First time reloading 300blk

[Cannonsville69]

Good info, nothing to add here but i'm following.
Thanks everyone for posting.

[Barndoor]

Well it's all changed now, on a recent trip to the range I shot for the first time at the electronic targets, thee problem now is that the microphones don't pick up the supersonic crack and show a hit as I'm shooting subs.
Looks like I need to find a load that will keep 190gr pills supersonic at 300yds now!

[dellet]

Are you able to use a magazine, or is the rifle a single shot, no magazine?

If you do not use a magazine, how long can you load the cartridge?

It will be very close to work up a load with the 190 grain bullets and R7 but I think it’s possible. It will probably need to be close to 1550 fps. To safely be 1200 fps at the target.

[Barndoor]

Are you able to use a magazine, or is the rifle a single shot, no magazine?

If you do not use a magazine, how long can you load the cartridge?

It will be very close to work up a load with the 190 grain bullets and R7 but I think it’s possible. It will probably need to be close to 1550 fps. To safely be 1200 fps at the target.

It's magazine fed, I would've thought 190 would be OK as I'm using 200gr magtech at the moment.

[dellet]

Are you able to use a magazine, or is the rifle a single shot, no magazine?

If you do not use a magazine, how long can you load the cartridge?

It will be very close to work up a load with the 190 grain bullets and R7 but I think it’s possible. It will probably need to be close to 1550 fps. To safely be 1200 fps at the target.

It's magazine fed, I would've thought 190 would be OK as I'm using 200gr magtech at the moment.

It will depend on the bullet profile, not all can be loaded to 2.260". Always good to double check. There are some bullets as light as 110 grains that can not be loaded to magazine length.

Around 16 grains of R7 should be very close, but knowing bullet length and how long it can be loaded will be helpful.

[Barndoor]

Are you able to use a magazine, or is the rifle a single shot, no magazine?

If you do not use a magazine, how long can you load the cartridge?

It will be very close to work up a load with the 190 grain bullets and R7 but I think it’s possible. It will probably need to be close to 1550 fps. To safely be 1200 fps at the target.

It's magazine fed, I would've thought 190 would be OK as I'm using 200gr magtech at the moment.

It will depend on the bullet profile, not all can be loaded to 2.260". Always good to double check. There are some bullets as light as 110 grains that can not be loaded to magazine length.

Around 16 grains of R7 should be very close, but knowing bullet length and how long it can be loaded will be helpful.

Bullet length is 1.275", will be going in a standard AR magazine.

[dellet]

It's magazine fed, I would've thought 190 would be OK as I'm using 200gr magtech at the moment.

It will depend on the bullet profile, not all can be loaded to 2.260". Always good to double check. There are some bullets as light as 110 grains that can not be loaded to magazine length.

Around 16 grains of R7 should be very close, but knowing bullet length and how long it can be loaded will be helpful.

Bullet length is 1.275", will be going in a standard AR magazine.

That Bullet is a bit short for its weight, It would be a good thing to find out what length it will jam in the rifling. Load one to 2.265" and make sure it chambers correctly

[Barndoor]

It will depend on the bullet profile, not all can be loaded to 2.260". Always good to double check. There are some bullets as light as 110 grains that can not be loaded to magazine length.

Around 16 grains of R7 should be very close, but knowing bullet length and how long it can be loaded will be helpful.

Bullet length is 1.275", will be going in a standard AR magazine.

That Bullet is a bit short for its weight, It would be a good thing to find out what length it will jam in the rifling. Load one to 2.265" and make sure it chambers correctly

It's a ppu 190gr match, tip is a tiny HP like a Sierra matchking, I'll load up a dummy & see how it goes, if this isn't going to happen I'll try some 175's I load my Steyr up with.

[dellet]

Bullet length is 1.275", will be going in a standard AR magazine.

That Bullet is a bit short for its weight, It would be a good thing to find out what length it will jam in the rifling. Load one to 2.265" and make sure it chambers correctly

It's a ppu 190gr match, tip is a tiny HP like a Sierra matchking, I'll load up a dummy & see how it goes, if this isn't going to happen I'll try some 175's I load my Steyr up with.

There are so many different 308 bullets of the same weight, it's always good to check. Example the 150 grain FMJ bullets. Winchester and Sierra can be loaded longer than magazine length, the Hornady will jam the rifling much shorter than 2.260".

I think if you can load that bullet to 2.250" and fit 15.5-16 grains of R7 in the case, you will stay above 1250 fps past 350 meters. that should give plenty of extra to trigger the target.

I have to work with some other 190 grain bullets and have the powder so I might be able to load some and see in the next few days.

[ironhead7544]

It may take some work to get a good target load at that distance. I would try match bullets of different weights. IIRC, the original Whisper load was a 240 gr Sierra MK.

I have not loaded any subsonic ammo yet so I cant help you with the powder. My Lyman AR Reloading Handbook lists A1680, Rx7, and H4198 as the powders for subsonics. It also shows loads for the 175 gr Sierra HPBT for velocities of almost 1900 fps from a 16 inch barrel.