375 Raptor, thoughts and opinions

[mac86951]

Was discussing with friends why 300 blackout is a niche roll solution, and thanks to this site for posting the 223 chambering issues. Friends aren't reloaders so they saw that article and instantly questioned their need.

So I get to thinking; what if one started with a 308 case instead; and sure enough I'm not the first one, and I stumble on 375 Raptor.

Easy forming and I've got a pile of Mil-Surp brass.

Looks like good energy / ballistics within 300-400y, and looks like a gas-gun with 18" barrel would be great. Add in the subsonic capabilities and this whole package makes me quite curious.


Thoughts / opinions? At this point I'm just investigating 0.473 case head options from a 2.820" length restriction.

-Mac

 

[TC260]

I've been close many times to getting one for a 700 SA but haven't pulled the trigger. I used to deer hunt a lot with a 375 JDJ and still have a lot of Hornady 220 and 225's on hand along with a nice mold from Accurate for 265's so that's why the interest in the Raptor. As much as I like the idea though, I'm on a big downsizing kick these days and getting rid of all the "just because" stuff in the safe so unlikely to get one in the near future.

 

[Hausser]

I know the post is over a year old, but 375 Raptor discussions are few and far between. As it turns out I just finished with my build... AR 308 (DPMS style) Frankengun with 24" X-Caliber 10 Twist. Instead of using 308 brass, I went with 358, so case mouth forming is even easier with much less stretching.
I've got some handloads ready to try out in the middle of next week, with initial emphasis on IMR4166 since it's less temperature sensitive than the powders listed on the 375 Raptor load site. The available load recipes are quite scant as well, so it's a work in progress. @ mac86951, did you pursue a build over the last year plus?

 

[284winner]

Was discussing with friends why 300 blackout is a niche roll solution, and thanks to this site for posting the 223 chambering issues. Friends aren't reloaders so they saw that article and instantly questioned their need.

So I get to thinking; what if one started with a 308 case instead; and sure enough I'm not the first one, and I stumble on 375 Raptor.

Easy forming and I've got a pile of Mil-Surp brass.

Looks like good energy / ballistics within 300-400y, and looks like a gas-gun with 18" barrel would be great. Add in the subsonic capabilities and this whole package makes me quite curious.


Thoughts / opinions? At this point I'm just investigating 0.473 case head options from a 2.820" length restriction.

-Mac

I think it's like the 450 BM and 350 Legend comparison. There's a niche for it I'm sure.

 

[mac86951]

I know the post is over a year old, but 375 Raptor discussions are few and far between. As it turns out I just finished with my build... AR 308 (DPMS style) Frankengun with 24" X-Caliber 10 Twist. Instead of using 308 brass, I went with 358, so case mouth forming is even easier with much less stretching.
I've got some handloads ready to try out in the middle of next week, with initial emphasis on IMR4166 since it's less temperature sensitive than the powders listed on the 375 Raptor load site. The available load recipes are quite scant as well, so it's a work in progress. @ mac86951, did you pursue a build over the last year plus?

I went the 'easier' route and instead build a 308. While fun, i figured I'd let some others continue the pioneering first.

-Mac

 

[Earnhardt]

Don’t you have to cut the brass to a shorter length after you button size it up to 375?

 

[Treerat-sniper]

Thanks for bumping this, I had looked into the cartridge briefly a year or two ago. Ended up dismissing it as a "why?" type of case. Since then, that cartridge has recently become deer legal in my state. I ended up going the .358 Win route in a bolt gun due to my bullet supply and an aftermarket pre-threaded barrel in stock, but the cartridge is still intriguing.

 

[Hausser]

Don’t you have to cut the brass to a shorter length after you button size it up to 375?

Yes, there is some trimming required after running the 358 Win Brass thru the 375 Raptor die. I was able to get by using my RCBS Power Case Trimmer. It wasn't bad though. Good project on a crappy weather day..

 

[Hausser]

Thanks for bumping this, I had looked into the cartridge briefly a year or two ago. Ended up dismissing it as a "why?" type of case. Since then, that cartridge has recently become deer legal in my state. I ended up going the .358 Win route in a bolt gun due to my bullet supply and an aftermarket pre-threaded barrel in stock, but the cartridge is still intriguing.

There are some reportedly interesting facets to this cartridge. I'll know more once I start running various test loads over the chrony and checking for pressure signs.

 

[Hausser]

Good morning all.
Took the rifle out for some range time. Unfortunately, the cartridges wouldn't completely feed and the bolt got jammed. Despite the time-tested process of holding the charging handle latch open and bouncing the stock, it wouldn't come free. Took it home, separated upper from lower, and got it unjammed with a rubber mallet and make-shift wooden ramrod. I loaded the cartridges to specified COALs per the 375 Raptor Loads website, which are well short of the normal 2.8". I'm thinking there's something wrong with the camber length or case clearances aren't adequately reamed out. Will call X-Caliber today.

 

[Earnhardt]

Same thing happened to my 45 Raptor barrel.
What bullets did you use?
Do you know the free bore of your barrel reamer?
Did you set your bullets to that free bore? Or did you seat bullets to a COAL determined by an online post/forum?
Have you checked the chamber mouth, and the chamber neck area?
Thanks

 

[Oso]

I went the 'easier' route and instead build a 308. While fun, i figured I'd let some others continue the pioneering first.

-Mac

300 HAM'R ... 300BO on steroids without the hassle of the 350 Legend tuning or bullet limitation.

THis was my solution to something more powerful then 300BO. With same bullet weigthts it is either equal to or 100fps faster than a 6.5 Grendel out to 300 yards. It uses all of the great .308 cal bullets from 95gr - 150gr, and it is based on the 223 case. It fits in AR15.

300 HAM'R THread

 

[mac86951]

300 HAM'R ... 300BO on steroids without the hassle of the 350 Legend tuning or bullet limitation.

THis was my solution to something more powerful then 300BO. With same bullet weigthts it is either equal to or 100fps faster than a 6.5 Grendel out to 300 yards. It uses all of the great .308 cal bullets from 95gr - 150gr, and it is based on the 223 case. It fits in AR15.

300 HAM'R THread

Interesting for those small ARs. By 308, I'm meaning 308 Win; or 7.62x51. i don't think anyones fit one of those into an AR-15 yet, so we're talking the large format AR. Bullet prices for 375 bullets did contribute to my decision to stick to 308. Hate to say costs matter, but...

-Mac

 

[Oso]

Interesting for those small ARs. By 308, I'm meaning 308 Win; or 7.62x51. i don't think anyones fit one of those into an AR-15 yet, so we're talking the large format AR. Bullet prices for 375 bullets did contribute to my decision to stick to 308. Hate to say costs matter, but...

-Mac

Absolutely agree on cost and component availability from reloading perspective. I also like ability to easily source cases with option to convert 223 cases.

For me the AR10 gets heavy dragging around and not easy to handle in tight spaces or around ATV. I'm not hunting any Large Game, just hogs and killing paper, so an AR15 with the right cartridge fits the ticket for me.

 

[Tusker6N]

Don’t you have to cut the brass to a shorter length after you button size it up to 375?

Yes, it gets trimmed

 

[Tusker6N]

I'm in the process of putting together a 375 Raptor. I have a 45 Raptor already thats good to 300yds with 200gr ammo and I've developed a 450gr sub load that cycles.

The current problem with the 375 Raptor is the 4 month wait on reloading dies that I ordered today. CH4D gave me a 2 year wait and Lee isn't currently taking orders for at least 2 months.

I'm impressed that it only requires a barrel change, 308 brass converts easily, mag capacity doesn't change and the down range energy is impressive.

Main drawback for me is suppressed loads will only work in a bolt gun. However, I'm looking to extend my range to 400yds.

 

[Dragster]

Good morning all.
Took the rifle out for some range time. Unfortunately, the cartridges wouldn't completely feed and the bolt got jammed. Despite the time-tested process of holding the charging handle latch open and bouncing the stock, it wouldn't come free. Took it home, separated upper from lower, and got it unjammed with a rubber mallet and make-shift wooden ramrod. I loaded the cartridges to specified COALs per the 375 Raptor Loads website, which are well short of the normal 2.8". I'm thinking there's something wrong with the camber length or case clearances aren't adequately reamed out. Will call X-Caliber today.

Good morning,
I also have an X-Caliber barrel and experienced the same exact problem. My rifle is Aero Precision M5 based with an X-Caliber 18" barrel with carbine length gas system. After I was able to clear the jam and upon inspection of the cartridge, I could see clear rifling engraving on the bullet. I'm loading Speer 270gr SPs with Vihtavouri N530 and loaded them to the recommended COAL listed on 375 Raptor's web page (2.790"). My fix has been to shorten the COAL so that the cartridge smoothly chambers and comes to full battery. I ended up with a COAL of 2.760" as reliably feeding in my rifle. It just seemed odd to me that the Barnes 270gr LRX, which is a longer bullet, would have a listed COAL of 2.725". What did X-Caliber have to say about the chamber and/or reaming of the chamber?

 

[Sandstorm]

Looks like they need more freebore. Are you magazine feeding or do you single Feed.

 

[Ray123]

I looked at tbe 375 raptor recently, but no barrels, no dies, were in stock readily available. Plus 375 bullrts were expensive for a pinker...so I went with the 358 win in an AR...loaded up a variety of bullets readily available. Even several varieties of 9mm 147 Gold Dot & 147 HST....350 legend 250 gr SubX, 350 legend 160 gr, plus a bunch of regular 358 bullets...all in necked up 14 cent ea. 308 brass...super fast, no trimming...homemade double bump mandrel go from .308 to ist bump .338 to 2nd bump .358 one press stroke with no loss of brass.
It'll shoot 9mm, 350 legend, and 358 dia all the way up to 310. Very versatile & inexpensive.

 

[Dragster]

Looks like they need more freebore. Are you magazine feeding or do you single Feed.

Altered 308 MP 10 round mags per the 375 Raptor site's specs. I have it feeding well now with 270gr Speer at a COAL of 2.760". I will get back out to the range in a few days to see how it cycles live. If no problems, I will begin developing loads using H322 and also using load data for N530 for accuracy, etc.