.223 SAAMI Chamber Bullet Choices

[BigBlueandGoldie]

I have a Pierce .223 action on order that is being built into a range/training rifle (100-500yds). I will be sending them an 8 twist Krieger for chambering before they ship out the action. After talking with them they have (2) reamers to chose from; the first being a PTG .223 SAAMI spec reamer and the second being a PTG F-TR reamer with .169" throat. I'm limited to ~ 2.45" COAL due to using BDL bottom metal (modified for extra length), so I will likely be shooting 69smk's or 77smk's, which are more than sufficient for the distances the rifle will be used.

With all of that said, will the SAAMI chamber give me good results or will there be drawbacks that I'm not aware of? The .169 freebore of the F-TR chamber seems really excessive as I won't even be able to load an 80gr bullet in my bottom metal. My gripe with the spec reamer is the 3° lead in, as I would prefer the 1.5° of most of the match chamberings.

Thoughts?

 

[XTR]

The 169 freebore is designed specifically for 90VLDs. If you want to shoot mag length you are better off with the other reamer. You can use pretty much all of the 70s, the 77smks. On the other hand, the 75Amax and any of the 80s might be too long to seat correctly at mag length.

Edited to make last statement a bit less confusing.

 

[mac86951]

SAAMI chamber would be oriented toward 2.260" COL loadings which lists a freebore of 0.045" (not including tolerances). I happen to have two match rifles and shoot both at 600y in a high-power prone configuration. SAAMI chamber works wonders with a 2.260" loading and a 70gr Berger in 1:9tw (my barrel of 24" has an accuracy node at an easy 2850fps). My 1:7 is a 20" barrel with a wylde chamber (2.450" col max.) My 77gr loading produces 2650fps (near maximum), but also shoots well with 2.260". My Wylde chamber allows me the benefit of 80gr and others seated to the limit, and still shoots the 52 and 69gr fine, however, it does NOT like VLDs.

For 69/77gr either chamber is fine, and I'd recommend more barrel length to keep velocity up. I really like the SAAMI chamber for the ability to load to the lands easily, but your magazine is larger than mine, thus I'll say the 2.260" loadings will shoot just fine with a jump of 0.190" as mine do, however, having the ability for 80gr really makes a difference for 400y+.

-Mac

 

[BigBlueandGoldie]

The barrel will finish at 26", which should give me decent velocity (not 30" numbers) to reach out 500yds. This is my first .223 bolt rifle; all my .223 loading to date has been for mag fed gas guns which obviously restricts my COAL. Seeing as though I'm looking for a range toy I think the 77smk's (or similar) will get the job done.

 

[Dgd6mm]

SAAMI chamber would be oriented toward 2.260" COL loadings which lists a freebore of 0.045" (not including tolerances). I happen to have two match rifles and shoot both at 600y in a high-power prone configuration. SAAMI chamber works wonders with a 2.260" loading and a 70gr Berger in 1:9tw (my barrel of 24" has an accuracy node at an easy 2850fps). My 1:7 is a 20" barrel with a wylde chamber (2.450" col max.) My 77gr loading produces 2650fps (near maximum), but also shoots well with 2.260". My Wylde chamber allows me the benefit of 80gr and others seated to the limit, and still shoots the 52 and 69gr fine, however, it does NOT like VLDs.

For 69/77gr either chamber is fine, and I'd recommend more barrel length to keep velocity up. I really like the SAAMI chamber for the ability to load to the lands easily, but your magazine is larger than mine, thus I'll say the 2.260" loadings will shoot just fine with a jump of 0.190" as mine do, however, having the ability for 80gr really makes a difference for 400y+.

-Mac

I have a 24".sammi spec .223 on the way. I am going to try 68 - 77 grain bullets of various brands. I see 2850 is your target speed for that length barrel node. If you don't mind , which powder are you using? I have a 26" Benchmark throated for the 80 grain Amax for FTR that shoots excellent, using H4895in it.

 

[mac86951]

I have a 24".sammi spec .223 on the way. I am going to try 68 - 77 grain bullets of various brands. I see 2850 is your target speed for that length barrel node. If you don't mind , which powder are you using? I have a 26" Benchmark throated for the 80 grain Amax for FTR that shoots excellent, using H4895in it.

N140/540 is working great with longer barrels. As does h4895

Varget is another, AR-comp and R15, imr 4166 or even 4320 will do as well.

-Mac

 

[dkhunt14]

Your other option would be get a short or zero freebore and a throater. Then you can make it what you want or make it longer if it doesn't work. That is fit all for all bullets. Matt

 

[BigBlueandGoldie]

Thanks gstaylorg, I actually just read that thread and found your comments very helpful.

 

[John from MN]

It's not terribly difficult to remove the spacer from a factory 223 mag box and modify a milled 308 follower to fit and function. I did one yesterday for a similar build I'll be doing for myself in the near future. You still need to choose the correct freebore for the bullets you intend to use, but the purchase of a milled follower and the right spring, combined with a couple hours of careful filing or dremel work (did mine with a mill and a benchgrinder) will yield a 2.8 inch mag if it's necessary. Might be overkill, just throwing it out there.

 

[swadiver]

Both my SAMMI spec Krieger 20 inch AR 15 barrel and my SAMMI spec Criterion 26 inch bolt action barrel love 73 gr Berger Target bullets. the Criterion likes them on the lands but the Krieger AR barrel likes 'em jumped. add those to your list of potential bullets to try