Gentlemen, I present... the ".220 REDLINE"

[fredo]

Be careful with powder choice as bridging with extruded powders could be a problem. Stick with ball powders. Look for Kirby Allen in Long Range Hunting. An example https://www.longrangehunting.com/threads/necking-down-7mm-stw-to-257-stw.191690/#post-1342350.

Thank you for bringing the topic of "bridging" up. Those Allen Mags are sooooo long, and their sharp 'improved' shoulder angle seem to be conducive to allowing that 'log jam' effect to occur. Hopefully, those outrageous shaped AM wildcats are the exception, rather than a norm! Definitely something to keep in mind, though...noted & very much appreciated!

I run H1000 in my .22-243AI, and have a few pards (and at least one member here) that runs Retumbo in theirs. That is a long, skinny case with sharp 40° shoulder, thankfully have not heard of those guys having any negative "bridging" effects from burning ~50 grains of Retumbo thru a .224 hole, via such a sharp transition angle...

Aside from wanting to retain use of my current SAUM dies, maintaining parent case shoulder angle @ 30° will hopefully mitigate any 'log-jammin' of stick powder inside the REDLINE case. A finished REDLINE case does seem to retain a nice "funnel shape", from the case body...thru the shoulder and into the long neck. But...FOR SURE...I'll be 'tip-toe-ing' when it's time to do pressure testing!!! Have long since grown to accept my facial features in their present state & condition! Fun as this 'wildcat' stuff is, can't ever forget that we're purposely building & detonating little bombs right next to our heads...a sobering reminder to any reloader.

Left out two details:
1. I'll be likely be moly coating bullets for the REDLINE
2. Will most definitely anneal cases after the 3 step neck down procedure

That was alot of squeezin' on those necks! Was actually pleasantly surprised how nicely that supple Norma brass went down, but they've prolly experienced some 'work hardening'. Quick run in the torch will take care of that...

Thanks to EVERYONE for all the well wishes & glad to have ya along on this ride! Sourcing a barrel today, nobody seems to have 1:9s in stock? Will keep this thread updated as progress allows...

 

[AckleymanII]

I love to see these kind of wild cats! Best wishes!

I have a coyote hunting friend that lives in Colorado. He shoots the 80g A max at deer, antelope, and coyotes 3650, no pressure issues. I suspect that you will blow the doors off that load!

 

[B23]

I've never really been one to worry about barrel life and I'm always ok trading velocity for barrel life so this sounds like a cool project. It'll be interesting to see if you can match accuracy with it's blistering velocity potential but sometimes to much of a good thing, is just to much of a good thing.

 

[357Mag]

Fredo -

Howdy !

Boy..... I'd like to encourage you to make an informed bullet choice.

You'll need them for making up sample rounds, as an aid during chambering/headspacing.

As you go heavier on bullet wt in .224"calibre bullet choices narrow-down, compared to the common medium-wt .224" cal choices.

With an imagined lowering of barrel life the rifle's expansion ratio will present, you probably won't want to do a whole bunch of bullet testing anywayz. Here again, a good bullet choice will be helpful.

I am wondering whether your selected powder's burn rate might not be as slow as 5010, or some such ?


With regards,
357Mag

 

[357Mag]

Fredo -

Howdy, again !

Say... I perhaps spoke too soon, w/ respect to powder selection.

What barrel length are you thinking about, for that thing ?


With regards,
357Mag

 

[fredo]

Morning update:

JGS has already received my 'dummy' round, and Grant already worked up a reamer print for the .220 REDLINE...WOW! Everything looks good to me, so we're going with it! I guessed FB would fall somewhere between .060-.080", and it did...

The REDLINE will retain use of standard SAUM go/no go gauges for chambering. That also allows for the ability to use my Redding 7SSAUM Type S Die set for reloading operations. Bushings again are: .291, .270, .258, and .252" for final neck tension) I was able to seat bullets with the Comp seater, as is, but might just wanna swap a .224 seater plug into the Comp. seater. Or maybe I'll buy a smaller seater die & ask my 'smith to run the REDLINE reamer in the sleeve to make a custom seater??? We did the same for my .30-338Norma Improved, and that worked out real well!!!

Philip found a 1:9 Krieger in stock @ Brunos (thanks for searchin', dude!), but it was a bit heavier in contour than I want to go for this project. Really want to stay in the 11-12lb. finished range, to maintain a nice balance of mass & carry weight. A #4 contour is a full pound lighter than a #6 Sporter/Rem Varmint, (3.5 vs. 4.5lbs) and its a perfect fit in a Micky GameScout. I don't mind toting a 14+ lb rifle, just want this build to be a lean, mean meateater like my .22-243AI. So, called up Brux & got another #4 contour ordered up, just in 1:9 this time. Will finish @ 27", too. Have to wait a few months on the reamer, anyway...so, wut da heck...

As for a handle, given this is a "one of a kind" project, think it deserves a new stock to set it off! McMillan quoted 6months as lead time, but this one is gonna have a brandy new, adjustable GameScout to sit in! Needless to say, it will have the appropriate color schematic 'swirled' in...

If the barreled action gets completed sooner (it should!), I sure ain't gonna wait on that stock, though! Have an A3 that it'll drop right into & get the ball rollin' with testing. So, figure we're looking @ right around the end of the year for this sucker to get fired up! JGS has already impressed with expedited customer service, so maybe we'll have a pleasant surprise & get a reamer done ahead of schedule! A guy's gotta dream, right?

P.S. Barrel life consideration ain't worth a tinker's damn on this one! However, given the projected ~300K rpm and semi-tolerable case pressure, I wouldn't mind being pleasantly surprised with 1K rounds. Sure gonna be fun to do some "terminal effect" testing on 'chucks with snert next spring!!! Might hafta wear a rain poncho on the close ones to keep the jell-O chunks from stickin', though...

 

[Phil]

Morning update:

it will have the appropriate color schematic 'swirled' in...

I can only imagine.........

Peanut butter...........gone.

Jelly.........gone.

Yeller.............gone.

Hmmmmmm..................................

 

[Andy Work]

That should be one bad @$$ round! Thanks for sharing.

 

[357Mag]

Fredo -

Howdy !

"Sure gonna be fun to do some "terminal effect" testing on 'chucks with snert next spring!!! Might hafta wear a rain poncho on the close ones to keep the jell-O chunks from stickin', though... "

....Looks like rain. Smells like.....


Haaaa... haaaa ....HAAAAA !!!


With regards,
357Mag

 

[7887mm08]

Wow you must really hate chucks! Hate to see what you would build if you hated deer!

 

[snert]

Wow you must really hate chucks! Hate to see what you would build if you hated deer!

You should see the deer rifle he has....no kidding.

 

[RGRobinett]

Morning update:

JGS has already received my 'dummy' round, and Grant already worked up a reamer print for the .220 REDLINE...WOW! Everything looks good to me, so we're going with it! I guessed FB would fall somewhere between .060-.080", and it did...

The REDLINE will retain use of standard SAUM go/no go gauges for chambering. That also allows for the ability to use my Redding 7SSAUM Type S Die set for reloading operations. Bushings again are: .291, .270, .258, and .252" for final neck tension) I was able to seat bullets with the Comp seater, as is, but might just wanna swap a .224 seater plug into the Comp. seater. Or maybe I'll buy a smaller seater die & ask my 'smith to run the REDLINE reamer in the sleeve to make a custom seater??? We did the same for my .30-338Norma Improved, and that worked out real well!!!

Philip found a 1:9 Krieger in stock @ Brunos (thanks for searchin', dude!), but it was a bit heavier in contour than I want to go for this project. Really want to stay in the 11-12lb. finished range, to maintain a nice balance of mass & carry weight. A #4 contour is a full pound lighter than a #6 Sporter/Rem Varmint, (3.5 vs. 4.5lbs) and its a perfect fit in a Micky GameScout. I don't mind toting a 14+ lb rifle, just want this build to be a lean, mean meateater like my .22-243AI. So, called up Brux & got another #4 contour ordered up, just in 1:9 this time. Will finish @ 27", too. Have to wait a few months on the reamer, anyway...so, wut da heck...

As for a handle, given this is a "one of a kind" project, think it deserves a new stock to set it off! McMillan quoted 6months as lead time, but this one is gonna have a brandy new, adjustable GameScout to sit in! Needless to say, it will have the appropriate color schematic 'swirled' in...

If the barreled action gets completed sooner (it should!), I sure ain't gonna wait on that stock, though! Have an A3 that it'll drop right into & get the ball rollin' with testing. So, figure we're looking @ right around the end of the year for this sucker to get fired up! JGS has already impressed with expedited customer service, so maybe we'll have a pleasant surprise & get a reamer done ahead of schedule! A guy's gotta dream, right?

P.S. Barrel life consideration ain't worth a tinker's damn on this one! However, given the projected ~300K rpm and semi-tolerable case pressure, I wouldn't mind being pleasantly surprised with 1K rounds. Sure gonna be fun to do some "terminal effect" testing on 'chucks with snert next spring!!! Might hafta wear a rain poncho on the close ones to keep the jell-O chunks from stickin', though...

Interesting project - I am completely unfamiliar with the bullets you mentioned (75 Gr. VLD and 75 Gr. A-Max): unless the two bullets are of equal length, and/or, the calculator factors specific gravity, it may leave you wishing for a faster twist.

I offer this, because, typically, the "tipped' bullets are substantially longer - thus of lower specific gravity - than their [equal weight] hollow-point counterparts.

Again, I confess my ignorance regarding the A-Max design - just extrapolating comparisons with V-Max, etc., which usually are about .125" longer, thus, call for up to 2.0" faster twist rate than a conventional HP of equal weight: in a .22 Cal., a mere 1/32nd of an inch longer will call for 1/2" faster twist.RG

 

[2dogs]

I would have to rate this project under the "Smokin' Cool" category!

 

[Tommie]

After a couple hundred rounds you can rename it the 230 Redline!

 

[onelastshot]

Was wondering how you decided on a 1-9 twist?

 

[fredo]

Was wondering how you decided on a 1-9 twist?

Basically explained that in post #1, with comparsion to my 1:8 .22-243AI.

Interesting project - I am completely unfamiliar with the bullets you mentioned (75 Gr. VLD and 75 Gr. A-Max): unless the two bullets are of equal length, and/or, the calculator factors specific gravity, it may leave you wishing for a faster twist.

I offer this, because, typically, the "tipped' bullets are substantially longer - thus of lower specific gravity - than their [equal weight] hollow-point counterparts.

Again, I confess my ignorance regarding the A-Max design - just extrapolating comparisons with V-Max, etc., which usually are about .125" longer, thus, call for up to 2.0" faster twist rate than a conventional HP of equal weight: in a .22 Cal., a mere 1/32nd of an inch longer will call for 1/2" faster twist.RG

Mr. Robinett, thanks for your input!
I always thought the V-max bullets had a rather long bearing surface for their weight...

Basically hoping that the extreme velocity will mitigate stability concerns with the lower drag bullets I'll be trying. Given that I live near sea level, but hunt in higher (and colder) conditions, if my chosen bullets will spin @ my local range, they'll be golden everywhere else. Also, the 80 Amax is the longest of the bullets I'll likely shoot. So again, if the 80 will work, all these other bullets will be golden, too...

Some measurements, for conversation:

75Amax: 1.070"
80Amax: 1.160"

75JLK: 1.050"
80JLK: 1.136"

75VLD: 1.063"
80VLD: 1.117"

77TMK: 1.072"
80SMK: 1.066"

 

[roadkill61]

I don't have any stability problems with my 9 twist and 75 gr at 3650 and 2000 ft . My barrel thou is a 5r

 

[RGRobinett]

Basically explained that in post #1, with comparsion to my 1:8 .22-243AI.



Mr. Robinett, thanks for your input!
I always thought the V-max bullets had a rather long bearing surface for their weight...

Basically hoping that the extreme velocity will mitigate stability concerns with the lower drag bullets I'll be trying. Given that I live near sea level, but hunt in higher (and colder) conditions, if my chosen bullets will spin @ my local range, they'll be golden everywhere else. Also, the 80 Amax is the longest of the bullets I'll likely shoot. So again, if the 80 will work, all these other bullets will be golden, too...

Some measurements, for conversation:

75Amax: 1.070"
80Amax: 1.160"

75JLK: 1.050"
80JLK: 1.136"

75VLD: 1.063"
80VLD: 1.117"

77TMK: 1.072"
80SMK: 1.066"

Please forgive my tardy response - beeen away hunting. Sans all of the DATA points, it appears that none of the 80 Gr. bullets you list will approach a gyroscopic stabiliity factor (Sg) of the 1.4, which is needed to damp the yaw and pitch, thus, provide the full BC potential. They may remain stable, and could shoot great in 60-70 Deg. temps, and fall apart in 10 deg. or, colder - yep, I've experienced this very thing with "cold weather" coyote and fox hunting! More altitude is better, however, cold may mitigate that!

A quick calculation via the very reliable [Tioga Engineering] Bullet Design program, predicts a twist rate requirement of 1:6.8" for the 80 Gr. A-Max, at Std. sea level conditions and 3500 FPS MV: this would produce a solid 1.5 Sg.

A comparison with the JBM (Robert McCoy based) DRAG/TWIST calculator produces a similar result: for a bullet of this length, recommending a 1:6.7" (2790FPS) to 1:6.8" (4000 FPS) twist rate for Sg 1.5. Via a 1:8" twist barrel, at 3350 FPS, the actual stability factor would be 1.1, and would remain thus for a MV of 4,000 FPS! In short, ominously marginal. I don't have time to do a bunch of comparisons for you - just did this to point out the danger of relying on velocity to mitigate marginal twist - "you cannot get there from here"! Of course, the shorter [80 Gr.] bullets would be better options.

Do yourself and your cartridge a favor: opt for a properly twisted barrel - then, hope the bullets can take the heat! RG

P.S. while the exact DATA points used may be (probably are) incorrect, it is extremely unlikely, that, for a .224 bullet, of the over-all-length (1.160") you listed for the 80Gr. V-Max, that the twist rate requirements would/could be favorably altered by even 0.10" of twist rate.

 

[AMG04]

Tagging in to follow progress! Love the idea and Fredo's desire to dive head first into the unknown!

 

[RGRobinett]

I did a DATA point 'guestimate' on the shortest 80 Gr. bullet - the Sierra MK - that you listed, and calculated the following: via a 1:8" twist barrel, at STD sea-level, and MVs between 2800 and 3900 FPS, the Sg would be about 1.3; for Sg 1.5, that bullet would need a 1:7.5" twist. In short, it has a much better potential than the longer bullets, of equal weight. Good shootin'! RG