375 ultra mag

I saw some data for a 26" Cheytac. Using 123gr Retumbo they were getting 2850 w/ the 390gr. You might want to run a little extra barrel…
who the hell built a 26" cheytac? There must be a massive fire ball out the end of the barrell.
 
Final follow-up until I take it out to 1000+. I think the load will be 105.3gr N570 at 40 Thou off. 2820fps. Not sure if my barrel sped up a little or what but 105.5 started out like pictures but then the groups spread horizontal (I tested 106.2 as well but it had more vertical) so I dropped down to 105.3 and it seems to be back to shooting a cluster. Shot 3 confirmatory groups today and 2 of them were 1/3-1/2 MOA at 525. Absolutely drilled it at 300. I think I'm going to leave well enough alone and stretch it out.
You're making me want to dig out my 375 barrel and screw it back onto an action!

who the hell built a 26" cheytac? There must be a massive fire ball out the end of the barrell.

It's probably not that bad honestly. This is a 338 SnipeTac firing 140gr of H50bmg from both 20" and 30" barrels. There's not that much of a difference in muzzle flash, especially if you shoot it mid-day.
 
Nice rifle;
I am currently building a 375 Lapau AI; was hoping for 2900 fps with a 350 Sierra or Cutting edge with a 26 in tube, looks like I should be able to it.

6500 Ft lbs, awesome.
I'm sure you will. Is it throated long enough? You can probably squeeze enough r33 in that case to get 3000. I got to 118gr but I have to use a mandrel to tamp the powder before seating the bullet or the boattail jams a grain in the neck making a bump that won't chamber. Retumbo compressed is what I stuck with for now, and I'm sure that or 570 will be great for yours as well.
 
Yes, rifle is being throated to have .020 bullet jump with the boat tail junction being a few .000 in front of the shoulder neck junction. The chamber, etc is specifically set up for the Cutting edge 350 MTH / 350 lazer (.89 G1 at 2900 ought to be quite the hammer!!) I know it will not be mag friendly, but the idea is to have a long range load and then something with a lot of jump that will be mag friendly and used for 400 yards and less.

My rifle is built on a Defiance Anti, carbon fiber M40 stock and will wear a Leupold Mk5 or March 2.5x25 (I have both) I also have a .25 lbs. Neopod bipod. Rifle, scope and bipod should weigh 12 lbs +or - a few oz.

Have you tried a little faster powder than Retumbo?
 
12lb is really about perfect. My 14lb stock is a pretty heavy to haul, but the 10.5lb setup bounces you around quite a bit so I need more breaks on range day.

Tried h4350, old can of norma magnum, 7828 r33, and r22. 7828 could go higher than this but I ran out, and retumbo was seated short to the mag so got sticky there. R33 could go on up but I'm probably out of luck at 120gr. Bullets are pushing out at 118 and it's full to the very top. I recently broke down and bought h1000 but I dont expect it to beat retumbo by much.

My throat is ~.050" jump at 4.1" with smk, and a step in the rifling beyond that. So none of this applies if any of you have a standard leade.
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I'm sure you will. Is it throated long enough? You can probably squeeze enough r33 in that case to get 3000. I got to 118gr but I have to use a mandrel to tamp the powder before seating the bullet or the boattail jams a grain in the neck making a bump that won't chamber. Retumo

Any idea / guess how fast a 250 grain bullet could be driven given 2900 with a 350? I am thinking 3300- 3400.
I might try some Swift A-frames at that very high velocity on Cape Buffalo next year.
 
Any idea / guess how fast a 250 grain bullet could be driven given 2900 with a 350? I am thinking 3300- 3400.
I might try some Swift A-frames at that very high velocity on Cape Buffalo next year.
I have a hard time getting 3100 with 270gr speers without pressure. I haven't messed with it much. I only have 24" of barrel so it takes a bit more load fiddling to get that last 100fps or so. 3000 is way more than I'll ever need for anything I'll shoot them at so I stayed there. Think it was 3010 average With 102gr r22. R17 is kinda magical so maybe thatd be the ticket with your 250's. Or h4350. Dunno. This summer I'll figure it out. I only load those 2 bullets. I have 285 grand slams as well, but haven't loaded any. The 270 speer is spectacular killer. Brother got a doe last fall with one. Liver hit and it still dropped where it stood. Most of the liver was hauled out the exit along with 2 ribs and whatever else.


It's weird that almost everyone poo poo's the 375rum. On here, it might as well be called the 375NCT cuz its just "Not a Chey Tac". Well the cheytac isnt a BMG, so it sucks too?
Go on any dg forum like Africa Hunting and they absolutely despise It. But they swear the 375hh is God's gift, and their second favorite is the 404 jeff..... trying to explain the Rum is literally the best of both is equal to Satan worship at church! Stupid.
 
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The issue with the 375 RUM / 416 Remington in the mind of guys who hunt Africa is pressure related to high temps; keep in mind the vast majority of guys who can afford to hunt dangerous game do not reload- and are not very knowledgeable about ballistics. Reloads are also looked at sideways by a lot of the same guys.

The 375 H and H is really a great round for 99% of the game in Africa; powerful enough with a big enough bullet with relatively low recoil. It is an awesome round.

I have a 26 in barrel with a very long throat and more case capacity than the RUM. I will report back on how fact I can push the 250 A-frames.
 
How much free bore you guys have to run those 390gr a-tips? I'm trying to sort out a reamer but I'm waiting on bullets right now.
 
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