29” factory dt. Havent checked speed yet. Forgot to put my radar up when i shot. Ill get it sometime soon.
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390 grain Hornady A-Tip load development 375 Cheytac
- Thread starter secondofangle2
- Start date
1200mtrs today...
133gr AR2218 (H50bmg)
Bertram Brass.
"3" shot.. 4" Group '3' shot.. 1 3/4" Group...
133gr AR2218 (H50bmg)
Bertram Brass.
"3" shot.. 4" Group '3' shot.. 1 3/4" Group...
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Thanks mate...
Makes a big difference when you have 100% confidence in the gear you are using!!
My load in Peterson brass is 141 grains at 3020 fps in a 8 twist Bartlein 36 inches long. Your 2 nodes down and 7 inches shorter on barrel length.
Post your velocity when you get a chance
Post your velocity when you get a chance
There is NO WAY in hell i could use 141gr of AR2218 in my rifle !! 135/136 was MAX ..
Velocity is circa 2900fps..with 133gr
Ran a 5 shot ladder from 134,134.5,135,135.5 and 136 grains. 134g was 2780fps and out of the group but the 4 others went into same hole with an sd of 8.6 and es of 21 Kind of a crazy big node. What would you guys do? Take a charge weight in the middle and run with it? Or chase more speed.
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Peterson Brass?
132 gets me 2900 but that’s a 34” pipe. Figure about 15 fps per inch and you’re not too far off my load.
When it comes to that last 50 fps, I don’t chase it. I’d rather have good brass life that has wiggle room for hot temps, as long as I have an accurate load with good SD
132 gets me 2900 but that’s a 34” pipe. Figure about 15 fps per inch and you’re not too far off my load.
When it comes to that last 50 fps, I don’t chase it. I’d rather have good brass life that has wiggle room for hot temps, as long as I have an accurate load with good SD
There is another node around 137-138 and another at 141-142 you just have to see what your brass and gun can handle safely.
We have 3 guns and have a dozen barrels all done with the same reamer and the 2 using Stiller tac 408 actions like 141 grains at 4.24 inches with the A-tips.
The gun with the BAT action reaches pressure around 3 grains lower so that is where it gets loaded.
We have 3 guns and have a dozen barrels all done with the same reamer and the 2 using Stiller tac 408 actions like 141 grains at 4.24 inches with the A-tips.
The gun with the BAT action reaches pressure around 3 grains lower so that is where it gets loaded.
I am in the United States and I have been shooting this cartridge since 2013 literally thousands of rounds (~5000?), through 6+ barrels and load development for several others. I have been through Jamison which does suck, Bertram, the first batch of Peterson, and later batches of Peterson. I stick with Bertram for its significantly larger case capacity.
This load, I wager, is going to be over pressure in the majority of barrels. I’m interested in seeing a case head also.
If guys work up to 140+ and it’s safe, great. What I don’t want them to take away from your post is that it’s a “target” charge weight and they or their brass are pussies if they don’t get there.
There are a lot of variables that *may* allow that charge to be safe. It may also be that you’re over pressure and either don’t know it or are ignoring it.
Not only too much pressure, waaaaaaay too much pressure, a place where I would never find myself except by accident
Yessir peterson brass. Im running with 135 grains at 2815 fps. No need to push the limit. Its one hole accurate and very consistent. Crazy how big that node is. 1.5 grains wide. Super happy!
The Bertram case is weak and the primer pockets don't handle pressure well so more case capacity doesn't really matter as your not utilizing what you already have.
The cases in the photo are 338 Snipetac taken when it first came out and the reason it never succeeded was due to the lack of good brass back then.
If you look at the picture that is Bertram brass so when I post it isn't from crazy emotion about too much pressure only gotten by accident it's by real world experience with those actual components.
The pictures show 2 of my cheytacs.
I will edit this post and add a video of myself winning the URSA 3K Match in 2021 with another one of my cheytacs.
Again real world not keyboard typer world
Edit. watch until the end and the rifle is pictured. Stiller Tac 408 1.6 diameter 36 inch Lilja 8 twist in a barrel block so the action doesn't bend and ruin the bedding 2 ounce jewell trigger March 5-42 wideangle scope and tracking rails so it returns to battery after each shot rifle weighs 67 pounds as pictured barrel is 1.750 doameter
The cases in the photo are 338 Snipetac taken when it first came out and the reason it never succeeded was due to the lack of good brass back then.
If you look at the picture that is Bertram brass so when I post it isn't from crazy emotion about too much pressure only gotten by accident it's by real world experience with those actual components.
The pictures show 2 of my cheytacs.
I will edit this post and add a video of myself winning the URSA 3K Match in 2021 with another one of my cheytacs.
Again real world not keyboard typer world
Edit. watch until the end and the rifle is pictured. Stiller Tac 408 1.6 diameter 36 inch Lilja 8 twist in a barrel block so the action doesn't bend and ruin the bedding 2 ounce jewell trigger March 5-42 wideangle scope and tracking rails so it returns to battery after each shot rifle weighs 67 pounds as pictured barrel is 1.750 doameter
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The “keyboard typer world” constitute most people on this thread and they’re all settling out in the low-mid-130s not the low 140s. I advise them to stay in this false world until they get out into the “real world” and win competitions whereupon they will be able to get into the 140s like you.
137gr AR2218 in my DT i had to "bash" the bolt open with my fist...so way over pressure in my setup.
I actually tried Peterson Brass with Berger 379 Solids...136gr AR2218 flattened primers and bolt lift was extremely hard...so very near max..
I can open my bolt with one finger then put the fired case back in the gun and close it with one finger.
FarmerBrown32
I would go up in 1 grain increments until you see pressure then back it down until you hit a node were it shoots well.
Your velocity is gonna be a little off due to the shorter barrel.
Start where you left off and quit when your caseheads exceed 0.001 or your bolt drags.
The picture shows 650 rounds of the latest batch of Peterson brass alongside 5 chambered barrels. The one with the rope is ready for determining the correct tuner weight and then barrel 7 is just a blank.
I would never encourage a new shooter to start at the highest node and I would never recommend Bertram brass either.
FarmerBrown32
I would go up in 1 grain increments until you see pressure then back it down until you hit a node were it shoots well.
Your velocity is gonna be a little off due to the shorter barrel.
Start where you left off and quit when your caseheads exceed 0.001 or your bolt drags.
Yeah and 81 million people voted for Joe Biden doesn't mean much when your trying to win matches against the same chambering.
The picture shows 650 rounds of the latest batch of Peterson brass alongside 5 chambered barrels. The one with the rope is ready for determining the correct tuner weight and then barrel 7 is just a blank.
I would never encourage a new shooter to start at the highest node and I would never recommend Bertram brass either.
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We’re right back to where we started. Work up the best under pressure in your gun and roll with it.
I've never said otherwise.
You on the other hand are telling people which loads are safe and which are not
I didn’t see where he was telling folks what loads are safe and what ones aren’t. I had pressure at 138 grains and that was in the “winter” here.
Are you putting 140 grains into new Peterson brass? Behind a 1:8 twist barrel? I thought they had problems staying together at speeds above 2800 with the tight twists?
Have you tried them at 3050 with an 1:8 twist? If so how did they work? What powder and brass did you use?
This is what I was talking about.
8 twist bartlein 36 inches 141 grains of H50BMG 3020 fps and no issues at all.
In the barrel pictured above with the barrel block that is a Lilja 36 inches long 8 twist with zero issues.
The barrel with the Stiller action is a Lothar Walther 10 twist 1.650 straight cylinder just for the A-tips. I won't post the load so nobody faints.
@MarcC11B have you tried 20N29 with the ATIPs in your SnipeTac? Early on in this thread @secondofangle2 mentioned it only getting 2760 fps, due to case limitations & powder kernel size in the standard Cheytac case. If so what were your results?
Isn’t 20N29 about the slowest burning powder available on the US market?
Isn’t 20N29 about the slowest burning powder available on the US market?
I’m Ohio with my buddy and HIS DT HTI 375 w factory 29” barrel. Wanted to try my H50 BMG load in his gun.
133 of H50BMG at 2.250” COAL in Bertram brass was 4-shot groups about .75” - not bugholes like my barrel. SD of 5 shots was 3.9 which is excellent but importantly his speed was just 2778 fps avg. 134 grains was just at 2800. Interestingly, 134 had minor primer flow and faint ejector swipe, 133 had none so I do think this is just at the edge of pressure for this particular combination of variables.
For comparison, we got out the ammo I loaded him 3 years ago with 138 grains RL50. I sunk the first 3 in 3/8” group and stopped. SD was 6 (n too small I know) but all three speeds were in the 2920s in his gun. Since he has 60 more of these loaded, we stopped there. He’s a long range hunter and that extra 125 fps sealed the deal for him.
(Will add target pics later for those interested.)
133 of H50BMG at 2.250” COAL in Bertram brass was 4-shot groups about .75” - not bugholes like my barrel. SD of 5 shots was 3.9 which is excellent but importantly his speed was just 2778 fps avg. 134 grains was just at 2800. Interestingly, 134 had minor primer flow and faint ejector swipe, 133 had none so I do think this is just at the edge of pressure for this particular combination of variables.
For comparison, we got out the ammo I loaded him 3 years ago with 138 grains RL50. I sunk the first 3 in 3/8” group and stopped. SD was 6 (n too small I know) but all three speeds were in the 2920s in his gun. Since he has 60 more of these loaded, we stopped there. He’s a long range hunter and that extra 125 fps sealed the deal for him.
(Will add target pics later for those interested.)
With two factory HTI barrels and Peterson Brass 133-134 grains of H50BMG has yielded me 2900-2915 FPS and no pressure.
When the third one gets here I’ll post results.
That is pretty wild. Im at 135 grains of h50 with my factory dt barrel and only gettin 2800 fps with the 390 atip. But its super accurate.
You are right there with the gun I shot today. Indeed, I found him this gun for sale by a DT employee, new, and unfired about five or six years ago. I set it up for him and then shipped it to his FFL. It’s a good shooter, and the other load that it likes is 134 or 135 of N570 pushing a 350 grain sierra match king at about 3100 to 3125. For whatever reason, it prefers my original load with RL 50 for the 390. Granted, we did not shoot a big enough sample size to discern the difference today but the speed was the clincher.
We should talk about these velocity discrepancies. Humidity? Temperature? Velocity estimation techniques? Barrel round count?
Me....2890fps SD 4fps..
Factory 29" DT barrel ...133gr AR2218 ( H50BMG) ..Bertram Brass , Remington 9 1/2 Magnum Primers 390gr A-tip.. OAL...4.375" Ambient temp 17c. Elevation 685mtrs
Barrel Round Count...980 Rnds..
Chrony Master Chrono..
Factory 29" DT barrel ...133gr AR2218 ( H50BMG) ..Bertram Brass , Remington 9 1/2 Magnum Primers 390gr A-tip.. OAL...4.375" Ambient temp 17c. Elevation 685mtrs
Barrel Round Count...980 Rnds..
Chrony Master Chrono..
Charge weight 133-134 grains, velocity was 2900-2915
Humidity 8-12%
Temp 50-78 degrees
Altitude 5400 ASL
Round count 1st barrel 2-300 rounds
Round count 2nd barrel 30 rounds
Velocity readings from Magnetospeed.
FED215M primers
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Im using new peterson brass,215m primers, 135g h50bmg @ .130 off lands. 2600’ elevation, 70’ F. With an avg speed of 2795 and an sd of 6.1 over 6 shots.
Thats with a lab radar to. Ended up seating the atip a lil deeper then .100. Maybe thats why im still slower?
I took some 133 grain H50 BMG loads in Bertram with 50% RH in the jug (freshly opened, measured with Kestrel D2 drop)to Ohio to try in my buddys HTI w factory barrel and they were right at 2800
137 of RL50 (49% RH) gets him 2900 fps and was just as accurate so he stuck with that and I just loaded him up 100 more rounds
20 thou seating depth won’t make much difference (maybe 10 fps) unless it pushes you close to the lands of close to 100% case capacity. Even then…
FarmerBrown32
What brass are you using? And if you haven't seen any pressure signs why haven't you gone higher?
Seating fully jammed into the lands changes pressure 3000-5000 psi and won't blow your gun up.
This internet myth stuff about touching the lands has zero credibility.
Before the troglodytes scream don't listen to this lunatic go to the Berger Bullets website and read what actual testing shows.
My gun likes 2970 fps with a 36 inch barrel so take that extra 7 inches into account.
I am north of 140 grains of H50BMG at 4.24 inches and this barrel has a 8 twist.
I have a slow twist Lothar Walther 1.650 straight cylinder barrel chambered up by BillyGoat Machine and when I do my load workup I will make a you tube video for you and link it here.
bergerbullets.com
What brass are you using? And if you haven't seen any pressure signs why haven't you gone higher?
Seating fully jammed into the lands changes pressure 3000-5000 psi and won't blow your gun up.
This internet myth stuff about touching the lands has zero credibility.
Before the troglodytes scream don't listen to this lunatic go to the Berger Bullets website and read what actual testing shows.
My gun likes 2970 fps with a 36 inch barrel so take that extra 7 inches into account.
I am north of 140 grains of H50BMG at 4.24 inches and this barrel has a 8 twist.
I have a slow twist Lothar Walther 1.650 straight cylinder barrel chambered up by BillyGoat Machine and when I do my load workup I will make a you tube video for you and link it here.
Getting the Best Precision and Accuracy from VLD bullets in Your Rifle
VLD bullets are designed with a secant ogive. This ogive shape allows bullets to be more efficient in flight (retain more velocity = less drop and wind deflection). While this result is desirable for many rifle shooters the secant ogive on the VLD bullets produces another result in many rifle.
bergerbullets.com
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Peterson brass. I dont wanna sound like im tooting my own horn but im def not a beginner reloader. Id venture to believe that i shoot and reload way more then the average guy and i do know what im doing. The reason i havent pushed it up is because im not worried about gettin another 100 fps because it shoots sub half moa consistently with great numbers and the reloading component’s are so dang expensive that i hate to use up more just for finding a better load. Also want to save on barrel life because i like to shoot alot and have a 11 year old that likes to shoot just as much or more haha.
This is my current attitude now also. I want wiggle room for when it speeds up for any of multiple reasons. I hate it when a load with 100+ loaded up that previously was pushing max but was safe starts showing ejector swipes in summer then I have to either abuse the brass shooting the rest of it, or pull it which is a major PITA, or save it as a "winter load". Much easier to just load a little on the lighter side
