Loading sub-sonic rounds for 7.62x54r...

[McGuiver]

I started collecting bullets the last couple of weeks in hopes of loading some sub-sonic rounds for 7.62x54r.

I started with a Missouri Bullets that are for 300AAC...215gr hard cast and Hi-Tek coated.



My next bullet choice is a 200gr Lapua Bullet. It was designed for sub-sonic use in mind.





My third choice is a Sierra 174gr HPBT.



I loaded the first 2 bullet choices up with both Trail Boss powder versions, and another set with Red Dot powder.

I will be working my loads down to get sub-sonic, hopefully without sticking a bullet.



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[SkyHawk]

What rifle will you shoot it out of - will it have a fast enough twist rate to stabilize it?

[McGuiver]

Loading sub-sonic rounds for 7.62x54r...

I will be using my Mosin Nagant. It has a 29" barrel. I think it is a 1 in 10 twist rate. It should stabilize. I will test and report back.


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[SkyHawk]

I will be using my Mosin Nagant. It has a 29" barrel. I think it is a 1 in 10 twist rate. It should stabilize. I will test and report back.


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Might be borderline with 1:10, these usually like to be shot 1:7 or 1:8. The long barrel may help if you get the load just right so the barrel doesn't slow the round too much and it is right under subsonic at the muzzle. Let us know how it turns out! (Pun intended)

[McGuiver]

Might be borderline with 1:10, these usually like to be shot 1:7 or 1:8. The long barrel may help if you get the load just right so the barrel doesn't slow the round too much and it is right under subsonic at the muzzle. Let us know how it turns out! (Pun intended)

I did some initial calculations. I could not find data for the Missouri Bullet, so I found another similar bullet for BC. It looks like BC will be .4 for anything under 1600 FPS. Here is my calculation for the 215 gr bullet.






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[kevins750]

You have .308-.309-.311 bullets......

Is your mosin a Finish model?

Did you slug the bore?

[McGuiver]

Loading sub-sonic rounds for 7.62x54r...

I have a Russian Mosin. It has at least a 0.312" bore. I have shot .312 and .314 projectiles, and it is very accurate at 200 yards.

Today I shot the subsonic rounds I made up. The 215gr Missouri Bullets were stable out to 50 yards. Beyond that they were everywhere. At 200 yards I could not hit a 40 foot semi truck trailer if I wanted to. They were 30 feet high, or low, then 20 foot left or right. They were tumbling badly. The Missouri Bullets are 0.309" diameter. I only shot the ones I made with Red Dot powder. I forgot the Trail Boss ones at home this morning. I don't think the Trail Boss powder version ones will shoot any better.

The Lapua Sub-Sonic Bullets were spot on.



They dropped like a rock. At a 200 yard target, my Mosin had it's sight set to 550 (iron sights). They were very stable out to 300 yards also. At 300 yards my sights are 750 (iron sights). I did not chrono them, but My guess is about 1400 FPS with a 200gr Lapua Bullet with 13gr of Alliant Red Dot powder. These bullets are sized to 0.308" but have multiple driving bands along with a cannelure.



I will buy the Lapua Bullets again. Rick at Phillips Wholesale special ordered them for me. Now to put more Lapua Rounds together and Chrono them.

When the Lapua Bullets hit a 12" steel plate at 200 yards, they did not splatter like supersonic ones. The had a distinctive thud on the gong.






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[rsrocket1]

Custom loads for 91/30's are a lot of fun. I use the Lee C312-185-1R mold "beagled" to make 0.315"-0.316" diameter bullets because my 91/30 slugged at 0.313" I then size and gas check (or simply size for cheap plinkers) to 0.314". The Hornady 30 cal gas checks do fit on the bases and crimp nicely with the Lee push through sizer. I then use 10-12g Unique for some low noise, low recoil rounds that work very well at 25-50 yards at 1" or to ring a 200 yard 3' gong.

10.1g Unique averages 1296 fps while 11.8g give me 1440 fps.

I haven't loaded down to subsonic with the 7.62x54R, but with cast 200g .308 bullets, I have some very good results with 6.5g Red Dot which gives me 1005 fps in a Remington 788 in .308 Win. No risk of a stuck bullet so long as you use a decent amount of fast burning powder and work down carefully. You'll easily notice the difference in recoil between a low speed bullet exit and a stuck bullet which will feel like nothing more than the primer going off.