Home Forums Hunting & Shooting Custom Rifles & Wildcats 7.62 x 45 Czech in Mini Action

I’m probably going to go a bit further with it just because I’m that way. Going to have a carbon fiber stock put on it, custom profiled barrel of some sort to keep weight down but still have threaded. Stock will have some sort of internal box magazine. However, the 30 BR seems to match case capacity to velocity very well. Quick load shows with a 14” barrel I can push the 110 grains to 2500 fps and have about 86% of powder burned

If I were to make the 7.62 x 45 cases from .220 Swift brass, I would cut the Swift cases at the case body/shoulder junction (1.723") before running them through a full-length 7.62 x 45 sizing die. The case diameter of the Swift case at that point is .402 inches and it would need to be squeezed down to .341 inches to form the neck. Does anyone know whether squeezing down the cut-off case .061 inches would be easily done with a full-length sizing die without buying a forming die?

This is what Donnelly says.

Thanks for that. It seems that only a full-length sizing die is necessary as I suspected.

I ran a Grendel reamer into a 7.62x39 Howa mini to clean up to the shoulder, creating a .311 bore Grendel cartridge. Don’t think it was enough to get a 150 to 24-2500 fps, but it gave the 125’s a bit of a boost. Easy fire form with loaded Starline 7.62x39.

Would you happen to know what velocity you get with the 150's?

What dies are you using after the clean up?

Only shot 125’s, no 150’s. I have a Grendel bushing die w/ 30 bushing. Haven’t played w/ it much since I built it. Had several takeoff mini barrels and was just messing around one day.

Riflehunter,

Thanks for starting this thread.

I'm considering something semi-similar...

I've got a Rem. M7 in 300 Blackout, really love shooting subsonics, but I've also shot a lot of super's through it and have been looking at building something with a bit more zip.

So been looking at the 300 Ham'r, 150's allegedly at 2,300 fps (in a 16" barrel). No brass issues, should be easily formed from .223, plus Starline brass is avail., 223 bolt face... opens up a lot of rifle options.

Some of the above options sound intriguing too... particularly the Kimber Hunter.

Jerry

More like 2100 fps with 150's in an 18 inch barrel- see Hodgdon load data. To get reasonable performance in a .30 caliber, the case needs to hold about 36 grains or more IMO to duplicate .30-30 performance with 150's.

You're estimation is off a bit...

My Remington Model 7 in 300BO has a 16" barrel, shooting Speer's 150 grain bullet (#308150BLKGDB) I get approx. 2,150 fps using Speers load data for Lil'Gun. Granted this is the only powder they list as doing 2,100+ fps.

Regarding Speers load data, my results are pretty close to their velocity, except with Accurate 1680, which is a little faster in my rifle.

So, getting 2,150 fps in a 300BO, I'm confident that 2,300 fps in the 300 Ham'r should be doable... But I would like to see some real world data.

Jerry

It's often the case that the most accurate load is less than maximum. If they list 2154 fps as maximum, the accurate loading is quite probably somewhere around 2100 fps. Also, I don't usually want to be on maximum, unless the pressure isn't close to maximum (such as when the case is full). Do you know what barrel length Speer is using for its figures?

This is the Speer 150 grain 300 Blackout bullet load I settled on. As you note... I settled for less velocity for the accuracy, even though the faster loads were far from inaccurate. Probably couldn't do this again if I had to (note that it's only 50 yards);



16" Barrel.

Here's the first page with the details;