Thread: 6x45/6mm223 projectiles ?

Originally Posted by Pommy

@Doon, you might want to think about dialling those loads down.

Hodgdon provide data for 6x45. Under the 95gr section there is data using Accurate and Ramshot powders. None of the speeds exceed 2600fps and they're all right on 55,000psi of pressure. I don't see how you're going to get ~175 fps more from a 4" shorter barrel with 8208, without it being way over that.

For the 70gr and 85gr bullets, you're at the max load and again you're getting more speed from your shorter barrel. The pressure on the Hodgdon site is given in CUP for 8208 though which is a bit vague.

Thanks for your concern @Pommy
Yes I am at max load as per ADI load data but worked up using a magneto speed observing velocitys.
The chamber has been throated so will not be as compressed as a normal load data.
Data – Rifle – ADI World Class Powders and Ammunition
As per velocitys maybe im lucky and have a fast barrel, it has over 400 dowm the pipe.

Yeah so if your rifle is throated longer and you're seating the bullets out, a given charge weight should give less velocity because you're increasing the effective case capacity which is reducing pressure.

The fact you're still getting more despite your 4" shorter barrel, suggests something else (such as lot to lot variation) is going on. The chrono numbers that you're carefully observing are a red flag.