212eldx in .308 hybrid cases?

Eo12 · Mar 9, 2025

Is anyone else loading these in the hybrid cases? Read about them here and they sound like absolute hammers in a lightweight hunting rifle.

308 +P+ and Musings from Elk Camp

Walter recently concluded a two-week trip to Southern Colorado elk hunting with the Noveske crew.

sobchaksecurity.substack.com

redbullitt · Mar 10, 2025

45-90 has done a lot of awesome stuff... we all appreciate the sharing very much!

I bet he can help you quite a bit there.

Eo12 · Mar 10, 2025

@45-90 have you tried any of the hybrid cases with this bullet in .308?

45-90 · Mar 10, 2025

Eo12 said:
@45-90 have you tried any of the hybrid cases with this bullet in .308?

Been shooting hybrid cases in various 308 bases cases since they first came out.
308, 358, 6.5 CM, 8.6 blackout.
I don't shoot as many game bullets these days, but alot of match bullets...depending on caliber.

I recently fired some hybrid cases with 308 in a 22" barrel 9 twist barrel.
These were Berger 208 gr and Berger 215 gr. With 6.5 Staball, notice the 208 Berger hybrid have a high BC and low S/ D and better accuracy in my rifle.
If you shorten the overall length take out a few grains of powder and work up.
I manderal up to 30 cal and run through a 308 FL die anneal, and neck turn as shown in the lathe with a ground carbide tool that has a sharper radius in the neck shoulder junction and slightly cuts the 20° angle.
No donuts for pinch points at high pressure and little spring back. It all can be done with hand tools just takes longer.
As always be careful work up slowly, they safe in my rifle, but every barrel and chamber is different. ...For Bolt Gun Only.
I have 8 308s for various purposes bolts and autos, long action and short.
The long action 30" 8 twist has some fantastic velocities for a 308 case, like 225 eldm at 2700 fps, or 168 gr at 3255 fps, 200 SMK at 2952.
But if ya want short barrels you'll lose alot of velocity.
If you shoot short barrels stay with heavy bullets, the velocity difference will be considerably less.
The 308 of today doesn't have to be the 308 of 50 yrs ago.

45-90 · Mar 10, 2025

I don't always have time to work on hybrid case load data, because I like to do other weird projects....today I shot some test loads out of the 510 whisper....the usual subsonic 650 gr FMJ...and some 300 gr Barnes that hit 2875 fps for 5500 ft/bs of energy.
But that's not the end of the dream...only the beginning.
I can fit this in an AR10,... but also in an AR 15!
18" barrel low pressure round would get close to 3600 ft/lbs of energy out of the 300 gr Barnes 510 cal AR 15.
But you have to machine a barrel complete from a barrel blank. And cut the brass case heads down to 308, and cut a new extractor groove, a 450 bushmaster bolt, and alter the 450 BM mag, 450 bushmaster barrel extension.

Just like the 30 RAR I built from scratch, if ya want one gotta make it yourself.
These wild out of the box projects take time and money, from practical reloading experiments... and its all just a hobby.
Here is the .510 Whisper cal in bushmaster mag, needs machining. And here it is in the 450 bushmaster AR 15.
Notice the back of 2nd from left has a home machined rebated head & new extractor groove to fit an AR 10...the AR 15 even more drastic.
So I've been contemplating this idea. The subs will be 560 gr homemade for this particular endevor, already machined the sub bullet, in AR 15 mag...AR 10 has more room, and more pressure available.
Tons of experiments like 350 gr Makers at 1806 fps instead of the 1000 fps limit in the 6.5 twist instead of the 3 twist, with the bore rider concept emoyed...plus the tiny 338 Spectre with a 350 gr Maker achieving 1100 fps.
Everyone's shooting standard stuff, let's think outside the box....time to talk to Elon.

...

Eo12 · Mar 10, 2025

45-90 said:
Been shooting hybrid cases in various 308 bases cases since they first came out.
308, 358, 6.5 CM, 8.6 blackout.
I don't shoot as many game bullets these days, but alot of match bullets...depending on caliber.

I recently fired some hybrid cases with 308 in a 22" barrel 9 twist barrel.
These were Berger 208 gr and Berger 215 gr. With 6.5 Staball, notice the 208 Berger hybrid have a high BC and low S/ D and better accuracy in my rifle.
If you shorten the overall length take out a few grains of powder and work up.
I manderal up to 30 cal and run through a 308 FL die anneal, and neck turn as shown in the lathe with a ground carbide tool that has a sharper radius in the neck shoulder junction and slightly cuts the 20° angle.
No donuts for pinch points at high pressure and little spring back. It all can be done with hand tools just takes longer.
As always be careful work up slowly, they safe in my rifle, but every barrel and chamber is different. ...For Bolt Gun Only.
I have 8 308s for various purposes bolts and autos, long action and short.
The long action 30" 8 twist has some fantastic velocities for a 308 case, like 225 eldm at 2700 fps, or 168 gr at 3255 fps, 200 SMK at 2952.
But if ya want short barrels you'll lose alot of velocity.
If you shoot short barrels stay with heavy bullets, the velocity difference will be considerably less.
The 308 of today doesn't have to be the 308 of 50 yrs ago.

Thank you so much for sharing your insight on this. Hopefully my results will be similar to yours. That article really got me excited about the possibilities of the 308 again.

Eo12 · Mar 10, 2025

45-90 said:
I don't always have time to work on hybrid case load data, because I like to do other weird projects....today I shot some test loads out of the 510 whisper....the usual subsonic 650 gr FMJ...and some 300 gr Barnes that hit 2875 fps for 5500 ft/bs of energy.
But that's not the end of the dream...only the beginning.
I can fit this in an AR10,... but also in an AR 15!
18" barrel low pressure round would get close to 3600 ft/lbs of energy out of the 300 gr Barnes 510 cal AR 15.
But you have to machine a barrel complete from a barrel blank. And cut the brass case heads down to 308, and cut a new extractor groove, a 450 bushmaster bolt, and alter the 450 BM mag, 450 bushmaster barrel extension.

Just like the 30 RAR I built from scratch, if ya want one gotta make it yourself.
These wild out of the box projects take time and money, from practical reloading experiments... and its all just a hobby.
Here is the .510 Whisper cal in bushmaster mag, needs machining. And here it is in the 450 bushmaster AR 15.
Notice the back of 2nd from left has a home machined rebated head & new extractor groove to fit an AR 10...the AR 15 even more drastic.
So I've been contemplating this idea. The subs will be 560 gr homemade for this particular endevor, already machined the sub bullet, in AR 15 mag...AR 10 has more room, and more pressure available.
Tons of experiments like 350 gr Makers at 1806 fps instead of the 1000 fps limit in the 6.5 twist instead of the 3 twist, with the bore rider concept emoyed...plus the tiny 338 Spectre with a 350 gr Maker achieving 1100 fps.
Everyone's shooting standard stuff, let's think outside the box....time to talk to Elon. ...

Your creativity with those rounds is what is needed. Keep doing great work. I’m sure we are all enjoying watching your mind at work.

45-90 · Mar 27, 2025

Need to start a hybrid case thread to share information.
I've been at it since they first came out there is definitely an advantage to these cases.
So ya don't put up with all the naysayers.

I was asked but the 175 gr SMK and 177 gr SMK so I did a test yesterday with two rifles a 22" 9 twist and a 30" 8 twist...and two powders.

I seated the 177 SMK out a bit longer and the 175 at 2.830" to fit most magazines.
The longer barrel for the 177 gr was 3126 fps with a .545 g1 BC not too bad, and 3049 fps in the 22" barrel. Over 3800 ft/ lbs of muzzle energy from the 177gr in the long barrel

Others might be interested in the heavy bullets the 230 gr Atips and the 250 Atip.

The 230 Atip was 2708 fps on the long 8 twist and accurate, especially in the 2680 fps area.
And right at 2601 average for the 22" 9 twist.
The 250 gr Atip was 2515 fps for this test.
Without changing the seating with a throating reamer to around 3.4" as this is a long action max effort 308, 2600 fps could be possible...but that would require shorter bullets to jump alot. But with a 250 gr bullet the 308 runs out of powder capacity.

Plus the 230 gr Atip at 2708 fps area is no slouch.

Also ran the Barnes copper tipped 110 gr bullets to 3530 fps, but thought it was quite a bit slower than predicted...almost no recoil was noticed. In the 8 twist it was accurate and over 316,000 rpm.

The 230 Atip at 2700 fps on the long action 308 will be supersonic to 1900 yds...at 1500 ft and 70°....alot farther as altitude increases...here you can go from 200 ft to 10,000 ft elevation in 60 miles.

Not interested in that one can still make a short barrel faster than normal with hybrid cases in a bolt gun.

A picture of a standard Rem 700 with a Bartlein 9 twist running 230 Atips to 2601 fps. Single load ...but just buy a used 30-06 action, add an 8 or 9 twist Bartlein and an aluminum chassis with 3.4" mags and have a 308 monster.
My Bartlein 8 twist is more accurate than the 9 twist with most bullets from 130 gr to 250 gr, but it liked the longer copper Barnes 110 gr tipped bullets...but that could be it's a much higher dollar rifle and scope with a much more adjustable aluminum chassis.

BJames · Mar 27, 2025

45-90 said:
Need to start a hybrid case thread to share information.
I've been at it since they first came out there is definitely an advantage to these cases.
So ya don't put up with all the naysayers.

I was asked but the 175 gr SMK and 177 gr SMK so I did a test yesterday with two rifles a 22" 9 twist and a 30" 8 twist...and two powders.

I seated the 177 SMK out a bit longer and the 175 at 2.830" to fit most magazines.
The longer barrel for the 177 gr was 3126 fps with a .545 g1 BC not too bad, and 3049 fps in the 22" barrel. Over 3800 ft/ lbs of muzzle energy from the 177gr in the long barrel

Others might be interested in the heavy bullets the 230 gr Atips and the 250 Atip.

The 230 Atip was 2708 fps on the long 8 twist and accurate, especially in the 2680 fps area.
And right at 2601 average for the 22" 9 twist.
The 250 gr Atip was 2515 fps for this test.
Without changing the seating with a throating reamer to around 3.4" as this is a long action max effort 308, 2600 fps could be possible...but that would require shorter bullets to jump alot. But with a 250 gr bullet the 308 runs out of powder capacity.

Plus the 230 gr Atip at 2708 fps area is no slouch.

Also ran the Barnes copper tipped 110 gr bullets to 3530 fps, but thought it was quite a bit slower than predicted...almost no recoil was noticed. In the 8 twist it was accurate and over 316,000 rpm.

The 230 Atip at 2700 fps on the long action 308 will be supersonic to 1900 yds...at 1500 ft and 70°....alot farther as altitude increases...here you can go from 200 ft to 10,000 ft elevation in 60 miles.

Not interested in that one can still make a short barrel faster than normal with hybrid cases in a bolt gun.

A picture of a standard Rem 700 with a Bartlein 9 twist running 230 Atips to 2601 fps. Single load ...but just buy a used 30-06 action, add an 8 or 9 twist Bartlein and an aluminum chassis with 3.4" mags and have a 308 monster.
My Bartlein 8 twist is more accurate than the 9 twist with most bullets from 130 gr to 250 gr, but it liked the longer copper Barnes 110 gr tipped bullets...but that could be it's a much higher dollar rifle and scope with a much more adjustable aluminum chassis.

I vote for you to start a dedicated thread here. Super cool stuff. Your 250gr data is only 125fps slower than a 300 WSM 28” a buddy was trying to sell me. Thought it was cool, just not what I want to do with that case.

I’m curious what round counts you have on the rifles you’re shooting the hybrid cases? Looking for wear patterns, not so much barrel life but any lug set back, other action wear or anything else?

45-90 · Mar 27, 2025

BJames said:
I vote for you to start a dedicated thread here. Super cool stuff. Your 250gr data is only 125fps slower than a 300 WSM 28” a buddy was trying to sell me. Thought it was cool, just not what I want to do with that case.

I’m curious what round counts you have on the rifles you’re shooting the hybrid cases? Looking for wear patterns, not so much barrel life but any lug set back, other action wear or anything else?

I do not do round count on my rifles ...anymore. Quit doing that around 22 yrs ago.
When I was doing round counts, on LR shooting with the 308 I ran them 8000 rds and kept good track, then do a barrel change. One Rem 700 action has over 20,000 heavy match rounds on it.

On the hybrid cases I checked for lug set back on several rifles and there was none.

The barrel wear will likely be accelerated, but I haven't checked lately. When accurate falls off, I start looking.

I've reloaded some of the hybrid cases 5 times no change in primer pockets.
The ones yesterday were newly formed cases.

I am in a unique position as I do all the gunsmithing to these rifles and have my own reamers snd gauges.

So a barrel change is just a online trip to Bugholes or SPR for a new usually Bartlein 5 R barrel these days. Its only $420 but the price is going up to change out barrels...about the price of am 8 lb jug of powder, no big deal... so my concern about barrel life isn't like most, so I stopped round count many years ago.
I run all kinds of brass through the 308 these LC primed and ready to load thousand rounds have already been fired,
These are the newly formed hybrid cases, fired for the above testing about 100 cases.
I have around 1500 hybrid cases.
What a 308 barrel looks like after 8000 rds, in the throat area and down the barrel a ways ...still shot pretty good.
So I cut out most of the bad area and made an AR 15 barrel out of the 308 bolt barrel, it's now a 30 RAR.

The information on hybrid cases is there for those who want to try it..carefully, and work up. You do not have to go full throttle to have an advantage and sometimes ya just want plinking ammo, and LC brass is fine ...or even subsonic loads, and hybrid cases are not used.
I like the 9 & 8 twist 308 barrels for the heavy bullets.

Eo12 · Mar 27, 2025

@45-90 have you tried shooting the 212eld out of the 308 with those cases?

45-90 · Mar 27, 2025

Eo12 said:
@45-90 have you tried shooting the 212eld out of the 308 with those cases?

I don't have any 212 eld bullets, had some shot 215 gr Bergers, and 208 ELDM, 208 Berger 225 eldm, 230 SMK & 230 Atips, and 250 Atips.
Plus all the light ones 100 gr lapua, 110 gr Barnes, 125 gr 130 gr 150 gr 155 gr 168 gr 169 gr 175 gr 177 gr & 200 gr SMK.

Eo12 · Mar 27, 2025

45-90 said:
I don't have any 212 eld bullets, had some shot 215 gr Bergers, and 208 ELDM, 208 Berger 225 eldm, 230 SMK & 230 Atips, and 250 Atips.
Plus all the light ones 100 gr lapua, 110 gr Barnes, 125 gr 130 gr 150 gr 155 gr 168 gr 169 gr 175 gr 177 gr & 200 gr SMK.

What powders did you use with the 208s and 215s? Did they work as you expected them to?

45-90 · Mar 27, 2025

Some background I am a retired machinist with machine tools. So I do all my own rifle building along with what some would term outrageous projects.

So I do not spend all my time on hybrid cases but employ them in any caliber I want to improve velocity ...bolt actions only.
The rifles all have "trued: actions, to distribute the pressure forces equally on the locking lugs.
It only takes me a day to build a rifle.
Example Ordered a Bartlein barrel from SPR it arrived in 7 days at noon.
I unpacked the barrel, trued the action, took measurements, chambered and threaded for a muzzle break, threaded the bolt handle, installed the m16 extractor, made a bolt knob, reloaded for it and the next day was shooting my new 6 Dasher.

Haven't done any competition in years...don't miss it. And no one cares.

So this it for those who actually want to try the hybrid case improvement.... not open to criticism of, "ya can't do that." Because you actually can.

You are responsible for your actions and loading practices. This is to help you get started successfully...and share information.
How I do this may or may not appeal to you, so don't do it... simple.

This is the one day rifle build, plus reloading the ammo to shoot the next dqy.

Bacarrat · Mar 27, 2025

308 Lapua brass, 6.8x51 Hyrbid, necked and sized, and 6.8x51 out of the box. Have 25 prepped, just going to fireform this weekend with normal 308 loads. Would eventually like to see how well they do with some of the heavies. I have 200.2, 208ELDMs 215s Bergers and 225ELDM. I think the last 3 would not be able to stabilize out of the AI barrel.

45-90 · Mar 27, 2025

Now to the more important subject, hybrid cases in the caliber of your choice...here the 308 Win.
I've been ordering them from American Reloading...a super sale just a few days ago a bunch came in...45 cents ea including shipping and a primer.
Never had them that cheap...but the latest military pull downs have some ball powder in them I use an air compressor nozzle to blast out the powder left in tbe sides of the case.
Deprime the live primer and re use later.
Mandrel up the 277 caliber with a 308 Wilson mandrel die. Use Lee Resizing lube.
Lube with Lee Resizing lube and run through a 308 FL sizing die...a Lee die is fine for forming incase ya don't lube it enough, the average guy will have a serious problem.
Always lube your cases well, and keep the lube off the shoulder area.

I skim neck turn into the case shoulder with a sharper radius to help with donuts.
You do not want pinch points at high pressures.

You can anneal here and spray lube and run through the FL die of your choice, checking with a cartridge gauge that you are settling the shoulder back enough, .001" or. 002" to your desire, so the case chambers easy.

I neck turn in a lathe, cause I have one.
Plus a diamond grinder to get the full 20°
Angel and sharp radius.
But this can be accomplished with simple neck turning tools.
I think this step should be done on all hybrid cases regardless of caliber.
The Wilson die with bump ups to make larger calibers like 338 in one pass.

45-90 · Mar 27, 2025

Now the

Eo12 said:
What powders did you use with the 208s and 215s? Did they work as you expected them to?

So here is the important part that everyone wants to know...the load data used.

Here is the load data for the 308 Win Standard SAAMI chamber, my reamer, in a trued 700 action with a 9 twist 5 R Bartlein barrel 22" long.

The 208 gr hybrid in hybrid cases for this rifle is a good load, accurate and low SDs plus a better BC than the 215 gr Berger.

But sometimes I shoot these hybrid loads in the 8 twist long action, (because these are single load here), and get a much different accuracy event.

Or run them out of the MDT center feed without the center support for almost 3" in the rifle shown I believe it's 2.990" or 2.980" will get ya off the ogive. ... it's the same barreled action buy different stock, as I wanted to try the other stock used in this test.
But if you shorten the COAL be sure to drop the power charge about 1.5 grains...or more and work up.

So nothing is predictable here. Sometimes it's what is expected... sometimes not.

45-90 · Mar 27, 2025

Bacarrat said:
308 Lapua brass, 6.8x51 Hyrbid, necked and sized, and 6.8x51 out of the box. Have 25 prepped, just going to fireform this weekend with normal 308 loads. Would eventually like to see how well they do with some of the heavies. I have 200.2, 208ELDMs 215s Bergers and 225ELDM. I think the last 3 would not be able to stabilize out of the AI barrel.
View attachment 8650670

I have loaded all of those bullets, but use a long action for my serious 308 work, and a 8 twist barrel. I like the 200 SMK over the 200.2 Berger, both are accurate, but many times the SMK is the winner plus it's bullet profile offers a higher BC and more powder capacity in the long action...faster and higher BC.
Lot's of shooters praise Berger bullets, I like them in the 6mm arena, but not always in other calibers. Their profiles and BCs are falling behind.
Plus the worst bullet ever was the 168 gr VLD Hunting 308 Berger, no 30 caliber rifle I have, has ever shot this bullet accurately with any load.
I got them on sale, a box of 500 pcs, probably out of balance, off center J4 jackets... or something...still trying. But they shoot more like 147 gr military FMJs.

Eo12 · Mar 27, 2025

45-90 said:
Now the

So here is the important part that everyone wants to know...the load data used.

Here is the load data for the 308 Win Standard SAAMI chamber, my reamer, in a trued 700 action with a 9 twist 5 R Bartlein barrel 22" long.

The 208 gr hybrid in hybrid cases for this rifle is a good load, accurate and low SDs plus a better BC than the 215 gr Berger.

But sometimes I shoot these hybrid loads in the 8 twist long action, (because these are single load here), and get a much different accuracy event.

Or run them out of the MDT center feed without the center support for almost 3" in the rifle shown I believe it's 2.990" or 2.980" will get ya off the ogive. ... it's the same barreled action buy different stock, as I wanted to try the other stock used in this test.
But if you shorten the COAL be sure to drop the power charge about 1.5 grains...or more and work up.

So nothing is predictable here. Sometimes it's what is expected... sometimes not.

Thanks for the info.

BJames · Mar 27, 2025

45-90 said:
Now the

So here is the important part that everyone wants to know...the load data used.

Here is the load data for the 308 Win Standard SAAMI chamber, my reamer, in a trued 700 action with a 9 twist 5 R Bartlein barrel 22" long.

The 208 gr hybrid in hybrid cases for this rifle is a good load, accurate and low SDs plus a better BC than the 215 gr Berger.

But sometimes I shoot these hybrid loads in the 8 twist long action, (because these are single load here), and get a much different accuracy event.

Or run them out of the MDT center feed without the center support for almost 3" in the rifle shown I believe it's 2.990" or 2.980" will get ya off the ogive. ... it's the same barreled action buy different stock, as I wanted to try the other stock used in this test.
But if you shorten the COAL be sure to drop the power charge about 1.5 grains...or more and work up.

So nothing is predictable here. Sometimes it's what is expected... sometimes not.

Are you using quickload or standard work up practices when determining your upper limit?

Also, what speeds were you seeing, specifically in 308, with 175-185 class bullets and are they mag fed?

I just snagged a couple hundred of the hybrid cases to experiment with. My goal is to see if I can get standard barrel length type speeds out of 16-18” barrels. Anything faster would be gravy.

Eo12 · Mar 27, 2025

The hybrid cases are actually 50% off if anyone is looking for some.

memilanuk · Mar 28, 2025

Link?

Eo12 · Mar 28, 2025

277 Fury / 6.8x51mm SIG Primed "Hybrid" Case - 100ct

ALL CASES CONTAIN STUCK POWDER Pulled, Primed Brass - Casings may contain minor dents/scratches *All casing should be resized prior to loading

americanreloading.com

45-90 · Mar 28, 2025

BJames said:
Are you using quickload or standard work up practices when determining your upper limit?

Also, what speeds were you seeing, specifically in 308, with 175-185 class bullets and are they mag fed?

I just snagged a couple hundred of the hybrid cases to experiment with. My goal is to see if I can get standard barrel length type speeds out of 16-18” barrels. Anything faster would be gravy.

I should get a commission on hybrid cases but I bought 1500 at the higher price...
I have already wrote about most of this cause guys ask me about certain bullets.

I feel like I answered these questions a million times... maybe the name to find more answers, some have been private responses.
And you should neck turn... and make quality cases, no punch points or donunts at high pressures.
I just shot the 175 and 177 SMK cause someone wanted to know.
They use the same powder charge but the 177 is much better bullet seated out a bit longer, for 2.8" and shorter ranges the 175 gr may suit your rifle.

Everybody wants performance in a short barrel ...it won't happen like a long barrel but definitely a big improvement.

The 177 gr with a .545 G1 at 3126 fps and 3800 ft/ lbs is what a long barreled 8 twist 308 win puts down range with hybrid cases...it kind of smokes the factory 6.5 CM.
At 70° 1500 ft elevation
1000 yds 23.2 MOA drop 10 mph wind 62.7" 1673 fps remaining with 1100 ft/lbs.

Go to the 230 Atip at 2708 fps
Same as above
1000 yds
Drop 26.6 MOA wind 10 mph 46 1
Remaining velicity 1775.7 fps 1610 ft/ lbs of energy.
308 Win hybrid case 8 twist 30" Bartlein 5R heavy palma in alum chassis 4 oz trigger supersonic to 1900 yds.
Can not do that with a short barrel...but great improvements can be had.

Also shoot 250 Atips 2515 fps...but unless long throating and maybe get enough slow powder behind it could get to 2600 fps...but would leave a long jump for lighter bullets.

The 22" barrel 9 twist Bartlein 5 R does 3049 fps with 177 gr SMK. The 175 SMK was 10 fps slower on average.

It takes alot of resesrch, range time, and money to do this for multiple calibers.
QL helps in a general sense...but its accuracy varies alot, with the same cartridge and barrel lenght, moderate to high pressure loads...then go subsonic more variation.
Powder burns more complete at high pressure...lower the pressure and it's less efficient.

45-90 · Mar 28, 2025

BJames said:
Are you using quickload or standard work up practices when determining your upper limit?

Also, what speeds were you seeing, specifically in 308, with 175-185 class bullets and are they mag fed?

I just snagged a couple hundred of the hybrid cases to experiment with. My goal is to see if I can get standard barrel length type speeds out of 16-18” barrels. Anything faster would be gravy.

Yeah mag length 2.830 for the 175s and a bit longer for the 177s.
I don't do 185s there is no advantage low BC for the weight. I jump to 200 SMK .715 BC, 208s okay, 225s better, then rhe 230 and .8 plus g1 bcs is where its at with 8 and 9 twist barrels.
The best powders are not always readily available.

22" 9 twist Bartlein 230 Atips 2600 fps single load, or put a long action on your 308.

The shorter the barrel the larger the handicap.
And 18" would be around 2800 to 2850 with 177 gr SMK...powder availability hurts this project...but there is always an improvement on any powder, but some not as much.

BJames · Mar 28, 2025

45-90 said:
Yeah mag length 2.830 for the 175s and a bit longer for the 177s.
I don't do 185s there is no advantage low BC for the weight. I jump to 200 SMK .715 BC, 208s okay, 225s better, then rhe 230 and .8 plus g1 bcs is where its at with 8 and 9 twist barrels.
The best powders are not always readily available.

22" 9 twist Bartlein 230 Atips 2600 fps single load, or put a long action on your 308.

The shorter the barrel the larger the handicap.
And 18" would be around 2800 to 2850 with 177 gr SMK...powder availability hurts this project...but there is always an improvement on any powder, but some not as much.

Thanks for taking the time to answer my questions, and your patience. I’ll search around more before I get into it.

I’ve converted cases before and now have access to some high end equipment to make the job way easier and faster. No more neck turning with a hand held cutter and a dewalt, thank god.

All my SA stuff has mags 2.950 internal, little bit more room to put bullets where they need to be.

Looking forward to this project, your 308 speeds are right there with my 24” 300 wsm.

XP1K · Mar 28, 2025

45-90 said:
The 177 gr with a .545 G1 at 3126 fps and 3800 ft/ lbs is what a long barreled 8 twist 308 win puts down range with hybrid cases...it kind of smokes the factory 6.5 CM.
At 70° 1500 ft elevation
1000 yds 23.2 MOA drop 10 mph wind 62.7" 1673 fps remaining with 1100 ft/lbs.

That's 3 moa flatter than my 300winmag with a 215. I'm usually 80-100 degrees around 400 ft in elavation. You're starring about 200 fps faster also.

I'm in the short barrel 308 camp. 20" lilja 9 twist. I picked up some hybrid cases after reading some of your other posts about them. What powder do you like for the 175-178gr bullets ? I'm down to a pound of 2000mr.

45-90 · Mar 28, 2025

RL 17 was the powder for 3126 fps with 177 gr. and the long barrel.

With the 22" barrel RL 17 showed 3049 fps while 2000 MR was 2946.

Got a 9 twist RL 17 ran 230 Atips to 2601 fps average in 22". 6.5 Staball was a little behind but available and pretty good for 208 gr and heavier.

Bacarrat · Mar 30, 2025

Fireformed 25 cases. These were just normal loads, 44gr Varget 178ELDMs. Compared the same load with Lapua brass. Shot about the same size group, but was 25FPS slower. Did check case volume when I got home, 56.8gr vs 57.1gr of water. Didn't have any kinds of issues in the first 5 rounds and started to shoot 500-850 yards at steel to fireform the cases. Next week, I will start to ramp things up with different powders.

45-90 · Mar 30, 2025

Bacarrat said:
Fireformed 25 cases. These were just normal loads, 44gr Varget 178ELDMs. Compared the same load with Lapua brass. Shot about the same size group, but was 25FPS slower. Did check case volume when I got home, 56.8gr vs 57.1gr of water. Didn't have any kinds of issues in the first 5 rounds and started to shoot 500-850 yards at steel to fireform the cases. Next week, I will start to ramp things up with different powders.
View attachment 8652818

Yes hybrid cases have a little more case volume.
So when the exact same powder charge is used in both the pressure and velocity will be slightly lower for the hybrid case.

45-90 · Mar 31, 2025

Messing with hybrid cases and the 6 Dasher.
It's successful, but a bit more involved.
107 SMK 3200 fps? Maybe 3300?
Is it worth it?
Probably not...
Not something you'd shoot a lot of rounds in a day.
Also doing laundry, besides messing with this Dasher project...and we all know how exciting that cam be...

XP1K · Mar 31, 2025

45-90 said:
Messing with hybrid cases and the 6 Dasher.
It's successful, but a bit more involved.
107 SMK 3200 fps? Maybe 3300?
Is it worth it?
Probably not...
Not something you'd shoot a lot of rounds in a day.
Also doing laundry, besides messing with this Dasher project...and we all know how exciting that cam be...

Oh now that's interesting. I'm contemplating a couple dasher builds at the moment. Thinking about getting away from 243AI and going to dasher to for less powder consumption but I still want the speed. I need to place an order for a few more hybrid cases. I think I've got five firings on my first batch of 100 now. Still rocking strong. I don't think the primer pockets will ever give out, I wonder how long that case head will hang on though?

supercorndogs · Mar 31, 2025

I am not sure what kind of 175 the PRC mentioned in the article was shooting.
But
His load in my calculator

212 at 2420 11mil 2mil 10mph
5mil 600y

My 280 loads in my calculator
162sst 8mil 1.9mil 10mph 1000y
3.2mil 600y
175 eld-x 8.7mil 1.7mil 10mph 1000y
4mil 600y
At 2790 and 2650

I would be interested to know the actual pressure for some of loads mentioned in this thread. And what actions they and use cases they could be safe.

Bacarrat · Apr 1, 2025

Guess which powder is which. One pile of powder is the residue left in the hybrid cases. The other is a common powder, not so hard to find. I am almost positive they are the same powder.

45-90 · Apr 2, 2025

Bacarrat said:
Guess which powder is which. One pile of powder is the residue left in the hybrid cases. The other is a common powder, not so hard to find. I am almost positive they are the same powder.

View attachment 8654719

Probably not ...the hybrid round had over 60 powder blends tested and tweeked to meet the velocity and pressure spec requirements of this military round.

With millions in investments, this US Army powder was listed as top secret during development...so probably not available over the counter...wait a few yrs it might be surplus powder...that doesn't meet specs.

212eldx in .308 hybrid cases?

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