338 yellow bastard- fastest 338

[Andy]

Isn't EDM the same guys that oversold the Chey Tac and have relegated it to a curiousity?

Interesting bullet seating technique. That throat and leade are going to look very interesting.

Also, why would you use TOOL STEEL in a case?

Sizing you necks are going to be pretty hydraulic

Be interested in seeing some REAL world results.

Jerry

I think that this arrangement does not require resizing. It appears that the "cartridge" is really a removable and reusable chamber insert. It is disassembled, powder is inserted, then the bullet, and the top is screwed on, somehow securing the bullet in place (using a taper?). An innovative approach.

As you mentionned, the freebore would be measured in inches!

 

[Meph]

It looks like a sabot for 338 being used in a 50 cal casing.
I would bet barrel life is LOW and efficiency nearly non existant.
I wonder why they went 250 gr rather than the higher BCed 300 gr SMK

I am skeptical about the claims of the worlds strongest action, THAT is a pretty big statement.
Thanks but I will stick with a KNOWN winner, the 338 Lapua Improved.

Good day sir, I would like to learn your reasoning behind the statements you have made here. Now I can understand that you're skeptical of a few of their claims, I am as well, as I also do not think that they have the strongest action on the market. However I am puzzled when you said that barrel life would be low and case efficiency would be nearly non existent. If it's not too much trouble, can you answer in this thread? I have put my questions and reasoning down in that thread.

http://www.canadiangunnutz.com/forum/showthread.php?t=594250

If possible, please address the questions I have asked in my opening post. I understand that you're a busy man so if you have more important things to do, don't worry about it.

Thank you for your time.

 

[alberta tactical rifle]

Good day sir, I would like to learn your reasoning behind the statements you have made here. Now I can understand that you're skeptical of a few of their claims, I am as well, as I also do not think that they have the strongest action on the market. However I am puzzled when you said that barrel life would be low and case efficiency would be nearly non existent. If it's not too much trouble, can you answer in this thread? I have put my questions and reasoning down in that thread.

http://www.canadiangunnutz.com/forum/showthread.php?t=594250

If possible, please address the questions I have asked in my opening post. I understand that you're a busy man so if you have more important things to do, don't worry about it.

Thank you for your time.

http://www.canadiangunnutz.com/forum/showthread.php?t=594250 I can not open this, can you enlighten me?

The 300 GR SMK HAS a higher BC than the 250 Gr SMK has. The 300 in my experience has a FAR better trajectory and is more predictable at extreme long range. This is universally agreed upon by nearly all who shoot the bigger 338s so there must be some merit to it.

Barrel life in most UBER fast calibers IS low, that has been established as fact time and time again, it is compounded significantly by grossly overbore cartridges.

There have been attempts and successes to neck down many casings to smaller bore bullets, in almost every case the barrel life has been very low when done with the extremes of case size and necking to significantly smaller diameter bullets.

Case in point I have experience with the 408 Cheytac casing necked down to 30 cal and the 300RUM necked down to 6mm, in both cases the barrel life was under 500 rounds which to me is very low.

In the case of the 408x30 we got velocity of 3785 FPS when shooting a 210 gr CNC turned copper bullet, in the 300RUMx6 3600 fps was attained with a 105 gr CNC turned solid copper bullet.
We used turned copper bullets as most conventional bullets came apart prior to contacting the target.

In both cases these cartridges were EXTEMELY inefficient as most grossly overbore tend to be.

By inefficient I am referring to how much powder is required to do the job, 1 gets to a point where it takes much more powder to make any appreciable velocity gain. Case in point my 6PPC requires less than 30 gr of powder to get a 70 gr bullet to get just over 3000 FPS, which IS efficient when compared to the 300RUMx6 that required 98grs of powder to 35 more grains of bullet to an increase of under 600 FPS.
Barrel life of the 6PPC is well over 1000 with best accuracy and several thousand with acceptable accuracy to anyone short of a competing BR shooter.
In the case of the 2 wildcats I worked with the barrels were so badly firecracked and throats eroded that hitting a 4x8 sheet of plywood at 100 would have been difficult.

This 338 wildcat appears to be a saboted 50 cal case, which unless there are things undisclosed, would lead me to the assumption that over 200 grains of powder are being used to propel a 250 gr projectile, which IS inefficient and certainly is GROSSLY overbore for a 338 cal bore, which would lead 1 to surmise that throat erosion and fire cracking will be extreme, hence barrel life short to the point of nearly non existent for any practical purpose.

 

[Meph]

http://www.canadiangunnutz.com/forum/showthread.php?t=594250 I can not open this, can you enlighten me?

The 300 GR SMK HAS a higher BC than the 250 Gr SMK has. The 300 in my experience has a FAR better trajectory and is more predictable at extreme long range. This is universally agreed upon by nearly all who shoot the bigger 338s so there must be some merit to it.

Barrel life in most UBER fast calibers IS low, that has been established as fact time and time again, it is compounded significantly by grossly overbore cartridges.

There have been attempts and successes to neck down many casings to smaller bore bullets, in almost every case the barrel life has been very low when done with the extremes of case size and necking to significantly smaller diameter bullets.

Case in point I have experience with the 408 Cheytac casing necked down to 30 cal and the 300RUM necked down to 6mm, in both cases the barrel life was under 500 rounds which to me is very low.

In the case of the 408x30 we got velocity of 3785 FPS when shooting a 210 gr CNC turned copper bullet, in the 300RUMx6 3600 fps was attained with a 105 gr CNC turned solid copper bullet.
We used turned copper bullets as most conventional bullets came apart prior to contacting the target.

In both cases these cartridges were EXTEMELY inefficient as most grossly overbore tend to be.

By inefficient I am referring to how much powder is required to do the job, 1 gets to a point where it takes much more powder to make any appreciable velocity gain. Case in point my 6PPC requires less than 30 gr of powder to get a 70 gr bullet to get just over 3000 FPS, which IS efficient when compared to the 300RUMx6 that required 98grs of powder to 35 more grains of bullet to an increase of under 600 FPS.
Barrel life of the 6PPC is well over 1000 with best accuracy and several thousand with acceptable accuracy to anyone short of a competing BR shooter.
In the case of the 2 wildcats I worked with the barrels were so badly firecracked and throats eroded that hitting a 4x8 sheet of plywood at 100 would have been difficult.

This 338 wildcat appears to be a saboted 50 cal case, which unless there are things undisclosed, would lead me to the assumption that over 200 grains of powder are being used to propel a 250 gr projectile, which IS inefficient and certainly is GROSSLY overbore for a 338 cal bore, which would lead 1 to surmise that throat erosion and fire cracking will be extreme, hence barrel life short to the point of nearly non existent for any practical purpose.

It's a thread called "Sabots." on general firearms talk.

I agree with the bullet choice, for more than one reason, I will expand upon this in a bit.

First, from what I understand, high velocity calibers have low barrel lives as they require a relatively large case compared to the bullet size. This is easily observable through simple physics on the way the energy is transferred. As energy squares with velocity and is just multiplied with weight, we can see how most high velocity calibers have the "fat case with pin sticking out".

What I'm getting to is that sabots are not necking down. The necking down of a case increases the temperature and burn at the neck and throat, decreasing the barrel length excessively. I have no doubts that .408 Cheytac necked down to .308" didn't last very long. However, I strongly beleive that a .408 cheytac cartridge that HAS NOT been necked down and is pushing a full bore sabot holding a subcaliber projectile will havethe same barrel life as the normal .408 cheytac, or close to it, not to mention that the sabot is often a plastic that should theoretically reduce friction and barrel wear from the direct contact of the projectile

Also, we have to assume that this reduction in friction from the projectile and this great reduction in bullet weight would warrant a COMPLETELY different powder. If they are using the usual large caliber powders, I think that the bullet would be almost out of the barrel by the time peak pressures are reached. One would surmise that they should use the powder for a 300 grain .50 BMG bullet to get the most out of the powder they're using. I don't even think there are that light of a bullet for that caliber, and I don't know what the powder load would be.

It would be interesting to see just how fast a saboted bullet could go with the proper powder load.

I think necking down into overbore is what's causing the inefficency, coupled with improper powder for what's actually going down the barrel.

 

[X-fan]

I never saw Skip do any thing like this do you have any articles.

Sorry, can't find it.

Pretty sure it was in precision shooting.
It was an interview with him. Skip talked about some of the different and diverse things he had tried over the years.
He mentioned messing with a 338/50BMG (not sabots) and I believe he also had a shortened 338/50bmg.

Too bad he is gone...The guy had a great brain for long range concepts.

Big shoes to fill Rick (Sir)!

 

[alberta tactical rifle]

Sorry, can't find it.

Pretty sure it was in precision shooting.
It was an interview with him. Skip talked about some of the different and diverse things he had tried over the years.
He mentioned messing with a 338/50BMG (not sabots) and I believe he also had a shortened 338/50bmg.

Too bad he is gone...The guy had a great brain for long range concepts.

Big shoes to fill Rick (Sir)!

I believe the was an article in the FCSA magazine several years ago regarding Skip's necking down the 50 to 338. In conversation years ago with #### Davis at McMillan this came up and as I recall #### had some involvement as well.
IIRC barrel life was about 200 rounds and accuracy non existent at that time keeping bullet together long enough to hit paper was the biggest issue.

 

[alberta tactical rifle]

Meph

"However, I strongly believe that a .408 cheytac cartridge that HAS NOT been necked down and is pushing a full bore sabot holding a subcaliber projectile will have the same barrel life as the normal .408 cheytac, or close to it, not to mention that the sabot is often a plastic that should theoretically reduce friction and barrel wear from the direct contact of the projectile"

I think there may be merit to this, I was thinking more of the 338 bore, and forgetting the sabot. I really should read the posts more thoroughly.

 

[Meph]

Meph

"However, I strongly believe that a .408 cheytac cartridge that HAS NOT been necked down and is pushing a full bore sabot holding a subcaliber projectile will have the same barrel life as the normal .408 cheytac, or close to it, not to mention that the sabot is often a plastic that should theoretically reduce friction and barrel wear from the direct contact of the projectile"

I think there may be merit to this, I was thinking more of the 338 bore, and forgetting the sabot. I really should read the posts more thoroughly.

I was also suspecting that you were under the impression that the barrel was of a .338. Don't worry about it, I've made worse mistakes

So what would you think of sabot loads for rifle calibers (even smaller ones like say the .308 Win)?

 

[alberta tactical rifle]

I was also suspecting that you were under the impression that the barrel was of a .338. Don't worry about it, I've made worse mistakes

So what would you think of sabot loads for rifle calibers (even smaller ones like say the .308 Win)?

The only experience I have with sabot in a 30-06 was the Remington Accelerators, which on a good day inside of a closed barn allowed me to hit the barn.
I have not tried anything else with a sabot simply because I am all about accuracy and find it hard to figure out how 1 can obtain perfect concentricity when loading a bullet into a plastic sabot and then into a casing.
I know that real large bore cannons and artillery use sabot rounds but given most are loaded with an explosive payload accuracy is not such an issue.

 

[Meph]

The only experience I have with sabot in a 30-06 was the Remington Accelerators, which on a good day inside of a closed barn allowed me to hit the barn.
I have not tried anything else with a sabot simply because I am all about accuracy and find it hard to figure out how 1 can obtain perfect concentricity when loading a bullet into a plastic sabot and then into a casing.
I know that real large bore cannons and artillery use sabot rounds but given most are loaded with an explosive payload accuracy is not such an issue.

Speaking of 30-06 accelerators, my buddy has a 30-06 and I'd like to see how they'd perform if the inside of the sabot was made a bit rougher (sanding the inside of the sabot just to make it rougher, as if to prime it before painting) not to remove material. Some shooters simply stick the sabots in the tumbler with some media and say it helps. I think I'll try that.

I believe that a large part of the massive loss in accuracy might be due to the explosive acceleration along the axis of rotation - I've heard of muzzle loaders that use sabot bullets speak of this happening. The sabot starts spinning so fast (I mean most 30-06s have about a 1 in 10 twist or so, and getting through the bore in times measured in thousandths of a second is a pretty stiff impart of spin) that the bullet stays relatively without spin. I've read of people that have shot the 30-06 Accelerator loads saying how the bullets keyholed, and I bet it's that the .224" bullet is just not actually spinning when it exits the bore.

I'll see if I can find a box and report back either in this thread or in the sabot thread on general firearm discussion (don't know what's wrong with the link, sorry).

 

[Cameron SS]

Guys, guys guys, you are missing the point. Short barrel life, no accuracy, heavy as sin, poor bullet choice, you guys are missing the point.

THINK OF THE CASE LIFE!!!!

In all seriousness, check this guy's website. They make some other tall claims, like its only 11 MOA adjustment to 1000 yards if zeroed at a hundred. I tried three different ballistic calculators using the Sierra 250 GR HPBT MK the best I could get was 14 MOA. Which is still pretty damn impressive, so why fudge?

They also repeat the claim made by Rocky Mountain Bullets that one of their .338 bullets has a BC of over 1. It's been a while since high school physics, but I am pretty sure thats impossible.
IF he is relying on the manufacturers (obviously false) information, I wonder if this guy is scratching his head as to why the performance isn't living up to his long range calculations. But then I guess you would actually have to get out and shoot the thing a couple times to figure that out.

As for Sabots, the only sabot that I have experience with is the 25mm kind. A 5 Ft grouping at 3000 m is still only 2 MOA. And that was common with mass produced military ammo... A novice operator could hit an oil drum at 2 km 3 times out of 5. On a smaller scale, could there not be some merit to this idea?

 

[LongBomber]

Most of the tank sabot rounds are for a smooth bore and contain a fin stabilised projectile no? I was pretty sure that most of the tank rounds are now a small (20mm?) penetrator rod (tungsten or DU) with a carbon fiber sabot bringing it up to 120mm.

I would think that slippage between the bullet and the sabot would be a major limiting factor in using this in a standard bore rifle. I wonder how hard it would be to build a dart of 30 cal and shoot a fin stabilised projectile?

As for the claims of a G1 BC of over 1. Just looking at the data in Bryan Litz book, the G1's seem to get higher with higher velocity. I am not sure if you could go fast enough to get a 338 over 1, but somewhere in the high 0.8 - 0.9 may be possible, just looking at the trending in the charts.

 

[surfclod]

My .17-20mm is faster than the speed of light.

I'm having all kinds of problems with it however, as the bullet keeps getting there before I pull the trigger, which makes aiming difficult.

Well....you started it.

Yeah and its not flat shooting at all as the bullet weight increases to near infinity as it approachs the speed of light, thus negating the speed advantage

However the energy of a .17 cal bullet that weights 830 tonnes at 983,571,055 fps is really impressive on gophers.