Some questions, 223AI build

[JayCarver]

Hello, I have been gathering components for my first custom.
So far I have:
-Surgeon 591 223 boltface (ordered)
-Surgeon DBM
-Kreiger #17 Heavy Varmit 1 in 7" 32" blank 0.224cal
-McMillan A5 (ordered)
-S&B PMII 12-50x56
-Atlas bipod

I have decided it will be a 223AI, my gunsmith dosent have a reamer, I am going to buy one from PT&G, thats were the questions start.

(1) What size neck? .251" and .252" seem to be common.
(2)How long to throat it?
(3)Where to chop the barrel?

Some info: This rifle wont get packed around so weight is not an issue. The place I shoot offten is 1000yds, so I will be loading most likely 80 and 90gr vlds, maybe 80gr Amax's. What throat would be a good compromise between these?

I already neck turn for other calibers, I like to at least take off enough to uniform the neck, would .251" neck work well for me? I want to work the brass as little as possible.

Since this won't be a tactical rifle I see no need to chop the barrel short, might as well get all the fps that I can with out going overboard on length. I'm thinking no shorter that 26", maybe 28" or 30" but that seems so long, how much more fps would a 30" get over 26"?

Thanks for reading, I look forward to your responses.
Jay

 

[excess]

Re: Some questions, 223AI build

One of your statements caught my attention, specifically neck turning. Being a cutting process I don't feel it would really "work" the brass much. The sizing and firing cycles are going to do much more working than turning will.

 

[Niles Coyote]

Re: Some questions, 223AI build

.251 works great without turning on every brass I have used in my .251 223 EXCEPT Lapua. That would need to be turned to gain a little more clearance. If you wish to shoot Lapua brass then .252 would be better, unturned they are just a hair over .001 clearance.

 

[JayCarver]

Re: Some questions, 223AI build

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CNC</div><div class="ubbcode-body">One of your statements caught my attention, specifically neck turning. Being a cutting process I don't feel it would really "work" the brass much. The sizing and firing cycles are going to do much more working than turning will. </div></div>

I should have been more clear, I know that neck turning will not work the brass. I will be neck turning to uniform the necks, therefore I would want my chamber neck smaller than someone that does not neck turn as my case necks will be alittle bit smaller, I'm just not sure how much.

 

[JayCarver]

Re: Some questions, 223AI build

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Niles Coyote</div><div class="ubbcode-body">.251 works great without turning on every brass I have used in my .251 223 EXCEPT Lapua. That would need to be turned to gain a little more clearance. If you wish to shoot Lapua brass then .252 would be better, unturned they are just a hair over .001 clearance. </div></div>

Thanks Coyote, I will be using Lapua Brass so maybe once I uniform the neck 0.251" will work well for me. What is optimal neck clearance?

 

[Niles Coyote]

Re: Some questions, 223AI build

That was my same question a couple years back. The answer I got is .002 if the rifle and ammo are going to see only bench conditions (in other words non dirty environments at the range) and .003 or more for use in the field for hunting and/or comps.

I run Lapua for the range and Winchester and lake city in the field. Those last two have about .003-.004 of clearance so they are still seeing minimal sizing and work great.

 

[JayCarver]

Re: Some questions, 223AI build

Ok, sounds like .251 neck is the way to go, anyone have any ideas about throat length ?

 

[BillCh]

Re: Some questions, 223AI build

I got my .223 A.I. reamer from PT&G after a couple of phone conversations with Dave Kiff. I chose to go with a .253 neck because of Lapua brass. I didn't want to get into neck turning for this rifle. A .77 throat length seems to be working out well for me. This was all set up for a 26", 1/8 twist barrel. If I had a 32 inch blank to start with I'd have had it finished at 30 inches and gone form there. You can always make it shorter.
My Max OAL (to lands)
80.5 gr. Berger Fullbore - 2.479
80 gr. Berger VLD - 2.473
75 gr A-MAX - 2.520

B

 

[762frmafr]

Re: Some questions, 223AI build

I have a 223AI that I had specifically throated for the 90 grain Bergers. I also had the AI 223 mags modified for the addd length. My COAL is 2.62" with a 90 grain Berger. This puts shank seating depth at .224". I would also go with a 28-30" barrel to get maximum velocity. Feeding and function is great. Just have your gunsmith ream the chamber as he normally would. Then give him some dummy rounds and he can go in with a throating reamer and finish throat to your specific length.

 

[JayCarver]

Re: Some questions, 223AI build

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BESETbyAPOSTATES</div><div class="ubbcode-body">I have a 223AI that I had specifically throated for the 90 grain Bergers. I also had the AI 223 mags modified for the addd length. My COAL is 2.62" with a 90 grain Berger. This puts shank seating depth at .224". I would also go with a 28-30" barrel to get maximum velocity. Feeding and function is great. Just have your gunsmith ream the chamber as he normally would. Then give him some dummy rounds and he can go in with a throating reamer and finish throat to your specific length. </div></div>

Thank you, this helps alot.

I keep hearing that I should make up a couple dummy rounds and this seems to make the most sense. Only thing is I wont have any 223AI brass until the rifle is done, should I try to have someone send me some?

Thanks

 

[762frmafr]

Re: Some questions, 223AI build

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JayCarver</div><div class="ubbcode-body"> should I try to have someone send me some?
</div></div>

Yes.

 

[bachelorjack]

Re: Some questions, 223AI build

Given your goals why not go 22-250AI instead? Because you seem to be ignoring/not interested in the real awesome points about a .223ai.