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Ive been researching about how short you can go with a 6.5x55 barrel without dramatically effecting ballistics.
All the talk seems to be about how the .308 is probably the most efficient in shorter barrels ,and the results in a few of the other popular calibers , but Ive struggled to find out much about the Swede .
Does anyone know or have a link to info on shortening the Swedes barrel lenght and the subsequent ballistic effects .
How far is to far ?
Ken
Modelling it in QL, 120gr TTSX, 40.0gr H4895 (AR2206H), 3.150" OAL.
22": 2834fps
21": 2802fps (-32fps)
20": 2767fps (-35fps)
19": 2691fps (-76fps)
18": 2612fps (-79fps)
17": 2528fps (-84fps)
16": 2438fps (-90fps)
Based on that, and that alone (i.e. no real-world testing), I wouldn't go less than 20".
Hard to attempt to answer your question. What would you like to be able to use your 6.5x55 for?
Similar-ish discussion:
https://www.thehighroad.org/index.ph...6-5x55.530170/
Factory loads are generally milder pressure but even so the muzzle energy of the 6.5x55 Swedish is more than twice that of the 5.56x45 along with a better ballistic coefficient. If you hand load there are many options, see this article for starters.
But, "how far is too far"? Answer to that is, <762mm (<30") overall gun length.
In a modern action for hand loads start at 2,950 fps for a 22". Deduct 35fps for each inch loss and I would be quite happy shooting a 120 grn Speer or Ballistic Tip at 2.8K from a 18" barrel at deer out to 300 yards or so.
Use a faster burning powder and you might even recover some of the velocity loss.
+1 mates got a chopped swede shooting 129 LRABs pretty well.Quote:
Originally Posted by Tahr
in a 6.5 cal you don't really want to be trading off speed/energy imo. If you're only bush hunting < 200 yrd then you will be ok, but if you want to stretch out the effective range i would not trade off too much fps
The 6.5 has a very high SD. Using softish bullets at lowish velocities they penetrate like hell and expand well. That trauma makes up for a lot of horse power in my experience, and in any event they don't shed so much energy in flight because of their high BC.
Not withstanding my experience with the 6.5 I shoot a lot of deer with my 7-08, 18" barrel and 120 grn BT. That's at 3000fps. Ive pushed it to 400 yards but don't recommend it. The 6.5 at 2800fps with its higher BC and SD 120 grn I bet will perform the same. I would tote a 18-20" 6.5x55 any day.
In fact my 6.5x55 has a 21.5" barrel and clocks 2830fps with a 140 grn. So 2700 & a 140 out of a 20" wouldn't be out of the ball park. That's deer medicine.
I'm talking modern actions here, not the old mod 96 Mauser.
Thanks for the replies fellas .
I think 19 inch is probably the compromise that I will settle on , not to long but still potential to push a lighter 120gr - 130gr bullet at a respectible speed .
I have mine at 20", and push a 143gr at 2740 fps.
Yeh speed is just that, speed, I think the key is like already stated, what length do you want and pick a projectile that suits. I find 20” is a suitable compromise, that’s what I have.
i had an 18" was allgood
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I know that rifle, was a hammer on deer out to any distance, loaded right, the Swede doesn't overly suffer being short.Quote:
Originally Posted by buzzman
With the great range of powders we have now, the Swede, just simply works.
They should make a Tikka Tac in one.
Same bullet, velocity is at 2754 fps Average. 20 " barrel.Quote:
Originally Posted by chalkeye
I have personally run a 6.5x55 18.5" + DPT can on a Tikka T3 action running the old 140grn AMAX rounds at approx 2675 fps ( I've double checked my data). That particular load absolutely sacked a ton of Reds and plenty of Sika that I shot from 10m to 350m with no doubt it would do fine at longer range.
Don't get caught up with the FPS figure, the 6.5mm round kills deer well with an appropriate shot.
+1Quote:
Originally Posted by Danny
Chronographs give a fair idea but in the end if your ballistic app says one value for a 1km gong, and you try it and hit the dirt in front..... there's your results. 2735fts for a 140gn in a 24" barrel using 2209 is about right imo.