Wildcats

[2004LB7]

anyone here have experience with wildcats?

What I'm really looking for is the hardest hitting round, or the most energy from the round that will fit in the AR-308/LR-308 magazine. probably won't use it much past 100 yards but having good energy and minimal drop out till 3 or 4 hundred yards would be nice.

.308W is 2.8" max overall length so that does limit options.

338 Federal does look better than the .308 for ME and at 100y but there are a few that do better. there is the necked up 308 cases to .35 and .375. I'm liking the .375 sized bullets. for everything I read it seems the .375 has about the best mass per area. or in other words most efficient for hard hitting and velocity with minimal drag so it can reach out further if needed and doesn't take enormous case size or long actions to get decent performance from them.

the one I've been looking at is the 375-08 but I also keep running across the 375 raptor which seems to be nearly identical except for the angle of the shoulder and trimmed back neck. I can't seem to find any real data on the 375-08 performance but I would think it would be identical to the 375 Raptor. the 375 Raptor can do around 3600 ft/lbs at the muzzle and about 3200 at 100 yards using a 260 grain bullet

375 Raptor resizing dies appear to be out of stock and special order with very long lead times. the 375-08 looks to be easier to get even if it's a special order as more places seem to list it. each of these two cartages don't have much shoulder left after resizing the neck. I'm a little worried about head spacing issues with such a small shoulder. I think this is the reason the Raptor changed the angle but the 375-08 would have stock angle. pro are just a barrel swap away from using the standard .308 if it doesn't work out or end up costing too much to reload

the other option I have been looking into is the 284 necked up to 375 making it a 375-284. this does give me a little more case capacity for more velocity and energy. not much info on this one either but maybe 200-300 fps and 100-200 ft/lbs. it does look to run a bit longer overall but maybe bullet selection can keep it at 2.80". the biggest issues I've read about using it in the AR-308 is after loading just a few rounds into the magazine it bulges, gets stuck and doesn't feed. don't know what size magazine was used and if a 20 or 10 rounder would work. if I could get this to work I would probably want to go this route. would have slightly more shoulder, more case capacity, higher velocity and ft/lbs over anything else I could find that has any chance of working in a AR-308. the 284 also seems to use the same bolt as the 308 so a barrel change and nothing lost. can't use the same brass as the easier to find 308 but 284 shouldn't be too hard to find

any other recommendations for another cartridge that would fit in the AR-308 that I should consider? what about the 338 RCM? is that still a thing?

maybe I should make this a poll between the 338 fed, 375-08, 375 Raptor, 338 RCM and other

 

[2004LB7]

I think I'm going to add the 338 WSM and 375 WSM to my list of possibilities. looks like a few people have done it a while back but doesn't seem to be any lately. different bolt and custom barrel will definitely need to be used. dies can be obtained from CH4D so that looks like a possibility. pros, slightly more case capacity the the RCM, brass should be easier to acquire. cons, more bolt modifications to get it to feed and extract, ejection port needs to be opened up more then others

for the RCM, looks like the few that have done it says it feeds well out of the stock magazine with little to no modifications. little ejection port widening over the WSM, still decent case capacity. cons, cartage is probably on its way out. support is dwindling and finding brass is getting hard.

I'll probably drop the 338 federal from the list as it is not much better then the 308 which I already have. and drop the 376 raptor because it's not supported by enough vender for dies or the lead time can be a year or more out. some say not taking orders right now

not sure if I should keep the 284 on the list as it is less potent as the other two mentioned above but it does have the advantage of using a 308 bolt so finding the necessary parts will be easier and cheaper

then its 338 vs 375

 

[PureHybrid]

What's the primary use going to be?

 

[2004LB7]

What's the primary use going to be?

Blast holes in s#it .

I actually don't really have any specific use in mind for the reason want to build it. It's just, I have a spare AR308 lower that I'd like to put to use and as I already have a .308 rifle I wanted something different and the big bores intrigued me enough to want to try it out. anything lower powered seems like too little benefit over the 308 so I want to find something that is as big a jump above the 308 as possible but still can fit in the AR receiver

 

[PureHybrid]

Ah I see. Never messed with any big bore stuff, I like speed. Best thing to ever happen to the 308 case was pinching it down to 6mm haha

 

[2004LB7]

I can definitely see the appeal of high speed rounds. Better for distance and doesn't loose as much energy past 300-500 yards as some of the heavier ones do. for under 300 yards big and heavy seems to pack more punch.

where I'm at it's hard to find a good place to reach out more then 200 yards so I figured if it does 300 well then I'm happy. plus I like the idea of not needing a 24"+ barrel to get the best from the round. larger bore creates a more efficient energy transfer in a shorter time so a sorter barrel on a large bore cartridge can do better then a smaller bore at the same barrel length

 

[N2BRK]

Ah I see. Never messed with any big bore stuff, I like speed. Best thing to ever happen to the 308 case was pinching it down to 6mm haha

solid copper except for the hollow pointed tip. Zipping along in my .243 lol.

 

[2004LB7]

solid copper except for the hollow pointed tip. Zipping along in my .243 lol.

what are you pushing? 3200+ fps? 85 gr?

 

[N2BRK]

Correct. IMR 4350. I’m making up a few batches to find the best charge weight. I have another .243 that I run a 105gn Berger Hybrid target bullet with an ass load of H1000

As for wildcats I just do 460 Rowland in a modified Glock 21.

 

[PureHybrid]

I can definitely see the appeal of high speed rounds. Better for distance and doesn't loose as much energy past 300-500 yards as some of the heavier ones do. for under 300 yards big and heavy seems to pack more punch.

where I'm at it's hard to find a good place to reach out more then 200 yards so I figured if it does 300 well then I'm happy. plus I like the idea of not needing a 24"+ barrel to get the best from the round. larger bore creates a more efficient energy transfer in a shorter time so a sorter barrel on a large bore cartridge can do better then a smaller bore at the same barrel length

I agree, makes sense for the short barrel. But I'd also think running something heavy/ subsonic in the 308 case might just be easier?

solid copper except for the hollow pointed tip. Zipping along in my .243 lol.

Do they shoot good? Mine didn't like the 80gr Hornady GMXs. Been shooting the 87gr vmax, I don't really need the bullet to stay together for my use

 

[N2BRK]

Not sure yet. I’m working too much to get to the range until probably Mid-April. The plan is to let my sister use that for a hog hunt in Florida this summer. Those bullets are supposed to be tits for that purpose and work well in the 1:10 twist in an old Mauser clone that I have. The heavier loads I run in a 1:7.7 twist in my RPR.

 

[Mikey52]

I forget cause I don't have one, but does the 300 blackout fit the 5.56 or the .308 lowers? If it's the 5.56, then a 300 blackout magnum for the .308 might be the thing.

 

[2004LB7]

the regular 300 blk fit the 5.56 lower. I have one of those. it's nice because it uses the same bolt. only a barrel change. have to be careful though as it will chamber into a 5.56 barreled rifle but go boom instead of pow

never heard of the 300 blk magnum. I'll have to look into it

 

[Cougar281]

the regular 300 blk fit the 5.56 lower. I have one of those. it's nice because it uses the same bolt. only a barrel change. have to be careful though as it will chamber into a 5.56 barreled rifle but go boom instead of pow

never heard of the 300 blk magnum. I'll have to look into it

I don't think there's such a round as "300 blackout magnum".

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[2004LB7]

I don't think there's such a round as "300 blackout magnum".

Sent from my Pixel 5 using Tapatalk

I think you are right. after reading it again, I see that I missed the "might" part of his comment

the closest I think there is to it would be the 338 federal in a standard, non wildcat, cartridge

 

[PureHybrid]

The 300 Hammer is supposed to be a longer 300 Blackout I think? But might as well stick to something 308 based like you planned

 

[2004LB7]

first piece of the puzzle done. settled on a .458 WSM. ordered a custom barrel so it may be a while before it's done. also acquired a few pieces of 300 WSM brass to play around with. need to get some reloading and sizing dies made but I may wait and see if I could fire form some of the brass first so I can send them it to get perfectly matched dies.

for comparison. the .308/7.62x51 has about double the powder volume over the .223/5.56x45. the WSM cartridge has about 50% more powder then the .308/7.62.

after running some simulations on GRT between a few dozen cartridges and bullet weights it looks like a can get the best velocity vs energy from the 458 WSM over the other options

 

[2004LB7]

in continuing this project I started modding the LR308 upper for a left side charging handle. it's a slick side so no forward assist. this could take it's place if needed. I also plan of capping the original charging handle hole in the back.

all done by hand with a lot of filing. drilling and tapping the bolt carrier wasn't too hard. lots of cutting oil and sharp bits and it went right through. one tap didn't want to cut the threads but a second one I found worked great. 10-32 right now but I may upsize it to 12-24. maybe keep it as is and if it works loose or the threads don't hold the I have room to tap it larger

 

[2004LB7]

Also the barrel arrived so I can start putting things together. may need to pick up a few odd and ends, springs, lower parts, etc. not sure what buffer weight I'll need. I suspect at least an H3 or heavier.

need to figure out what stock I want to go with. I want to go minimalist style. I have a spare Battle Arms Development Sabertube stock I could use but I think it looks hideous. maybe I'll use it for testing. probably would be good to have a thick butt pad

then I need to see if the barrel manufacturer can send me the specs for the reamer used for the chamber so I can get some resizing dies made. either that or try and fire form some brass and send that in

 

[2004LB7]

Build is done. just need to start expanding some brass so I can fire form it. then send the brass in to get some custom dies made

Now if I could just find me some Accurate 2230 and large rifle primers

some information on the build: Raw upper and lower that I anodized at home. barrel is mcgowen. custom chambered in 458 WSM. 16" with muzzle attachment. I don't plan on keeping that stock but it's what I have so until I get a replacement it will have to do. KAK bolt and carrier. haven't weighed it yet but it doesn't seem to be real heavy so it will likely kick hard. hopefully the adjustable gas block can tame it a little. overall length of 33"