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Posted: 12/22/2025 6:09:19 PM EDT
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Anyone shooting the .375 Raptor? I'm thinking of doing a 16" build just for fun, don't expect it to do anything better than rifles I have, just wanting to tinker. I like the fact it's case is .308 based. Mix info on line about brass forming, no one seems to have .375 marked brass anymore. Comments... suggestions? |
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I don't know anything about the Raptor but if brass isn't available and you don't want to mess with it GA Precision is supposedly working on a 375 GT. If it's like the other stuff they've done there will be headstamped brass available. The Raptor is a bit bigger case it sounds like. I've seen a few people talking about the Raptor on SnipersHide. GA dropped a teaser vid a while back but I haven't heard any updates. https://www.instagram.com/p/DOqmwcWjTBo/ |
BikerNut:
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People who don't like motorcycles are just... weird.
Normal people like motorcycles. Real people like motorcycles.
People who don't like motorcycles are just... weird.
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Originally Posted By ALASKANFIRE: I don't know anything about the Raptor but if brass isn't available and you don't want to mess with it GA Precision is supposedly working on a 375 GT. If it's like the other stuff they've done there will be headstamped brass available. The Raptor is a bit bigger case it sounds like. I've seen a few people talking about the Raptor on SnipersHide. GA dropped a teaser vid a while back but I haven't heard any updates. https://www.instagram.com/p/DOqmwcWjTBo/ Thanks... after looking at that it seems that's geared more towards subsonic use. I won't use this build subsonic. |
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I've been heavily invested in 375 socom for some time and the 375 raptor has always been interesting to me . I think im primarily interested in a supersonic 12" ... sfar based . * I have a like minded younger brother that also liked the 375 raptor , but went 358 winchester. |
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Originally Posted By 9D1Alpha: I've been heavily invested in 375 socom for some time and the 375 raptor has always been interesting to me . I think im primarily interested in a supersonic 12" ... sfar based . * I have a like minded younger brother that also liked the 375 raptor , but went 358 winchester. This would be a companion to my 16" .358 Win build I recently took a deer with. 
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I've been tinkering with and running a 375 Raptor for about 6 years now. Mine is an 18" mid length custom pipe from X-caliber. It's definitely been an adventure. The published load data is very much on the hot side and I spent a good bit of effort working up loads that functioned well in a gas gun. Been through six or seven powders, about the same for bullets and ended up running a 250g Sierra GameKing over 44g of 1200R at 2354fps. For the subs I run the 400g Maker over 16.4g of 4227 using a large pistol magnum bang button. I use a Rifle Speed gas block so I can go between supers and subs but I don't get reliable function on the subs with the block open all the way even after having tried many different pins in the block. Still working on how to get it to run both reliably. If I had to do it again I'd go rifle length gas or even +1. If doing a 16" your probably stuck with mid length but if you can do rifle length I'd go with that. Brass took a lot of experimenting to get the needed results. I have a 5gal bucket of Fed GMM brass and that's what I use. Have also used various other 308 and 7.62 brass and they all seem to work out about the same. My process is to mandrel up to 335, cut off the excess neck, anneal, run through the sizer with expander ball up to 375, anneal again, and trim to length. The ball in my die gives 3 thousandth neck tension. I don't know if Medesha firearms will still have any case gauges but even if they do there's some variation as the two I have aren't cut quite the same. You need to put a fairly heavy crimp with the Lee crimp die because the bullets move forward in the case quite a bit during chambering without it. They'll still move even with the crimp but not as much. Haven't found a way to stop it completely. I've experimented with the crimp all the way to making the bullet look like it's wearing a corset just to see if they still move which they do. I'd say it's a fun one to play with and even going through the tribulations I dealt with it's been worth it in the end. It hits like a truck and it's unique. It won't win any benchrest competitions but I've run it out to 500yds on pig size plates with no issues. I would suggest an LPVO or some other lighter weight optic. I couldn't get any of my longer range heavier optics to stay in place in the rings. It might work with three of four rings though but I didn't try that. I direct threaded a Hybrid 46 to it with some blue locktite. The ASR mount wouldn't stay tight and stripped some of the locking teeth. Both the optic and suppressor mount issues are all due to the recoil. It's not terrible but it's definitely more than 308. Hit me with any other questions you have. |
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Originally Posted By tsymonds: I've been tinkering with and running a 375 Raptor for about 6 years now. Mine is an 18" mid length custom pipe from X-caliber. It's definitely been an adventure. The published load data is very much on the hot side and I spent a good bit of effort working up loads that functioned well in a gas gun. Been through six or seven powders, about the same for bullets and ended up running a 250g Sierra GameKing over 44g of 1200R at 2354fps. For the subs I run the 400g Maker over 16.4g of 4227 using a large pistol magnum bang button. I use a Rifle Speed gas block so I can go between supers and subs but I don't get reliable function on the subs with the block open all the way even after having tried many different pins in the block. Still working on how to get it to run both reliably. If I had to do it again I'd go rifle length gas or even +1. If doing a 16" your probably stuck with mid length but if you can do rifle length I'd go with that. Brass took a lot of experimenting to get the needed results. I have a 5gal bucket of Fed GMM brass and that's what I use. Have also used various other 308 and 7.62 brass and they all seem to work out about the same. My process is to mandrel up to 335, cut off the excess neck, anneal, run through the sizer with expander ball up to 375, anneal again, and trim to length. The ball in my die gives 3 thousandth neck tension. I don't know if Medesha firearms will still have any case gauges but even if they do there's some variation as the two I have aren't cut quite the same. You need to put a fairly heavy crimp with the Lee crimp die because the bullets move forward in the case quite a bit during chambering without it. They'll still move even with the crimp but not as much. Haven't found a way to stop it completely. I've experimented with the crimp all the way to making the bullet look like it's wearing a corset just to see if they still move which they do. I'd say it's a fun one to play with and even going through the tribulations I dealt with it's been worth it in the end. It hits like a truck and it's unique. It won't win any benchrest competitions but I've run it out to 500yds on pig size plates with no issues. I would suggest an LPVO or some other lighter weight optic. I couldn't get any of my longer range heavier optics to stay in place in the rings. It might work with three of four rings though but I didn't try that. I direct threaded a Hybrid 46 to it with some blue locktite. The ASR mount wouldn't stay tight and stripped some of the locking teeth. Both the optic and suppressor mount issues are all due to the recoil. It's not terrible but it's definitely more than 308. Hit me with any other questions you have. Much appreciate the detailed info. A LPVO would certainly be my pick, 1-4 or 1-6. I don't don't see shooting past 150-200 for my needs and intended use. X-Caliber is who I was looking at and I'd like a 16" MLG set up. I was wondering if forming brass from .358 Win cases would be easier and produce better results, seems forming from .308 is hot and miss. I can't find any Raptor brass, must have been a one and done thing. Thanks again... |
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Originally Posted By Bowhntr6pt: Much appreciate the detailed info. A LPVO would certainly be my pick, 1-4 or 1-6. I don't don't see shooting past 150-200 for my needs and intended use. X-Caliber is who I was looking at and I'd like a 16" MLG set up. I was wondering if forming brass from .358 Win cases would be easier and produce better results, seems forming from .308 is hot and miss. I can't find any Raptor brass, must have been a one and done thing. Thanks again... Would likely be significantly easier to form from 358 and is something I've considered. I just have buckets of 308/7.62. I run one of the older Vortex 1-6 Strike Chickens and it works just fine. The head stamped brass was indeed a short run and disappeared. Wes at Omega Rifles who was a big proponent of the Raptor quit doing most of anything as far as rifle stuff goes and now does primarily Ceracote and engraving. Last time I was there for a visit he told me he was sick of trying to source parts and such and the lack of support from the sources of the cartridge and data. |
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I have been shooting the 375 Raptor for a few years now, but mine is a 12" bolt action pistol. I have tinkered around with some supersonics, mostly 270gr, but I also bought some 190gr T-Rex bullets from MAKER to try to push them even faster. Mostly I have been using them with the MAKER 400gr for subsonic use. I am loading them with 17.2gr of IMR 4227 for about 1050fps, and the 270gr supers are 37.3gr of IMR 4198. I formed a bunch of brass from .308 Winchester. It is pretty straight forward, but you do need the intermediate step to either 338 or 35cal when necking up to avoid splitting necks. (I formed 500 cases without one split neck). If you are primarily shooting subsonic, you will probably put more work on your brass by resizing them; most of the subsonics that I shoot don't even have enough chamber pressure to fire-form the brass properly. 
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Originally Posted By HotLead: I have been shooting the 375 Raptor for a few years now, but mine is a 12" bolt action pistol. I have tinkered around with some supersonics, mostly 270gr, but I also bought some 190gr T-Rex bullets from MAKER to try to push them even faster. Mostly I have been using them with the MAKER 400gr for subsonic use. I am loading them with 17.2gr of IMR 4227 for about 1050fps, and the 270gr supers are 37.3gr of IMR 4198. I formed a bunch of brass from .308 Winchester. It is pretty straight forward, but you do need the intermediate step to either 338 or 35cal when necking up to avoid splitting necks. (I formed 500 cases without one split neck). If you are primarily shooting subsonic, you will probably put more work on your brass by resizing them; most of the subsonics that I shoot don't even have enough chamber pressure to fire-form the brass properly. https://live.staticflickr.com/65535/55005455890_c4c3f188f1.jpg @HotLead what kind of velocity are you getting with your 270’s? I’m waiting on a 16” shouldered barrel from Mos-Tek for a Ruger American and am planning to shoot Supers exclusively. |
Originally Posted By Samuel L. Johnson:
He who makes a beast of himself, gives up the pain of being a man
He who makes a beast of himself, gives up the pain of being a man
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Originally Posted By Goody454: @HotLead what kind of velocity are you getting with your 270’s? I’m waiting on a 16” shouldered barrel from Mos-Tek for a Ruger American and am planning to shoot Supers exclusively. I will have to let you know; I looked in my notes and only found the targets with load info, but no velocity. IIRC, it was about 1900fps, but I will let you know once the cold breaks and I can shoot without freezing. |
| Just throwing this in for reference. 18" X-Caliber pipe running the Sierra 250g GameKing over 44 grains of 1200r at 2354fps for right at 3k ft/lbs. Have run it out to 600yds but it tends to be best keeping it to under 400. I also run the 400 grain Maker for subsonic over 16.4 grains of 4227. Zeroed for the supers at 100yds. The subs have about 16" of drop relative to the supers at that distance. For the subs I did find that I get significantly better SD and ES numbers using a LPM primer for some reason. SD with those is about 4-6 so not gonna complain about that. |
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Originally Posted By Goody454: I don’t have any 1200R but may pick some up. Is it temp sensitive? Are you using mag primers? Can't speak to the temp sensitivity of 1200r personally thus far. I doubt there will be much accuracy variance that'll matter at the ranges the Raptor is useful at and I haven't seen any difference in pressure signs in Texas mid summer vs Texas winter time. I use Fed 210 or Ginex large rifle primers in the supers and CCI 350 large pistol magnum primers in the subs. |
| If anyone is interested I ordered some 358 Win brass to try for the conversion. I'd definitely suggest trying it as the conversion is literally just a trip through the sizer with ball and a trim. Hindsight being what it is I wish I'd tried it a long time ago. Would've saved a bunch of conversion work using 308 brass. Will use my converted 308 brass for now since I have a good amount of it but when they get loose I'll just toss em and use the 358 moving forward. |
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I shot my raptor yesterday using Alliant Reloader 10X and Speer 270’s. I’m getting 2260fps out of my 16” barreled American. I could go a bit higher with the charge, but think that’s probably plenty fast, and may be easier on my brass than a closer to max load. |
Originally Posted By Samuel L. Johnson:
He who makes a beast of himself, gives up the pain of being a man
He who makes a beast of himself, gives up the pain of being a man
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