6.5x55 N160 and 120gr sierra SP.

John,

Apologies, I made the last post without looking into this properly. I have the min and max amount of powder that you referred to written down in my reloading record book, but didn't check to see that the data was from the "6.5 x 55 Swedish Mauser" table and not from the "6.5 x 55 SE/6.5 x 55 SKAN" table.

I agree that this looks odd and I'm not sufficiently knowledgable to explain the reason.

I assume that the 120 grain HPBT Sierra bullet referred to in the Vit data is the MatchKing, ref. no 1725. The bullet I use is the 120 grain ProHunter SPT, ref. no. 1720.

I worked up a load for the 120 grain ProHunter bullet using the max and min data in the "6.5 x 55 Swedish Mauser" table for the 120 grain MatchKing bullet with no problems.

Regards,

Bob

Rifle reloading - Vihtavuori

Mauser data you're even further over!

If your best accuracy was about 3/4 of the way through your powder range why not back off to that? Accuracy kills, not speed, you'll also be closer to published max which is no bad thing and will be kinder on your brass and barrel.

What pressure signs are you looking out for?
 
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thanks Boydy - can I ask one of my usual curious questions ?

They quote starting and max for 120 Sierra 45.8-50.7 is a lot higher than the other 120gr bullets.

is this because of the shape of the projectiles? I had always thought you could use a same weight of bullet data, which is clearly something i have just learned not to do (luckily never practically applied this misinformation!)
 
thanks Boydy - can I ask one of my usual curious questions ?

They quote starting and max for 120 Sierra 45.8-50.7 is a lot higher than the other 120gr bullets.

is this because of the shape of the projectiles? I had always thought you could use a same weight of bullet data, which is clearly something i have just learned not to do (luckily never practically applied this misinformation!)

Different bullets have different shapes, different ogives profiles, bases etc. so thy will change internal case volume when loaded to the same COAL. so a longer VLD type bullet with a longer ogive and longer boat tail will take up more case volume than a stubbier flat base hunting bullet if loaded to the same length and you will therefore get higher pressures. If you look at the Mauser data the TSX is for some reason loaded shorter than the other 120s which may go some way to explaining why the TSX has a lower powder weight. The scenar is quite a bit lower but considering this is the Mauser data the Sierra data seems anomalous. From memory I think there was an error on Viht's website and the Mauser data was all higher than the SKAN which was clearly the wrong way around so maybe this is a hangover from that.

provided that you are sensible and work up I personally don't have an issue substituting bullets but it's a good idea to try find data for as similar a bullet profile in that weight so maybe don't use data for a flat base hunting bullet if loadinga VLD target bullet, you need to pay attention to COAL also as that affects pressure. That said if I can't find the exact bullet and combo I generally find 3 sets of data for that weight and powder (brass and primers will be variables as well) so if something does look over the top you will pick it up.

I use the nosler website a fair bit for cross referencing an that bears out that you can swap bullets to some extent as they don't give data by bullet, rather by bullet weight so the same data for several bullets, though COAL may vary from memory.

If substituting find as many sets of data for that weight/bullet combo as you can, start at minimum and work up looking for pressure signs.
 
6.5 X 55 Swedish Mauser Load Data - Nosler

you can see the nosler data (which is rarely more conservative than Viht) is way under the Sierra HPBT which would be enough to get me to stay away from the 50.7 gr

At the end of the day it's up to the reloader to decide how far to take it, accepted wisdom is not to exceed max loads but you will see different max loads from different sources, up to the individual to choose which but their gun, their face and any onlooker's too if they go too far!
 
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Thanks Boydy- super helpful and informative as ever. What you says makes absolute sense and it’s useful to consider the similar shapes of bullets for weight.

Learnt something today and it’s not even 10am!
 
I’m using 45g of N160 with 120g Pro Hunters set 40thou off the lands, great load, very accurate, mild recoil and little damage. I was using 48g, got the same accuracy but more recoil. Dropping back 3g hasn’t made any noticeable difference at normal stalking ranges so why burn more powder and put up with more recoil etc etc.
 
Most up to date vit data says 45.8-50.7. That said Sierra quote an accuracy load of 44.9 which is what I use with good effect with the PH. N160 is a slow powder and it depends on your barrel length as to performance. If you have a 20”-22” barrel increasing the powder will have little effect as the %age burn will just fall and velocity stay much the same. Find an accurate load and stick with it. My 44.9gr load easily does the job. Accuracy kills not speed.

BE
 
Most up to date vit data says 45.8-50.7. That said Sierra quote an accuracy load of 44.9 which is what I use with good effect with the PH. N160 is a slow powder and it depends on your barrel length as to performance. If you have a 20”-22” barrel increasing the powder will have little effect as the %age burn will just fall and velocity stay much the same. Find an accurate load and stick with it. My 44.9gr load easily does the job. Accuracy kills not speed.

BE


My most accurate load with 120 NBTs was 44 but found I was getting poor obturation frosty winter mornings on the roe does, 46 not far behind accuracy wise and obturation properly so that's what I use now 23.5" barrel .
 
Looks like Sierra agree with Nosler...

http://m-b-r.co.uk/PDF/Sierra 6.5x55.pdf

Assuming they are photographed to scale the 120s illustrate nicely the difference in profile and length of the hollow point boat tail and flat base soft point and therefore the difference in case capacity they would use if loaded to the same length.
 
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