Home Forums Hunting & Shooting Ask The Gunwriters Heavy Loads for the 6.5x55mm Swede...

Yes! Keep us updated on that. In my retirement firearm downsizing the last few years I sold both of my all original matching numbers Model 96's and only have the Mod. 96 sporter now. I miss those two stock Mod. 96's already; both are great shooters.

I like it too, I have a 1918 year with an excellent bore, and it is!

I'll report back to you this fall.

While have a VX1 2-7x33mm that is currently on the 9.3x62mm, tend to enjoy this rifle light and aperture sighted.

The M38 that isn't.

Shooting generally < 2.5 MOA with an aperture sighted rifle makes a 350 yd. shot doable, given a solid shooting position.




GR

Not that it won't.

Ballistics - is a fascinating physic.

Slower powder generally means more powder, longer burn, higher velocity, more recoil due to the mass of that powder, and possibly more muzzle blast as well...

... until it is too slow and velocity is lost due to lower pressure a/o lack of adequate Bbl. length.


But less slower powder works.


Double base powder has less mass to begin with, compared to a single base equivilant powder, and would add less per pressure increment as well.

But is burns longer.

And then there is load density and pressure/burn efficiency.


So, absent any mandate, tend to prefer single base powder of the lowest charge weight, that results in > 90% load density, and produces good velocity for a given bullet weight, low std. deviation, and acceptable precision.

Given that, Magnum seems like a better choice for a heavier/higher velocity/longer Bbl. problem.

Why I prefer the 4831 powder over both 4350 and 7828.


But that's just me.

8>)




GR

GA,

Just about any modern rifle powders, designed to work at pressures of 50,000 PSI plus, will burn within a few inches in front of the chamber--even the slowest-burning. This doesn't mean ALL the powder burns--but all that powder that's GOING to burn. Generally a 99.5% is about the best possible.

Once the powder burns, all that's driving the bullet faster is the rapidly expanding gas. This means that no matter the length of the barrel, the powders that result in the highest velocities with a given load will do so regardless of the length of the barrel--whether 16" or 26."

You'll have plenty of strength with the Ruger, i use:

09 DWM custom, 140gr npt's at 2780 with RL-22

NH model 70 custom, 147gr eldm's at 2960 with H-1000

Lapua brass for both.

Thanks.

That 147 gr. ELDM load is smokin'.

That kind of velocity w/ the 143 ELDX would be an outstanding long range hunting load.




GR

The multi-variables in the calculus of cartridge ballistics are considerable.

Case volume/bore area/powder charge/burn rate/bullet mass/bullet friction/etc...

Area under the curve, to me, seems to explain the process in the easiest way.

More, or higher energy powder, creates a bigger gas bubble, which increases pressure for a given case volume.

Enough powder energy and the pressure exceeds max.

The bullet, accelerating down the bore, creates more volume, which, in turn, lowers pressure.

So, an ideal charge would be one that creates a gas bubble, at max pressure, that expands at the same rate as the volume created by the available bore area from the accelerating bullet.


The artificially low max pressure is the interesting variable in the case of the 6.5x55mm.

Compare the .270 Win./140 gr. to the 6.5x55mm/130 gr. (Barnes/TSX), or .270 Win./150 gr. to the 6.5x55mm/140 gr. (Speer)

Similar SD.

Case Volume per Bore Area favors the .270 by 8.36%
Bullet weight favors the .270 by 7.69%

So, loaded to the same pressure, any given powder's charge wt. will generally reflect this amount, ~ 8%.


But the Barnes Load Data changes powder, and posts Magnum as the high velocity powder for the 6.5x55mm, and Hunter for the .270 Win.

Because a slower developing gas bubble allows the bullet to create volume at a rate that limits the peak pressure of the bubble.


So, the Magnum powder choice is based on the lower pressure requirement, and not for a higher velocity, given the same area under the curve.




GR

GR,

Gee, thanks for the explanation. But no, the difference is NOT due to the 6.5x55's "artificially low" pressure limit....

You might want to check out Ramshot's data for the .270 Winchester. Their Magnum data generally provides more velocity with 150-grain bullets than Hunter. The difference isn't much, but it's there.

The Ramshot data is interesting, partly because they test a variety of bullets with each powder, so there's a good indication of how pressure varies with different bullets.

I started using Ramshot powders 22 years ago, due to being one of the first writer-group invited to attend their introductory event in Miles City, Montana, which included a tour of their facility, including the piezo pressure lab, along with some prairie dog shooting. At the time only TAC, Big Game and Magnum had appearered. Hunter didn't show up until a year or so later, when they decided to plug the burn-rate gap between Big Game and Magnum. I was invited to help in the pressure lab when working up the first test-loads--and was also invited to use their lab to test other handloads whenever the need arose for my articles.

Have also become acquainted with several pressure labs at other facilities, include ammunition and bullet factories. One of the interesting things is that so far nobody at any of the labs has ever mentioned "pressure under the curve," even though it's been obvious on their computer read-outs while doing the shooting. Instead they're concerned with the consistency of the peak pressure and muzzle velocity.

FWIW, the highest velocity I recorded from any of my 6.5x55 rifles, with 140 grain bullets, was 2930fps (plus or minus fifteen or so). This was from a 26 inch barrel, throated to accept 140 Matchkings, and using 50 grains of VV165. A good load but one which produced over 1 moa of vertical at 900M so I went back to a slower load (2800 fps) using 4831sc. GD

Thanks.

2740 fps, w/ the 140 gr. GS bullet, appears to make a good 350 yd. load.

Am leaning toward the H4831 powder, and will look for a precise load from there.

Calculate 49.3 gr. from a 24" Bbl.




GR

The deer can't seem to tell the difference! The swede feeds nicer IMO as well and for those who have a passion for a fine feeding rifle that's a beauitiful thing to behold. I don't have a swede anymore but if I found a nice wood stocked swede I'd be very tempted to get another one

My Hawkeye African loves 140 gr npt’s with RL-22. I bought the 6.5x55 because I missed out on the .275 Rigby’s as they sold out so fast. Later on was able to find one on Gunbroker that had a decent buy now price. After developing loads and shooting both I prefer the 6.5 over the 275.

The only problem with the Swede... is that is was the Norwegians that did most of the development of the cartridge.

Yep--but American handloaders aren't generally concerned about the minutiae of history. But then neither are most humans.

Personally, I really like Ramshot powders. I use a lot of TAC and True Blue.

My only wish was that Ramshot would show load data for bullets heavier than 140 gr in the 6.5x55. Strangely, none of the powders in the Ramshot v8 guide show a bullet heavier than 140 gr in the 6.5x55.

Also, having been an engineer involved in pressure vessel design I've never in any way, shape or form discussed or even worried about "pressure under the curve" Peak pressure is what I'd be concerned about for failure under pressure load.

Was referring to performance, not failure.

Of course peak pressure would be the determining factor in that regard.

But area under the curve will express the aggregate force exerted on the bullet over time/distance in the bore.

F=MA




GR