100% agree.

I'm amazed at how efficient my .223 A.I. is. It is almost making .22-250 ballistics with nearly a third less powder. Red's wildcat is along the same lines.

CSD,

We are just discussing load info. Concur no one has to prove anything. I am just trying to make sure someone does not get hurt with data from a public forum. Red obviously is very experienced and knows what to watch to stay out of the danger zone, but many here do not.

The case design looks like a .338-06 AI variant to my eye. .338-06 and variants have been around for as long as I have been loading, which is more than a few years. It is an excellent cartridge and should be more popular.

However, there is no way a .338-06 AI can keep up with a .338 Win Mag with 210 to 250’s. .338 Win Mag is really dragging tail with 225 - 250’s, which is where stepping up to the Weatherby, RUM, or Lapua can push the bullet so much faster without pushing the boundaries of safe pressure.

6.5 Swede data specifically is held to low pressures due to the many old rifles in the market. In a modern rifle, 6.5 Swede can outrun the .260 and the 6.5 CM. A .264 Win Mag with its old design will out run all of them just because it has more powder.

A few years ago, a Nilgai guide and I chrono’d several loads he was using for Nilgai. His favorite load was a max power .338 Win Mag with 250 Partition in Ruger M77. The chrono showed it was barely topping 2500, which surprised him quite a bit, but it was safely within its limit in the heat. fwiw - he personally used a .375 H&H or .338 Win Mag.

There is no magic in AI’ing a case. It adds more powder. Adding more powder adds more powder, nothing else. I’ve not worked with .22’s, so will not comment, but I have worked with the .338 Barnes bullets, and other .338 loads worked up by men guiding for Nilgai, which is why I weighed in. Again, I am not being critical of Red, his cartridge design looks nice, just trying to make sure no one is bitten by their rifle.

I haven't seen the 338 Norma Mag mentioned. Seems like a pretty good one for a build.

Fits in a standard long action and duplicates the Lapua. Originally designed to shoot 300 SMKs if my memory serves.

I respectfully disagree, Jeff.

The A.I. body and shoulder makes for good fuel mileage. It makes the ppwder charge do more with less.

.22-250, 75 gr A-Max, 34.0 gr H-Varget, 24" barrel, 1:8 twist, 3200 fps MV

.223 A.I., 80 gr ELD-M, 26.4 gr IMR-8208, 24" barrel, 1:7.7 twost, 3075 fps MV

Way less powder in the .223 A.I., same barrel length, and right on the heels of the .22-250 that is loaded with a much higher percentage of charge. The A.I. design is more efficient.

7mm-08, 24" barrel, 162 ELD-X, 2700 fps MV
7mm-08 A.I. 24" barrel, 162 ELD-X, 2820 fps MV, with only 1.8 gr more powder.

Red's cartridge is no different, it is doing more with less, getting good fuel mileage. He called me back when we were 95° every day last summer, and we talked about some powder options. I reminded him to absolutely test this in hot weather, even though we are using temp stable powders. He found a winner the next afternoon, and of course it was hot weather.

While it is a comparison it uses different powders different bullets and a short barreled 22-250. No telling what is the limiting factor.

24" is a short barrel? No it is not.

Yes different powders, but that is still a major difference in powder charges.

Look at the 7mm-08 and 7mm-08 A.I. since you are failing to grasp the concept. Those are on the same powder.

Again I didn't fail to grasp anything. You gave a lame azz comparison

Yeah, OK.

Please, feel free to share your A.I. cartridge experience.

FJG,

AI’ing obviously can increase velocity as it is adding powder, but adding 2 or 3 grains in an AI’d case cannot produce the same velocity as a case using 10 grains more, much less cases using 20 - 30 or more grains.

Your 7-08 AI for example is still 300 - 400 fps slower than a 7 WSM with the same 24” barrel and 162 Amax. I used to run them at 3100 fps and took them to over 3200 fps in 24” barrels. They starting shedding jackets at that velocity so dropped back to 3100. A .280 AI cannot match that either for a closer comparison.

AI can add some extra performance, but not as much as moving up to a bigger category of case.

Again, Red’s design looks good assuming it feeds reliably, but a full power .338 Win Mag will be faster and a .338 Lapua will outpace it by 300 - 400 fps with the same bullet.

To illustrate my mindset on loads, I run my .308’s with a 175 and 43.5 Varget, which is below max. If I want more velocity, the .300 Win Mag comes out and it is loaded below max too. If more muscle is still needed, then it’s time to take the .338 Lapua out, again loaded with a full power load, but not max.

My loads are well below max in the worst summer heat, so they stay safe year round. Where I hunt and shoot, it was 34 degrees last week and 92 the day before. In summer temps go over 110. My loads need to work and be safe year round in all of those conditions. Where ITRDM will be hunting Nilgai can be similar. Working up loads in 100+ in the shade is still hard to account for a rifle and ammo sitting in the sun and baking. I read somewhere that temps inside a case can be over 140 in intense direct sun, much as the interior of a car can heat up very high in the summer.

So, my comments are made from that perspective of trying to produce heavy hitting rounds, but not on the margins pressure wise.

Again, Red’s design looks neat, especially for a competition round where high round count days would be wearing on the shooter with a big cartridge.

Your suggestion to him to make his 26 Nosler a .33 Nosler seems like the best proposal so far unless he just wants a new rifle.

Perhaps I should have said I respectfully disagree lol then maybe you wouldn't have started out with the insinuation I needed help to tie my shoes this morning, oh wait Im wearing boots lol.

If the AI and standard 7mm08 have the same pressure limit the max potential difference between the two could be calculated based on the increased volume of the AI, but im not sure I could apply the physics to get the change in velocity that would result. I do not think your sample size is large enough to be statistically significant. I guess im just on the other side of the coin from you. Im glad it works for you and I don't doubt it is an improvement. I think the water gets muddied when the improvements gets a decisive number attached to it.

All the best I hope you have a wonderful day. I am only trying to "respectfully" suggest your comparisons aren't exactly clinical or potentially statistically significant due to sample size and differences in testing.

Jeff, I think what you're saying is there is no replacement for displacement. And I agree. My 7 Rem Mag is much stouter than my 7mm-08 and 7mm-08 A.I. But lets add the 28 Nosler. It fits in the same action, with same bolt face as the 7 Rem Mag, 7 STW, 7-300, ect. Nosler reallly did good with their new cartridges. They got the case geometry right, and it makes for efficient burn. That's all I'm saying.

I worked up a load for a friend's 28 Nosler, with 195's in August. Inwas so happy I had hot weather to do this in (not happy about the mirage though). I was expecting north of 2900 fps, and would've been more than pleased with it. I ended up at 3050 fps MV shooting the best, and it was barely compressed. That's impressive for that cartridge, in my book.

Was curious so I went back and looked. Actual data for my 338-06

50.7 grains of Varget-225 Interbond-19” barrel- 2580 FPS

That load is not close to max but did everything I wanted.

Just an example of what the 06 can and cannot do with a short barrel. The barrel has since been cut to 17” and threaded but has not been shot since.

.22-250 is not an overbore, nor is .223 A.I.

"Little statistical value". My 7mm-08 and 7mm-08 A.I. is data from 10 rifles, I've loaded for, and ran out to 800 yards, 20°F to 110°F.

You disagreeing on the capability of the 7mm-08 A.I. is literally calling me a liar. And you have ZERO basis to do so. What I say it will do, it will do. And you continue to look more and more foolish since you have NEVER loaded or shot one. That's what pisses me off about you. You argue about something you have no experience with with someone that has a whole lot of experience with it. I'm wanting a S&W 686 right now. There are members here, I might not always get along with, but I know they know that pistol well. So, if they offer advice, I'm going to sit down, shut up, and pay attention. You should try it.

First I ever heard the 22-250 wasn't overbore.

You and Gary, as far as I know, both compared velocity from a fire forming load to velocity from a formed case, I don't think that is an accurate representation. To me that isn't calling you a liar at all.

I have paid attention and I have learned. Many things from you, I don't deny it. If the above is still what your basing the velocity gain on I do not believe that is a 100% accurate gain. About the only way I can see to get it perfect without a LARGE sample size well in excess of 10 guns(especially if the velocity differences all have the fire forming "error" in them) would be to take a 7mm08 max it out, then cut that chamber to AI and max it out again. Perhaps you have done that, last time we argued about it you hadn't that I know of.

FJG,

we are on the same page, as usual.

p.s. Nosler just announced the 27 Nosler with a 165 ABLR, long overdue. Watch and it likely will be the best seller of the whole lineup in a few years. These are the good old days.

Have a good one.

Gawd dang!

Straight 7mm-08, 24" barrel, 162 gr 2700 fps MV. Yes

7mm-08 A.I., fire forming, 24" barrel, 162 gr 2700 fps MV, and it takes MORE powder to do it, because chamber pressure is so low do to brass flowing so far.

7mm-08 A.I., 24" barrel, 162 gr, 2800 fps, or more.

^^All of those are real life, not theory.

I think there’s some misunderstanding. The 338 Sherman is significantly different than both the 338-06 and the 338-06ai, which has very little real world advantage over the unimproved 338-06 — maybe only a couple grains different.

The shoulder on the 338 Sherman is moved forward more than 1/8 inch and improved. Case capacity is significantly increased over both the 338-06 and 338-06ai. That allows more powder, and thus velocity, at same safe max pressure. Efficiency.

You can’t stuff enough powder in the 338-06 or 338-06ai to get safely get any where near the same velocity with any bullet without insane pressures. Nor, admittedly, can you upload the 338 Sherman to duplicate the 338 WM — which is what I am NOT trying to do. But it gives a huge bump in performance over the 338-06.

Red, do you have a 338-06 case laying around that you could set next to the Sherman case and snap a pic? To my eyes, when I first saw the Sherman, I said to myself "Thats a weird looking case", hence the reason I inquired about the external ballistics. I didn't mean to cause such a ruckus, and I surely didn't/dont think you are posting up BS numbers. While I do not have Quickload, I have a friend that has it who has run a bunch of hypotheticals for me while I was doing load dev. I think its an excellent program for experimentation without the risk of sending a bolt through your face.

I see the genius in the Sherman, thats why I was so inquisitive about it.

Since I recently began loading for .260 I realized how much case design can impact performance. I am still working on load dev for it, as I am not quite getting the velocity that I want. As an example, I am running over 6 grains more powder with the 260 using the same bullet as I do in the 6.5 creed and am only getting low 2700fps where as my old 6.5 creed load is 42.1 grains for 2810. Yeah, the 260 does have more case capacity, but is way less efficient at using the powder as Jason mentioned earlier.

Question - How does more case capacity result in more "efficiency"?

You're combining two things into one.

It has more case capacity AND the geometry is more efficient as well.

I provided an example right above your post. You might not have seen it, but no one said case capacity is the same as efficiency.

How do we determine the geometry is more efficient when the case capacity is increased simultaneously?

Once again, I provided an example above with the comparison between 260 Rem and 6.5 Creedmoor. Maybe you missed it again.

I guess what I am getting at is, if you "improve" a case, you cannot get away from increasing capacity. Unless there are 2 cartridges with the same exact case capacity with the exception of a 25 degree shoulder and a 40 degree shoulder, I do not know how to satisfy your question.

A 223 AI probably increases capacity the least while providing serious increases in performance. This was discussed earlier by Jason.

This might be a better example. These cases both shoot the exact same bullet at the exact same speed. The one on the left does it with 63 grains of powder. The one on the right needs 74 grains to do it. Using the exact same powder.

That brings up a good point - the case cannot be improved without increasing case capacity.

For the pic in your post, I understand the intent of emphasizing short/fat compared to traditional long/skinny, however, that particular short/fat is not an "improved" version of the long/skinny. Just a guess here - 7SAUM and 7mm RM?