Look up the ballistics of the 5.7 vs the .22 mag. Not really worth all the work. Then there's the Hornet.....

I'll just wait for the factory rifle.

 

the hornet action has a threaded barrel so the 77/22 barrel wont work. 99% of current prodution hornets use .224" barrels. if you run into a .223" bored hornet it was either a mistake or an older gun. you would ahve to make mags or retrofit something else. the 77 mags are desined around the geometry of one round. kinda hard to jack around with. if you want a 5.7 all the parts already exist for doing a savage conversion.

 

No Sir, rcarlson, I don't see any advantage to a FN 5.7x28 cartridge vs. a .22Hornet in a bolt action rifle. I'm afraid I only see negatives. You site the 77/22 so that is the only firearm I will discuss.
1)The 77/22Hornet is a factory chambering. It'll cost $500ish to rebarrel & rework the bolt! There is no ballistic advantage to the FN5.7x28 cartridge over the Hornet in a bolt action rifle. Don't consider the ability to shoot 55gr bullets better, it's simply due to FN choosing a fast twist just for that pupose. Put a 1in10 or 1in12 twist 22Hornet bbl on the 77 & it will do the same job.
2)The 77/22Hornet uses a .224 bullet. It has a 1in14 twist bbl, perfect for 30 to 40gr bullets at about 3200fps to 3000fps when handloaded.
3)FN5.7x28 dies & brass will cost more than the 22Hornet.
The 77/22RH has a 20" bbl & may cost you 60 or 100fps or so but it is pretty & handles like a dream. MSRP $750
For about $80 more you can get the one I have, 77/22VHZ target (varmint) model. It's about a pound heavier, with a thicker, less handy laminated stock and 4 more inches of bbl.
You have an interesting idea, but I think the Factory set-up is the way to go in this case, 77/22VHZ .22Hornet. If you feel the need have Randy at CPC rechamber it to .22K Hornet for fun.

 

I just picked up a 77/22 Hornet take-off barrel and have plans to set it back a couple turns and rechamber it in 5.7mm Johnson( 22-30 carbine). The Hornet bolt face will work without modification.

John

 

I did a little experiment once... I loaded up some Hornets in brand new WW cases using the same powder, primer ect only loaded some with 40 grain bullets and some with 52 gr bullets...
At 100 yards the 40's shot at 3/4" and the 52's shot at 1"... No big deal to me, - if I was a varmint hunter shooting coyotes and such I would opt for the heavier bullet... The groups opened up bigger but the extra bullet weight has a better knockdown and on a windy day it might be a advantage... Choice of bullets in 52 and 55 grain is large and good and prices are good...
If I kept on experimenting I figure I might find a heavier bullet that got closer to the light bullets group...
(p.s. Bullet seating depth is max that can go thru the magazine regardless of bullet nose type, heha)...

 

If one wishes to experiment with different cartridges, the best bet is to buy a TC Anchore or a G2 contender and install a shoulder stock.

There are aftermarket barrels in almost any chambering imaginable and whether for varmint shooting or target shooting a single shot is fine.

 

The 5.7x28 is a good cartridge and lots of fun to shoot, but the brass is thin and difficult to reload. Also the cartridge was originally designed for lite weight bullets and the civilian version of the ammo is loaded with 40gr bullets, don't recall what the military load bullet weight is but its a whole lot lighter than 40grs. I also don't believe that the 5.7 case has the capacity to effectively shot bullets heavier than 40-45gr. As mention by Redhawk, get yourself a TC it's a whole lot cheaper to play with. I have TC's in both the 5.7 and 22K-Hornet, both are very accurate, is one more accurate than the other? I don't think so both of my barrels are extremely accurate, good enough for shooting golf balls and dumdum suckers at 100yds

This is my 22K-Hornet built on a Encore frame with a 15inch barrel by TC's Custom Shop, scope is a Nikon Bushmaster 6-18 with a dot reticle and yes it's a rifle scope on a pistol

This is my 5.7x28 again built on a Encore frame with a 14inch barrel by MGM, scope is a Burris 10x pistol scope, which I'm looking for a Weaver V24 Rifle scope to replace the 10x pistol scope:bthumb:

docand

 

Rcarlson:
Look at the differences between Rimmed and Semi-Rimmed cases.
The Hornet, K or Not, dont headspace on the sholder..
Its a bit of an oddball.
I was glad I had experience in loading my 38 Super befor I got into the Hornet..
Not to say it cant be done..
As my Seebee son says,
" The difficult we do today, The impossible, may take a bit longer."
He is a "Can Do , Kangroo!" :bthumb: