.375/416 Barret?

[Black Diamond 408]

eddybo,

The case looks just like a Cheytac only fatter. 180gns of US 869 to the bottom of the neck shoulder junction, should be plenty of room for the large bullet. The case has a .012 body taper, 35deg shoulder. Heavy duty brass. I have been pondering on how to go with the reamers, i have the 416 version and was thinking about having them re ground to the 375, but now me thinks i will just order a new set so i will have both. I can't emagine what kind of speeds your going to get from the large case. I'm thinking i might be able to get an easy 3400 with the 350gn predators or the 355 GS customs. I dont think the SMKS will hold up to the speeds this can push.

I have several options i am looking at in building this rig, one is a standard type LR gun, my second choice (leaning) is a bull pup tube gun. I have several drawings i did a long time ago and dusted them off tonight. I would still use the full size action with a modified recoil lug system inside a split tube. I may start with a large dia tube and profile the od into a Hex shape, this would add to the cosmetics. With a carbon wrapped barrel i'm sure i could get the weight down to Idaho standards.

The center line is where the two halves will come together, sorta like a huge barrel block. What i was thinking is machining out the tube to fit the action and bed it in for a perfect fit. The other option is no split, just machine the inside dia of the tube so the action will slip in. Still in the dreaming stage! A magazine could be incorporated as well, but the trigger system would raise some design issues.

Im open to all ideas! This could be incorporated into any caliber rifle.

Dave

 

[Extremist458]

I like it Dave! I do have to admit, it does resemble the Barrett design, as well as the Desert Tactical, but you can make vast improvements from there! I think the design is great! I say leave it as a tube for strength and rigidity. Allow the bolt to be removed from the detachable butt plate (again, strength). Form an insert that will bed the action in the frame/tube and support it for strength, but only from one point...like free-floating the barrel and action! This is somewhat easy to do if you machine the piece with a wide base that uses a recoil lug block to lock into the tube frame. Then allow the bolt to lock directly into the barrel/barrel extention, and use a smooth, lightweight nylon bolt guide. Honestly, that is much like the DTA HTI rifle, but you can make a few improvments in not having a quick change barrel.

Now for the tricky part...what about electronic ignition? Oh, I know I hit a subject of much debate, but it's worth a thought or two. I worked with Crane on converting one of Anzio's take-down 20mm's to fire electronicly primed Navy cases, and it worked out very well! Trigger can be as light as you want...now what do you think a 20mm primer would do in that case?

What if we made the forward ignition tube a (solid) conductor and placed a standard Remington Etronix rifle primer fixed to it inside the case about 1/2" short of the neck? Wow, pushing it ain't I lightbulb but brilliant. Just remember, I said it first.

-AP


P.S. This isn't all BS, I've actually worked with electronic priming systems quite a bit, and I have found them to be superb. Only thing is they are expensive primers...and don't even try to get the big ones!

 

[Black Diamond 408]

AP,
I know absolutly nothing about the electronic ignition systems.

I do have an electronic trigger that i was looking into marketing one day.

I made up several rifles that had the bbl extension that the bolt locked into on
an aluminum frame. I like using a solid steel action inside the tube, i think this will
be one of the best improvments for long range accuracy. No take downs either, maybe
a switch bbl but thats all.

More ideas to come

Dave

 

[Black Diamond 408]

eddybo,

I found a picture of the project i was thinking about doing many moons ago. It is similar
to what your doing but i was going to use the 408 cal, at that time there was no high BC
375cal bullets. The case i was going to use was the 50 Spotter, this is a CNC turned rendition of
what my case would of looked like.

I can't wait to see your finished project and tests!

Dave

 

[Fiftydriver]

BD408,

Curious why you think the 350 gr SMK would have any problems at 3400 fps? I have never seen any SMK bullet above 6mm bore size have any issued with velocity even up to and including 3600 fps.

That said, MOST solids seem to have serious accuracy problems at velocity much over 3200 fps. Some will do a bit better but most drop off in accuracy dramatically and it seems the higher the BC the harder velocity is on these bullets.

I will admit that I have pushed the 300 gr SMK and 350 gr SMK FAR harder then they should be in my 338 AM and 375 AM using the old TTI cases which are simply amazing and sorely missed. In my 40" 338 AM I broke 3600 fps with the 300 gr SMK and with a 36" 375 AM I pushed the 350 gr SMK right to 3500 fps. Is this a practical load, certainly not, far to high in pressure. My goal was to see if the SMK had any limits as far as accuracy and velocity were concerned. Never was there any real change in accuracy.

Certainly we could do much better with a different bullet design but the 350 gr SMK does shoot very well in most barrels and is not limited to specific bore diameter that many solid bullets are handicapped by. Call me old fashioned but give me a lead core bullet over any solid just for their reliability in a variaty of bore diameters.

Also a bit surpised that your Bertram is as strong as your reporting. I have never seen any of their brass handle pressure well at all, weither it be the 408 CT, 505 Gibbs or 577 Tyrann case. They must have REALLY beefed up the case head on the cases your using.

I have talked with Jamison about building me a new case. Will not offer any details yet but it would work in 408 CT receivers, single shot or repeaters and would offer case capacities roughly 20-22 grains higher in powder charge then my 338 and 375 AM.

Only problem and the main reason I have not gone full steam on this is that brass would be estimated in the $6.50 to $8.00 range each and of all the potential customers I have talked to, they said they would not spend the money on the brass to get another 100 or even 200 fps over the 338 and 375 AM and have brass that is 2 to nearly 3 times more expensive then the fully formed and correct headstamped AMs based on the 408 CT.

Just wondering what market there will be for a rifle that shoots a round that takes $8.00 out of your pocket every time you buy a piece of brass. That has always been my hold up with these projects that go beyond the 408 CT case size. Hell, the 50 BMG is 1/2 the cost of even 408 CT brass. Admittedly, its much larger then needed but its cheap. Just wish we had some good brass at reasonable prices.

God I miss the TTI brass of days gone by. With that brass, the 408 CT based rounds would easily match anything on the 50 Spotter or 416 Barrett case. Oh well.



I have polled many of my customers that are interested or looking into a rifle in this class and ask

 

[Black Diamond 408]

Kirby,
Pretty simple on the brass, TTI was made by Bertram, ive never had any problems with his brass. He sent me a bunch of 408 brass
to play with and have various head stamps. TTi, BB, and one other i cant remember. He told me the whole TTi story.
Most of my projects are personal or special ordered to customer wants. Big Boys and their toys.
I have several other projects that are for me alone and would not dream of offering them
to the public. Most of my customers are only in it for pushing the extreme, i dont deal with
rem's, savages, rebarreling or truing actions. 95% of my work is dedicated to the cheytac case and its wildcats.


~if you have to ask the price, you cant aford it

 

[Fiftydriver]

That is very interesting, not at all the story I got about the TTI brass but no matter.

I have some Bertram and TTI brass here along with the Jamison brass and some samples of some cases that were supposed to be made in germany. I have sectioned all of them to measure case head thickness and case wall thickness. All are significantly different in case head thickness and case wall thickness except the TTI and supposed german made brass.

Not only that but I had them all hardness tested and the Bertram brass was the softest of the four. Jamison second softest and the TTI and Gernan brass were nearly identical. Even in case color, the TTI and German brass were nearly identical in color with nearly identical shoulder and neck annealing marks. The Jamison and Bertram brass were very unique in brass color. This was polished color, just to make sure some cases were not tarnished to effect color of brass.

If Bertram made the TTI brass, they really made it alot different then their own headstamped version of the 408 CT brass. Perhaps they are willing to use different alloys and make brass with different head hardness for specific customers. If they will do that, I think I will be getting ahold of them and see what they can do.

I only wish that we could get a brass maker to offer a Lapua strength 408 CT case!!! The jamison cases are decent and very functional, in fact work very well, just not the strongest in the case head is all.

Personally, I do not believe in your last comment but thats just me. Unfortunately thats getting to be a pretty common opinion these days.

 

[Extremist458]

Are you guys ready for the first peek? Can you handle it?

-AP

 

[Master Diver]

Ohhhh yeahhh
Bring it on gun)

Dave that looks like a good design.

What barrel length is needed to maximize ERL bullet in a 375/416 Barret?

What are the advantages wuth the 375/416 Barret cartridge over the 375 SnipeTac.

Kirby have you seen and tested the cases made by Dieter Horneber?

Cheers,

Master Diver

 

[Fiftydriver]

Master Diver,

Not the 408 CT cases but I have seen some of the 338 Lapua versions. Good brass, would not say any better then the Lapua but good. From what I have heard, the cost is what would keep me from using them. Likely just the import tarriffs but pretty spendy brass from what I have heard second had. Never talked to them or gotten a price list even though I e-mailed and requested one a couple years ago.

I have been talking to a few guys about the new Bertram brass made in the last year or so and they say its much better then the older versions which were extremely soft. Sounds like the same situation as Jamison but those I spoke to that had used both the new Bertram and curret Jamison brass said they were going to just stick with Jamison to support a US company as there was no real difference in brass quality.

So I stand corrected so some degree. Seems the new Bertram brass is decent strength but still no better then the US made Jamison as far as taking pressure. The brass I sectioned and tested was made several years go but the TTI brass which was also said to be made by Bertram was at least the same age and there was absolutely NO comparision between the two, the Bertram brass would loose a primer pocket long before the TTI brass even started to get rolling. In fact I looked up my test load log where I tested this brass and there is the max loads for each brass. By max load I mean the point where the there was a noticably loosening in primer pocket tightness on the first high pressure loading.

Bertram
300 gr SMK...........139.0 gr H-50BMG.............3223 fps

TTI
300 gr SMK............148.0 gr H-50BMG.............3418 fps

Current Jamison brass is around 142.0 gr with an average velocity of 3289 fps in a 32" barrel length. (As a comparison, Black Sunshine, my 40" barreled 338 AM produced 3502 fps with the same load with the TTI brass which was a usible load)

Now, this is not saying that the rounds could not be loaded a bit higher. I have customers currently using the Jamison brass that are pushing 3400 fps with 33" barrel lengths and getting many firings per case. I just have to be a bit more conservative in load recommendations and if I feel the primer pockets loosening on the first firing, I consider that about max.

 

[Master Diver]

Kirby,

I also had BIG problems with Bertram brass some time ago, it was in the caliber .500 Jeffery and sold as factory ammo by Kynamco (old renamed Kynoch) The cases was so thin that they could NOT be reloaded in CIP spec die-set. The bullet was not crimped enough and you could turn it with very little effert. Furthermore the cases where to short that the had a 25% missfire and was simply sushed forward in the chamber, This NEVER hapned with the Casas by Horneber cases.

I got a custom order of 375 SnipeTac casas made up by Dieter Horneber and they seem to be GQ, Dave also got some and has tested them.
I need cases with original caliber headstamp to match the caliber on the rifle for travel around the world, airport security staff DOES NOT undestand wildcat cartridges

Dieter Horneber can be hard to get in touch with, but give it a try again if you need custom brass he is the one in Europe to go to.

Cheers,

Master Diver

 

[Extremist458]

Jamison is the way to go here. If TTI would go public again, we would have some spectacular brass here again. One might be able to get their loaded ammunition and reload. I also heard Norma has stepped up with their 300 Norma Mag. Again, a .590 (LM) case head to go along with the 300LM as they did the 338NM. They are not double stamping the case heads and they are strong! Had one in my hand at the shot show, but have not got a chance to load one up yet. Might want to inquire.

So what every happened to the old two-part stainless steel case head brass they use to make?

Here's that pic:

 

[Fiftydriver]

Master Diver,

That is the exact reason why I invested the money to have Jamison make my 338 and 375 Allen Magnum brass with my correct head stamp so that you do not have the issued with airline security issues or the need for my customers to spend a load to get custom made brass for their rifles.

Jamison has been working on a 338 Lapua case as well, good brass, but just not quite as strong as the Lapua version. I would say on par with the Norma and Hornady version, good brass. I have been considering investing in getting Jamison to make cases for me on the Lapua case headstamped with 7mm Allen Magnum, 300 Allen Xpress, 338 Allen Xpress and 375 Allen Xpress. As you can imagine though, the cost is pretty high so that may come a bit at a time. It would really help customers getting these rifles over seas to hunt with though.

Thanks for the report on the German cases, very interesting. If you would not mind, how much per case do the 375 Sniper Tac cases run you by the time they are in your hand with shipping?

 

[Master Diver]

Nice,

Thanks for posting.

Cheers,

Master Diver