390 grain Hornady A-Tip load development 375 Cheytac

Hill Top

Private
Minuteman
Jun 15, 2022
25
19
Australia
I loaded the first lot of Atips up today today

With a “hard” jam in my chamber I was at 4.395”COAL, talking to some others shooting this projectile some were having success at 0.1” jump and others said 0.04”, I started with 0.04” and seated to 4.350” COAL, I don’t have a BTO measurement I need a new wheel for the Forster tool for 375 cal
BB brass, Fed gold primer, 2218 powder

I only have the CH4D dies but they are producing repeatable ammo, the neck tension looks to be 4 or 5 thou, getting tight but not silly, with SMK’s I had 3 tho but that was with many times fired brass

I have access to ADI 2218/H50BMG, I loaded from 130 to 134gr, at 134gr I had zero pressure sign the bolt fell open easy, no swipe or stamp on the case head and a SD of 5 on a 2825fps average, I will do another test from 134 upto 137 and see what can be achieved, I hoping to find the next node before pressure gets to high would be good to get to 2900fps but not sure I will achieve it

Just doing pressure tests at 100 everything grouped better than expected

We also tested the Bullet Seeker chrony out, with the parabolic adapter, same deal as before the muzzle blast of the Cheytac is to much for it to get reliable readings, the parabolic adapter did get more readings than without though, some strings only getting one shot reading, positioning under the barrel was best we got 3 readings out of a 5 shot string, the velocities matched the cheap and nasty Cauldwell chrony that reads every shot, the program for the bullet seeker chrony is good though once it is worked out, with smaller guns it is all good.
 
Last edited:

Hill Top

Private
Minuteman
Jun 15, 2022
25
19
Australia
5CA9342A-2A91-46CE-BB18-FC0A04C38BD2.jpeg
 

Hill Top

Private
Minuteman
Jun 15, 2022
25
19
Australia
Was a 5 shot string, first shot failed to read at all, 4th shot didn’t have enough detections for a real reading was only like 30 detections and a silly velocity, the program highlights these shots to edit them out
 
  • Like
Reactions: 232593

disky1

Private
Minuteman
Jul 24, 2013
21
22
Hill Top.

Im .025 off and they are wicked. 375 enabelr. Use something like retumbo powder.. 2925fps for me
 

disky1

Private
Minuteman
Jul 24, 2013
21
22
In my HTI 375CT i had early pressure signs with Retumbo ( AR2225) ...also had several hang fires even with 215m,s,
Thats odd... my case is at 90-95% capacity for sure. 124gr retumbo.
215m,s also.

I tried h50bmg and couldnt get enough in the case. And vhit n570 seemed too horny pressure signs but fast fps.
 

disky1

Private
Minuteman
Jul 24, 2013
21
22
Retumbo is too fast for a ct and 390s
Geno, the case capacity of the enabelr to the CT is basically the same, why do you think retumbos too fast in the CT case, do you think it has to do with the longer more slender case of the CT?
 

Geno C.

Dirty Carnie
Full Member
Minuteman
  • Oct 24, 2007
    6,755
    15,584
    38
    Wautoma, WI
    Geno, the case capacity of the enabelr to the CT is basically the same, why do you think retumbos too fast in the CT case, do you think it has to do with the longer more slender case of the CT?
    They aren’t basically the same at all. Look at the prints again. CT is bigger
     

    232593

    Gunny Sergeant
    Full Member
    Minuteman
    May 25, 2022
    567
    1,516
    Arizona
    Tested the ATIPS with 136 grains of RL50 & Bertram Brass again. .075” of the lands was about 1 MOA. .100” off the lands was about 1/4-1/3 MOA. However the ES went to shit. I may need to adjust the charge?
     

    secondofangle2

    Online Training Member
    Full Member
    Minuteman
    Jul 3, 2017
    1,086
    744
    Tested the ATIPS with 136 grains of RL50 & Bertram Brass again. .075” of the lands was about 1 MOA. .100” off the lands was about 1/4-1/3 MOA. However the ES went to shit. I may need to adjust the charge?
    Your “n” for the SD and ES needs to be 10-20 shots before you draw conclusions. Use Labradar during some long range work and re-evaluate later if the .100” off needs adjustment is what I would do.
     
    • Like
    Reactions: 232593

    232593

    Gunny Sergeant
    Full Member
    Minuteman
    May 25, 2022
    567
    1,516
    Arizona
    Your “n” for the SD and ES needs to be 10-20 shots before you draw conclusions. Use Labradar during some long range work and re-evaluate later if the .100” off needs adjustment is what I would do.
    When you do the 10-20 shots does your RL50 load ES stay in the single digits still? When you do how much time do wait between shots? I’m going to give that a go when I get a chance to shoot on private land out to 1600m, landowner has a Labradar he will set up.
     

    232593

    Gunny Sergeant
    Full Member
    Minuteman
    May 25, 2022
    567
    1,516
    Arizona
    Anyone plan on trying out 24N41? I’m debating it but I think I have a decent H50BMG load and am getting there with RL50 & Bertram brass, so I’m not sure if the juice is worth the squeeze. Really starting to like these ATIPS.
     

    secondofangle2

    Online Training Member
    Full Member
    Minuteman
    Jul 3, 2017
    1,086
    744
    Anyone plan on trying out 24N41? I’m debating it but I think I have a decent H50BMG load and am getting there with RL50 & Bertram brass, so I’m not sure if the juice is worth the squeeze. Really starting to like these ATIPS.
    I tried it. No advantage. Can’t fit enough in a case to get acceptable speed. Either that or can’t get speed without pressure I forget which but I abandoned it either way.
     
    • Like
    Reactions: 232593

    232593

    Gunny Sergeant
    Full Member
    Minuteman
    May 25, 2022
    567
    1,516
    Arizona
    Was a 5 shot string, first shot failed to read at all, 4th shot didn’t have enough detections for a real reading was only like 30 detections and a silly velocity, the program highlights these shots to edit them out
    BTW thanks for the report on the bullet seeker and muzzle break issues.
     

    secondofangle2

    Online Training Member
    Full Member
    Minuteman
    Jul 3, 2017
    1,086
    744
    I run suppressed, so I have to put my LabRadar is safe distance in front of the muzzle and just off to the side. In order to get the acoustic sensor to pick up.
     
    • Like
    Reactions: 232593

    secondofangle2

    Online Training Member
    Full Member
    Minuteman
    Jul 3, 2017
    1,086
    744
    390 ATIP in stock at precision reloading
    and even cheaper at Brunos
    and even cheaper at Graf:
     
    Last edited:
    • Like
    Reactions: Geno C. and 232593

    232593

    Gunny Sergeant
    Full Member
    Minuteman
    May 25, 2022
    567
    1,516
    Arizona
    390 ATIP in stock at precision reloading
    and even cheaper at Brunos
    and even cheaper at Graf:
    Awesome, thank you!!!