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Post by swampdonkey on Jun 11, 2015 12:06:25 GMT
My 260 loves lapua brass br2 primer 140 hybrid Bergers 42.2 gr h4350 COAL 2.877 26" barrel shoots at 2818 fps as above its a hot load so build up. Just got hold of some 140 Hybrid Bergers so beginning load dev for Summer RRC....looking to use these for the extended range as the 123g SMKs that I have been using seem to run out of 'puff' around 1100 yards according to Applied Ballistics.
My 'on lands' head-to-tip COL is 2.956 so WAY too long for the standard AI mag...I can just about get a Head-to-tip COL of 2.885 into the mag and will reduce this to 2.88 to ensure feeding.
Leaves a jump of about 75 thou !!! .....I normally hope to use .020 or preferably way less......hope the Bergers will group worth a light at that (enormous!) degree of jump!!!
Those hybrids don't like a jump, they like to leap !!!! You'll be fine with that Dave, it's the whole idea of the hybrids, to make them tolerant to a jump. |
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Post by tisme on Jun 11, 2015 18:52:38 GMT
The longest I've done them is 2.880 AI mag length and that's a 90 thou jump. They shoot fine
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Post by davet on Jun 11, 2015 19:54:40 GMT
Good to hear re the jump!
I was just a bit taken-aback at the degree of jump when fitting to a mag length..... but should not really be surprised as the elongated VLD nosecone is what provides the high BC !
Anyway I have 50 rounds loaded with N560 running in increments from 44g up to 46g so lets see what it does on the range!
I also have to find out what mag level my 2FP 50x Schmidt has to be set to for the mil hash marks to read true as I am sure that I will need reticle holdover as well as plenty of dialled-in elevation whne we get to 1400-1600 yards.....yum yum!
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Post by davet on Jun 11, 2015 20:01:05 GMT
Oops ...... hybrids but I found the 80vlds worked well in my .223 with 120thou jump. I tried a few at mag length. What are you paying for the hybrids and do you have a reliable supply? Rup
Norman Clarke seems to have a supply....Think they were £45 / 100 but would have to check/confirm.
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Post by oaken on Jun 11, 2015 23:09:37 GMT
I don't do Norm C on principle though that does seem a surprisingly fair price for him.
Rich, can you get them?
Dave. What velocity are you getting with the 123SMK?
46gr n560 seems a lot for 140's
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Post by davet on Jun 12, 2015 8:28:31 GMT
I don't do Norm C on principle though that does seem a surprisingly fair price for him. Rich, can you get them? Dave. What velocity are you getting with the 123SMK? 46gr n560 seems a lot for 140's Hi Rup
I run quite light neck tension .....001" ....and use Lapua brass with CCI Br primers.
I am getting 2904 (Magnetospeed chrono avg) out of a 26" 1:8 Krieger cut-rifled barrel using 41.5g of N550......it will go to 3000 easily and with no pressure signs but accuracy dropped off at higher loads up to 42.8g where I stopped.
Out of a 29" Truflite 1:8 buttoned barrel I get 3000 with a 42g load of N550 and am by no means 'pushing' pressures....I usually settle on a load for accuracy without worrying about MV extremes.
I have shot 139g Scenars with 44.5g of N560 and again see nothing on the pressure front.......I also remember going to 46g during load testing without problems but , once again, accuracy dropped off at higher loads and I backed down to a sensible accuracy node/load.
Despite the N5 powder series rep for burning up barrels it does appear to keep pressures tamed.....I am awaiting delivery of a Lyman borescope (Hawkeyes too eye-wateringly expensive!) to see what state my tubes are in!
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Post by oaken on Jun 13, 2015 18:32:15 GMT
Dave, I tried a few of the 140 bergers today and they shot exceptionally well, comfortably sub 1/2min at 600 with no load development. I loaded them the same as my SMK123s. 43gr N160 and same oal (probably 5-10thou off) Poi was just 1/2 min lower than 123s but very pleasing group. Next thing is to get them over the chrono and see where pressure starts and if there is an accuracy node.
Sticking with the 123s for now though as done the testing and got drop charts on my turrets etc.
Might be up for splitting cost on some bergers in July/Aug. I can't resist working up new loads :-)
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Post by davet on Jun 14, 2015 20:29:49 GMT
Rup
Good to hear ....I hope to start my tests this week.
I too am very happy with 123SMKs out to 1000 yds but feel that the heavier 140g Bergers should do better past that ....tests will tell as will next RRC.
How did you manage to get your Bergers only 10 thou off lands.....single feed?
I normally load much longer than SAAMI / CIP specs and so pressures typically lower but can't do the same with such a long bullet nose as the Berger has and still fit in mags.
I would be happy to go for group buy on Bergers if we can realise a saving...subject to my own tests showing good results.
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Post by oaken on Jun 14, 2015 21:09:06 GMT
Dave, I load the 123smks at 2.940 to give me 12thou jump. The rifle was chambered by McKillop for the 139 Scenar.
One of the reasons that I like the tikka 595 action is that at this length they fit comfortably in the mag :-D but only 5 shots :-(
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Post by davet on Jun 18, 2015 20:41:48 GMT
Load tests done with the 140 Berger hybrids today in a bloody awful mirage and 75 degrees heat....talk about target 'swimming' !!!
Started at 44.0g then up in .3 grain increments up to 46g.
Hell of a jump to lands (.075") even with an OAL of 2.885 which JUST went into an AI magazine but not at all bad results....... .5 moa at 100 yards with 44.5g of N560 and 5 shots touching with 46g of N560....rest of loads were under moa but only just so rejected!
No pressures showing at any load and 46g should be around 2900 (29" barrel) if Quickload predictions are somewhere handy.
Need to load up some more to confirm groupings still good, chrono and get drops for RRC.
Still wish PLOD would let me use my 338LM 'in the field' for RRC extended ranges but no joy yet so pinning hopes on 260!!!
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Post by swampdonkey on Jun 19, 2015 19:12:36 GMT
Still wish PLOD would let me use my 338LM 'in the field' for RRC extended ranges but no joy yet so pinning hopes on 260!!! You made a bad mistake moving away from Wilts, I could if I so desired  |
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Post by c18rch on Jul 1, 2015 11:17:24 GMT
I have called all my suppliers, and no one has any 140 Berger anythings in stock. I have put some on back order, but they are not due until September apparently. My recommendation would be if you see them, buy them all, because we are not guaranteed to get any in the next shipment from Berger either.
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Post by davet on Jul 2, 2015 16:20:54 GMT
Rich
I have tried Foxy where I got my last batch ....all 6.5 Bergers in 140g Hybrid gone!
Can you send me bank details so that I can take the 123g SMKs in 6.5 please ?
Cheers
Dave
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Post by tisme on Jul 2, 2015 20:41:30 GMT
I've been trying to get some as well ended up buying 142 MK. More testing to do now
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Post by davet on Jul 2, 2015 21:26:34 GMT
Can't go on forever load testing!
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