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Muroms for magnums


No i deer

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Another question to the experts.

These muroms seem very popular with the f classers and way cheaper than the BR2's that have become silly moneys as the BR4's.

Will the muroms be better in the magnums or equally be suited for my 284.ive not my BR2's left now and need to decide.

Cheers No I deer

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The KVB-7 is popular with F-Open shooters up to and including some 7WSM users. I use it in the 284 happily with N165 with good results.

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Muroms great  BUT ....... supply-wise seems they are victim of sanctions on Putins Russia?

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  • 2 weeks later...
On ‎21‎/‎01‎/‎2018 at 3:13 PM, Catch-22 said:

What about LARGE magnums (e.g. .338 Lapua / .338 Norma Mag)?

Would the Murom KVB-7 be suitable for igniting 85-95gn of powder?

cheers

I've got a handful of 338LM primed with KVB7's to try on Saturday. Not loaded particularly stout, 93gr of N570 under a 250gr SMK in RUAG brass.

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23 hours ago, Grum87 said:

I've got a handful of 338LM primed with KVB7's to try on Saturday. Not loaded particularly stout, 93gr of N570 under a 250gr SMK in RUAG brass.

Fantastic, I'd be really keen to know the results of your testing.

The Federal GM215m prices are just going bananas, so hopefully the Muroms will be a good alternative.

cheers

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I'll let you know. Really just firing a handful to see how the primer cups look after firing. If they survive, I may well work on a load with them. They are cheaper. Not available locally for me, but I have a couple of thousand, and I've found them to be very, very consistent in the past.

 

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22 hours ago, Catch-22 said:

Yeah, I use the kvb-223m magnums in my 6.5x47 and they reduced my ES to single digits, down from an ES of 50-70 or so I was getting with the CCI250s.

Good luck with the tests.

I get single figures Es's with br4's.

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12 minutes ago, No i deer said:

Accuracy wins accuracy kills ;)

I get that and have a good load at the mo for my 1000 yd duties (sub half moa) but to buck the wind a little better at distance, I was chasing 2800fps over my current 2600fps with 139 Laps without going to silly pressures in my 24 inch 6.5 barrel.  Just wondered if magnum primers were an appropriate solution for a little more gain.

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From what I've read from laurie's posts there maybe a gain from using a magnum primers but that may make your load to hot if your on the edge now.alternatively use a creedmore brass with a small rifle primer or last but not least RS60.

I ran my hunting load of 140gr amaxs on 39grs and 2850fps was easy.i never tried going higher as accuracy was superb.my 6.5x47 has a 27 inch barrel.offhand I can't remember what time of year I chronied them.i wouldn't be surprised is they would run in excess of 2900fps on it. 

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SR brass I use is the Lap SR primer brass and I'm nowhere near max pressures yet but approaching a full case using RS62.  I won't use double base powders.   I'll have a play with KVB Magnum primers and start lower than where I'm currently at and work back up.

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I load the 139gr scenars on 39.8grs of H4350 and when I chronied them it was about 2815fps.them too shot superb out to 1000yds.that was a load that seemed the norm after asking around so I loaded them too that and not looked back.

The RS60 140gr amax load was chronied when temp was 66f and around 67 humidity so on a warm day that amax could touch 2900fps

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I'm getting no-where near that.  I think with  24 inch barrel and small primer brass I'd be happy with 2700 fps which should be doable.  I may try Viht N150 if the RS62 won't achieve those figures.  We'll see what magnum primers bring to the party first though.

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KVB7's are a no go for 338LM, atleast with N570 anyway. Not enough grunt to reliably ignite it. Every round was a click....bang. Primer cups held up fine though.

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Watch out for seating them deep enough for positive ignition.

I came a cropper on first use of Muroms with  what looked like light strikes with a second attempt setting them off.

I seated them with the same 'feel' that I had done for CCIs........the cups on Muroms are .007" shallower than CCIs and need to be seated deeper...so deep that they look too deep!

Might this be your issue?

 

 

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1 minute ago, DaveT said:

Watch out for seating them deep enough for positive ignition.

I came a cropper on first use of Muroms with  what looked like light strikes with a second attempt setting them off.

I seated them with the same 'feel' that I had done for CCIs........the cups on Muroms are .007" shallower than CCIs and need to be seated deeper...so deep that they look too deep!

Might this be your issue?

 

 

Well versed in seating KVB's, definitely not the issue. I seat all my primers deep and hard(fnar fnar). Just not manly enough to ignite 90 odd grains of a slow burning powder in one instantaneous go.

 

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14 minutes ago, Grum87 said:

Well versed in seating KVB's, definitely not the issue. I seat all my primers deep and hard(fnar fnar). Just not manly enough to ignite 90 odd grains of a slow burning powder in one instantaneous go.

 

Ok, that's very helpful to know. Seems I'll stick with the Fed GM215m in my .338NM then.

thanks for experimenting and updating us!

17 minutes ago, DaveT said:

Watch out for seating them deep enough for positive ignition.

I came a cropper on first use of Muroms with  what looked like light strikes with a second attempt setting them off.

I seated them with the same 'feel' that I had done for CCIs........the cups on Muroms are .007" shallower than CCIs and need to be seated deeper...so deep that they look too deep!

Might this be your issue?

 

 

I too had this issue with the KBV223M's - got some light strikes on a few rounds. I fixed this by buying the simply wonderful 21st Century ultra fine hand priming tool, and seating them deeper as you note. No problems since!

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Both the KVB-7 and KVB-7M are very 'mild' examples. If you look at my LR primer tests of three years ago, it is the standard Remington model (#9 1/2) - but surprisingly not the 'magnum' #9 1/2M;  the Federal 215M, and the Winchester WLR that proved really 'hot'. Although the tests were done in 308 Win, anything that can generate  another 10-15 fps MV has to be producing a lot of extra energy

http://www.targetshooter.co.uk/?p=1471

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Laurie at the end of your  excellent article you mention Palma brass and small primers is there a drop off in performance using the small primers with the same amount of powder,as an accurate load using large primers? 

Ive gone over to Palma brass for my 308 FTR rifle but I'm wondering if this was a good move as I've left the load the same as using large primers?

155.5 Berger RS52-47.3g Lapua brass small primers are CCI dr large are Fedral gold match 

 

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