Hobbit Posted September 29, 2018 Report Share Posted September 29, 2018 Hi I am about to work up a load for a new 300WM 30" bartlein that Mik put on my AI AXMC planning to use 225gr ELD-Ms and N165 (gets to where I need it with the 30" tube and not too savage on the barrel) I have Peterson brass that sorted very uniform indeed I was wondering about primers - should I use a magnum primer or not - will be aiming for a stiff if not actually hot load I have a redding competition die set but suspect I will actually use the lee collet die over the neck bushing die or at least do a comparison I understand that magnum primers are more about pressure resistance that any ignition effects - is this correct?? any suggestions on the primer front or any other aspect of this small project thank you Link to comment Share on other sites More sharing options...
duey Posted September 30, 2018 Report Share Posted September 30, 2018 Use magnum primers, there is a large column of powder to ignite not saying none Magnum primers won't work but may not give the consistency of ignition required Link to comment Share on other sites More sharing options...
Hobbit Posted September 30, 2018 Author Report Share Posted September 30, 2018 Duey Thank you - does that mean magnum primers have 'more oomph' and help with ignition rather than just being harder and able to cope with higher pressures without flattening etc?? Link to comment Share on other sites More sharing options...
Incisor Posted September 30, 2018 Report Share Posted September 30, 2018 I used to use magnums with my 300 win mag under 70ish grains of RS70. Been using ‘standard’ LR Muroms for last few years as they gave lower ES than either CCI or Federal magnums and never had one fail or delay in conditions from -20 to +30 degrees C regards Link to comment Share on other sites More sharing options...
duey Posted October 1, 2018 Report Share Posted October 1, 2018 Hobbit to be honest I've never looked into the difference but I believe that there is a bigger bang from the magnum primers, I'm sure that Laurie would be able to give a more definitive answer also I was happy with my load so wasn't going to waste barrel life searching for a little bit extra Link to comment Share on other sites More sharing options...
Andrew Posted October 2, 2018 Report Share Posted October 2, 2018 Non magnum primers.~Andrew Link to comment Share on other sites More sharing options...
Hobbit Posted October 2, 2018 Author Report Share Posted October 2, 2018 Andrew Whilst I applaud you economy of words I would like to clarify your position ? for the avoidance of doubt your are suggesting, like Incisor, that non magnum primers are the way to go?? Duey I completely get it - if it works crack on with the shooting - my barrel was not cheap and it s a lot more finite that a 308 so agree hence my aim to get a solid steer and go with that I have seen a lot of love for the federal 215 magnum primers from the US Cheers Link to comment Share on other sites More sharing options...
Andrew Posted October 3, 2018 Report Share Posted October 3, 2018 Better grouping and lower ES/SD. I once used magnums but a long range shooter friend told me he never uses them so I tried straight Match Primers with excellent results on the chrono and target.~Andrew Link to comment Share on other sites More sharing options...
Laurie Posted October 4, 2018 Report Share Posted October 4, 2018 N165 is a very easily ignited powder grade and even though you'll be running charges around the 70gn mark, it doesn't need a magnum primer for match use. In fact as Andrew and others say, some LRMs will most likely increase groups, ES/SDs. LRMs are routinely specified for cartridges like this in US manuals and sources as their primary use is 'hunting' often in (low) temperature extremes we would never see in the UK, and certainly not in range use. A primer that is perefectly adequate at say a low 5 or 10-deg C, can struggle at minus 20 or 30 and even if the cartridge goes 'bang' OK may see such a large MV reduction that anything other than very short distance shots strike low as well as producing reduced terminal energies and bullet expansion. LR Primers though are a really mixed bunch. My tests have shown some standard LRs (eg Remington 9 1/2) as being 'hotter' than other makes of LRM (eg the Russian KVB-7M that works very well in match use in much smaller cartridges). The Federal 215 and 215M alongside both versions of Remington are the ones to be wary of. I'd try CCI-BR2s and Fed 210Ms, both match jobs if you can find any, plus the Murom KVB-7 / PMC LR. The S&B primer gave very good consistency for me in 308 tests and would likely do so even in this larger cartridge. Ball powders in the 70gn plus charge range may be a different matter as some older types need a more vigorous primer to provide consistency in all temperatures. It's difficult to be prescriptive in this matter as many manufacturers have made great strides in making this type of propellant easier to ignite and cleaner burning in recent years given that their main clients are military ammunition suppliers and the military become ever more demanding on reliability, reduced bore fouling, wanting anti-coppering agents, and most demanding of all temperature stability. P B Clermont's Ramshot powders seem to have few or even none of the traditional ball type downsides other than a narrower efficient chamber pressure band. Conversely, although a recent introduction, I found that Hodgdon's CFE223 simply doesn't ignite properly with the reduced primer power of Lapua 308 SR primed 'Palma' cases. Link to comment Share on other sites More sharing options...
Hobbit Posted October 4, 2018 Author Report Share Posted October 4, 2018 Laurie Very helpful as ever - I'll look up some of the match primers you suggest Thanks Link to comment Share on other sites More sharing options...
Catch-22 Posted October 4, 2018 Report Share Posted October 4, 2018 Sorry to hijack, but what about even larger magnums, like the .300 and .338 Norma Mag, .338 Lapua Mag etc. Would a standard LR match primer do the job or does the additional powder (20+ grains more than a .300wm) necessitate a LR Magnum, like the Fed 215m? thanks Link to comment Share on other sites More sharing options...
gyr Posted October 11, 2018 Report Share Posted October 11, 2018 Laurie is 170 as easily ignited? txs Link to comment Share on other sites More sharing options...
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