Vit N135 in .308 ?

[wigone]

Good afternoon all,
Just starting to do a little homework on hopefully developing a load for my .308 win using Barnes 130 grs TTSX and the only Powder choice I seem to have at the moment which is Vit N 135.
The Vit web site states 43.7 grs being the maximum load giving 2946 fps.
I've plumbed these figures along with my Case length and capacity into Quickload and to be honest its coming back looking a bit anaemic, pressure wise its looking like I could have a bit of wiggle room but case capacity is running at 107.2%.
Does anybody have any experience of N 135 in .308 capacity wise, that they would mind sharing before I stump out £100 on a tub of powder?
Also if anybody with Quickload could just double check my Data it would be greatly appreciated.
Thanks in advance.

 

[Mike L]

Can’t you get 140, works well with my barnes in .308?

 

[Muir]

Not smart.
Quick Load is a computer model. Vhit actually pressure tests the loads. (I would hope)
Maximum pressure in a given load is not necessarily set by the 'max' allow able pressure for that cartridge, it is the charge weight of a given powder at which there are no pressure excursions over that max limit. You will often see loads that top out at , say, 59K when the 'max' allowable might be 62K. It doesn't mean they got tired and quit, it means that the load spiked over the limit during testing. The charge was reduced until these spikes did not occur. That becomes the max charge and resulting pressure for that load.
Second guessing a manufacturer and their pressure gun is foolish, to say the least.
Find a different powder. ~Muir

 

[Selous]

N135 works well with the 130g TTSX. N140 will do too but is a bit slow

 

[Alantoo]

I have been using N135 with both 130 and 110gr TTSX in my 308W and it has been working okay. I have just worked up a great load for the 126.5 Yew Tree bullets with it as well.

Vihtavuori load data wasn’t available for the bullets I was trying at the time so I stayed well below any pressure signs. When the data was published however it showed I was still some way over recommended max. So I dropped the loads down to a lower node and it is still working okay.

 

[Laurie]

N135 is the canister version of the bulk propellant Lapua uses to load standard 7.62 Nato ball, ie 2,800 fps to a 146gn FMJBT bullet out of a 20-22 inch barrel. It should therefore be pretty well suited to a 130gn all-copper bullet in 308 Win.

Don't use QuickLOAD with its default settings for N135. I can't comment on 308, but it seriously underestimates MVs (hence pressures) in 223 with 77-80gn bullets, by between 80 and 100 fps with the 77, equivalent to 5-6,000 psi PMax. It also may overstate bulk giving a highish fill-ratio. Use Viht's data in this case.

QL's default case volume is 56.0gn water and Viht data also use a Lapua case. 56gn is around right for this make, likewise RWS, but many US makes have thinner walls and a bit more capacity, so give lower pressures and MVs than the factory maximum. Add in many factory rifle chambers being at the upper end of SAAMI specs with freebore verging on the excessive and way above SAAMI's, and that's why cross-checking actual results against those expected with a reliable chronograph is a good idea to check results in either 'direction'.

 

[borbal]

Barnes bullets are solids, so the shot start pressure will be higher than the 3626 psi you used in QL. Running this in P-Max using the 48.8 grains H2O usable case capacity specified in QL for the powder space in P-Max, here are the results.

 

[Border]

Not smart.
Quick Load is a computer model. Vhit actually pressure tests the loads. (I would hope)
Maximum pressure in a given load is not necessarily set by the 'max' allow able pressure for that cartridge, it is the charge weight of a given powder at which there are no pressure excursions over that max limit. You will often see loads that top out at , say, 59K when the 'max' allowable might be 62K. It doesn't mean they got tired and quit, it means that the load spiked over the limit during testing. The charge was reduced until these spikes did not occur. That becomes the max charge and resulting pressure for that load.
Second guessing a manufacturer and their pressure gun is foolish, to say the least.
Find a different powder. ~Muir

It is also only applicable to that test barrel in reality. I see many try and replicate loads shot in 'long" test barrels when they have a short barrel and either over load to try and achieve the same velocities or complain that they can't match the listed velocity.
Same with factory loads. The data on the box is just a guide. Chronographing the result in your barrel is what counts....

 

[wigone]

Thank you all for your input.

 

[plumber01]

Every time i seem to test MV in every caliber, 270, 223, 308 6.6x55, i would say Viht is "optimistic" with its speeds compared with their tables
N135 works a treat with lighter 308 bullets , at least when i tried them.
good luck

 

[Adey]

Ramshot tac was better in my sako 308

 

[Adey]

Also Barnes recommend powder for 130g ttsx according to there web site