N160 6.5x55 Velocity

[josh759]

Hi guys,

First go with N160 powder - 11 rounds starting at 43.5gr and .3gr increment. Norma 1x fired case full length resized, CCI LR primers and Speer 140gr Hot Cor. CBTO is 2.515. Rifle is a Tikka T3X SS with a 22" barrel and Leupold Vx-3i 3.5x10 scope. Here are the MagnetoSpeed Sporter chrono data:

43.5 - 2569
43.8 - 2539
44.1 - 2556 (Lyman Max)
44.4 - 2587
44.7 - 2567
45.0 - 2628
45.3 - 2610
45.6 - 2626 (Speer Max - 2630) Velocity very closed to Manual
45.9 - 2603
46.2 - 2656
46.5 - 2669 (Vithavouri Max - Non SE Load)

Was diligent in checking casings after each firing. No pressure signs at max. Photo of first 5 shots taken at target changed. Rained hard after, target was soaked and destroyed completely. Surprised still group like this 1.2 gr of powder difference. I am a mediocre shooter at best.
Finding the velocity data very odd as there are no real flat spots or nodes. Just gradual (+/-) change throughout. Not really sure how to interpret it. Have used the 11 shots laddered test twice on my 223 using Varget and H335 and have found 3 distinct nodes on both powder charges which turned out to be pretty good (5 shots - 1" groups). I am going to load up 5 rounds each at 44.1 and 45.6. 3 rounds at 46.5 (just in case pressure signs shows up)

Would appreciate any comments or suggestions.

Thanks !

p.s. Standard disclaimer of caution and discretion as these loads exceeds certain manuals maximum recommendation ! Load at your own risk.

 

[Harry mac]

Howmany shots fired ateach charge weight?

 

[big ears]

N160 to slow in a 22” barrel. You are getting variable percentage burn causing what you are seeing. Try N150

 

[Sinistral]

Interesting level of detail.
Oddly enough I have the same rifle in another form, and the Speer #13 manual too (this one?). Mine is a Tikka M595 LH - also with the 22" barrel.

The velocities matched the Ruger M77 results closely, just like you found. That seems to be the situation with the Speer book no matter which calibre I'm clocking.
Oehler 33 chronograph btw. The later #14 manual switched from testing in factory rifles to pressure barrels, so I don't think the editions are comparable any more.

The maximum load of 45.5 Vit N160 gave the best results, with the Sierra 140gr GameKing BTSP @ 3.063"/77.8mm in Winchester cases using different load increments.
Until the book maximum was reached the results were erratic. I now use IMR 7828 which is much slower, a little bit slower even than N165.

(February @ 35F / 1.7C)
44.0 2495
44.5 2490
45.0 2503
45.5 2541 2542 2549 2570

—----------------------------------------------------------------------
(August @ 74F / 23C - same batch)
45.5 2621 2628 2635

 

[Andy seatrout]

Interesting minus 2fps difference between the 43.5gr charge and the 44.7 charge….. I’d not heard of variable burn….

Thanks for posting

 

[josh759]

Howmany shots fired ateach charge weight?

1 shot per each charge weight.

 

[josh759]

N160 to slow in a 22” barrel. You are getting variable percentage burn causing what you are seeing. Try N150

Unfortunately, N160 is all I have in the Vithavouri line. I am happy with the velocity around 2600 fps if I can get it to group. Would love to try N150 but no supply available.

 

[josh759]

Interesting minus 2fps difference between the 43.5gr charge and the 44.7 charge….. I’d not heard of variable burn….

Thanks for posting

You are welcome. With only one round per charge weight, there could be variations in loading factors. I did sort the projectiles by by ogive length to at least have a consistent factor there. The projectiles varied in weight. I did a random 10 projectiles weighing, and they ranged from 139.4 to 140.2. Just too many factors to take into consideration when it comes into reloading.

 

[HandB]

I use RS62 in my 7x57 and it produces about 2,900fps with 50gr of powder under a 139gr SST bullet. So I suggest trying that as the case design is similar to yours.

 

[josh759]

Interesting level of detail.
Oddly enough I have the same rifle in another form, and the Speer #13 manual too (this one?). Mine is a Tikka M595 LH - also with the 22" barrel.

The velocities matched the Ruger M77 results closely, just like you found. That seems to be the situation with the Speer book no matter which calibre I'm clocking.
Oehler 33 chronograph btw. The later #14 manual switched from testing in factory rifles to pressure barrels, so I don't think the editions are comparable any more.

The maximum load of 45.5 Vit N160 gave the best results, with the Sierra 140gr GameKing BTSP @ 3.063"/77.8mm in Winchester cases using different load increments.
Until the book maximum was reached the results were erratic. I now use IMR 7828 which is much slower, a little bit slower even than N165.

(February @ 35F / 1.7C)
44.0 2495
44.5 2490
45.0 2503
45.5 2541 2542 2549 2570

—----------------------------------------------------------------------
(August @ 74F / 23C - same batch)
45.5 2621 2628 2635

Since I had the details, mind as well post them, especially if I am asking for opinions and suggestions. Thanks for sharing the temp you tested. I see that it will run faster during hotter days. When I shot these around 8 degrees and would be typical fall hunting day so I need to be careful if I am doing any load testing during the 25 degrees summer days.

I will be loading 45.6gr (along with some at 46.5gr) and if I can get this group less than 1", I will be happy with it. This is a hunting rifle and will always be more accurate than me.

I also have many other 140gr (hunting and target) projectiles that I will eventually try them around 45.5gr charge weight. I also have H4350, RL22, RL23 but I decided to start with the N160. Will keep you guys posted.

 

[josh759]

I use RS62 in my 7x57 and it produces about 2,900fps with 50gr of powder under a 139gr SST bullet. So I suggest trying that as the case design is similar to yours.

Just looked into the RS62. Looks like a good powder and would work for the 6.5x55 cartridge. Unfortunately I have never seen them offered in Canada.

I see them priced around 94pounds per KG in the UK which is reasonable for today's prices. In 11/2021, before supply dried up, I purchased some RE22 on sale for CDN$35/pound. I miss those days, not just on price but availability. I paid like $50.pound for the N160 a couple of months ago but they are all gone now. Privately, people are selling powder for around $80-$100 per pound now.

 

[HandB]

Yes RS62 is a nice mild low energy powder. Even with 50gr in my 7x57 it kicks less than my .308s which use RS52.

 

[HandB]

Just looked into the RS62. Looks like a good powder and would work for the 6.5x55 cartridge. Unfortunately I have never seen them offered in Canada.

I see them priced around 94pounds per KG in the UK which is reasonable for today's prices. In 11/2021, before supply dried up, I purchased some RE22 on sale for CDN$35/pound. I miss those days, not just on price but availability. I paid like $50.pound for the N160 a couple of months ago but they are all gone now. Privately, people are selling powder for around $80-$100 per pound now.

If you can't get RS62 in Canada then you should go for IMR4350 as the burn rates are a close match.

 

[josh759]

If you can't get RS62 in Canada then you should go for IMR4350 as the burn rates are a close match.

I don't have IMR4350 but I do have H4350 which I will be trying after I figure out the N160 load. I am not after super velocity on the 6.5x55. I think around 2600 fps, it is more than adequate for most of my hunting needs and I wont be shooting past 250 yards. Even for elk, I think with a premium bullet like Nosler Partition/Accubond or Barnes TTSX, the 6.5x55 will perform inside 250 yards. I also have a .308. 30-06 and a 7mm Rem Mag if I needed more punch or reach.

 

[big ears]

Unfortunately, N160 is all I have in the Vithavouri line. I am happy with the velocity around 2600 fps if I can get it to group. Would love to try N150 but no supply available.

Thought that might be problem. One way now is to choose the velocity you are happy with. Ideally not max load and then adjust the seating depth in and out by 10thou and see what happens. I bet within 20-30thou you will group well

 

[josh759]

Thought that might be problem. One way now is to choose the velocity you are happy with. Ideally not max load and then adjust the seating depth in and out by 10thou and see what happens. I bet within 20-30thou you will group well

Good advice and that will be the plan going forward. I know the gun will shoot well, better than the shooter at least.

 

[big ears]

Good advice and that will be the plan going forward. I know the gun will shoot well, better than the shooter at least.

Always the same with Tikka. I have a T3 best gun I’ve ever had. Always accurate

 

[Foxyboy43]

If you are not target shooting and the load is accurate enough for hunting, a 140 gns bullet clipping along at 2550 fps will kill anything you hunt so I would stop there - easier on the rifle, you and the powder.
My “go-to” round with N160 is 130 gns Sierra Gamechangers at 2650 fps - super accurate and flattens anything hit in the right place.

 

[hunta]

My go to load in my Sako 75 using N160 is Sierra 140g Game King at 2750 ft/sec. The Sako 75 does have a 580mm barrel so a little longer than your Tikka. During load development I did work up to around 2800 ft/sec but settled on the slightly slower load as it was the most accurate. Admittedly I am above book max but at no stage did I see signs of excessive pressure. The 6.5 x 55 is capable of a trajectory that is close to that of a 270. I stalk fallow on open field and woodland edge so a flat shooting load is an advantage. I also shoot muntjac in woodland so have a much softer load for this purpose as ranges rarely exceed 150m. One of the great things about this calibre is its flexibility when hand loaded. My advise would be to work up a load that suits your needs. As Foxyboy says a 140g bullet at 2550 ft/sec will kill anything that you hunt but If you regularly hunt at ranges beyond 200m then more velocity will be an advantage.

 

[josh759]

If you are not target shooting and the load is accurate enough for hunting, a 140 gns bullet clipping along at 2550 fps will kill anything you hunt so I would stop there - easier on the rifle, you and the powder.
My “go-to” round with N160 is 130 gns Sierra Gamechangers at 2650 fps - super accurate and flattens anything hit in the right place.

Couldn't agree more. From what I have read, I have a lot of confidence in this round as long as the shooter does his part. I really like the "easier on the rifle part" as I will be passing this on to my son. It is one of those guns I have no plans in selling.

My go to load in my Sako 75 using N160 is Sierra 140g Game King at 2750 ft/sec. The Sako 75 does have a 580mm barrel so a little longer than your Tikka. During load development I did work up to around 2800 ft/sec but settled on the slightly slower load as it was the most accurate. Admittedly I am above book max but at no stage did I see signs of excessive pressure. The 6.5 x 55 is capable of a trajectory that is close to that of a 270. I stalk fallow on open field and woodland edge so a flat shooting load is an advantage. I also shoot muntjac in woodland so have a much softer load for this purpose as ranges rarely exceed 150m. One of the great things about this calibre is its flexibility when hand loaded. My advise would be to work up a load that suits your needs. As Foxyboy says a 140g bullet at 2550 ft/sec will kill anything that you hunt but If you regularly hunt at ranges beyond 200m then more velocity will be an advantage.

I also have a Sako 85 Hunter 22" in this caliber. One I get a load dialed in for the Tikka, I will start playing with a load for this. I will probably just start out with the same load, play with the seating and go from there. This Sako will likely just spend time on the range as I bought the SS Tikka for the wet rainy weather we have here in the Pacific West Coast.

Great to see all the 6.5x55 and Tikka/Sako fans on here. The cartridge is still not all that popular in North America.