G&A 222 load looks off

[Greg Langelius *]

The latest issue (June 2011, P28) of G&A publishes a 50gr NosBT Load of 26.6gr of W-748. This is somewhere around 2 full gr above both Hodgdon's and Nosler's W-748 max for the bullet and chambering.

I was considering trying it until I started comparing it against other sources.

Is it just me, or does anybody else have reservations about this?

Greg

 

[Clark]

Re: G&A 222 load looks off

I am shocked, shocked I tell you, that you are shocked.

The 6mmRem, 22-250, and 270 are SAAMI registered at 65kpsi, but can be run at 67kpsi and get long brass life, a 2kpsi margin.

The .223 is SAAMI registered at 55kpsi, but can be run at 75kpsi with long brass life, a 20kpsi margin.

Quickload thinks that 223, 50 gr Nosler BT, 26.6 gr W748 2.26" is 53.4 kpsi and 103.7% fill ratio.

If it would fit, 29 gr would give 75kpsi and long brass life, but at 113% fill ratio, that ball powder may not fit, and will not compress.

 

[bohem]

Re: G&A 222 load looks off

222 or 223?

I'd be surprised if you can get that much powder into a 222 case actually.

W748 is very close to H335 (or is it BLC2) in burn rate, in a 223 I run 27.0gr of BLC2 under 55gr FMJ's and don't have any pressure signs or problems in my AR15. I run 25.5gr of H335 as well, though I've pushed it to 26.5gr without trouble.

With 55 Blitzkings I use the same loads and have still round primer edges and not a whiff of cratering primers.

 

[Greg Langelius *]

Re: G&A 222 load looks off

.222 or Deuce.

 

[armorpl8chikn]

Re: G&A 222 load looks off

Greg I am sure from reading some of your posts you are probably a long time reloader. There has never been a time in my loading career that I have used a load like this without reducing, I simply don't trust data that did not come from my gun when it is beyond the manual. I dug around a bit and can find loads up to 27.4gr of 748 and 50gr bullet in the triple deuce, but you know that can be approached with caution.

 

[Clark]

Re: G&A 222 load looks off

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">.222 or Deuce. </div></div>
Pardon me.
The .222 is SAAMI registered at 50kpsi, but can be run at 75kpsi with long brass life, a 25kpsi margin.
Quickload thinks that 222, 50 gr Nosler BT, 26.6 gr W748 2.26" is 71 kpsi and 115.2% fill ratio.
If it would fit, 26.9 gr would give 75kpsi and long brass life, but at 116.5% fill ratio, that ball powder may not fit, and will not compress.

My 222 does not have the firing pin fit to do this test*, but the .223 uses the same 1950 222 Rem case head design.
This 223 test from left to right in Quickload pressure prediction:
0 kpsi brass ok
69 kpsi brass ok
80kpsi brass ok
92kpsi brass .0005" extractor groove expansion
106kpsi brass .0030" extractor groove expansion

*My 222 is a BRNO LUX and is based on a 22 rimfire action. It only locks up on the .625" bolt's .39" handle base into the .15" thick wall of the tube receiver. The locking surface is a .15" long on a .15" flat spot on a .39" diameter circle = .0225 sq in.
The inside of a .222 case is .3" diameter = .071 sq in.
At 70kpsi proof pressure, the bolt handle base could see 5,000 pounds thrust. That would be 222kpsi compression on the steel.
This sure scratches like 120 ksi 4140 steel. That worries me.

 

[Greg Langelius *]

Re: G&A 222 load looks off

OK, I was just looking for second (..and maybe third) opinions here.

Tomorrow, I'll restart the reloading bench (it's out in the unheated garage) after the Winter layover, and see what fits in where. Then some workup pressure test loads.

My current load is about 1gr under the G&A load, and I'm already employing caution. My .223 load is 27.5gr w/52gr SMK.

Thanks for the info/help.

Greg

 

[Greg Langelius *]

Re: G&A 222 load looks off

P/M'ed (cleaned, oiled, verified adjustments and clearances...) the the Dillon RL550B press, resized and primed 100 new Rem .222 cases.

Experimenting with charge drops; unfired Rem brass overflows above 26.0gr of W748 using the Dillon powder measure.

Experimenting with larger charges and a drop tube, the case still won't accept 26.6gr of W748.

Not sure, I may be dealing with a magazine typo here.

Greg

PS I just reviewed my data from an older Sierra manual, and they show Rem brass and their 50gr bullets using up to 27.1gr of W748. Even accepting that their bullets were all flat based, I still don't see how they were getting that much powder into a Rem case.

What am I missing here...?