6x45 Load data

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After looking at A LOT of data, I'll try the 8208 for the 80 grainers and find some AA2200 or AA2015 for the 58 grainers.
 
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Any reason that 6x45 load data is held to around 50k psi?

If loading for an AR 6x45 with 5.56 brass, a system with max avg SAAMI pressure spec of 62k psi, wouldn't one be able to safely approach similar pressure levels?
 
Originally Posted By: eneranchI imagine this would only be applicable if you have a Firearm chambered for 5.56 NATO, not 223 REM.

Here are the SAAMI Specs

Here is a good write-up about the difference

5.56 NATO vs. 223 REM

And what does any of this silliness have to do with a 6x45?
 
If you had a rifle with a 5.56 NATO chamber and a 6mm tube, then it most likely could be loaded to NATO pressures.
Given the fact that the 6x45 is based on a 223 Remington chamber, then the lower pressures are applicable.

Originally Posted By: WWAYoteAny reason that 6x45 load data is held to around 50k psi?

If loading for an AR 6x45 with 5.56 brass, a system with max avg SAAMI pressure spec of 62k psi, wouldn't one be able to safely approach similar pressure levels?

Just because you are loading 5.56 brass does not mean your chamber can handle pressures of 62k psi.
 
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How exactly does one get a chamber differing from the tube? Yours talking perfect nonsense.

There is no difference in 223 stamped and 5.56 designated brass. No more than any normal difference between manufactures and lots of brass. The only difference, sometimes, can be the leade between the 2. The 6x45 is nowhere considered in the 223/5.56 nonsense.
 
Strength of the components / barrel / bolt is what I was referring to. A 6x45 AR using 5.56 brass should be just as safe @ 62k psi as a 5.56 AR using 5.56 brass @ 62k psi.

The root of my curiousity came from studying 5.56 load data with max avg pressures around 60k vs. 6x45 data with max avg pressures around 50k. My assumption was 6x45 data was built around acceptable pressure for its"parent" case - .223 rather than its "step parent" case 5.56.
 
Just curious why the limit on max avg pressure of 6x45? Variety of rifles so chambered? Two ARs chambered for 5.56 and 6x45 using identical components except for bullet should be safe at safe pressure levels, right?
 
Originally Posted By: WWAYoteStrength of the components / barrel / bolt is what I was referring to. A 6x45 AR using 5.56 brass should be just as safe @ 62k psi as a 5.56 AR using 5.56 brass @ 62k psi.

The root of my curiousity came from studying 5.56 load data with max avg pressures around 60k vs. 6x45 data with max avg pressures around 50k. My assumption was 6x45 data was built around acceptable pressure for its"parent" case - .223 rather than its "step parent" case 5.56.


Don't worry about it, there is no difference between the 2 cases. Start low and work up until you find your load or you see pressure signs on the case/primer.
 


Originally Posted By: midwestpredatorDon't worry about it, there is no difference between the 2 cases. Start low and work up until you find your load or you see pressure signs on the case/primer.

^^+1 ; When I see flattened primers & extractor/ejector marks, I know I've reached the top end.
 
I just finished building a 26" Savage 11 in 6x45mm, and IMR has load data for the cartridge online. I was able to work up a 90gr Berger VLD Target over 25.5 grains of 8208 XBR (I haven't chrono'd it yet). I tried seating the bullet up to the lands and I think it was a bit much for this load. All of the .223 once fired brass had slight bulging at the webbing and the primers showed a little flowing. HOWEVER, all of the 5.56 Nato brass that was converted had no signs of excessive pressure on the case, but the primer still had the outie belly button (from flowing). I was able to score a 0.132" three shot group at 100 yards (after subtracting bullet diameter). I have a picture, but I'm having image hosting issues...

I'll see if I can get this load chronographed and we can get some numbers on paper.

Here is a summary:
Rifle:
Savage 11 Action (with Accutrigger)
McGowen 26" Chromoly barrel - 1 in 9" twist
Basic savage 11 tupperware stock
Nikon Prostaff 4-12x40 Mil Dot

Load:
Brass - PMC Bronze .223/Lake City 5.56
Bullet - Berger 90gr VLD Target
Powder - IMR 8208XBR - 25.5gr
Primer - CCI BR-4
 
i'm new to this forum since i had a beautiful and very accurate 6x45 bolt gun made: kreiger 13.5 tw, stiller predator V lprb, jewell 1.5 oz in a #11 shurley bros thumbhole laminate. an 8-32 sightron 1/8 min tgt dot scope is the icing on the cake. i downloaded the load data and really appreciate the work done to provide this data. i loaded new brass with n133 and a 62 gr knight and shots 2,3, and 4 printed in the ones! i have never had a gun so blasted accurate!!! just about every combo of bullet and powder shoot small hole but n133 seems to be the most accurate. currently trying LT 32 and it has promise. i have a problem(posted on the 6 MMBR site also). my redding 6x45 fl and neck die leaves .003 of runout in the neck. neck expansion in the die or with a wilson neck xp doesn't correct it. i now run the brass into a redding .223 body die(brings the neck to .257) then exp with a wilson 6mm mandrel and the r/o is gone. anybody with the same problem? any suggestions? thanks.
 
LT 32, 25.1 and 25.3 .020 into the lands at 3330 fps and it shoots in the ones and the lower load shot in the zeros! using 65 gr fb conaway bullets. i'll have to try the LT 32 with other lighter bullets even though n133 works very well also.
 
Would like a little more speed with the very accurate 65s and recall how my 223 ackley increased my 223 performance. Has anybody any experience with a 6x45 Ackley improved? I expanded the neck of a 223 Ackley and seated a bullet and it looks good. Case volume with LT 32 increased almost 2 grains. Anybody done this? Thanks.
 
Originally Posted By: lpreddickWould like a little more speed with the very accurate 65s and recall how my 223 ackley increased my 223 performance. Has anybody any experience with a 6x45 Ackley improved? I expanded the neck of a 223 Ackley and seated a bullet and it looks good. Case volume with LT 32 increased almost 2 grains. Anybody done this? Thanks.

The Ackley approach might be intersting but I wonder if the gains will be worthwhile vs cost, silly concept, in performance. A rule of thumb is that for every 4% increase in case volume you realize about a 1% increase in velocity. Not hard and fast just a guesstamete. You are gainging right on 8% in volume so by that rule you are looking at 60-70 FPS.

You might post up in the reloading area. If most guys are like me they don't look here much even though I own four of them.

Greg
 
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