.270 Win Improved

[redrider03]

Has anybody ever had one or shot one? What did you think of it. Give me some info about it. It hasnt been as successful as the .280 AI so I havent been able to read much about it. I have a .270 Win and was wondering what the advantage would be if I had it reamed to a .270 AI.

 

[SakoSteve270wsm]

redrider03,

The 280AI is popular because you not only get the normal gain from AIing it you also can run it at a higher pressure.The Speer reloading manual list the 270 with a max pressure of 54000 cup and the 280 at 50000 cup.Because of that reloading manuals never show the 280 at its best.Its alittle underloaded compared to the 270.So when people AI a 280 they also run it at 54000 cup pressure because there hasn't been any SAAMI specs for pressure in the 280AI.Nosler has made the 280 a SAAMI round so there is SAAMI specs for it now.

So when you AI the 270 the velocity gain isn't as dramatic as with the 280.The other advantage of AIing is improved case life.And you will have a unique chambering.

Hope this helps.

 

[FOTIS]

I almost had one built. Not worth it especially since the 270 Short is around.

Now the 280 with its huge bullet selection is another story.

 

[redrider03]

I almost had one built. Not worth it especially since the 270 Short is around.

Now the 280 with its huge bullet selection is another story.

POP,

Is there any info for a .270 AI in the Quick Load program?

 

[JD338]

You will get a gain in velocity with the AI plus you can also shoot factory 270 Win ammunition.

JD338

 

[old #7]

One of the advantages of Ai a cartrige is increasing the size of the "boiler room".
The 280 and the 30-06 are good cantidates because you can fill the case and compress the powder without exceeding the pressure limits. When you AI the cartridge you are increasing the amount of internal space thus increasing the amount of powder you can fit in the case
If you look at 270 load data, most of the max loads do not exceed 90% case volume and I have never seen a compressed load.
I asked the same ? a while back.

 

[YoteSmoker]

Here's my take on this. Does 100 FPS really make that much difference? If it does, ok but me, I would just step up to a 7mmMag and gain 200 FPS with the same weight bullet or go to a 20-30 grain heavier bullet with increased BC and energy. Rather than try to hot rod a caliber to make it potentially better, it would be much more efficient to step up to larger caliber, IMO.

 

[Antelope_Sniper]

If you are not compressing the loads, you are just not using a slow enough powder.

 

[alpinecrick]

Has anybody ever had one or shot one? What did you think of it. Give me some info about it. It hasnt been as successful as the .280 AI so I havent been able to read much about it. I have a .270 Win and was wondering what the advantage would be if I had it reamed to a .270 AI.

P.O. Ackley said the only cartridge he wasn't able to "improve" was the 270W............



Casey

 

[bullet]

If you want the best 270 performance in a 270 that is better than them all without all the trouble of fire forming then get a 270 Weatherby Magnum and you will have a very good, accurate, fast hard hitting 270 and the recoil is not bad at all.

 

[FOTIS]

I almost had one built. Not worth it especially since the 270 Short is around.

Now the 280 with its huge bullet selection is another story.

POP,

Is there any info for a .270 AI in the Quick Load program?

QL does list the 270 Howell

Cartridge : .270 Howell
Bullet : .277, 130, Nosler BalTip 27130
Cartridge O.A.L. L6: 3.340 inch or 84.84 mm
Barrel Length : 24.0 inch or 609.6 mm
Powder : Alliant Reloder-22

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 83 52.40 2559 1890 30897 10452 88.2 1.497
-18.0 85 53.71 2627 1992 33085 10816 89.7 1.457
-16.0 88 55.02 2695 2097 35436 11168 91.1 1.418
-14.0 90 56.33 2764 2206 37959 11508 92.5 1.378
-12.0 92 57.64 2833 2317 40678 11834 93.7 1.333
-10.0 94 58.95 2902 2431 43603 12142 94.8 1.290
-08.0 96 60.26 2971 2549 46751 12433 95.9 1.249
-06.0 98 61.57 3041 2669 50148 12704 96.8 1.209
-04.0 100 62.88 3110 2792 53811 12954 97.6 1.170 ! Near Maximum !
-02.0 102 64.19 3179 2917 57735 13180 98.3 1.133 ! Near Maximum !
+00.0 104 65.50 3248 3045 61943 13382 98.9 1.097 !DANGEROUS LOAD-DO NOT USE!
+02.0 106 66.81 3317 3175 66475 13558 99.3 1.063 !DANGEROUS LOAD-DO NOT USE!
+04.0 108 68.12 3385 3308 71363 13705 99.7 1.030 !DANGEROUS LOAD-DO NOT USE!
+06.0 110 69.43 3453 3442 76640 13824 99.9 0.998 !DANGEROUS LOAD-DO NOT USE!
+08.0 113 70.74 3521 3579 82347 13913 100.0 0.967 !DANGEROUS LOAD-DO NOT USE!
+10.0 115 72.05 3588 3717 88529 13977 100.0 0.937 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 104 65.50 3406 3350 75311 13006 100.0 1.011 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 104 65.50 3028 2647 49327 12991 92.9 1.211

 

[Guest]

If you want the best 270 performance in a 270 that is better than them all without all the trouble of fire forming then get a 270 Weatherby Magnum and you will have a very good, accurate, fast hard hitting 270 and the recoil is not bad at all.

I'll second this statement. I have one, and won't ever be without it. I get 3450-3500fps out of 130gr bullets, and 3200+ from 150's. There's no way an AI is going to come close to that, nor is the short mag (without pushing the limits of pressure up close to and beyond 70kPsi).