.375 Raptor Recipe

Keep us posted on the results!!
Well, here you go. Its kinda confusing and frustrating.

The filed down shellholder works. I can make brass that passes the case gauge. However, I have discovered other issues.

If I run a case through either the Lee or CH4D die with a unmodded shellholder, then the case has too much headspace. But if I run one case through both dies, then it has almost too little headspace. So I am not really sure whats going on there, yet.

Additionally, it seems that I have to size the brass closer to the minimum headspace according to the case gauge in order for it to chamber in my rifle. I headspaced my rifle using go and no-go gauges.

So I not sure what the ultimate issue is. I don't know if its just people using different tolerances, or maybe its the Starline brass I am using, or maybe I am missing something. I will keep working on it. Bottom line is that I can at least make ammo that will work for my rifle. I might try to get some commercial ammo and see how that runs in my rifle.

Why can't any of my projects be simple.😩
 
Well, here you go. Its kinda confusing and frustrating.

The filed down shellholder works. I can make brass that passes the case gauge. However, I have discovered other issues.

If I run a case through either the Lee or CH4D die with a unmodded shellholder, then the case has too much headspace. But if I run one case through both dies, then it has almost too little headspace. So I am not really sure whats going on there, yet.

Additionally, it seems that I have to size the brass closer to the minimum headspace according to the case gauge in order for it to chamber in my rifle. I headspaced my rifle using go and no-go gauges.

So I not sure what the ultimate issue is. I don't know if its just people using different tolerances, or maybe its the Starline brass I am using, or maybe I am missing something. I will keep working on it. Bottom line is that I can at least make ammo that will work for my rifle. I might try to get some commercial ammo and see how that runs in my rifle.

Why can't any of my projects be simple.😩
Case gauges and headspace gauges are just as fallible as chambers. After all, how do you think they're made?

Use your chamber as a headspace gauge. That will be more telling as you try to match your die setting to your.... chamber.
 
Chassis came the other day. Just need to torque everything down to spec.

As pictured, just under 7lbs.
1000004131.jpg
 
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Nice build. Tikka receiver with a mostek barrel?
Yep.

What are you using for a suppressor? Has the new .375 Magnus peeked your interest?
I am using the AB Raptor 8 in .375. Haven't look at the magnus much; need to save some pennies before I get another suppressor.

Just a brief update on the weird die issues I was having:

So I made a low charge round to do a test fire, and nothing blew up, so thats good. Anyway, the fired case looked... hmm... sharper to the dimensions if that makes sense. So I ran the fired case through the CH4D die with a NORMAL shellholder, and then tried it in the case gauge and it was perfect to minimums.

So it appears to be a brass issue, I guess. I will have to try with some different brands of brass.
 
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Brief update on the die issue: No neck tension when using the CH4D die on fired brass. I believe there is an issue with the die. Lee die works okay. If anyone is using a CH4D die, I would be curious if they are having any issues.

But this thread is about load data. Well, I have a little.

Disclaimer: My reloading data is only for use by me and my rifle.

I had some time to kill, so I made some 270gr speer loads.
18" barrel. OAL 2.790 RL-10x
41.5gr- 2175
42gr- 2195
42.5gr- forgot to write down
43gr- 2238

Top brass is 41.5, bottom is 43.
The last picture is the 43gr. I can see a faint ejector mark, I think. Your thoughts? I'm new to reading pressure signs.
 

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Brief update on the die issue: No neck tension when using the CH4D die on fired brass. I believe there is an issue with the die. Lee die works okay. If anyone is using a CH4D die, I would be curious if they are having any issues.

But this thread is about load data. Well, I have a little.

Disclaimer: My reloading data is only for use by me and my rifle.

I had some time to kill, so I made some 270gr speer loads.
18" barrel. OAL 2.790 RL-10x
41.5gr- 2175
42gr- 2195
42.5gr- forgot to write down
43gr- 2238

Top brass is 41.5, bottom is 43.
The last picture is the 43gr. I can see a faint ejector mark, I think. Your thoughts? I'm new to reading pressure signs.
That's good data. I appreciate you posting it. As far as the CH4D dies, I heard enough bad things about that kept me from ordering a die set from them. Luckily I found a set from Lee. I haven't been able to use them yet because I am still waiting on my barrel. Going on 14 months now.
 
I have not tried 10x, because I haven’t found any. Accurate 1680 and 2200 have both been good to me. 1680 for subs and supers and 2200 for supers only.
You mentioned trying 2200 with 270speers but hadn't chrono'd them.

Did you ever get the chance?

With 1680, SW blackout, and CFEBLK, I have gotten the 190gr makers to 2600+ fps. I need to do more testing to see where the pressure limits are.

However, for my 230gr VLR4, I think CFEBLK might be a bit fast. From the old website, they show 2575fps with a 235tsx using 1200-R. I'm not quite to 2500fps with CFEBLK. I can't find 1200-R, but heard Accurate 2200 was similar.
 
You mentioned trying 2200 with 270speers but hadn't chrono'd them.

Did you ever get the chance?

With 1680, SW blackout, and CFEBLK, I have gotten the 190gr makers to 2600+ fps. I need to do more testing to see where the pressure limits are.

However, for my 230gr VLR4, I think CFEBLK might be a bit fast. From the old website, they show 2575fps with a 235tsx using 1200-R. I'm not quite to 2500fps with CFEBLK. I can't find 1200-R, but heard Accurate 2200 was similar.
I have not had the chance yet. I will try to get out ASAP.
 
Accurate 2200 might be the key to replacing 1200-R. I heard 1200-R can be really temp sensitive which isn't ideal for me.

With 10x and the 260gr accubond, it's almost like I'm running out of capacity before I hit pressure. I think 1200-R was a similar burn rate, but in a ball powder.

I just ordered a bunch of different powder to try. 2200, 2015, x-terminator, and N120.
 
I wish I knew the pressure. The casehead looks fine. Primers are still round on edges and no cratering.

But pressure could be 65,000psi, which is over pressure, but not enough to show signs.
I like Starline and use in several cartridges but youl know when there’s pressure. It’s not like lapua taking 70k + and appearing fine. 65k in Starline and youl be seeing ej flow and flattened primers in most cases.
 
I'd like to use as little powder as possible. Something faster. I've got a 9" barrel and 9" suppressor, all integral. I'd like to burn as much powder inside the barrel as possible.
 
The only load data I can find for 400gr subs shows 10gr of Tin Star. In that same burn range is Unique, Universal, and Power Pistol. Anyone try any of those?
 
I haven't had a chance to get out and shoot the barrel anymore but over the last couple of days I've been looking at powders for subsonic data. I'm using 8gr of Lil Gun in .338 Spectre with 300gr subs. I initially tried Longshot because that's what I use in heavy 300BO subs but reached high pressure right at 1000fps in the Spectre. It's too fast for that cartridge. Thinking about this, I'm pretty confused how a powder as fast as Tin Star is used for subs in a 400gr sub. Regardless of the fact that Tin Star is discontinued, powder in that burn rate just seems too fast. I'll Chrono the Power Pistol load and see if I can get it to 1050 safely but my guess is that the 9gr load I test fired is way slow and as I work up, I may run into pressure spikes. I probably need something closer to H110.
 
1000005564.png

10" of rifling, 10" of baffles. 20" total length.

13gr Lil' Gun - 1045fps (90fps per 1 grain of powder)

10gr Power Pistol - 1055fps (200fps per 1 grain of powder. Probably don't want to use this powder for subs. Too volatile)

44gr Xterminator, 235gr Speer Hot Cor - 2020fps
47gr Xterminator, 235gr Speer Hot Cor - 2130fps
 
View attachment 8483587
10" of rifling, 10" of baffles. 20" total length.

13gr Lil' Gun - 1045fps (90fps per 1 grain of powder)

10gr Power Pistol - 1055fps (200fps per 1 grain of powder. Probably don't want to use this powder for subs. Too volatile)

44gr Xterminator, 235gr Speer Hot Cor - 2020fps
47gr Xterminator, 235gr Speer Hot Cor - 2130fps
Use at own risk:

400gr maker, Accurate 1680, 18" barrel
21gr- 1194 fps
20gr-1187 fps
Thats all I have tested. Need to see how much to reduce to go subsonic. Hard with 18" barrel.

235gr speer, reloder 10x
43.5gr - 2300fps
I need to try CFE BLK with the 235 speer. CFEblk pushes my 230gr VLR4 to 2450 (might go higher, need to test).

Speaking of the VLR4, if anyone is interested: https://discreetballistics.com/shop/vlr-4-375/
 
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I'm seeing a few comments here and there online about the 375 Raptor being harder to get cycling in an AR.

Have any of you ran into that? Was it a matter of finding the right powder?

I think people may be running into issues with the gas system configuration, barrel length, and powder selection. They want to blame the cartridge, but it may have more to do with the rifle and ammo. It is a wildcat after all, you have to know what you are doing.
 
I'm seeing a few comments here and there online about the 375 Raptor being harder to get cycling in an AR.

Have any of you ran into that? Was it a matter of finding the right powder?

I think people may be running into issues with the gas system configuration, barrel length, and powder selection. They want to blame the cartridge, but it may have more to do with the rifle and ammo. It is a wildcat after all, you have to know what you are doing.
These are 300 blackout issues but exaggerated. Trying to get a gas system in a AR-15 to run both supers and subs can be more difficult than people think. And it is almost always a compromise. If you set the gun up for subs, you're going to be most definitely overgassed for supers. If you tune the gas system for supers, there's a lot of subsonic loadings that won't cycle the gun. Powder charges for subsonic loads can vary anywhere from 5 grains to 12 grains. The difference in those powders and charges can be the difference in cycling reliably cycling unreliably and not cycling at all. A subsonic load of h110 is probably right around 10 grains while a supersonic Max load is probably around 18.5 to 19 grains. Now compare that with 375 Raptor where your subsonic loads can be 12 to 15 grains and your supersonic loads can be 40 to 45 grains. The variance in chamber pressure and back pressure coming down the barrel to run the gun is a much bigger spread than 300 blackout.
 
The minimum Starline will do is 50,000 cases and there's an additional retooling cost. (In this case the retooling cost would already be covered.)

They don't mess with trying to sell wildcat cases in small amounts, which is understandable.



Just curious, how many cases would you be willing to get if you could get any quantity?

They are headstamped 375 Raptor.
Ever get that order off I am good for 5K units, I have talked with Starline as well
 
Just a heads up, it sounds like the black collar guys are going to have ammo and components available soon. They sounded confident.

I know they made the load data available from the old raptor website on their own website.

They even mentioned working on making 7 raptor stuff. (It's a 223 case necked to 7mm)
 
Just a heads up, it sounds like the black collar guys are going to have ammo and components available soon. They sounded confident.

I know they made the load data available from the old raptor website on their own website.

They even mentioned working on making 7 raptor stuff. (It's a 223 case necked to 7mm)
They've been saying that for something like 2 years
 
USE AT OWN RISK:

18" 10 twist barrel

350gr maker
2.780"
17gr N120
1038fps

230gr vlr4
2.737"
44gr cfeblk
2500fps

Going above 44gr cfeblk the velocity plateau'd. 44.5gr gave a sticky bolt and ejector kiss. 44gr might be too much, not sure.

Trying n130 next. Also need to try lt32 with heavier bullets.
 
I knew some were using AA1680. N120 is similar, but I heard it was cleaner. A powder that fills the case is prefered, but the powder also needs to burn fast and fairly clean. Tin Star and Trail boss had these characteristics. I also don't have any powders faster than 1680 or N120.
I've found, in general, the larger the powder charge the louder it is through a suppressor.