.223 Rem. Neck Questions

[NV_Dmax]

Is a .252” neck a no turn neck with Lapua brass in a 223 Rem?
Thanks for your input.

 

[Ned Ludd]

It might be. However, I will qualify that statement by adding that my .223 Rem match chambers are cut with 0.2527" neck diameter, according to the reamer print, so that number is +/- whatever the reamer tolerances were. I use a 0.248" bushing with Lapua .223 Rem brass [un-turned necks] to achieve ~.0025" neck tension (interference fit), which leaves just a little under .0015" clearance per side with my chambers. Lapua brass prepped using a 0.248" bushing would be just under half a thousandth tighter in chamber that really was cut to exactly .2520" neck diameter, or right at .001" clearance per side. That might be ok as long as the reamer wasn't half a thousandth under on the neck tolerance.

Edited for correction

 

[Edd]

Is a .252” neck a no turn neck with Lapua brass in a 223 Rem?
Thanks for your input.

My Lapua 223 brass with bullets seated measure about .250". For me, the answer to your question would be no. If I was running .002" total clearance, I would want the necks turned.

 

[Nick Caprinolo]

I may be wrong, but .002 is the right amount of clearance in most rifles, with seated bullets. My 6PPC has a 262 neck and requires a seated bullet of .260 or less.

 

[joshb]

I may be wrong, but .002 is the right amount of clearance in most rifles, with seated bullets. My 6PPC has a 262 neck and requires a seated bullet of .260 or less.

Nick, I like 3-4 thou for safety. I don’t trust my measuring abilities to hit a “guaranteed “ 2 thou clearance. Might just be me.

 

[K22]

Assuming we are talking the same measurement, .252 (neck diameter w/ bullet seatwd) is pushing the SAMMI max of .253 for a 223 Rem.

I'd be more concerned about excessive pressure than neck tension.

I've never come close to .252 with Remington, Winchester, Federal or Hornady cases. Most of mine are running about .247 to .249.

I also believe that consistent neck tension contributes more to accuracy than a specific number; at least that's been my experience but I'm not a bench rest shooter or a long range (>300 yard) shooter.

 

[Nick Caprinolo]

Nick, I like 3-4 thou for safety. I don’t trust my measuring abilities to hit a “guaranteed “ 2 thou clearance. Might just be me.

Josh

You are right. My necks are .258 prior to seating bullets and .260 with bullet seated.

Nick

 

[NV_Dmax]

My Lapua 223 brass with bullets seated measure about .250". For me, the answer to your question would be no. If I was running .002" total clearance, I would want the necks turned.

Thanks,
That's what I was afraid of.

 

[Ned Ludd]

Thanks,
That's what I was afraid of.

Thanks,
That's what I was afraid of.

I just re-checked some recent measurements with Lapua brass and the average neck diameter of cases with seated bullets is the same as what Edd listed, 0.2500" (0.2475" average OD after re-sizing with 0.248" bushing, 0.2500" OD after seating bullets, above post edited for correction). So the 0.252" chamber might be a little on the tight side. Nonetheless, the best approach would simply be to load a few dummy rounds and determine empirically whether they chamber reliably in your setup before turning all the necks. It may be you will need to do so with Lapua brass, but it may also be that you can get away without doing it. Let the rifle tell you what it will or will not tolerate.

Another alternative would be to use a different brand of brass. I have tested different brands of .223 Rem brass. Until recently, none matched up to Lapua in terms of precision. However, I recently acquired some Norma .223 brass and the precision is every bit as good as Lapua. The flash holes require a little more cleanup than Lapua, but it costs half as much, so no surprise there. The average case volume is slightly larger than Lapua, and the average case weight slightly less. This was initially a concern for me if it meant that the webbing was thinner, as my competition loads open up the primer pockets of Lapua brass in three or four firings. I noticed when first loading the Norma brass that the neck walls were visibly thinner than Lapua. The thinner neck and case walls might well account for the slight average weight difference without affecting the thickness of the webbing. So far, the Norma brass primer pockets seem to be holding up just fine, although I have not run quite full-pressure loads through it yet, having chosen to fire-form it first with a slightly reduced load (~1.5% reduced charge weight). My point is simply that if the rifle is already chambered with the 0.252" neck, you may have other options besides turning necks if the Lapua brass doesn't give you enough neck clearance. I know a few people that turn necks of their .223 Rem Lapua brass for F-TR competition, and I have the equipment to do it myself. I just haven't been willing to put forth the effort and the good results I've had using these rifles in competition hasn't warranted it at this point.