223 Rem with 30 or 35 degree shoulder
- Thread starter RonS
- Start date
Sounds like half-way to an Ackley Improved. . .
A tight neck chamber with neck turned brass in a bolt action would be my choice.
A loaded rounds neck diameter , using cheap brass , just doesnt come close to SAAMI OD of .253" Mine are around .246" unturned.
My guess.
B23
Gold $$ Contributor
With the extra powder capacity, a higher node can be reached. Will it be the "grail node"? Try and see.
That's funny.
Even with a 40 degree shoulder, the increase is eensy weensy, so a 30 or 35, would be even less. I have a 223AI, it's a great little gun and shoots crazy good, but I'm not sure the tiny increase you get was worth it so I'm not sure I would do it again.
TAJ45
Silver $$ Contributor
W/o going to the print, I'm thinking the body taper is decreased as well as shldr angle being changed. 
Caveat: IF an Ackley Improved w a change of shoulder angle, above will be relevant.
IF only a shoulder angle increase, then yes, barely any increase in capacity. Of which do you speak?
Caveat: IF an Ackley Improved w a change of shoulder angle, above will be relevant.
IF only a shoulder angle increase, then yes, barely any increase in capacity. Of which do you speak?
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Save yourself the heartburn and either stay .223 Rem or fully commit and go to 223AI (reamer and reloading dies are readily available).
When I did this exercise I decided the factory barrel was an average shooter (not the rare 1/4" unicorn). If I was going to chase accuracy and spend money re-chamber then I might as well add a new premium barrel.
When I did this exercise I decided the factory barrel was an average shooter (not the rare 1/4" unicorn). If I was going to chase accuracy and spend money re-chamber then I might as well add a new premium barrel.
I did a 35* with a .222 and really like it. Old bench rest caliber.
If you're really wanting to stay with the ".223" sized cartridge, blow your skirt up a bit and just up it to 6X45.
Heavier bullets and higher Vel. possible. With IMR-8208 and Sierra 95's single-load pushing 2920 fps. Hornady 6MM 85gr are loadable to magazine length but I don't remember the Vel off the top of my head.
Heavier bullets and higher Vel. possible. With IMR-8208 and Sierra 95's single-load pushing 2920 fps. Hornady 6MM 85gr are loadable to magazine length but I don't remember the Vel off the top of my head.
Increasing shoulder angle will not improve accuracy per se. Headspacing might be a little more precise...might. The incremental increase in powder capacity could possibly allow reaching the next highest node (as previously mentioned) but give up any ideas of any sizable gains in velocity. Most of the amazing velocities reported by .223 AI shooters are the result of running pressures beyond SAAMI limits.
Longtrain
Gold $$ Contributor
I love my 223 AI, I shoot 69 SMK's or 80.5 Bergers, 3200 and 3050 fps, respectively. The 69's I shoot for fun, ringing steel, the 80.5's I shoot in F Class competition, with a Tikka 595. The Tikka 5 round mags feed just fine with the 69's, 80.5 are single load. BTW 30" Hart barrel.
I just built a 6x45AI...went AI to reduce risk of loading into wrong rifle. I have a few 223's.
Ch4d has a 30* improved in their chamber list. At $76 for just a sizer, I would probably just get a custom from Whidden. Would suggest making a seater from your chamber reamer. Don't go expecting any big gains from this. You might want to look at the 224 Valkyrie. Could be just what your looking for.
https://www.ch4d.com/products/dies/caliber-list?page=46
https://www.ch4d.com/products/dies/caliber-list?page=46
Ned Ludd
Silver $$ Contributor
In response to the original question, no - the inherent accuracy/precision is unlikely to be affected noticeably. What will most likely happen is a modest gain in velocity by increasing the effective case volume. Slightly greater velocity does not guarantee any better precision.
Another way to accomplish the same goal is simply to use a higher BC bullet in a standard .223 Rem case. For comparison using Longtrain's velocity data from a .223 AI above, the windage predicted by JBM in a full value 10 mph wind at 1000 yd for 69 SMKs and 80.5 Fullbores at 3200 fps and 3050 fps is ~13.2 MOA and 9.0 MOA, respectively. Running the 90 VLDs at 2850 fps from a 30" barrel using a standard .223 Rem case returns a predicted windage of only 7.7 MOA, or 13.9" less wind deflection at 1000 yd than the 80.5s from a .223 AI cartridge. Greater than one foot less windage at 1000 yd using a higher BC bullet from a standard .223 Rem case illustrates how increasing bullet BC will almost always trump minor gains in velocity.
A number of F-TR shooters have been using loads similar to this with the 90s for some time and it works. There are certain considerations that go along with this choice, such as decreased brass life, the necessity for a chamber with very long freebore (0.169"+), a 7.0-twist barrel, and single-feeding rounds. Nonetheless, it is a good illustration of the difference wind deflection between a modest increase in velocity, and using a higher BC bullet.
Longtrain
Gold $$ Contributor
I never intended to shoot the 223AI at 1K, although your numbers are interesting. Generally, I limit it to 600 yards. Going back to my XTC days with service and match rifles, a legit 80 grain 223 load would run in the 2700 to 2800 FPS range. So, when I see that I can shoot a good bullet over 3000 FPS, that gets my attention within the confines of 80 grain bullets.
Never played with 90’s, maybe something for the next barrel as this one is a 1:8 twist.
Ned Ludd
Silver $$ Contributor
You really want a 7-twist throated long for the 90 VLDs, preferably in a 30" finish length. The new 85.5 Hybrid might be a good alternative. I'd still recommend a 7-twist barrel, but the throat doesn't have to be quite as long. The 80.5 Fullbore is also a great bullet, IMO, good BC, great precision, and easy to tune. Nonetheless, it can't compete with the higher BC of the 90 VLD at realistic velocities. As far as the AI case goes, nothing wrong with going that route at all, IMO. It will definitely buy you a little more boiler room to work with. It may not be a HUGE increase, but it's an increase regardless. I was solely using the values you had posted previously out of convenience to illustrate the point about velocity versus BC, not as any comment on the relative wisdom of going the AI route.
Guys, I'd like to thank everyone for there comments. I was curious because all of my BR's shoot great even my 6x47L shoots great. It just seems that every cartridge I have with a 30 degree shoulder is easier to tune than the ones without. Oh, I do have a 223AI w/ 12T, a 6x45 w/ 12T and a 20 Prac and they are descent shooters. I wanted to know if anyone else had actually tried this and was happy with there results. I've even thought of improving my 221 Fireball... I have been trying to figure out what to do with my Rem 788 SA 222 Rem 14T (I'm not the original owner) which has a throat/freebore just over 0.200" that barely shoots 1 MOA at 100 yards.
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