300rum, 208 A-Max, Moly coated, Slow

[joel0407]

I'm loading 87gn of Retumbo behind the 208gn A-Max which I have moly coated and only getting 2751fps(AVG).

83gn = 2650fps
84.5gn = 2709fps
87gn = 2751fps (No sign of pressure)

All loads over crony and all 3 shot averages with retumbo.

Max listed load is 86gn but I'm far from getting any signs of pressure. Web site "steve 8" lists from 79.3 to 96 gn for a 200gn projectile.

Rifle is a factory Remington Sendero SFII 26" barrel.

I was expecting around 3000fps for this projectile.

Should I keep pushing up the charge.

Help needed.

 

[ZSteinle]

96 gr. sounds about right for a 200gr. projectile. Also i am almost positive that moly coated bullets require more powder to build pressure and get equal velocity being that they slide down the barrel easier.

 

[joel0407]

96 gr. sounds about right for a 200gr. projectile. Also i am almost positive that moly coated bullets require more powder to build pressure and get equal velocity being that they slide down the barrel easier.

Been doing a bit of reading and getting the idea that 96 is about max and alot load up around 94 - 95.

Dont know why Hodsgon lists such a low load as max. Theres being careful but at 86 I might as well use a 308win.

 

[GLZ]

Hodgdon lists 86 as Max with the Barnes XFB but lists 95.5 as max with the Nosler Accubond. I would think the A-Max is closer in profile to the AB than the XFB

 

[Autorotate]

I think you have say this first when posting load data nowadays.....Don't blow up your gun!

That said...here's what Quickload suggests with a COAL of 3.600.

Your current 87 grain load...Quickload suggests a muzzle velocity of 2749 fps, with peak chamber pressure of 48210 psi.

Quickload also suggests SAAMI max pressure will occur with a load of 95.0 grains of Retumbo, and a COAL of 3.600. It also suggests you should achieve a muzzle velocity of 2976 fps with your 26" barrel.

As with any loading data, ensure you start with a lower charge and work up from there.

Hope this helps.

 

[Autorotate]

Oh yes...I almost forgot. That 95 grain charge may "crunch" some when seating the bullet, as it's listed as 101%, a slightly compressed load. With any luck you may very well achieve what your goals prior to getting to the max load.

 

[Spanners]

The old Hodgdon data was wrong.. as as ADI (same powder) however the new Hodgdon manual online that you can DL, had the right loads listed.

 

[joel0407]

So wrong if fact you can count the time between the firing ping sticking and the bullet firing at 82 grains. DANGEROUS