.222 chamber design?

[clatarar]

I am in the process of putting together a varmint/ informal BR rifle in .222. Already have a rem 700 action and have ordered a shilen 12 twist barrel. I've yet to finalize details as to what chamber dimensions I will run but have decided that I will use winchester brass (I'm prepared to lose a few cases of win brand brass... not lapua) and will test most budget bullets from 50 grain vmax's through both sierra and hornady 52 grain hp's and the amax. What would you reccomend for chamber dimensions? Neck dimensions and freebore?

 

[areaone]

.250 neck no turn. .020 FB for 52 gr. 12 twist will take you to 64 gr Bergers. 222 works best with 50-55 gr bullets. Could go longer on FB but you will be chasing the throat if you shoot it very much. Love that 222. If you go to Lapua brass you will need a .252 neck., I use Winchester brass and a .250 neck, loaded are .2475 with sierra or hornady or bergers. With a .020 FB you will be about 2/3 into the neck with plenty of room for tension and still have case capacity for powder.

 

[Ackman]

First get your brass and measure it before you spec the reamer. Seat a bullet and you'll know what neck dia. to order. The 222 has a long neck. With NO freebore a Sierra 52hp just touching the lands will seat to .050" above the neck/shoulder junction. Other bullets will seat further up, some of them quite a bit further up.

 

[BoydAllen]

Buy your FL die. Get some well used brass that was fired in a factory rifle. Size several cases, and make a drawing of the biggest one. Figure it out from there. If you know what your die gives you, and the clearances you want in the chamber, it should be a simple matter to work it out, I have do it that way a half dozen times. The reason for the well used brass is that it comes out of the die bigger, because it becomes springier as it work hardens. I have to tell you, that if you are going to use it for varminting, that the plastic tipped 40 grain bullets make a whole new caliber of the .222. The BCs are the same as the old 52 gr, HPs and the velocity is considerably more. I have a couple of .222s that I have shot from the bench a lot (52 gr. HPs), and shot a fair number of California ground squirrels with. The only thing that I would suggest is that you skip the 12 twist and go for the 14" it will handle 40s, 50s, and 52s just fine, and I can't think of a good reason to go heavier with this caliber. Just one man's opinion.

 

[LHSmith]

What Boyd said.......DON"T go with a Match....or Minimum SAAMI chamber...you will forever fight brass issues with it

 

[SmokinJoe]

What Boyd said, but just send a few of those cases to Dave Kiff or whomever your reamer maker is, and he can decide on the best dimensions for you.

Oops, forgot to mention that Dave Berg is working with a similar project right now, so you might drop him an e-mail (doesn't do PM's) & he probably has some good advice, too.

 

[222 rem]

Mike Bryant chambered a krieger with .250 neck.
Very pleased with this barrel.

 

[boltman223]

Clatarar,

I don't know if you have not order a reamer or not, but here is what I know from experience.

I have a shilen 14 twist chamberd with a no freebore .250 neck ptg reamer. First off I wish I would have went with the 12 twist, it would allow me to use a wider selection of bullets and the the 53 vmax (way higher bc). My 50 vmaxe's boat tail sits a roughly .003 into the neck/shoulder juction and that is with the bullet touching the lands. My 52 gr sierra match hp's are about flush with the neck/shoulder junction while the bullet is touching the lands. thi is why i would advise against a zero fb reamer. Also the two bullets I listed measure .219 at the case mouth.

If was going to do it again I would go with a .025 fb reamer so I would have room to play with bullet jump and use a wider selection of bullets. If affraid to go with .025 at least go .010 or .015 fb.

Those are my actuall measurements I dont know why achman and mine are different

 

[fdshuster]

boltman223: I understand your problems with a 0 freebore, had a similar one with one of my 6BR's.

Simple fix: Lengthen the throat to any dimension you want, using a throating only reamer. If your gunsmith does not have one, PTG sells them for about $66. If then having no further use for it, it could easily be sold to get most of your cost back.

With the really long barrel life of the 222, the cost would more than pay for itself over time. If a barrel burner cartridge were involved, then maybe not.

 

[boltman223]

Thanks fdshuster, I did actually buy the uni throater. I am just waiting to see how my 222 shoots before I try it, once it warms up here in minnesota. Talk about driving a guy crazy with anticipation!

Do you have any experience wig the uni throater?

 

[fdshuster]

No, not the uni throater in particular. Did buy a 20 cal throater to correct a too short throat (my fault when I spec'd. the PTG reamer) in a 204 Ruger chambering. Discovered too late that it needed some jump before it would start to shoot. Then with one of my 6BR's that also had 0 FB, discovered that the longer bullets were seating right on top of the donuts. My 'smith has a 6mm reamer so did not have to buy one. Opening up the throats solved both problems.

Being too short is still a better option than being too long, the only choice then being to setback the barrel, a costlier "fix".

 

[Ackman]

Clatarar,

My 50 vmaxe's boat tail sits a roughly .003 into the neck/shoulder juction and that is with the bullet touching the lands. My 52 gr sierra match hp's are about flush with the neck/shoulder junction while the bullet is touching the lands.

Those are my actuall measurements I dont know why achman and mine are different

Maybe your throat angle is different, or the bore is a little different. The 52gr hp bullet I checked was in an unmarked box....I believe it's Sierra but maybe it isn't. I use a window gauge made with a Krieger cutoff, 1*30 throat, and a split neck case. The window gauge lets you see a bullet actually going into the throat and sliding down the neck. With the split neck you see exactly where it's seating into the case. With 1.7" caselength and .005" clearance, touching the lands a 50Vmax seats about .030" above the neck/shoulder. The flatbase 55 VMax seats about the same. A 40VMax seats .135"-.140" above the neck/shoulder. I wouldn't be wanting any freebore in a 222 chamber.

 

[boltman223]

Ackman, I have the same reamer, a pacific tool and gauge 1*30 throat. I use the hornady modified case, I push the bullet in until it (stops) touches the lands. if our reamers are the same which they sound like they are I wonder how we are getting such different results. This is kind of interesting, I would like to figure out what is going on.

 

[BoydAllen]

One thing that makes a difference in how far out a bullet is when it touches is the diameter of the back of the leade angle. This is the equivalent of free bore diameter.

 

[boltman223]

I talked to dave kiff about the differences in our zero freebore reamers. To be honest some of it was over my head, but yes there can be differences in two zero freebore and 1*30 leade reamers. It depends on what side of the tolerences the reamer is cut on. So the best thing to do is talk to dave kiff and tell him what bullet(s) you want to shoot. That is what I did and my throat is set up perfect fo the 40's, but too short for the 50's. With my reamer .025 freebore would not have hurt.

 

[chevi_guy]

I may be a little off topic here.
Does anyone know what the freebore might be in a pre 1970 Rem. 700 heavy barrel Varminter Special .222

 

[clatarar]

Thanks guys, I wound up going with .250 neck and .025 fb manson reamer. I have sized a few pieces of brass with an old rcbs die that i found locally and it sized to .245 on my calipers and a 69 grain matchking (only thing locally available) loaded to 249 with my brass. Just about perfect as I plan to do some very light neck turning. I'll likely order a sizing die from forster honed to .246 to do sizing duties and I have a wilson seater for seating duties. I have to bulk order everything (joys of living in northern canada) so will likely just order 1000 of each 40 grain vmax, 52 grain mk, 52 grain amax and 53 grain vmax (interesting bullet) which will last me a long time. What should I go with for powder? I'll have to go with 1 8 lb jug as I am in a fly in only community and shipping on the barge gets expensive, already have some h4350 and h4895 coming and am hoping to stick with the extreme line of powders as temperatures range from -40 up to +30 celcius.

Clayton

 

[Steve Blair]

Ackman, I have the same reamer, a pacific tool and gauge 1*30 throat. I use the hornady modified case, I push the bullet in until it (stops) touches the lands. if our reamers are the same which they sound like they are I wonder how we are getting such different results. This is kind of interesting, I would like to figure out what is going on.

[br]
What you are describing with Sierra 52g MK HPBT is simply not possible. That bullet has a .193" long bearing surface. A .222 case has a .313" long neck. You could seat the Sierra so that the bearing surface was .120" below the case mouth before the shank was at the neck-shoulder junction. Even if you included the boat tail, it could be seated with the shank .060" below the case mouth. [br]
I have a zero freebore barrel on a Sako Vixen. When I seat Sierra 52 MatchKings to jump .010", they are well clear of the shoulder. The .222 has a long neck.

 

[BoydAllen]

Thank you. I didn't want to speak up because all of my .222 stuff is buried and I have no reason to dig it out right now. My bench rifle has a .244 neck, degree, a half leade angle. and zero freebore, and the bases of any 50, 52, or 53 grain bullet that I have tried come nowhere near the neck shoulder junction, for the reasons that you have mentioned, the lengths of their shanks, and the length of the case neck. Perhaps the fellow has a carbon ring in his chamber throat, or has gotten a false reading using the Hornady/Stoney Point tool.

 

[Ackman]

The relationship between throat and neck is the same no matter what case it's attached to. I don't shoot heavy bullets and most of my .22's in several different chamberings are 14 twist.....they all have the same throat angle with NO freebore. The .221, 223, 22-250 all have a much shorter neck than the .222. The 221 neck is shortest of those. Even with that short neck, the only 50gr that'll seat below the neck/shoulder is a VMax, and those bullets seat deeper than others. At the lands a 50BT or BK will seat about to the neck/shoulder radius or slightly higher......a 40gr will seat about .050" above and the 50TNT seats out further than that. The .222 neck is .110" longer than a .221 neck. There's simply no way a 50gr. bullet, even VMax, will seat anywhere near the base of a .222 neck. With .22's and what's now considered to be "light" bullets, you don't need freebore.