Thread: Attempting a new .224 wildcat

Originally Posted by nor-west

Just curious how would that compare to the Weatherby .224 magnum? I'm thinking of getting a fast twist barrel for mine.

@nor-west I found some ADI load data for that cartridge with 70gr projectiles listed as a max charge of 32gr of 2209 giving 2777fps from a 23" barrel.
That doesnt seem very hot/fast? My 24" .223 shoots the 69gr pills to 3200fps with 26gr of 2206H.

Spent a good part of my day testing this Wildcat hard..
My new cartridge holds 49.0gr of H2O, I spent a lot of time researching start and max loads of all the similar volume cartridges I could find. Here's a list of water volume held by each cartridge and its all I had to go by:

.22-250 Rem 44.0gr H2O
.22X47 Lapua 46.6gr H2O
.220 Swift 47.0gr H2O
.22-250 AI 50.8gr H2O
.22 Creedmoor 52.0gr H2O
.22-243 Win 54.0gr H2O

My Wildcat holds a fraction less than a .22-250 Ackley Improved but the brass is a lot stronger so I used its start loads and worked up until I saw the slightest primer cratering and then stopped. These were by no means hot loads and could have been pushed much harder but I really want to stick to my intention of conserving this barrel.
The powders I tested were of the faster end of the burn spectrum as my barrel is only 21" long so I want it to run as efficient as possible.
A list of the powders tested as follows in order of fastest to slowest burn rate :

BM 8208
AR 2206H - H4895
AR 2208 - Varget
RL16
AR 2209 - H4350


I put quite a few over the chrono with ladder tests documenting speeds, extreme spreads and finding my modest "max loads".
Even the start loads were faster than ADI's listed .22-250AI max load speeds from a 24" barrel which makes sense looking at case volume alone.
Once I was happy I picked a few loads that I thought should do well on paper and headed out to the 100 yard range.

Feeding from the mag was floorless and the accuracy nodes are wide and forgiving, all loads tested were boringly accurate ranging from a 0.84" at the largest down to a 0.40" at the smallest.
I havent messed with different projectiles as I have a heap of the 69gr TMKs and the jump to lands was 5 thou on all loads. Primers were CCI BR-4's.

I settled on two loads right around the 3200fps (mild) one with BM 8208 and one with RL16. The BM 8208 shot constant tiny bug hole groups and was noticeably quieter and softer to shoot but actually gave the best velocities of all powders tested. It is clearly running the most efficient in the short barrel.
RL16 gave tiny extreme spreads at 3 to 7 fps but didnt quite match the 8208 in the accuracy department.





I think this Cartridge could really give the .22 Creedmoor a run for its money if set up with a 26" 1-8" barrel. From my test results today Id say it will send an 80gr projectile to about 3500fps with a slower burning powder such as 2213SC or RL26. I have now doubts at those speeds it would only get about 1000 rounds before the throat was shot out though.

man that looks just plain ol sexy....... a while back I tried to look up info on the other cartridge the AKs run the .224 cal one....from the little data I could find it seemed to do less than the .223 rem...... wasnt the 22BR based on the x39mm case to begin with????

Yeah I personally think its a nice looking cartridge.
The soviet .22 AK chambering is the 5.45x39.
The .22BR is a BR case, same case head dimemtions as a .308win. That case is necked from .17 to .358 in many different chamberings with a shoulder angle from 28 to 40deg.
The .22 cartridge based on the X39 (actually the 5.6x39 aka the .220 Russian) is the .22PPC.

ppc yip THATS what I was thinking of.... so its diferent from the 5.45x39 but has same front and rear LOL....

Originally Posted by Micky Duck

ppc yip THATS what I was thinking of.... so its diferent from the 5.45x39 but has same front and rear LOL....

Nah the 5.45x39 is different again, it is a thinner case than the PPC, it has a base diameter of 10mm where the .22PPC, .220 Russian (5.6x39) 6.5 Grendel and 7.62x39 etc has a 11.3mm base.
They all have different shoulder angles and body tapers too.

LMFAO.....so many cartridges so little time...wonder why the ruskies didnt just use the x39mm case necked down.......you wouldnt be able to chamber the 7.62x39 in one chambered for the 5.45 and if you did it the other way around you would get a interesing "pattern" down range LOL.Im quite happy with the wee bolt action 7.62x39mm but sometimes wonder how it would go with a fancy new barrel...which in turn brings up cartridges that would feed/function with existing bolt face/mag......

Just had a quick play with some Hornady Z-Max 40gr and BM 8208.. crazy fast varmint round!

ffff ffff fff fffff ffff golly geepers thats fair honking along!!!!!!!!! look out Mr bunny......could do amazing things to deer with a mono load I be thinking...

@Wingman what causes the shiny rings at the shoulder? Are they just chamber marks?

Originally Posted by wsm junkie

@Wingman what causes the shiny rings at the shoulder? Are they just chamber marks?

@wsm junkie no, not from the chamber, that is where the old 30 degree shoulder used to be on the 6.5x47 Lapua..
I short size the case neck to create a false shoulder for the cartridge to headspace on along with annealing to encourage the shoulder section of brass to migrate forward rather than the base of the case to migrate rearward to meet the bolt face which thins the brass in all the wrong places and can cause case head separation. The new 40 degree shoulder is blown forward 50 thou leaving the old elbow imprint of the angle slightly visible as shiny polished rings in its now straight wall. It generally smooths out after the second firing or in the media tumbler.
It is very visible in that pic as that case had just been made and fireformed with trailboss and capped off with wax. A full case of trail boss is not quite enough pressure in this case to blow the new shoulder angles out really sharp but the next load with a projectile does.

@Wingman cheers for that.

I have had a few private messages with questions in regards to this build and how the barrel life etc was holding up so I figured Id do an update here too.

The barrel is still going strong although I dont use it that often.
At the time I built it I torture tested the Lapua brass by testing the same case load after load, in fact all of the documented data on this thread apart from the group tests was done with the same single piece of brass. Well 30+ reloads later the primer pocket is still tight and the necks have not needed cutting from brass migration.
The case is only 2/3rds full with most loads with a lot of rattle space in fact with BM8208 which shot the best groups I was getting hang fires so stopped using that powder.

My load I run now of RL16 is quite light and I mostly shoot the 69gr and 77gr TMKs.
No sign of throat wear as yet but its not running hot and fast like a .22-250 shooting 50gr bullets.
Running the 69 and 77gr TMKs at 3200 is super accurate and does all I ask of it.
The brass is 10 times better than any .22-250 brass so its not something you need to make a lot of.
Annealing them helps a lot when forming them not to over stress the brass etc.
The barrel got a light carbon fibre sleeve added but thats about all Ive changed since it was built.

Bump because its worth re-reading...did you ever give it a whirl with monos???

@Wingman, sorry about the Thread Hijack, but wanted your opinion on another potential Wildcat.
You have had quite a lot of experience with both the 6.5 Grendel and the 6.5x47 Lapua, and I was wondering how easy it would be to Wildcat a Hybrid between these 2 Cartridges ?

Idea being, something that would chamber in the Howa Mini and offer a little more Powder Capacity, granting a boost in FPS.
Is it as simple as opening up the Bolt Face from .445" to 0.470", using a 6.5x47 Reamer but cutting a Chamber 0.275" Shorter, shortening a 6.5x47 die by 0.275" etc, and seating the Projectile to the the same length as a Grendel ?