in Switzerland (ie the 'Reload Swiss' people). This goes back to a US government pre-WW1 anti-trust ruling that split the USA's single propellant / explosives combine up. In smallarms propellants, all single-based products and manufacturing facilities went to what later became IMR and all double-based equivalents went a new outfit the Hercules Powder Co. Alliant ATK eventually bought this side of the business and rebranded its products 'Alliant'. There is no legal requirement these days (at least AFAIK) for Alliant grades to be in this form, but the company has stuck with it. Likewise, all Norma powders come from Karlskoga and are also double-based. Norma quotes the nitroglycerin %s and they range from low single figures to barerly into double figures. (Viht N500 series are generally considerably higher.) All of the new IMR 'Enduron' powders are also 'double-based'. There is a tendency it seems for new additions / results of recent R&D to have at least some nitroglycerin in the recipe. I imagine this is partly about performance, but also all the other things that prpopellants are expected to do nowadays from accepting temperature stability to copper fouling reducing additives.
  9. Laurie

    6.5 creedmoor and RS62 temperatures

    I've got a couple of pounds of Alliant Re16, yet to try it - but on paper it looks a good option in this bracket. This is one of the new Swedish (Bofors) made Alliant grades with the company's 'TZ' temperature technology and is claimed to be as good as H4350, possibly better in this respect. As to applications and burning speed, it's very close to H4350 but can usually produce higher MVs if loaded to maximum levels. See: http://bulletin.accurateshooter.com/?s=Alliant+Reloder+16&submit=Search Norma (all of whose powders are made by Bofors) appears with a couple of additions such as URP to be offering an unchanged range from say 20 years ago without any updates, and this seems rather unlikely given the way all propellant manufacturers have ugraded their products in recent years. So, it may be that today's Norma N204 and Alliant Re16 are one and the same thing. (I have some N204 on the way too and will be able to compare their grain structure, density, and performance.) Right now, the reintroduced Norma grades are considerably cheaper in the UK than Alliant powders, worth considering by British forum members. (Re15 and Norma 203-B are one and the same thing for instance.)
  10. Laurie

    Pierced primer! Trip to the gunsmith?

    The original model SR primers were designed for the low-pressure .22 Hornet in the 1930s. Many such rifles had weak firing mechanisms as they were converted rimfires or built on elderly small single-shot Martini or falling-block actions. So primer cups were made of a soft brass alloy and are 0.020" thick to ensure reliable ignition and they were plenty strong enough for 22H pressures and the similar cartridges that followed it like the Bee. When Remington introduced the .222 Rem cartridge with its 52,000 psi peak pressure in 1950, the company decided its model 6 1/2 primer was inadequate for these pressures, so introduced the model 7 1/2 'Magnum' primer for this cartridge. It had the same explosive pellet as the 6 1/2 so the 'magnum' bit was solely the increase in cup thickness from 0.020" to 0.025" and maybe a bit tougher alloy. (It has since been replaced by the 7 1/2BR model originally introduced for the 17 Rem which needed a slightly 'hotter' recipe.) The 'soft' / weak models are: CCI-400 Rem 6 1/2 BR Murom KVB-223 / older copper coloured PMC SR Winchester WSR (0.021" cup thickness) - but only more recent brass colour WSRs, older silver ones were thicker / tougher. Federal 205s and 205Ms are nominally 0.225" thickness. Everything else is 0.025" The thin / weak models shouldn't be used in higher pressure cartridges such as 223 with full loadings. For decades Remington printed this on its 6 1/2 packaging but dropped it in recent years for some reason. So the OP has fired thousands of his loads with a too-weak primer and had no problems no doubt due to a mild load / pressures. Fair enough, but there will be little margin and as another post points out, there can be the occasional faulty or thinner example or production lot. Personally, I know what my choice of primer would be for 223 - always a thicker model - but in this case, I probably wouldn't worry ............ until or if it happens again.
  11. Why are you reading and commenting on a topic in the Forum's Handloading section then?
  12. Laurie

    Best reloading manual

    They can vary a lot - I just saw 3gn difference in a maximum load for a 6.5mm Grendel combination, ands believe me that is a huge amount in this tiny cartridge. In this case, much of that may be that US SAAMI MAP is 50,000 psi and European CIP is around 8,000 psi higher. 5-10% variances between manuals aren't unusual and can depend on make of brass (different internal capacities), primer model, powder lot variances and the test barrel internal dimensions. The components (case + primer) differences can be great enough to make a major change and that's why most manuals say somewhere in the introductory text section that the printed loads apply only to combinations using the specified items. Occasionally, a manual says that the loads apply to that make of case and that only. Speer does that for 243 Win saying that there is an unusually wide spread of case capacities in this cartridge and that its loads are specifically for Winchester brass only and no others. Sierra tends to use Federal cases whenever available for the cartridge and in contrast IME these are usually on the heavy / low capacity side increasing pressures / reducing max loads. Also, of course whether the supplier is super-cautious or wants to impress the manual owner with maximum possible MVs. I like it when pressures are shown as this gives some indication on this issue, also whether as sometimes applies a maximum load is determined by how much powder the case holds with the particular bullet at that COAL not the PMax generated. Then there are 'dodgy' cartridges, usually elderly originally military such as 6.5X55, 7X57mm, 7.5X55mm Swiss etc where the testers / compilers have to decide whether to provide max loadings for modern rifles, for SAAMI which is often lower, or for some yet lower PMax in case the shooter has the oldest, weakest rifle model that the cartridge was ever chambered in.
  13. Laurie

    NRA RCO Handloading Rule

    I'm intrigued by a spot-check on 6.5X47L as it's pretty difficult to get outside of the MoD envelope at least with anything other than light varmint bullets. 6X47 or various other 6mm wildcats could easily be an MV issue though. Everybody 'thinks' HME / ME on this topic, but remember there is an MV ceiling too that in effect rules out 204 Ruger, 22-250 Rem and many SAAMI / CIP sixes with anything less than the heavier match bullets in fast-twist barrels. https://nra.org.uk/nra-bisley/ranges/latest-range-information/range-regulations/ 1,000 m/s = 3,280 fps
  14. Laurie

    New 223 lapua brass

    Foxpig has got it right. You do need to chamfer the inside case-mouth edges as with any new case to ease bullet seating. IME, new Lapua brass has very consistent OALS, so I never bother with trimming. Neck tension out of the box is usually very tight indeed with this make irrespective of cartridge, too tight in fact, so inside lube the necks and run them over either a mandrel expander or the expander ball in your sizer die if using a conventional FL die set. Some people FL size and if you're using that die's expander for the previous step, you might as well size at the same time. Again, IME Lapua cases of all calibres usually arrive in pristine condition, so IMO FL sizing isn't required. If there are some 'dinged' necks, size them - although if the ding is big, better to carefully open it up manually beforehand with the bullet in a same calibre inert round or dowelling. Foregt flash-holes, primer pockets, necks, weight and all the case-prep tips unless you're loading for a custom rifle. Some of these practices may be useful / ncessary with other makes but not Lapua's 223 Rem cases - you've paid for Lapua to get it right in the factory and no rectification is needed. Oh, and do inspect cases closely. Lapua is good, but the very occasional shoulder or neck flaw escapes factory inspection - a slight longitudinal fold is the most likely. Better to junk that case now before doing the other steps or worse only noticing it on final inspection after priming, charging, bullet seating etc.
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