Thread: Pressure / barrel speeds?

Yeah your right about pressure VC, you can throw Plastic shotgun shells in an open fire and they will fizz every time.
There is absolutely no pressure there.

Ahh I had wondered about pressure for jump, but makes sense when going from throat to lands that there would be a pressure increase when the bullet hits the rifleing

How would you work it when playing with jump to dial in a load?

Load it close to the lands to start and start low or shift back to a lower pressure node and filddle there, then ramp back up to bigger charges once you have found a COAL/jump that your rifle likes?

I usually start at max mag length or just touching the lands whichever is shorter.
ladder for pressure then load a few at steps close to max, if no joy accuracy wise start moving back.(can't go forward cos already on lands or won't fit mag)
load up some more shorter at say .5gr steps and try again.
often need more powder to get same speed after moving back.

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Cool man cheers

Ok so im going to do up some loads and find my pressure limit. Im already at .4 grains over max with no signs and no need to length size yet. May i ask how the gurus find pressure? Do I load 1x load and go up by .5 or liad 3x loads and go up slower say .3 and chrony at same time?
Keen to know what you guys do

No one got any advice on how to find the pressure for my rifle?

the only way to find max is go over it, when you get sticky bolt lift and or case head bolt marks (with decent brass) or anything else bad you are over max ,then drop down till it just goes away and you have max.

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Originally Posted by veitnamcam

the only way to find max is go over it, when you get sticky bolt lift and or case head bolt marks (with decent brass) or anything else bad you are over max ,then drop down till it just goes away and you have max.

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Cheers VC
What do you go up by? And how many do you load per charge weight?

half a grain should be good in 270.
one of each up from your current load.

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Originally Posted by veitnamcam

half a grain should be good in 270.
one of each up from your current load.

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Sweet, im working a grain under where i have been to so far so will go from where ive been

Originally Posted by Gibo

Sweet, im working a grain under where i have been to so far so will go from where ive been

So what is your current powder type/gns/projectile type/weight/barrel length?

Originally Posted by Gibo

Sweet, im working a grain under where i have been to so far so will go from where ive been

Hey gibo, with the Tikka. You will notice that your bolt lift will get quite hard when the pressure rises.
Or at least that's what I find. I can struggle to open the bolt at times when finding max load. But there won't be a mark on case and primer is only slightly flattened

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Originally Posted by 257weatherby

So what is your current powder type/gns/projectile type/weight/barrel length?

2209 51.5 grns fed 210 norma brass 21 3/4 inch barrel tikka 270 140 grn nosler ab. Been up to 52.4 grns no signs at all

Originally Posted by puku

Hey gibo, with the Tikka. You will notice that your bolt lift will get quite hard when the pressure rises.
Or at least that's what I find. I can struggle to open the bolt at times when finding max load. But there won't be a mark on case and primer is only slightly flattened

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Cheers K, never had trouble opening the bolt yet

Im getting reasonable slap marks on my brass before i get any other signs of pressure with my tikka (norma brass)

Remember it's winter and pressures can rise as the weather gets warmer. This will vary depending on the powder.
I would stay away from any signs of maximum pressure at the moment. Maybe back off a full grain instead of half.