Low B.C. High FPS hunting loads.

You can get 200 gr .375 bullets, they are made for the 375 Winchester.

You can get ~ 150gr bullets in .358 caliber, they are designed for handgun cartridges.

Do you think a max loaded 158 gr Gold Dot would hold?
What about 125 grain?

I don't think so.

We need .358 Cal 150-180 grain heavy jacket aluminum core bullets or lead core.

Sectional density should be below .20

Penetration should be no more then 12 inches.

Velocity should be 3400 fps.

Think Magnum Varmint.
 
Had a long chat today with Dale.

He agreed that basketball sized exited wounds would be better then Grapefruit sized. Working with Aluminum is a different animal altogether.

Low to no market on soft lead and regular copper 150-180 gr large bore projectiles as well. I detect a large chink in the armor of the North American market.
 
Demand and performance. Not many people looking for light for caliber bullets in non-varmint calibers. Most people consider 150gr on the light side for 30cal, nevermind 35 or 375cal. From a big game hunting perspective you want the weight for penetration, and otherwise you can always just get a smaller faster cartridge for varmints or targets.

Also typically when bullets are light for caliber like that they tend to be designed for weaker cartridges - 125gr 358 bullets are common for 357mag/38spl, but they aren't designed for 3500fps.

True fer sure on those points, but Speer 110 gr HP's pushed from a 35 Rem or 35-284 and such at a tad below 3000 fps are very entertaining on raccoon sized pest critters inside 100 yds. Push 'em beyond 3000 and you will likely see a dust ring in the air around the 50 yd mark as they come apart. Been there, done that.
 
True fer sure on those points, but Speer 110 gr HP's pushed from a 35 Rem or 35-284 and such at a tad below 3000 fps are very entertaining on raccoon sized pest critters inside 100 yds. Push 'em beyond 3000 and you will likely see a dust ring in the air around the 50 yd mark as they come apart. Been there, done that.

Copper would hold. However 160gr .338 Lapua would penetrate too much.

A .375 Accubond jacket profile filled with epoxy or wax might be the ticket. Hollowed out TSX's would work. Fill it up and thread on a steel or ceramic head.

I need to watch some bullet manufacturing videos to get better ideas.
 
If you google 7.92x40. This will give you a visual.
My idea is basically a jumbo version of 7.92x33....but it had a baby with 7.92x40. The result is basically .375 RCM or .40 CT A.I.

It fits in SR25 Mags and Pmags ( Slight widening). Can go in bolt guns too.

3400 FPS is not too much for modern barrels. M16A1 could handle 3200 fps...in 1959. Pencil barrel too.
Modern German barrels can handle the heat and speed.
Lothar Walther for example.

A gap exists in the SR25 market. Casings that are 1mm wider then .308 and 1mm thinner then WSM.

This gives you the RCM. Basically, magnum .308.
62k psi. Trimmed down 1 CM. Necked up to .375 or .40.
Long, sleek, and light bullets in a magnum powered Semi Auto or Bolt gun.
 
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Do you think a max loaded 158 gr Gold Dot would hold?
What about 125 grain?

I don't think so.

We need .358 Cal 150-180 grain heavy jacket aluminum core bullets or lead core.

Sectional density should be below .20

Penetration should be no more then 12 inches.

Velocity should be 3400 fps.

Think Magnum Varmint.

What do you mean by "would hold"
 
If you are worrying about the bullets holding together maybe one of the Barnes all copper selections would work.

Absolutely not.

The round that I have in mind would essentially have to perform like a
.35-40 cal Ballistic Tip.

Heavily built varmints do not go down fast enough for my liking inside 50 yards. Like pigs for example.

Sometimes takes like 2-3 .300 Blackouts or .300 HAMRs to take them down.

I want instant kills. Massive trauma. Like a 3400 FPS soft point partition.

Speed has its own qualities.

What is better on a gut shot?

A max load .357 Magnum or Maximim 125 gr SJHP @ 2050 fps from an 8 inch .357?

Or a .224 77gr TMK @ 2050 fps?

The correct answer is .357 Magum.

8-10 inches of penetration is fine.
 
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Not fly apart in the barrel or air from forces associated with high velocity.

Its not the high linear velocity per say that is the issue, its the high rotational velocity. That can be addressed by getting a slower twist barrel.

30-378 Weatherby, 150gr nosler ballistic tips, in a 12 twist barrel would probably do the trick...
 
Just reply about your magnum pistol powder post.

I have a 300 rum, change powders while reloading....load it down to 300wm, 30-06, 308 power level. That's not what your talking about though. Literally you could load a 2700 ft/sec caliber down to subsonic. You want hyper velocity in a short barrel. Powders burnt in 12", more like 30-06 or 308 fast powder in a super magnum case.

Lots of research and be safe. Don't blow your face off.
 
Absolutely not.

The round that I have in mind would essentially have to perform like a
.35-40 cal Ballistic Tip.

Barnes pistol bullets are intended to fully expand at pistol velocities. Push them to 3400 fps they will perform more like a BT upon impact. The petals will fly off, the shank will keep shedding material until there is not much left. I've shot Barnes .308 caliber TTSX at 3500FPS into bears at close range and that's what happens. A pistol bullet would be even more dramatic.

Heavily built varmints do not go down fast enough for my liking inside 50 yards. Like pigs for example.

Sometimes takes like 2-3 .300 Blackouts or .300 HAMRs to take them down.

If it takes 2-3 shots the most pragmatic solution would just be to use a .308 or similar, rather than re-invent the wheel. But please let us know how your project turns out.
 
Its not the high linear velocity per say that is the issue, its the high rotational velocity. That can be addressed by getting a slower twist barrel.

30-378 Weatherby, 150gr nosler ballistic tips, in a 12 twist barrel would probably do the trick...

Yes. That kind of 150 Grain BT performance in an SR25 SBR platform.
 
Barnes pistol bullets are intended to fully expand at pistol velocities. Push them to 3400 fps they will perform more like a BT upon impact. The petals will fly off, the shank will keep shedding material until there is not much left. I've shot Barnes .308 caliber TTSX at 3500FPS into bears at close range and that's what happens. A pistol bullet would be even more dramatic.



If it takes 2-3 shots the most pragmatic solution would just be to use a .308 or similar, rather than re-invent the wheel. But please let us know how your project turns out.

I am talking about 3400 ft lbs in an SBR semi auto.

More of a U.S. Military trick question. I was asked if I can figure out stupid MIL requirements without going to Hybrid case design.

I am here to gather info.

Also. A .357 SJHP going 2050 fps will do more physical damage to meat then a 125 gr DPX (Solid copper HP) going the same speed.

DPX petals will sheer off and it will penetrate like 15-20 inches. Way too much. Wound channel will not be as wrecked either.

Lead and Aluminum open up at low velocities as well. Copper doesn't.
"Lower velocities" I should say.

Also lead and aluminum is FAR cheaper then copper.
Think of a 225 Grain .338 Accubond filled with Aluminum?
Dirt cheap and devastating. Flies better then a lower b.c. lead round as well.
 
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Just reply about your magnum pistol powder post.

I have a 300 rum, change powders while reloading....load it down to 300wm, 30-06, 308 power level. That's not what your talking about though. Literally you could load a 2700 ft/sec caliber down to subsonic. You want hyper velocity in a short barrel. Powders burnt in 12", more like 30-06 or 308 fast powder in a super magnum case.

Lots of research and be safe. Don't blow your face off.

I'm not physically testing right now. Too much info left out to even start with that.

How would you propell a 156 gr .375 Dia projectile in a 11.5 inch or 12.5 inch gas gun?

SR25 to be precise. Gas port on barrel is....I forget. But that doesn't matter just yet.
 
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