New Long Poker- Loading Questions

[Mickp7]

Finished setting up the reloading room just as my Short Action Customs 300 PRC was completed. I am excited to try my hand at reloading and see what I can do with this set up. I'll be working on a 7 PRC hunting rifle after. Any help getting started would be much appreciated. I have been reading a ton of forums, manuals, and articles in preparation, but have always appreciated the wisdom on this forum.

The build:
Defiance Deviant action
MPA BA Comp Chassis
Bartlein barrel- 28"
1/9 twist
Triggertech Diamond 2-stage
TBAC SR brake
TBAC 338 Ultra suppressor (man, this thing makes shooting even more fun)

The cartridge:
Lapua brass (only prep will be neck sizing for fresh brass)
215 Berger
CCI 250 or Fed 215M primers
H1000, Retumbo, and RL26 powders

I've been breaking in the barrel with some factory Hornady 225 ELDM's (2920 FPS +/-). So far, bore sighted and shot steel at 170 yards just to get some rounds down the barrel (it was almost dark already). Appears to be within 1moa, but will set up some paper and fine tune as I shoot. My plan is to get about 80 rounds through it, give it a good cleaning, shoot some fouling rounds, and begin shooting development loads.

Based on Lyman manual and research, guessing pressure will begin in the low 80 grains with H1000. My thought was to work back from 82 grains in .3 or .5 increments, start at the bottom and shoot at 400 or 500 yards to see what happens. Hopefully find a vertical node and play with bullet depth a bit (if needed) to see how tight I can get it to group.

My questions are:
-Go with H1000 or try one of the others (or try a couple)? (If it matters, I'll be working on a 7 PRC hunting rifle soon as well and plan to dedicate a powder to each gun. I have enough H1000 and Retumbo for both. RL26 will need to be picked for one gun.)

-Is my plan sound or is there another approach you'd recommend?

Any feedback is appreciated. Pic of the rig below (Currently displayed on a tripod, but I'll be shooting prone for development).

 

[Trm82]

Finished setting up the reloading room just as my Short Action Customs 300 PRC was completed. I am excited to try my hand at reloading and see what I can do with this set up. I'll be working on a 7 PRC hunting rifle after. Any help getting started would be much appreciated. I have been reading a ton of forums, manuals, and articles in preparation, but have always appreciated the wisdom on this forum.

The build:
Defiance Deviant action
MPA BA Comp Chassis
Bartlein barrel- 28"
1/9 twist
Triggertech Diamond 2-stage
TBAC SR brake
TBAC 338 Ultra suppressor (man, this thing makes shooting even more fun)

The cartridge:
Lapua brass (only prep will be neck sizing for fresh brass)
215 Berger
CCI 250 or Fed 215M primers
H1000, Retumbo, and RL26 powders

I've been breaking in the barrel with some factory Hornady 225 ELDM's (2920 FPS +/-). So far, bore sighted and shot steel at 170 yards just to get some rounds down the barrel (it was almost dark already). Appears to be within 1moa, but will set up some paper and fine tune as I shoot. My plan is to get about 80 rounds through it, give it a good cleaning, shoot some fouling rounds, and begin shooting development loads.

Based on Lyman manual and research, guessing pressure will begin in the low 80 grains with H1000. My thought was to work back from 82 grains in .3 or .5 increments, start at the bottom and shoot at 400 or 500 yards to see what happens. Hopefully find a vertical node and play with bullet depth a bit (if needed) to see how tight I can get it to group.

My questions are:
-Go with H1000 or try one of the others (or try a couple)? (If it matters, I'll be working on a 7 PRC hunting rifle soon as well and plan to dedicate a powder to each gun. I have enough H1000 and Retumbo for both. RL26 will need to be picked for one gun.)

-Is my plan sound or is there another approach you'd recommend?

Any feedback is appreciated. Pic of the rig below (Currently displayed on a tripod, but I'll be shooting prone for development).

You can't go wrong with the 215's but I'd suggest trying 245 gr elites if you can find them. They are unreal with retumbo in my 300 prc.

 

[Mickp7]

I would not have thought of that. Thanks!

Where did you end up on powder and velocity?

 

[Trm82]

I would not have thought of that. Thanks!

Where did you end up on powder and velocity?

78 gr retumbo , 215m primer , 245 elite seated 0.020" off , adg brass 2808 fps

 

[K.E.C.]

Howdy, CONGRATULATIONS on your new rifle. What is the purpose for your rifle.
I notice you live in Ohio?
I like the 215 Hybrid Berger's.
And I would look at N-570 powder.
But with what you have I would work with
Retumbo and H-1000.
If your hunting Whitetail, I would look at
185gr Juggernaut Berger bullets.

 

[Jeff Heeg osoh]

You should reach out to Tom Sarver at Thunder Valley in Kimbolton, Ohio and get some coaching on brass prep and reloading as well as load development and testing.

So above you got some advice on powder charge and overall length, the jump to the lands compared to your chamber and throat may differ

Look up Tom and get a little hands on, you will have a fun time and move forward in accuracy.

Your right theres a lot of valued and experienced folks here, a great place

Cheers
Osoh

 

[Mickp7]

Thanks fellas.

This rifle is 90% shooting long range and a little hunting. The same place we shoot seems to have some good hunting, but it would be long range and no moving, so I could use the 20# beast. The 7PRC coming will be the hunting rifle.

Great idea on Thunder Ranch. I think it's only a couple hours away. I'll check it out.

I'll check out the 245 EOLs as well.

I loaded some bullets today (my first ever). Did a guess load and tried it out. 2865 fps and shot a very tight group at 100 yards (didn't measure but all were touching. I went off the bullet depth of a factory load (.060 off the lands) and 78 grains of Rotumbo.
A lot of fun learning here!

 

[std7mag]

Personally, i full length size new brass. Not just the neck.

Sounds like quality builds your doing!

You shouldn't have a problem with H1000, but if you go to other powders, try to stay above 85% case fill.
And good luck on finding RL26!

 

[Mickp7]

Personally, i full length size new brass. Not just the neck.

Sounds like quality builds your doing!

You shouldn't have a problem with H1000, but if you go to other powders, try to stay above 85% case fill.
And good luck on finding RL26!

Thanks std7.

I compared my fired Hornady brass to the new lapua brass with the comparator and it was basically dead on, which is why I just sized the neck.

I did notice the brass oal was a few thousands longer than the trim length in the Lyman book. I was thinking I'd trim on the 2nd firing but am not sure if that is a bad idea. I've heard of the carbon ring that develops at the end of the case but was hoping it's ok to go shorter, but probably not longer?

Overpaid for an 8 lb jug of RL26 on Gunbroker, but was thinking of saving that for the 7 PRC hunting rifle. The 300 will be shot year round so I thought a more temperature stabile powder like Retumbo or H1000 might be better. (Note: this is me trying to understand all this... I have a lot to learn!)

Appreciate the responses and feedback!