Hi there,
I've been doing some load testing using Viht powders since Hodgdon and many other American powders are as rare as hens teeth at the moment. My go to load has always been 44 grains of H4350 behind a 140gr SMK at 3.1 OAL. Bloody superb. I'm trying to match it with N160 and N165. I thought I was getting close with N165 but even at 50 grains I was getting serious sooting down the brass and pretty crap groups. Virtually no obturation at all. I dropped down to N160 and accuracy was mostly non existant, even when doing a ladder test from 45.5 grains to 47 which should be getting toasty. Cases were as sooty as hell, right down to the rim. Switched back to my precious H4350 loads and all was back to super accurate, clean cased normal. I've all but given up on Viht powder but how does Accurate 4350 stack up to Hodgdons H4350 and anybody got an offering in Ramshot flavour? I've got Hunter, Magnum and Big Game on hand if all else fails.
Cheers guys.

It has been my experience that AA 4350 is a fair amount slower than the Hodgdon variety.
Most loads require about 1-1/2 to 2 grains more than H-4350. At least the one 8 lb. keg that I have used up recently was so.

I have most always used and preferred the AA variety to either Hodgdon or IMR. It seems to be more consistent lot to lot. It is a grain to 1.5 grains slower than the Hodgdon variety, but from my experience only about half a grain slower tham the IMR powder. But a lot of that depends, as you know, on the individual lot.

I have only one rifle that I load the IMR for. The rest that require it, all get the AA variety.

Haggis,
I have a 96 Swede and it shoots real well with Norma MRP(50 gr)/120 gr Sierras in Lapua brass.

Stepchild

Thanks for the comments fella's.
I'll have a go with the Accurate 4350 I've got here. See if it works.
Stepchild, I've not seen any Norma powder in this country since the pistol days - they were banned in '98! The current official importer of Norma products can't be bothered importing the powder.
I'll start at 42 grains and move up, see how things go...

It has been my considered opinion that anything that is worth doing with a 5.5x55 s best done with some sort of 140gr bullet propelled by RL19

The 6.5x55SE has been a problem since inception. Sako/Tikka developed the 6.5x55 SKAN probably as a result of this. The differences between the USA family of 6.5 mm / .264" cartridges and the 6.5x55SE are:

6.5x55SE

Barrel Bore = 6.50 mm (.256")
Barrel Groove = 6.73 mm (.265")
Freebore diameter = 6.84 mm (.269")
Freebore Length = 14.4 mm (.555")
Chamber Neck diameter = 7.65 mm (.301") / 7.55 mm (.297")
Bullet diameter = 6.71 mm (.2642")

260Rem

Bore = 6.50 mm (.256")
Groove = 6.71 mm (.264")
Freebore diameter = 6.73 mm (.265")
Freebore Length = 5.62 mm (.221")
Chamber Neck diameter = 7.59 mm (.299") / 7.57 mm (.298")
Bullet diameter = 6.72 mm (.2645")

It is a situation where the 6.5x55SE has a larger diameter barrel and freebore, with a smaller diameter cartridge and bullet, compared to the 260Rem, for example.

The difference between the larger chamber and the smaller cartridge is much more generous with the 6.5x55 than the same dimensions with the 260Rem.

Every time that we have a situation where the difference between cartridge and chamber becomes too great, accuracy/repeatability becomes a problem and fliers and large groups are the results.

We do not know what the dimensions of the 6.5x55 SKAN are, I have given up asking after several years.

To solve this problem, one needs a bullet that is made to accommodate the dimensions of a 6.5x55SE. Such a bullet is unique to the 6.5x55SE and best not to be used in other 6.5/264 cartridges.

If obturation, or the lack thereof, is the issue, then the cure should be more pressure. In a modern sporting rifle this is not a problem, but in the old 96's (and even some 98's) I would approach with caution. You might measure your lot of SMK's as well. While it is unlikely that they are undersize, I would consider the possibility. A little faster powder, that still gives good load density, might help.

quote:

Originally posted by Gerard:
The 6.5x55SE has been a problem since inception. Sako/Tikka developed the 6.5x55 SKAN probably as a result of this. The differences between the USA family of 6.5 mm / .264" cartridges and the 6.5x55SE are:

6.5x55SE

Barrel Bore = 6.50 mm (.256")
Barrel Groove = 6.73 mm (.265")
Freebore diameter = 6.84 mm (.269")
Freebore Length = 14.4 mm (.555")
Chamber Neck diameter = 7.65 mm (.301") / 7.55 mm (.297")
Bullet diameter = 6.71 mm (.2642")

260Rem

Bore = 6.50 mm (.256")
Groove = 6.71 mm (.264")
Freebore diameter = 6.73 mm (.265")
Freebore Length = 5.62 mm (.221")
Chamber Neck diameter = 7.59 mm (.299") / 7.57 mm (.298")
Bullet diameter = 6.72 mm (.2645")

It is a situation where the 6.5x55SE has a larger diameter barrel and freebore, with a smaller diameter cartridge and bullet, compared to the 260Rem, for example.

The difference between the larger chamber and the smaller cartridge is much more generous with the 6.5x55 than the same dimensions with the 260Rem.

Every time that we have a situation where the difference between cartridge and chamber becomes too great, accuracy/repeatability becomes a problem and fliers and large groups are the results.

We do not know what the dimensions of the 6.5x55 SKAN are, I have given up asking after several years.

To solve this problem, one needs a bullet that is made to accommodate the dimensions of a 6.5x55SE. Such a bullet is unique to the 6.5x55SE and best not to be used in other 6.5/264 cartridges.

Does the 6.5x57 suffer similar issues?

I, too, found AA4350 to be slower than either IMR4350 or H4350. As a matter of fact, I found AA4350 and my dwindling stock of 35 year-old N204 to be close in burning rate.
This may be previously covered but does your 6.5x55 have a long throat? That may give your case noticeably more volume. I find my long throated 7x57's gain significant capacity when bullets are seated out near the lands.
Have you tried using the Powley Computer to refer a correct amount of powder? It's listed somewhere on the Internet and I find it useful in getting me to a realistic powder charge in cartridges which are loaded down in deference to the large numbers of old rifles still in use.
In short, I think you need to find your actual case capacity in H2O and work from there.

ColoradoMatt,

The dimensions for the 6.5x57 are again different but does not make a regular .264" bullet unusable.

The case neck wall of a 6.5x57 is thicker than that of a 260Rem and takes up the space between the cartridge neck diameter and the chamber neck diameter.

Ideally, the cartridge neck diameter should be 0.03 mm (0.001") less than the chamber neck diameter for commercial ammunition. If we are talking reloaded ammunition and a specially cut chamber, the tolerance can be even smaller than that.

Clearance is clearance, whether it is a foot or one thou. The tighter the tolerance between case neck and chamber neck diameter, the less the blow by is and the longer the barrel will last.

6.5x55SE

Barrel Bore = 6.50 mm (.256")
Barrel Groove = 6.73 mm (.265")
Freebore diameter = 6.84 mm (.269")
Freebore Length = 14.4 mm (.555")
Chamber Neck diameter = 7.65 mm (.301") / 7.55 mm (.297")
Bullet diameter = 6.71 mm (.2642")

260Rem

Bore = 6.50 mm (.256")
Groove = 6.71 mm (.264")
Freebore diameter = 6.73 mm (.265")
Freebore Length = 5.62 mm (.221")
Chamber Neck diameter = 7.59 mm (.299") / 7.57 mm (.298")
Bullet diameter = 6.72 mm (.2645")

6.5x57

Bore = 6.45 mm (.254")
Groove = 6.70 mm (.2637")
Freebore diameter = 6.75 mm (.268")
Freebore Length = 30.00 mm (1.18")
Chamber Neck diameter = 7.68 mm (.3023") / 7.67 mm (.3019")
Bullet diameter = 6.70 mm (.2637")

We make a range of bullets suited to the European 6.5x57, 58, 64, 65 and 68 as well.

The 6.5 / .264" family of cartridges are sometimes so different, they are almost different calibers.

Cartridge : 6.5 x 55 Swedish
Bullet : .264, 140, Sierra HPBT MatchK 1740
Cartridge O.A.L. L6 : 3.100 inch or 78.74 mm
Barrel Length : 24.0 inch or 609.6 mm
Powder : Vihtavuori N160

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1,0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt Btime
% % Grains fps ft.lbs psi psi % ms

-10,0 90 43,20 2497 1938 42146 9507 94,0 1,421
-09,0 91 43,68 2524 1981 43487 9622 94,5 1,400
-08,0 92 44,16 2552 2024 44870 9734 94,9 1,380
-07,0 93 44,64 2579 2068 46298 9844 95,4 1,360
-06,0 94 45,12 2606 2112 47772 9952 95,8 1,340 ! HOT LOAD !
-05,0 95 45,60 2634 2156 49294 10056 96,2 1,320 ! HOT LOAD !
-04,0 96 46,08 2661 2201 50865 10158 96,5 1,301 ! HOT LOAD !
-03,0 97 46,56 2688 2246 52488 10256 96,9 1,283 ! HOT LOAD !
-02,0 98 47,04 2715 2292 54165 10351 97,2 1,264 ! HOT LOAD !
-01,0 99 47,52 2743 2338 55898 10443 97,6 1,246 !DANGEROUS LOAD-DO NOT USE!
+00,0 100 48,00 2770 2385 57688 10532 97,8 1,229 !DANGEROUS LOAD-DO NOT USE!
+01,0 101 48,48 2797 2432 59539 10617 98,1 1,211 !DANGEROUS LOAD-DO NOT USE!
+02,0 102 48,96 2824 2479 61452 10698 98,4 1,194 !DANGEROUS LOAD-DO NOT USE!
+03,0 103 49,44 2851 2527 63431 10776 98,6 1,177 !DANGEROUS LOAD-DO NOT USE!
+04,0 104 49,92 2878 2575 65477 10850 98,9 1,161 !DANGEROUS LOAD-DO NOT USE!
+05,0 104 50,40 2905 2624 67595 10920 99,1 1,144 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 100 48,00 2892 2600 68048 10386 100,0 1,144 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 100 48,00 2607 2112 47538 10186 91,9 1,338 ! HOT LOAD !