.375 GSC 414 VS CEB 425 at 2050 yards

[Kiwi Greg]

I finally got some GS Customs .375 414 SP projectiles to try out in the 375 DCM.
On Saturday I loaded some up with RL50 & went to the range to try to match the speed to my CEB 425 load.
The only one I fired went through the Oehler at 3170 fps a little faster than I wanted so I went back, pulled them, reloaded 6 more dropping the powder back by three grains & worked up.
This was the group they shot at 100 yards, things looked promising & I got my target speed of approx 3140 fps
It is 1/2 moa low & 1/4 moa left of the 100 yard zero for the CEB 425s.



My goal was to shoot the GS Customs 414, Cutting Edge 425 & my custom tipped Cutting Edge 425s at extreme distance to compare the BCs
I have been tipping the Cutting Edge projectiles for nearly a year now, it seems to hurt their BC a little but has no detrimental effect on accuracy & certainly makes them more aggressive on game.
So you can see the size of these projectiles they are here are next to a .223.



The barrel doesn't really like changing between the CEB & GSC bullets, it takes a while to settle down again.
The change from CEB to GSC is less noticeable than the other way around.
I HBN coat all the projectiles I fire except the GSC which appear to be Moly coated.
This and the different projectile materials, combined with the residues left in the bore could be the cause ?
A couple of things to note.
Before I shot this video I had only shot the seven GSC projectiles & had no idea how they would go.
I pay for all my own componets etc, no one gives me freebees, hand outs etc.
The rock I used as the aiming point is approx 1/8 moa, less than 3" around, about the size of you fist, the ATACR reticle nicely covers it.
I do this so I have a definitive point of aim, not some rock 4 moa across.
The three projectiles have different POIs at 2050 yards which is to be expected.
On the whole the groups sizes are very small & a testament to the projectile manufactures.
Here is the video I shot on Sunday, sorry it is so long I had a lot to fit in.

 

[BigBboy25]

What are the BC's of these bullets? I guess I'm really interested in what BC's you are going to use in your program for the future?

 

[Kiwi Greg]

What are the BC's of these bullets? I guess I'm really interested in what BC's you are going to use in your program for the future?

GSC quote the 414 as.

GS CUSTOM BULLETS - 375414SP256 Technical Data

The 425 isnt listed on the Cutting Edge site, I asked them to make them for me Feb last year, I use 1.0 as a BC

 

[royinidaho]

Greg,

A very interesting 24 minutes of video.

I'm shooting very similar cartridge, 375 Allen Magnum which is almost exactly the same as the 375 Snipeo-Tac.

My barrel is a 10 twist which keeps me away from the solid bullets. I've only shot the lowly 350 SMK which seems plenty (so far). Also I haven't stretched it beyond the 1K distance. She shoots real well at that distance.

I'll be moving to 1 mile in the next week or so. One shoot, last winter in the snow, hit within the scope's field of view. Hadn't shot nearly that far but was very impressed that the POI could be seen in nearly a meter deep snow.

A little advice please. I'm pushing the SMK right at 3250 (Kirby's published load). ES and SD are quite good. But. . . does one need that much velocity with the puny 0.8 or so bc?

My goal is to take an animal at those distances, should I live that long.

How do you think those solids would perform on game at your velocity goal?

Those bullets that hit a bit low seemed sufficiently accurate to at least consider taking a shot at that distance with only a bit more practice at that spot and under those conditions.

You're doing good work and breaking new ground.

I'll keep and eye on ya.

 

[Kiwi Greg]

Greg,

A very interesting 24 minutes of video.

I'm shooting very similar cartridge, 375 Allen Magnum which is almost exactly the same as the 375 Snipeo-Tac.

My barrel is a 10 twist which keeps me away from the solid bullets. I've only shot the lowly 350 SMK which seems plenty (so far). Also I haven't stretched it beyond the 1K distance. She shoots real well at that distance.

I'll be moving to 1 mile in the next week or so. One shoot, last winter in the snow, hit within the scope's field of view. Hadn't shot nearly that far but was very impressed that the POI could be seen in nearly a meter deep snow.

A little advice please. I'm pushing the SMK right at 3250 (Kirby's published load). ES and SD are quite good. But. . . does one need that much velocity with the puny 0.8 or so bc?

My goal is to take an animal at those distances, should I live that long.

How do you think those solids would perform on game at your velocity goal?

Those bullets that hit a bit low seemed sufficiently accurate to at least consider taking a shot at that distance with only a bit more practice at that spot and under those conditions.

You're doing good work and breaking new ground.

I'll keep and eye on ya.

Thanks

I would give the CE 330 or 350s a go.

The 350s have been giving good solid results for guys in the Std 375 Cheytacs.

The 350 SMK has a massive jacket so I would guess that the CE 350 could be more aggressive on game that the 350 SMK, the faster you push them the more agressive they should get, to that ends the 320 or 330 may be a better bet.

The GS is a solid projectile & won't expand at all, I'm sure it would do plenty of damage if it hit major bone but there is very little of that in an animal & plenty of the opposite, where a hit would be undesirable.

 

[Rocky Mountain]

Its very interesting that the GSC 414gr at the same speed and in the same rifle were 7moa lower than the 425gr CE as looking at there shape they should have a beter BC, could it be the seal bands creating a wind upset over the bullet in flight dragging the BC down at the longer ranges?

 

[Yrcan]

Great video.

I have been shooting 267 grs GSC bullets i my 338LM, they look the same as the ones used here.
I found the advertised BC to be very high. I used 103 grs of Viht N570 powder, and MV was 1010 m/sec. At 100 meters they grouped fantastic, and also at 690 meters. But at 1000 meters, they started do hit way low, and at 2200 meters, they did not even connect with the target, being a frozen waterfall, 60 meters high and 20 meters wide. I shot some 300 grs Bergers to see if something was off, but they hit the ice wall where they where supposed to.

I might not have enough twistrate to stabilize theese bullets, but since they grouped well at 690 and 1000 meters, just hitting low, I think the high MV replaces the lack of twist.

I get my 375 CT soon, so I will follow this thread with great interest, in my search for bullets

 

[JeffVN]

Yrcan

You must be shooting a 338/408 or similar cartridge to reach 1010m/sec and use 103 gr. VV570 as your load. You must be using the newer 300 gr. Bergers, as the older lots would not tolerate those velocities. The good news is the newer Berger 300s transition very accurately (as Broz and others can attest)

I agree that the bullets were stable if you could get them to group at all at 1,000 meters. From my experience if they are marginally stable they will group at your 690 meter distance, but will not group at all at 1,000 meters. The low hits at 1,000 meters were most likely telling you the bc was than expected.

My experience with 338 caliber solids tells me that your inability to see hits at all at 2200 meters relates to the projectile having a lower than expected BC and not transitioning well as it went subsonic before it got to 2200 meters.

Jeffvn

 

[Yrcan]

I shoot a standard 338LM, with a Lothar Walter 32" barrel.
The 300 grs Berger OTM has a MV of 890 m/sec using 93 grs of 570. The 267 grs GSC bullet was chronoed using 2 different chronographs, and the was correct at 690 meters, and maybe 3 moa low at 1000 meters. I did this test in december last year, so I do not remember exactly. But the loads and MV I remember.

I shoot a 250 grs Scenar using also 103 grs of 570, at 1020 m/sec. It is a very hot load, and brass life was short, using Lapua brass. My standard load is 98 grs of 570, which gives me 990 m/sec with the 250 grs.

We are heading off to shoot at 2000 meters this weekend, I will shoot both my 338LM and my 300WM, will post video of it.

 

[Kiwi Greg]

Great video.

I have been shooting 267 grs GSC bullets i my 338LM, they look the same as the ones used here.
I found the advertised BC to be very high. I used 103 grs of Viht N570 powder, and MV was 1010 m/sec. At 100 meters they grouped fantastic, and also at 690 meters. But at 1000 meters, they started do hit way low, and at 2200 meters, they did not even connect with the target, being a frozen waterfall, 60 meters high and 20 meters wide. I shot some 300 grs Bergers to see if something was off, but they hit the ice wall where they where supposed to.

I might not have enough twistrate to stabilize theese bullets, but since they grouped well at 690 and 1000 meters, just hitting low, I think the high MV replaces the lack of twist.

I get my 375 CT soon, so I will follow this thread with great interest, in my search for bullets

The 250 & 300 Begers certainly perform well in the 338s.

Have a look at the CE projectiles for your 375, don't be put off by realistic BCs, the ones I have tried have been pretty close or spot on to advertised one.

There is something about shooting ELR, ie past a mile, it gets quite addictive

 

[Fiftydriver]

Yrcan

You must be shooting a 338/408 or similar cartridge to reach 1010m/sec and use 103 gr. VV570 as your load. You must be using the newer 300 gr. Bergers, as the older lots would not tolerate those velocities. The good news is the newer Berger 300s transition very accurately (as Broz and others can attest)

The 338-408 class weapon systems will have a 135 to 150 gr powder charge so the 103 gr powder charge is a bit off the Cheytac class capacities.

 

[Fiftydriver]

Looks pretty good. I was honestly surprised when those GSC bullets dropped that much below the CEB bullets. They did shoot extremely well however and as you well know, its easy to set up a drop chart to comp for bullet drop as long as the load is accurate and consistant.

Good work. I thought I heard you mention that you were having trouble seeing the bullet impacts from recoil movement on the video. That surprises me as well as my XHS in my 375 AM driving the 350 gr SMK @ 3300 fps are easy to watch bullet impact at ranges over 500 yards.

Perhaps my XHS is a heavier rifle. The large PK muzzle brake may have something to do with that as well.

Anyway, great shooting. Odd to watch a video of shooting in the mountains when the impact dust cloud just hangs there for several seconds. Nice to get a morning like that to shoot in but can be a pain with mirage with very light winds at times.

Good shooting, good video, good report, thanks.

 

[royinidaho]

Last year at one of the Townsend MT shoots, bigngreen launched several shots to 1K.

His comment was something like "This thing breaks really sweet!"

He was able to see the reflection of the bullet's base all the way to impact.

The big girl, all up, is right at 19.5 pounds. (It's a good thing that I have a 240 pound pack goat trained to carry it and the other LR stuff

 

[Fiftydriver]

Ya the PKs do a decent job at recoil reduction and muzzle jump control.