Home Forums Hunting & Shooting Custom Rifles & Wildcats 22-300BO Thoughts?

Ive really been looking at doing some kind of Wildcat and I keep coming back to the 300 Blackout case.

I want it to meet some of these criteria.
1. Low powder consumption
2, Easily available and cheap brass
3. 22 caliber
4. Extremely low recoil
5. Available action and mag configuration to work with size of round.

I had thought about the 22 TCM but I have not seen anything good about its accuracy. My eyes keep going to the 300BO sized case sitting in my case collection. It seems like the perfect size yet will have a decent enough powder capacity and size to be easy to work with. Now that 300BO rifles are available they would be a simple conversion. Im wanting a 200yd and under shooter for fun and varmints. once I have a reamer made I can make dies. I also do all my own work.

Any thoughts? I already have plenty of 222, 223 and 222mag stuff so not looking for the simple standard cartridge to go to. Is there anything already like this out there, not counting Mashburns, Fireball etc.?

Thanks

Glenn

Isn’t the 300BO a 221 fireball necked up to 30 cal?
Instead of necking down a 300BO to 22 cal, buy a 221 fireball and you are there. And by the way 221 fireball rifles are scarce as is the brass.

dal06 is correct, the 300 Whisper / Blackout was nothing more than necking Fireball brass up to 30 cal

I’m not sure what the OP is trying to accomplish but it’s not just necked down or up case. It’s the same case but not the same case length.

Texas T is right on the money. I would want to shorten it a bit so I coul play with neck length as well as body length. The key was going with a donor case and action that is already close, easily acquired and inexpensive. The Fireball does not fit that overall description.
If you really want to go back to the beginning I believe the 221 Fireball is actually a 222 based cartidge.

I do have a few other changes I am looking at as shoulder angle and case sidewall angle. I like Ackley cartridges to keep down neck and case stretch so if you can imagine a small Ackley cartridge.

Maybe a 22 K Hornet would fit the bill?

22 K Hornet is a good cartridge as well. I have brass sitting here I dont think its the direction I want to go. You have to remember I am focused on a shorter case and I do want to stay with 224 bullet. If it comes down to it its pretty hard to beat the 222's sitting in my racks but you have to try! Lol

As I said before since i do my own work it leaves me open to a lot of options. I need to look at a ballistic and load type development estimating program, any suggestions?

Im thinking a capacity in the 11-15gr powder range and running mid 2k to 3k fps. 40-52gr bullets. 12"-14' twist.

How would that compare to a .222 Remington ?? In retrospect, the .221 Fireball would be a better comparison.

kwg

For a 22 of BO capacity I think I'd much rather start with the Fireball case and make adjustments from there as long as it would support the end goal. major case forming and necking down 30 to 22 cal on hundreds of cases doesn't sound like fun. I run a couple of wildcats for ground squirrels and competition and need 300-400 cases per rifle to start with.

I can always go back to the 221 fireball case if the 300BO case doesn't work out or is a pain. I can also just cut down 223 cases as well. Goal is to not have to search for 221 cases and pay the big money for them when you can find them.

I will be ordering die blanks and a reamer this week to get started. It will be an Ackley run short and should get me in the 2800-3100fps depending on bullets and powder. I have case capacity figured at maybe 17gr with bullet seated to shoulder. 3000 should be easily attainable and still get me a case that doesn't need trimming more than once or twice in its life. I think this will also get me a cartridge that will allow barrels to last for several thousand rounds easily. Pressures will be very manageable with case fill numbers and efficiency very good by the numbers I'm getting on the GRT program and a couple others. This should be an extremely mild shooting cartridge.

Im ordering a Gunsmith Edition barrel from Green Mountain, used them before and have had great luck with them. If Im not happy with the barrel, or chambering I can punch everything out so nothing wasted. As I said earlier I like Ackley's and if you look at most of the newer cartridges they copy Ackley cartridge designs just shorter fatter cases and they are taking advantage of different barrel twists, newer powders and bullets for the most part.

Man you must have lot more time and energy on your hands than I do. Talk about splitting hairs.

Yes I probably do. I have fun with this and don't feel like I'm wasting my time. Kids are out on their own, don't work do to third time around with cancer, treatments and the effects of it so trying to do what I love to do. Before all I did was work and spend time with family things like sports for kids etc. I have a great wife and family so we do a lot together but they have no problem with me shooting and gun work etc. They know I may not be here in a few years so like to see me having fun. I'm very fortunate.

If you're willing to wank about forming the case you want from 300BO, it makes WAAAYYYYYY more sense to start with even cheaper, super available 223/5.56 brass.

It’s been done before, making a 22 caliber cartridge out of a 204 Ruger, which is a 222 Remington magnum necked down to 204.

Kind of like sitting on a teeter totter…

TRPLM, I agree the 223 brass is the cheapest way as I have a few thousand rounds of brass sitting here. The goal in using BO brass was neck it down without having to cut it down first. May still end up going that route though.

Shrapnel, its pretty much all been done before. There isn't hardly a new cartridge made now a days that isn't a variation of something else. If it was there 50 years ago the big change may be barrel twist and bullets and powder available now to match better. There actually was a cartridge very similar to my design but it was a rimmed case and different shoulder angle. Built in the 40's it never survived. I don't really care what other people think of it, I just want it to do what I am designing it to do.

I'd like to see the new 30 super carry brass necked down to .224 at a length that works with 40g vmax bullets. Something near a fn 5.7 but easier to load for and without the proprietary case coatings etc.

The 30 SC cases are rated for decent pressure. It might end up only being like a 22 khornet with a more modern rim. It would be fun in both handguns and smaller rifles. A glock 19 sized gun with a 20 round mag. The 5.7 is already there but I'd like to see another option.

I need to send some empty 30 SC brass to someone with a khornet die and see if they can neck it down to mock one up.

Bb

Not many can relate to what you have/currently going through. Tear it up man, enjoy life..... make,build whatever you want. Spend your whole life working and raising a family just to be dealt a chit sandwich..... I say enjoy your project and keep us posted.

Well things have progressed and I am ready to spin up a barrel this week. I have made case forming dies and sizing dies and have about 40 cases to use to start with. As said earlier my goal is to have a cartridge that will shoot in that mid 2k range and reach up to 3100fps or so with a 40gr bullet. All the numbers I have worked out should allow it to get up into that 3-3200 range.

I will be short chambering a 223AI reamer. Case body will be in the .900-.950 range depending on where my test barrel and loads take me. 221 Fireball is right at 1.06 at the shoulder but I'm gaining capacity with a square case wall and 40deg shoulder. I really wanted to run just a hair longer neck length more like the 222 does but after shooting a 223AI lately I don't know that I will need that especially with the 40 gr bullets I'm focused on.

My big concern was that whatever case I used by the time it was shortened I would be dealing with real thick case wall in my now formed neck. I figured I would have to battle that and turning or reaming necks. How it turned out the 300BO case just doesn't want to size down without leaving flaws in the neck but the 222 or 223 actually works perfect. It is a couple of steps but its fun for me and really doesn't take long. I built 2 stages of forming dies to step a 223 case down then the final step is in the actual sizing die. After step 2 I do cut the case down to approx. length, run through my final sizing die then trim to length. May sound complicated and I had to get my head wrapped around this at first. The big issue with this wildcat is it is going into such a short cartridge. Not a big deal when you are making a cartridge in standard lengths of other dies. The cases after formed, trimmed and chamfered allow the bullet to be seated and measurements check out perfectly to my reamer with no neck turning, figure that.

The rifle I got to use as my donor for this build is a Ruger Predator in 223. I shot it in its factory form and it was very accurate, action was noisy and a little rough and the stock had a lot to be desired. I pulled it all apart, polished the action and bolt, went through the trigger, punched the barrel to 223AI and rebuilt the stock. It is an amazing gun now and shoots like a dream. I'm concerned the new rounds may not feed as well but have an idea on being able to extend the feed lips on a metal mag to allow it to load properly. My backup is a Rem 722 in 222 as it feeds my new round perfectly. If I need to I will just pull that barrel and and make a barrel for it. I would never usually pull a 222 apart but that one just doesn't quite shoot at the same level as the others.

If anyone has any comments or suggestions I'm always open to hearing them and appreciate everything that has been said so far. Like I mentioned this is my first wildcat so If anyone has a good suggestion I'm all ears, like just using 223 brass. Trplem, that hit me later and when stepping the brass down properly I realized that really was the cheapest and easiest way to go..

I cant for the life of me figure out how to download pictures on this site. Maybe I shouldn't be messing with guns. LOL

If you are willing to consider the Hornet you would be well advised to take a serious gander at the 22 Spitfire, as it is head and shoulders over the Hornet and fits the same bolt face.

Me, I settled on a Hornet.

As I said before there is nothing wrong with the Hornet. The 22 Spitfire is the closest thing to the cartridge I am building with the exception of the 40deg shoulder and the body taper. This is a cartridge and rifle I will shoot a lot so $2 a round for brass or loaded ammo does not appeal to me. Im not buying custom anything, Building everything myself and all in will have less than $250 invested. Naturally that doesnt include the rifle but does include the reamer which will be used for both this and 223 AI barrels, die blanks and a set of 223 Ackley dies which I will shorten to make things easy.

We all have our hobbies and this is what I like to do for fun. Its easier on my body than building 4wheel drives or old cars which Ive done, cheaper than sitting in the tavern several times a week which I have watched many people do, more fulfilling and enjoyable than sitting and watching TV which was all I could do at times after transplants and treatments. If I was working all the time though I would probably just shoot a Hornet, Fireball or one of the 222's I have so I definitely understand some peoples point of view.

If anyone has suggestions on powder I would appreciate it. I have 4198, 4227 and 2400 which all could possibly work well of which 4198 may be the best. If this cartridge works out, in a single shot pistol 4227 may be the winner but in a rifle barrel I don't think it will be. Going through powders on GRT VIHTAVUORI N110 looks like it may be a perfect powder but I have never used any of this brand. I'm also wondering about the new Winchester StaBall Match. Has anyone used this yet?

The portion of the case that becomes the neck, is thicker when forming from 300 whisper.
You'll need a reamer ground to the specs you arrive at once you've necked to the desired caliber.
I did this with a 6mmX300W and it worked out great. Using a type s die you can utilize the correct bushing to arrive at the desired neck tension.

I've already sized, trimmed to length and loaded bullets in the brass. Measures perfect without any neck turning. Once I chamber the barrel we will see but shouldnt be an issue. Just happened to work out perfect it seems using 223 brass.

I've made what seems like a million 221 cases from 223....and have yet to find a piece of 223 brass that didnt need inside reaming or outside turning to fit into a sammy 221 chamber , and the neck ends up being a smidge short with 300 Whisper brass.

You need to learn how to post pictures.... not very hard with an "Imgur" account. Would love to see the cartridges.

AKA Spook you may be right in I may be just a bit tight on neck tension but not by much. My reamer is cutting the neck area just about right for this and the cases I am using. I have some brass fireformed and went out to get some velocities. No pressure signs at all and so far I am in the 2550fps area with about 2 1/2gr capacity available for H4198 pushing a 40gr Nosler. That was at 14gr and should be able to seat bullets to the shoulder with 16 1/2Gr capacity. That is a BT bullet so may try some flat base and then a couple of other powders like VN110 and IMR110 as they both look like perfect burn rate for this.

Another thing is I spun up the barrel using a M37 Remington barrel for this. 1 in 16" rimfire barrel. I will get a 12' twist CF barrel for this but after a lot of reading realized most of the early Hornets were all made on rimfire barrels figured it would be worth a go. Not sure if the tighter barrel is slowing it down?
It is shooting good. At short distance just checking velocity but still aiming it was shooting one hole. At one hundred I was into just a couple loads 2rds each charge and they were very accurate. I wasn't checking for accuracy just speed but they ended up being good. Didnt get to take a pic of the target as my son ended up spraying it with his AR. LOL

I did this on a Ruger Predator action which I think feeding is going to be the big issue. I have an idea on how to modify the mag but i think the way Ruger does their feed ramp is just an issue. Not a big deal as the original barrel I punched to 223AI and it is a hammer so putting this back and leaving it as that wont hurt my feelings. I have a Rem 722 in 222 that lags a little behind my other 222's and I may pull the barrel and do my 12" twist barrel when I get it on this rifle. I have checked and it feeds these short cartridges perfect.

I had a Imgur account but haven't used it in a long time. Is that what you have to use?

Got my Imgur account going again so here are a few pics of the Ruger Predator and my cartridge. It loves 12.1-12.4gr of Lilgun on the top end so settled on 12.2, just over 3025 fps. At 100 its a consistent 1/4" Av. round. Shoots 3/4" at 160yds which is what the range I go to maxes out at. I also have some low velocity squirrel ammo figured out. H4198 running right between 2500 and 2600fps, also shoots very similar at both of those ranges. Well not so sure about pics.

I believe I will go to Brownells this week and grab a Douglas #2 barrel blank to spin up for one of my 722's. It seems to feed these rounds beautifully so will just have to make a block and modified feed plate for it. I have to work on the magazine for the Ruger as it is a single feed so far. I do like Martini rifles so if this cartridge pans out good for me there may be one chambered for a Martini some time.
Bottom pic is with my 223AI barrel.

AKA Spook you were correct. When using new brass I am neck turning them right away. The 223 brass does work the best and cheapest. Seems like if I stay away from military brass it all sizes perfect with no loss and pockets are not changing after 4 or 5 firings so far.

Interesting project, congratulations on your success.

Thanks, its working out. Cut four inches off and re-crowned the barrel so want to see what the change in velocity is. If its not much and the accuracy is still good I will cut it down to 20" then recontour it.