Home Forums Hunting & Shooting Hunting Rifles 6.5X55 Preliminary Tests 120 NBT

Jerry and Mike have seen this, posting just to show what a 6.5x55 can do (100 gr, not 120 gr.)

http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/9785470/1

Like they say, don't try this at home.

For sure, the old Swede isn't an 80K psi gun. But with a modern action, it's more than a 40K psi gun, for sure. Somewhere between 40K and 80K you'd think there may be a sweet spot...

DF

That's true, and that seems to be the case here.

Nominal case capacities

So that gives the Swede about 7.5% capacity advantage over the 260 Rem. Using JB's 4-to-1 Rule (any increase in case capacity results about 1/4 that much extra velocity) would yield the 6.5x55 an additional 1.9% velocity over the .260 Rem (when loaded to the .260 Rem pressure levels).

Hodgdon lists 120g Speer SP w/ 43.0g IMR 4350 for 2,885 fps (@58,000 psi). That would suggest you could safely get to ~2,940 fps at the same pressure level in the Swede. Although it would take more powder in the Swede to get to that velocity level due to it's larger case capacity.

Looks like jwall is already in that ballpark with Denton's loads.

MM -

Yep, I am there with IMR 4350 and tight primer pockets.
IMR 4831 was less than 2850.

My next steps will be grouping and hopefully be where I wanna be. I expect to get some H 4350 also.

Thnx
Jerry

DF -

I want to stay with a longer bullet than the 100gr. I understand the trade off w/100 at higher speed OR 120 w/ higher BC.

Thnx
Jerry

AZAR -

I think I am there too. It hasn't been easy cyphering this out, what with pressure limits for old rifles and conflicting data even comparing 260 loads.

After hanging around the 'fire' I have become somewhat apprehensive.

It's almost like being BACK in Hagel's day.

Jerry

Me, too.

That's why this gun will be shooting the 139 Scenar over a good load of MRP. It's the best grouping of the loads I've tried.

The 100 gr. load was just a test, didn't start out as a "pressure test"...

DF

Jwall, yes, my loads are chronographed at 2950. I'm at 10+ reloads on lapua brass and pockets tight.

I used to shoot 120s in mine too. Got better groups and a better b.c. with 123 scenars though. Mine was a dog with 140s.

H4350 is where it's at. Why bother with IMR?

If I was to acquire a 6.5 swede, I might look hard at Big Game in it...

Because I have it. H 4350 & IMR 4350 are NOT that much different. H is temp stable.

I believe you about YOUR velocity. In my rifle & my components it took more powder to get to 2950.

Jerry

Surprised, my gun has a really long throat.

Maybe something to the bore, bll. length, &/or components.

Be glad, it's more economical.

Jerry

I saw some other QL data that showed 49 grains of H4350 as at both 60 and 62,000 psi. It seemed to come down to the tenth of a grain of case capacity on the QL data so this would be affected by seating depth as well as case type.

Hoping I can get there with R26 for the 140s and MRP for the 120-129 grain pills. Suspect I can get close without "sploding" anything. One of the MRP loads was over 3,000 fps for the 120 BT from the Norma data.

I've seen the claim that MRP and RL-22 were near the same, or the same. MRP and 139 Scenars shoot one hole groups in my FN/Shilen 6.5x55. That combo beat out every other load I've tried.

Point being, don't limit MRP to 120's; it's slower than 4350 and one would think it would be as good if not better with heavier bullets.

DF

Re: H and I - all the data I've seen from reputable shoots showed H getting around 75 fps more than I - in a 260, and I would extrapolate that to say, if you have a velocity goal, invest in some Hodgdon. I did IMR is good stuff, accurate, but I now use H -

JUST for comparison -- I haven't posted the vel yet with IMR 4350

**49** IMR 4350 120 NBT = 2969 fps, yes the primer pockets are still tight. I can live with this! !

Yet compare IMR 4831 --- 50 gs = 2825

Seems odd to me there is such a diff w/ 4350 and THEN IMR 4831 is very close.

I'll be grouping IMR 4350 pretty soon.

I think I know where I can go pick up H 4350 locally.

Jerry

Given the case capacity and ROT, you should focus on accuracy now, as your speeds are very good for this bullet IMHO.

Enjoy flattening deer with a round that is to Europe, what the JOC is to America; And with a very respectable trajectory I might add

Very thoughtful, using "the JOC" in code to spare Ingwe the mental trauma/stress of seeing that unspeakable caliber mentioned...

DF

Well I guess the 7PM Ingwe Express might also qualify for the Euro title...

You read my mind ? <grin>


Jerry