H1000 300WM case capacity issues.

[Awag1000]

I've been trying to develop a load for 300win mag to use 210gr Nosler RDF bullets and H1000. The min load on Noslers website is 75gr and the max is 77gr I can only get to 75.6gr before it starts to become a compressed load.
The max COAL I can use is 3.515"
Is this something potentially dangerous or am I just psyching myself out?

 

[spife7980]

Shoot it and find out. Start low and look for pressure.

 

[Steel head]

I had similar issues with H1000 in 7 saum
Ran out of room before I found pressure or the speed I wan
A case stuffed full of H1000 shot really well though.

 

[Howland]

I wouldn't worry about a slightly compressed load, people do it all the time. The biggest concern is a hard maximum COAL. If you're loading right at max COAL or CBTO to fit in a magazine or avoid jamming lands with a maximum charge weight load, some folks have observed a compressed charge pushing the projectile out slightly over time, especially if the neck tension is light. Seat some, let them sit awhile and measure again to see if that could be a problem.

Have you tried a powder drop tube yet? That could help.

 

[Awag1000]

I wouldn't worry about a slightly compressed load, people do it all the time. The biggest concern is a hard maximum COAL. If you're loading right at max COAL or CBTO to fit in a magazine or avoid jamming lands with a maximum charge weight load, some folks have observed a compressed charge pushing the projectile out slightly over time, especially if the neck tension is light. Seat some, let them sit awhile and measure again to see if that could be a problem.

Have you tried a powder drop tube yet? That could help.

So my maximum OAL of my chamber before the bullets start to jam into the rifling is +/- 3.517".
When I pour the powder I give the cases a little bump to hopefully get the powder to settle in before I push the bullet into the casing.
No I haven't tried a powder drop tube yet.

 

[Howland]

I ran into compressed loads with near maximum charges while doing OCW with H1000 and 300 grain A-Tip in 338LM. The last couple grains were definitely compressed. I didn’t observe any bullet creep but I loaded them the same week I went to the range, I targeted 0.010" short of magazine length (my critical point, approximately 0.140" jump so no concern there) and I'm using a 0.335" mandrel giving me 0.003" interference fit, fairly heavy.

I've also heard of people running an electric toothbrush next to their cases to settle the powder with the vibration. I have no idea if that really works.

 

[Bambamoda]

The issued 220 grain 300WM run hot as eff. That uses H1000

I have about 3500 of em’ that I’m prob never gonna shoot.

 

[Awag1000]

The issued 220 grain 300WM run hot as eff. That uses H1000

I have about 3500 of em’ that I’m prob never gonna shoot.

Is that the Mk248 round?

 

[Silverjay]

Can also try a drop tube, gets an extra grain or two without crunching.

 

[nn8734]

Is that the Mk248 round?

He is likely referring to mk248 mod1. Awesome round, sends a 220 smk out of the barrel at 3035 fps (my average over 10 rounds out of my mk13 mod5) no pressure signs. I cloned it and it hammers steel at a grand.

That said, mk248 mod1 is NOT for rifles chambered with standard SAAMI reamers or “match” chambers. You need a chamber designed to handle it such as one cut with the mk248 mod1 reamer. If you aquire any Mk248 mod 1, use extreme caution as they’re designed to generate pressures in excess of 70,000 psi. I believe SAAMI for the win mag is 52,000 or so...

Besides, there are better bullets these days like the 215 or 230 as well as your RDFs that will do the same thing ballistically with normal loads.

What brass are you using? Win mag case capacity varies substantially across different manufacturers.

 

[Bambamoda]

Is that the Mk248 round?

AB43

 

[Awag1000]

He is likely referring to mk248 mod1. Awesome round, sends a 220 smk out of the barrel at 3035 fps (my average over 10 rounds out of my mk13 mod5) no pressure signs. I cloned it and it hammers steel at a grand.

That said, mk248 mod1 is NOT for rifles chambered with standard SAAMI reamers or “match” chambers. You need a chamber designed to handle it such as one cut with the mk248 mod1 reamer. If you aquire any Mk248 mod 1, use extreme caution as they’re designed to generate pressures in excess of 70,000 psi. I believe SAAMI for the win mag is 52,000 or so...

Besides, there are better bullets these days like the 215 or 230 as well as your RDFs that will do the same thing ballistically with normal loads.

What brass are you using? Win mag case capacity varies substantially across different manufacturers.

Holy smokes that's fast for a 220.
So I use only Swiss Ruag "T" marked brass.

 

[Bambamoda]

He is likely referring to mk248 mod1. Awesome round, sends a 220 smk out of the barrel at 3035 fps (my average over 10 rounds out of my mk13 mod5) no pressure signs. I cloned it and it hammers steel at a grand.

That said, mk248 mod1 is NOT for rifles chambered with standard SAAMI reamers or “match” chambers. You need a chamber designed to handle it such as one cut with the mk248 mod1 reamer. If you aquire any Mk248 mod 1, use extreme caution as they’re designed to generate pressures in excess of 70,000 psi. I believe SAAMI for the win mag is 52,000 or so...

Besides, there are better bullets these days like the 215 or 230 as well as your RDFs that will do the same thing ballistically with normal loads.

What brass are you using? Win mag case capacity varies substantially across different manufacturers.

I’m not sure if it’s worth buying a 300WM barrel for my DT SRS A2 to shoot it. At least not while I’m overseas and my home is Florida.
No gain of 300wm in FL.

 

[918v]

Use a long drop tube. It will settle better in the case.