Hmmm, .32/20 similar to .300BLK?

Discussion about rifles in 300 AAC BLACKOUT (7.62x35mm), hosted by the creator of the cartridge.

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BJK
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Hmmm, .32/20 similar to .300BLK?

Post by BJK »

OK, brain storming... let me know if I'm all wet. I never heard of anyone doing this today. The barrel was made for metallic silhouette and lobbing bullets in as far as I know. I'm definitely not discussing loads of the period when it was popular 100 years ago.

.32/20 similar to .300BLK? Not the actual cartridge but as far as potential similar ballistic results today. Bear with me for a bit. I know there are substantial differences in the chambering. But I have a 10" Contender barrel chambered in it (.308 bore). I'm thinking if I get it threaded for a suppressor it might do much the same things that the .300BLK can do. No rechambering required to give me a 2nd "300BLK" type firearm. Of course the actual load data will be different but yet somewhat similar. I'm pushing a 125gr bullet to 2000ish fps in it now. I would never think of doing that in a period gun, but the Contender is a modern action using todays steel. I'd probably think more along the lines of quiet subsonic rounds to make use of the quiet action and not supersonic ammo as I have for it now. But I think subsonic loads, similar to .300BLK, are doable. I'm not using it for much now.

I've been thinking of this lately since it's still so cold outside and the ground is covered in snow that I can't get out and shoot and tossing ideas around is pretty much all I can do. Before building my AR .300BLK I was looking for a Contender or Encore barrel in .300BLK. I completely forgot the .32/20 barrel. Wouldn't it be a hoot if I had what I wanted all along right in the safe? (not selling my AR build though, I'll part with that only from my cold dead fingers.

I'm thinking the quiet action Contender in .32/20 for subsonic only. I still want a .300BLK repeater.

I should probably pull the barrel out and see what the twist is. But since it's a manual action no matter what the twist I can make it work subsonically with some bullet weight. It was made in many twists. Hopefully mine is 1:10.

Anyway, comments?
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dellet
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Re: Hmmm, .32/20 similar to .300BLK?

Post by dellet »

You haven't been around here long enough for me to tell you what an idiot I think you might be, so I'll just give you a link.
viewtopic.php?f=141&t=96500

A 30/20 (32/20, .308 bore) is basically a rimmed 30 carbine. The 30 carbine is a straight taper, 32/20 really does not have much of a neck. Then there is a 30/357 which is almost a rimmed 300 Blackout. 357 necked down to .308, slightly shorter case.

Then there is the 30-30 Wesson that can be formed from 357 Max. Brass. 190 grain bullet for reference.

Image

The twist rate in the Contender will determine max bullet length, the 30-30 Wesson has a 1/16 twist and 165 grain lead bullets are about max for best stability. 1600 FPS is the limit for lead that I use, rifle is about 120 years old.

Since you won't have to worry about cycling the action, you will have far more choices for powder and bullet weight won't matter to stay sub sonic. I think you will find it a lot of fun.

The Blackout case works out to be about a 30/24, you might check volume of the 32/20 cases and dial back the loads accordingly.

Sorry about that idiot comment :mrgreen:
300 Blackout, not just for sub-sonics.
BJK
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Re: Hmmm, .32/20 similar to .300BLK?

Post by BJK »

Thanks for the time it took to think about that answer.
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dellet
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Re: Hmmm, .32/20 similar to .300BLK?

Post by dellet »

BJK wrote: Fri Mar 05, 2021 12:21 am Thanks for the time it took to think about that answer.
I enjoy outside the box thinking.

Something else to keep in mind is that an inherent problem with the blackout casrtridge is case capacity. Not enough for supers/ too much for subs. The reduced capacity can be helpful, depending on the powder you use.

Look forward to hearing what the twist is and some range reports.
300 Blackout, not just for sub-sonics.
BJK
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Re: Hmmm, .32/20 similar to .300BLK?

Post by BJK »

Yeah, I was thinking subsonic would be easier. I don't expect to be pushing heavy bullets. The best twist it can have is 1:10, that was the fastest they made. If I could push a cast 110-125 subsonic with stability I'd be happy with that from that handgun. I have too many projects for the few months of warm weather this year. Hopefully I'll get time for this project. I have no use for it, I just think think it would be fun to do and quiet fun at the range.

edit: My supersonic loads use a 110 grain bullet, not a 125. Not bad for data that I recorded in 1999 though. Using WW296 it pushes the 110gr Speer Varminter to 1963 fps, and a 110gr Sierra to 1982. I don't have accuracy data, but if it wasn't good I would have made a note of that. It certainly isn't the load that was sold for guns chambered in it 120 years ago.
BJK
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Re: Hmmm, .32/20 similar to .300BLK?

Post by BJK »

I apologize, I didn't read the 1st post and this post repeats lots of what was posted in it. But if your memory is as bad as mine is it'll bring you up to speed. Heck, I wrote the 1st post in the thread and couldn't remember what I wrote!

Soon I'll be able to play with the .32/20 subsonics. The barrel is headed back to me after having it threaded. Of course nothing was stopping me from shooting subsonics w/o a can all along. Or yes it was. I was waiting for warmer weather and before that had my hands full with the 300BLK and learning casting.

Before anyone suggests it. Yes, I intend to shoot test loads w/o the can until they are proven stable. If I need to I'll shoot 110gr .30 bullets since I don't need pressure to cycle anything and I can get them fairly inexpensively (plated or even a mould). But I think I can go significantly heavier (cast) since the twist data I found on line (T/C chart) stated 1:10. It may not stabilize 220s. But I just got a mould for 150gr bullets that should stabilize nicely.

I think it was mentioned that case capacities of .32/20 and .30 Carbine are similar (within one grain of water). But I couldn't find subsonic data for .30 Carbine. I guess everyone shoots it with a carbine and wants it to cycle. Does anyone know the water capacity of a 300BLK case? I'd like to have a starting point. I did a 'net search and turned up nothing.

In the closed breech with no action noise it should be fairly quiet with a can. Maybe I should have also gotten the barrel rechambered for 300BLK, but I have 1k .32/20 brass just sitting there waiting. I did consider rechambering if possible, but I never even inquired, having ditched the idea early on. I sorta like the century old cartridge. Not everyone uses it and I don't mind being different. In fact I rather enjoy it.
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dellet
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Re: Hmmm, .32/20 similar to .300BLK?

Post by dellet »

BJK wrote: Sat Apr 09, 2022 3:51 pm I apologize, I didn't read the 1st post and this post repeats lots of what was posted in it. But if your memory is as bad as mine is it'll bring you up to speed. Heck, I wrote the 1st post in the thread and couldn't remember what I wrote!

Soon I'll be able to play with the .32/20 subsonics. The barrel is headed back to me after having it threaded. Of course nothing was stopping me from shooting subsonics w/o a can all along. Or yes it was. I was waiting for warmer weather and before that had my hands full with the 300BLK and learning casting.

Before anyone suggests it. Yes, I intend to shoot test loads w/o the can until they are proven stable. If I need to I'll shoot 110gr .30 bullets since I don't need pressure to cycle anything and I can get them fairly inexpensively (plated or even a mould). But I think I can go significantly heavier (cast) since the twist data I found on line (T/C chart) stated 1:10. It may not stabilize 220s. But I just got a mould for 150gr bullets that should stabilize nicely.

I think it was mentioned that case capacities of .32/20 and .30 Carbine are similar (within one grain of water). But I couldn't find subsonic data for .30 Carbine. I guess everyone shoots it with a carbine and wants it to cycle. Does anyone know the water capacity of a 300BLK case? I'd like to have a starting point. I did a 'net search and turned up nothing.

In the closed breech with no action noise it should be fairly quiet with a can. Maybe I should have also gotten the barrel rechambered for 300BLK, but I have 1k .32/20 brass just sitting there waiting. I did consider rechambering if possible, but I never even inquired, having ditched the idea early on. I sorta like the century old cartridge. Not everyone uses it and I don't mind being different. In fact I rather enjoy it.
What twist rate did it end up being?

Most likely you will be able to stabilize bullets up to 200 grains in a 1/10. Remember it is the length and shape of the bullet more than the weight that will determine stability. Cast is heavy for length compared to jacketed and your bullet diameter will be larger. So a 308 150 grain jacketed bullet might be as much as 170 grains if it was a cast 311.

What you will need to keep in mind is chamber length, throat length in particular. How long you can load the bullet. If all the extra weight is in the case, pressure will go up. If you can keep minimal bullet length in the case and load long, pressure won’t be so much of an issue.

Sierra has subsonic 150 grain blackout data, that would be a good start. It will probably be super, but pressure should be safe.

Here is a good search that will have some info
32-20 150 grain site:www.assra.com

You might also search “32-20 Schuetzen loads”.

If you can post bullet length, weight, and loaded length, can come up with some Quickload generated loads.

Next we will have to get you a rifle more suited for the cartridge.
300 Blackout, not just for sub-sonics.
BJK
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Re: Hmmm, .32/20 similar to .300BLK?

Post by BJK »

Thanks.

I have 700 or so jacketed 200gr bullet pulls and no planned use for them.

Rifle? Not at this time :-) . I looked into a custom barrel ($400 if memory serves), but at my age I've been selling firearms. The ones I have been acquiring were to replace some long guns and to fill a niche that I didn't want to leave empty. I might SBR it to put a stock on it, but I've been wondering if I want to spend the $200. Right now it's just for kicks at the range and because I like doing stuff like this. Is it worth $200 for a shoulder stock? Time will tell. The gun and cartridge really fills no planned use, it's just for fun. If I could still hunt I'd get a mould for a bullet with a flatish meplat for decent energy transfer, But I can no longer hunt so I won't. I probably have bullets on the shelf that I can use too, 110s and 125s, maybe others.

edit: the handgun has been reassembled and is ready to go but on a back burner. 300BLK first, toys later. I did check the bullet situation and found some bullets, 150s with a large flat meplat that I bought and had forgotten. Typical. The 220s that I cast last year I can't find. Also typical. They'll turn up eventually. I looked everywhere except where they are.
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gemihur
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Re: Hmmm, .32/20 similar to .300BLK?

Post by gemihur »

Reeder's Raptor in 30 cal. uses 204 Ruger brass compares to 300 Blackout
Image
Both shown with Nosler 168 gr. HP
Gemi Hur
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