Catch-22

Don’t forget Viht N140 and N150.

Ive used N140 in several rifles with 120g and 123g bullets. Always a very easy powder to tune, readily available, very temp stable, clean burning and lowish energy so should be milder on barrels (see post #9 to see a powder energy chart)

https://thefiringline.com/forums/showthread.php?t=545581

N150 is used by a few people for 130g+ bullets.

Couldn't get on with RS52, ES/S.D. all over the place, whereas it was single digits with N140.

2 hours ago, John MH said:

I was using Elcho 17 (RS62 & RL17 equivalent/same), 39.5 grains and a 115 grain DTAC. Might try and get some KVB-223M primers to try but will have to switch to BR4 from now.

Just FYI, RS60 is the same as Elcho 17 & Alliant RL17.

RS62 is a single base powder...not the same.

1 hour ago, Brillo said:

Me and my colleagues in a FTR team use Murom KVB 223 primers and have for a long time we’ve never experienced that problem and between us I estimate 10000 shots.

The magnum  primer isn’t hotter, it simply has a thicker cup. I am reliably informed that this is correct from a main importer who was told this directly by Murom.

Interesting. I know the importer too but don’t know if he’s conducted any primary research into the differences himself?

All I can go on is Laurie’s informative, tireless and generous research. Quoting Target Shooter Magazine;

http://www.targetshooter.co.uk/?p=2662

“...The cardboard ‘outer’ marked with the useful factory product code had been ditched by the retailer unfortunately but I’m pretty sure this is the Murom KVB-223M, a thick cup, tough ‘magnum’ model that is slightly ‘hotter’ than the older KVB-5,56M ‘magnum’.

Murom KVB-223M 2838 fps average MV; 15 fps E.S.; 3.8 fps SD.

An excellent result that betters that of the previous test ‘winner’, the CBC Magtech model. The three groups averaged just over the half-inch, so a good result here too. The test was run exactly as for the others, so the mid-string restart shot was examined and, yet again, (the 10th occurrence) it fell below the rest of the spread – by 4 fps this time. Knocking that reading off and redoing the calculations gives a revised:

2838 fps average MV; 11 fps E.S.; 3.3 fps S.D”

Compare the above to his results to the standard Murom KVB-223;

2,815 fps average MV; 18 fps E.S.; 5 fps S.D.”

So it does appear that KVB-223M is indeed ‘hotter’ than the regular KVB-223, in addition to having a thicker cup.

BUT...my point in this instance is more that the primer makeup itself may not be suitable for this given cartridge (size, dimensions) with the given powder used. I don’t know, it might be the size of kernel, the type of powder used, whether the kernels were compressed or given the shape of the case internals, was there too little (or too much) air space in there to reliably ignite? Dunno...a lot of variables.

I would still suggest trying a different primer, regardless of whether it’s a magnum or not, just a change might fair better with the given powder. Worth a try to see?!?

I shoot a 6.5x47 in my Defiance Mutant XL switch barrel action. 

Admittedly I specified the .308 bolt came with a small firing pin hole & pin, but I don’t think that’s your issue.

I use Murom KVB-223 MAGNUM... not the standard 223 ‘mild’ version. 

The only issue I’ve had was a couple of delayed ignition rounds when I was conducting an OCW with RS52. For some reason, I had a few rounds that went ‘click, pop...wait...BANG’. 

I’ve never had any issues with any other powder, before or since (used N140, VARGET, RS62 in 6.5x47 guise) and (RAMSHOT Magnum, RS80 in .338NM).

I would suggest it is either the primer (not being ‘hot’ enough - I believe Laurie’s testing showed the Murom 223 being both mild and having a thin cup) or its the powder, or that particular primer isn’t best suited to that particular powder, as I think was the case when I tried KVB-223M with RS52.

Weekend bump.

Why not buy a second hand AI?

A few knocking about, mostly AT...same action as the AX...only difference is the chassis/stock. Some even with aftermarket barrels (6.5x47, 6.5 Creed etc). 

Why not buy one and the price difference you’ll save on a new one will allow you to buy a new barrel in whatever calibre you want...for the same price as a new AI in .308. It’ll save you around £900 I reckon! 

AI AX .308 = £4,600

or

AI AT .308 = £3,800

custom barrel = £800

or a second hand AT with .308 barrel = £2,800 

or second hand AT with custom barrel = £3,000ish

AI’s just don’t wear out (action wise), so a second-hand isn’t anything to be worried about.

Some options already up for sale here:

http://ukvarminting.com/topic/44671-accuracy-international-aw-65-x-47-for-sale/

AT in .308:

http://ukvarminting.com/topic/46985-accuracy-international-at-308-for-sale/

Going the route you’re originally thinking is gonna be costly...money that could otherwise go on thousands of bullets, primers and kilos of powder. 

Just a thought.

SOLD!

My father once had an Isuzu Trooper for lugging round work tools. 

I LOVED that thing, never failed to do the job. 

Good luck with the sale!

Terry

N140 has been brilliant for me with 120g and 123g bullets in several rifles, always consistently good and easy to tune.

But I’ve found N140 to be just a tad fast for 130g+ bullets. Velocities will be a bit on the low side whilst pressure rapidly builds. 

 Personally I’d try something slightly slower to maximise the velocity gain whilst keeping pressures lower. I liked RS62 (Accurate loads and low pressure signs) and I’ve head good things about others using N150.

Just my humble experiences & observations of course. 

The above unfortunately doesn’t seem to influence Landmark/MOD’s decision not to permit use of F Range at Sennybridge. 

Fixed firing points (trenches) firing on known , marked and fixed (tanks) and reactive targets out to 1300m. No movement or transition on the range with loaded weapons are permitted.

Shame...it’s a brilliant range to shoot on ☹️

Be mindful of N150 in extreme temps as it can be a little temp sensitive and suddenly spike pressures.

I’ve used Lovex SO70 in a previous rifle (6.5x47, 123g scenars) and simply couldn’t get good velocity, even from a fully compressed case. Accuracy was good but velocity was about 250fps slower than say N140 or Varget. SO70 gave me around 2650fps from a 24” barrel. I never tried it with heavier bullets (140g+). Doing so might produce better velocity. But I suspect SO70 has a very low energy rating, possibly around 3500kj. 

1 hour ago, Laurie said:

 

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.

Interesting Laurie.

The thing that got me scratching my head was the fact that Alliant seem to use the AR Comp data sheet also for Rel 15, 16, 19, 22, 23 and 25.

Either the makeup of the powders is the same (which I can’t believe is true...surely some powders will have different % of Nitroglycerin) or Alliant haven’t been bothered to make individual data sheets.

7 hours ago, Chanonry said:

Any links to the mod issue ?

I don’t. Hopefully someone with more knowledge on the matter than I can chime in.

48 minutes ago, terryh said:

C-22,,

without going into too much depth, what was the reasoning re. No civilians (the owners ) being able to shoot on the FF ranges - just a spin off of the 50 cal thing?

T

In all honesty Terry, I don’t know much about it.

Seemingly it’s a UK wide ban, something about the MOD being ‘unable’ to ‘prove’ safe arc’s of fire on FF ranges.

Obviously the MOD must be content with safety for its own military personnel, so why it doesn’t extend to civvies I cannot say?

And why on ranges historically used by the MOD and civvies the arcs are now seemingly different or have somehow suddenly changed (I know F range on sennybridge is the same as it as been for years)  is also unclear. 

It is supposedly only a temporary ban. But the MOD moves at a snails pace, so we shall see. Shame really.

Ok a bit weird. Seems Alliant use the same SDS data sheet (which lists all the specs and ingredients of each powder) for Rel 15, 16, 19, 22, 23 and 25.

Seems they all reference Alliant AR Comp powder.

If this is true and not quite a big content error on their website, then Rel 16 is a double base powder:

https://www.alliantpowder.com/products/powder/reloder16.aspx

https://www.alliantpowder.com/downloads/sds/Reloder_Series_SDS.pdf

Good news - after a very long delay, Offas Dyke Rifle club received a renewed Home Office approval the other day, meaning club shoots are up and running again.

The calendar is starting to fill up with range dates. However Sennybridge ‘F Range’ is still a no-go due to the MOD temporarily banning all civilian clubs from shooting on field firing areas across the UK.

ODRC calendar here: http://www.offasrifleclub.com/index.php/calendar

Price reduced

Quite comparable with SPHUR and just a little more than Tier One mounts.

https://www.optics-trade.eu/uk/era-tac-one-piece-mount-for-s-b-pm-ii-ultra-short-lever-20-moa.html

https://www.eratac.de/en/products/tactical-mounts/

2 hours ago, Popsbengo said:

If you go the one-scope way, QR mounts will inevitably mean checking zero every time you swap over.  If you have a zero-stop scope that will be wrong for one of the rifles.   If that's only occasionally swapped then it's not a big problem so one scope would suffice - but don't underestimate the ball-ache.

Personally, I’d have to disagree with this statement. Given my own experience using an extremely high quality QD mount (Era-Tac) over a number of years, I cannot fault them - nor detect any discernible shift in zero. 

I’ve used this system on multiple rifles now, more recently on the same rifle with multiple barrels. 

I remove the scope+mount every time the gun goes into the cabinet and into its storage case, and I’ve never encountered a problem - even when shooting a big .338NM. No shift and no need to constantly re-check zero before a range session.

Zero between barrels is easy. Simply zero for a given barrel and when using on a new barrel (or rifle) just note the difference between POI and dial accordingly. As long as you remember the right turret ‘zero’ settings for each given barrel (or rifle), and ensure you lock the mount in the same exact slot in the picatinny rail as before, there’s no issue!

Good video from Eric Cortina on the subject of tracking scope zero/settings between multiple barrels/rifles. I use the same principal and even have the differences between barrel / turret calibrations stored in my Kestrel to permit the correct adjustments without me needing to remember the turret calibrations. 😎

I’ve used the Era-Tac one piece QD mount for my S&B PMII 5-25x56 for the last few years and I cannot fault them.

Ive never lost my zero after repeatedly taking it on and off, even when shooting the .338NM barrel. 

The QD leavers are chunky, very well made, easy to manipulate yet can’t be accidentally undone. 

Mag arrived today - many thanks!

To the top ☝️

@woodsie99

ill have the AICS .308 mag please.

Just to confirm, it is a proper AICS pattern Double Stack, Single Feed?

Personally I agree with the above.

.223 will limit your range unless you buy factory ammunition loaded with heavy bullets (eg 77g, 80g +)...but you’ll need a rifle with an appropriate twist (1-8”, 1-7”) to properly accommodate and stabilise the heavy bullets...likely meaning a custom barrel = spendy.

A good off the shelf rifle should suit your needs, one in one of the following calibers will do you well out to 1000m. All these calibres have suitable factory and/or military surplus ammunition available, suitable to get you out to those ranges. In no particular order;

6mmBR, 6.5x55 Swede, 6.5 Creedmoor, .308/7.62 NATO

There are plenty of other suitable calibres out there but the above will be easily available to buy ammunition for. Personally I’d look at a .308w/7.62 NATO for hitting steel with, or entering F class, particularly if on a budget...ammunition will be a bit cheaper compared to the others. 

My 2 pennies worth.

Agree with the above, though you’ll need a medium/long action for the 6.5x55 Swede as it’s a fair bit longer than a 6.5x47, 6.5 Creed, .260 etc. 

Though I have owned several 6.5x47 and it’s a lovely round. Very easy to reload and find a very accurate load for.