For the OP's benefit, that 2842 is out of a 24" barrel, so out of an 18", a guy "should" be looking at around 2692 MV. Looking at the Hornady H4350 data for 176-180gr bullets (including the ELDX), they're calling 54.3 max at 2650 MV in a 23.75" barrel, so approximately 2500 MV out of an 18". I'm not sure bumping up 3.7 grains of powder gets you to 2850, but if you're able to do so without pressure that's awesome.
Get a Tikka .223 in 1:8” twist and use that for practice. Shoot both guns in a range session with the emphasis on the .223.
Where did I get after someone for using a charge under max? If I did, it wasn't intentional.This is false, and noted to be so by SAAMI. Note the bolded italics in the quote further down.
Velocity is a function of pressure over time. However, more than just pressure effects velocity.
Over pressure is about peak pressure, which is achieved very early.
One can have an average higher pressure curve with a lower peak pressure. Changes to the throat, groove diameter, Etc can effect that. Test barrels are cut to the minimum SAAMI specification to ensure the round is safe in every appropriately chambered rifle. This results in higher peak pressure.
What Affects Rifle Chamber Pressure and Critical Factors You Need to Know - RifleShooter
When a cartridge is fired, a progressive burn of the propellant converts it to rapidly expanding gas that exerts an equal amount of pressure in all directions. Maximum recommended pressure for a rifle cartridge is usually dictated by the action strength of the rifle for which it is developed.www.rifleshootermag.com
What SAAMI says about test barrels (Page 231 https://saami.org/wp-content/uploads/2018/01/206.pdf
"Chamber and bore dimensions of velocity and pressure test barrels shall conform to the dimensions of the chamber and bore at Maximum Material Condition (MMC) for each cartridge as originally introduced. Fabrication tolerances, however, are much reduced.
"It is recognized that changes may be made to cartridge or chamber dimensions in order to improve the velocity-pressure relationship, accuracy or functioning in rifles as production experience indicates. However, none of these changes should be of such nature that they would cause a significant increase in pressure level of a given lot of ammunition.
"No changes shall be made to velocity and pressure barrel dimensions which would result in a reduction of the recorded pressure level of any given lot of ammunition. This would result in the possibility of future lots of ammunition being loaded with increased powder charges, which would cause increased pressure in existing rifles."
Maximum Material Condition = the condition of a feature which contains the maximum amount of material, that is, the smallest hole or largest pin, within the stated limits of size.
Ridding someone for using a load that is 1 gr under max powder charge per the manufacture is silly.
My apologies, I should have taken more time to look at who you were quoting, I edited out that portion.
Appreciate it.
I’ve been working on this bullet for tikka 30-06. If I remember right i’m some near max load of varget and only seeing low 3100fpss which is slower then the load I worked up for my wife 308. So either my chronograph is wrong or varget isn’t the right powder. Which powder do you use?
Seems on the slow side for speed of a 130 gr TTSX. I agree, try one of the 4064 powders (Accurate or IMR) to get a comparison.
Thanks I’ll have to try and track some down.
I do have IMR 4064 and will have to do so testing with it. It hasn’t been this rifle’s first favorite powder with other bullets, but it’s worth a try.
