123 Amax jump

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#1 Post by **ovenpaa** » Wed Jul 20, 2016 7:52 am

I am going to try a few Amax 123 in my 6,5x47 - can anyone give me any pointers on what sort of jump I should start with? In the absence of data I was going to try 0.015"-0.020" however I am interested in hearing others experiences.

#2 Post by **Pete** » Wed Jul 20, 2016 9:05 am

I use approx 0.020" in mine with 123 Amax and Scenar. I've found the best way to determine the COL is to strip the bolt, make up an overlong dummy round, and try chambering it, seating the bullet a fraction deeper incrementally until the bolt will close with minimal pressure on the handle.
Then I seat it 20thou deeper and try it again. If it feels like it's a tad easier to close, then I take this COL as the baseline. If not, then go down another 20 and repeat.
When you consider that you're inserting a slightly tapered bullet into a slightly tapered hole, any minute variation (manuf tolerance?) in the bullet profile could easily make 10-20thou difference in COL.
I don't think it's possible to consistently get below +- 10thou as a tolerance in cartridge overall length.

Sorry, I strayed off there...........got a bit carried away.............

Pete

#3 Post by **WelshShooter** » Wed Jul 20, 2016 9:20 am

My Lapua Scenar's like to be loaded 0.005" from the lands. In my recent testing (RE: the thread where I was discussing your comparators) I found that a 0.015" jump worked great for me with Hornady A-max bullets. The grouping was starting to open up when I tried seating them closer to the lands, plus my ES was starting to creep up too. My base-to-ogive with A-max's are 2.110" whereas my Scenar's are 2.120".

The A-max's are travelling around 2,946fps out of a 27" barrel and they group really well (for me really well is <0.3"). I use Reload Swiss RS60 powder.

#4 Post by **ovenpaa** » Wed Jul 20, 2016 1:01 pm

Pete - I have an OAL gauge and fired/tapped case so determining the OAL is OK for me however the way you describe also works well in the absence of such a gauge.

Sounds like I should start around .020" and move forward slowly. I use Varget and tend to keep around the 2940 fps mark, I do have a more accurate load at around 3,000 fps however it is just a little hot for my liking.

I found my Scenars prefer a bit more jump - typically .0125" to .015"

#5 Post by **meles meles** » Wed Jul 20, 2016 9:40 pm

6.5x47 seems to be flavour of the moth: other than being compatibubblewith a short action, what does it offer that 6.5x55 Norsquegian doesn't ?

#6 Post by **ovenpaa** » Thu Jul 21, 2016 6:26 am

It can be easy and cheaper to load for, suits short actions and offers superb accuracy however it is down to personal choice.

I am not sure about the 6,5x47 being the flavour of the month as it has been around for the last 10 years. I would have thought the 6,6 Creedmoor would be the flavour of the month as it seems to be able to change the external ballistics of 6.5 projectiles when compared to the likes of the .260 Rem and the 6,5X47 Lapua.

#7 Post by **Pete** » Thu Jul 21, 2016 6:50 am

The 6.5x47 is better at long range than the 308, but for accuracy, in my experience anyway, the 6BR is streets ahead.
I shoot all 3 of these...............

Pete

#8 Post by **meles meles** » Thu Jul 21, 2016 6:54 am

We thought the x55, x47 and Creedmoor (x50?) were pretty much all similar ballistically ? Do any of them achieve anything a 7-08 doesn't ?

#9 Post by **ovenpaa** » Thu Jul 21, 2016 7:06 am

Pete - The BR is something I have never owned and it is years since I shot one. Maybe one day... :)

Badger, I can only go on personal experience which is I have had better accuracy with the X47 than the X55, same applies to the 6,5-284 however it does have the ability to push heavier bullets quicker than the X47 as does the X55 which does give some advantage over the X47. I usually shoot 123 Scenar bullets in the X47 and usually point them however they are not ideal for vermin so I have just worked my way through a box of 129grn Interlocks with average results. Downside of the 123 grain family is they tend to take a kicking on windy days versus the heavier and often better BC 7mm's.

I have no view on the 7mm-08 as I neither own one nor have shot one.

#10 Post by **Sim G** » Thu Jul 21, 2016 8:21 am

I've been running a 7mm-08 for about 10 years now. Accuracy is brilliant, but it's limited in its range. The better BC bullets come with weight and hence length. Because of weight, velocity cannot be achieved with the '08 to take advantage of the BC.

I may have a year or two left with this barrel. Once it's done, I'm looking to replace it with a 260 Rem barrel.

Nice little article on modern 6.5 comparison.

http://demigodllc.com/articles/6.5-shoo ... dmoor/?p=1

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123 Amax jump

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