.270-300jls ai

[CZ]

JUSTED finished a new toy for a friend.-
SAKO action, Broughton 4.1 5c flutted barrel 28in
cal. .270 Mcmillan stocked and glassbedded with
devcon 10-110 steel putty.

Easy round to form, and latest news.-
AccuBond .270 140gr 80 gr rl22 CCI 250 just 3690fps, no signs of
pressure, RL 22 almost seems to be the powder for large capacity
rounds, in my 7mmMag just works excelent.

almost 200fps over my 7mm STW, I think I should get one for me
very very soon hihi.

Any comments.-

 

[JD338]

cz,

What is the parent case of the 270-300 JLS

JD338

 

[CZ]

cz,

What is the parent case of the 270-300 JLS

JD338

EASY .300 WIN MAG.- Easy to get, will post pictures soon.

 

[FOTIS]

CZ are you sure about that load? This is what QL predicts for the 270-300 WBY which has more case capacity....




Cartridge : .270/300 Weath. Mag.
Bullet : .277, 140, Nosler AccuBond 54765
Cartridge O.A.L. L6: 3.640 inch or 92.46 mm
Barrel Length : 28.0 inch or 711.2 mm
Powder : Alliant Reloder-22

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.754% 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

-17.5 80 65.96 2933 2673 40080 11763 98.1 1.556
-15.8 81 67.37 2991 2781 42462 11983 98.7 1.514
-14.0 83 68.77 3049 2890 44973 12187 99.1 1.473
-12.3 85 70.18 3107 3001 47620 12373 99.5 1.434
-10.5 86 71.58 3164 3112 50411 12539 99.8 1.396
-08.8 88 72.98 3221 3225 53353 12686 99.9 1.360 ! Near Maximum !
-07.0 90 74.39 3277 3338 56455 12813 100.0 1.325 ! Near Maximum !
-05.3 91 75.79 3332 3452 59726 12925 100.0 1.291 ! Near Maximum !
-03.5 93 77.19 3387 3566 63177 13034 100.0 1.258 !DANGEROUS LOAD-DO NOT USE!
-01.8 95 78.60 3441 3681 66818 13141 100.0 1.226 !DANGEROUS LOAD-DO NOT USE!
+00.0 96 80.00 3495 3797 70662 13244 100.0 1.196 !DANGEROUS LOAD-DO NOT USE!
+01.8 98 81.40 3548 3914 74722 13345 100.0 1.166 !DANGEROUS LOAD-DO NOT USE!
+03.5 100 82.81 3601 4031 79012 13443 100.0 1.138 !DANGEROUS LOAD-DO NOT USE!
+05.3 102 84.21 3653 4149 83548 13538 100.0 1.110 !DANGEROUS LOAD-DO NOT USE!
+07.0 103 85.61 3705 4268 88347 13629 100.0 1.083 !DANGEROUS LOAD-DO NOT USE!
+08.8 105 87.02 3757 4388 93429 13718 100.0 1.058 !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 96 80.00 3606 4043 83586 12841 100.0 1.113 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 96 80.00 3326 3439 57666 13692 99.3 1.308 ! Near Maximum !

 

[JD338]

Pop,

It is AI so case volume would be even more.

JD338

 

[CZ]

Pop,

It is AI so case volume would be even more.

JD338

The round has a short neck, large capacity, and yes Im sure,you should consider buliding one of this toys, I have dave manson drawings, he made
the reamer and Pat at Redding made the dies.
You can load the round with .270WSM dies and 300win mag dies.
And yes Im going to build one for me.-
We tested Hybrid100,h4831,imr7828 and the winner is RL22.
Its like a hotrod hihi.

 

[JD338]

CZ

Post a picture of the round. :lol:

JD338

 

[SJB358]

Lets see some pictures of that beast! It sounds like a true long range cartridge. Should be flat as a wire for a long ways out with a long bullet like an AccuBond. Scotty

 

[CZ]

CZ

Post a picture of the round. :lol:

JD338

GIVE ME A LIL TIME WILL POST PICTURES OF RIFLE, ROUND, GROUPS AND VELOCITIES.

 

[FOTIS]

I understand it is the AI version. Even so the 300 win mag AI still has less case capacity than a 300 WBY.


For what its worth I put the 7mm STW necked to 270 140 AB.

With 80 gr of r22 I got 3450 fps and 72.8K psi

 

[CZ]

I understand it is the AI version. Even so the 300 win mag AI still has less case capacity than a 300 WBY.


For what its worth I put the 7mm STW necked to 270 140 AB.

With 80 gr of r22 I got 3450 fps and 72.8K psi

Pop Ive tested by now various 7mmSTW, the first one was made in
the 90s, I know that in each rifle everything changes but by now the
limit with 140 has been 82gr, pass that limit and problems start, I dont
know about this combination but seen very eficient, there is a dif between
3450 and 3690, and that using 80gr of RL22 no sign presures detected,
nor the Bees or the 7mmSTW aproaches the velocity of this round, in the fireforming I get those 3450 fps. I dont know if in the past was done, but
now with these powders for sure this round rocks, and for second has been a lot of fun during the process.

 

[FOTIS]

CZ

Post a picture of the round. :lol:

JD338

GIVE ME A LIL TIME WILL POST PICTURES OF RIFLE, ROUND, GROUPS AND VELOCITIES.

posting for cz

 

[FOTIS]

What is the water capacity of this round?

 

[CZ]

What is the water capacity of this round?

84gr

 

[FOTIS]

OK the example above of the 270-300 WBY has about 98 gr of H2O total.

 

[30-338]

CZ, Looking at the reamer print your case is pretty close to the 270/338mag. I'm shooting the 30-338mag also looked at doing the 270 on that case. I like the 40 degree shoulders very interesting. Good luck

 

[remingtonman_25_06]

Interesting cartridge...

Im a bit intrigued and surprised as to the velocity with the 140g bullets as well...

That velocity seems really really high. If you've ever heard of the 270 or 7mm Allen Magnums which are based on the lapua and or RUM cases, they are able to push those 140's to about that speed 3700 or so and the case capacity is A LOT more.

Not saying its not possible, but I dont think its normal either...

 

[CZ]

Interesting cartridge...

Im a bit intrigued and surprised as to the velocity with the 140g bullets as well...

That velocity seems really really high. If you've ever heard of the 270 or 7mm Allen Magnums which are based on the lapua and or RUM cases, they are able to push those 140's to about that speed 3700 or so and the case capacity is A LOT more.

Not saying its not possible, but I dont think its normal either...

You have to test it to see what Im talking about, I dont know if is the cal, the poly broughton barrel, or is an efficient round as a .308 but for sure
works, and Pop in your example the .270-.300wby for sure is a round
not too eficient ( quantity of powder to velocity), you have to compare
apples with apples, I dont have a Quckload but maybe you can get some info in and see what does it says.

 

[SJB358]

Either way, it sounds fast and like it would be an awesome long range cartridge. Makes my 270WSM look like a little pipsqueak! Scotty

 

[bullet]

One trucking cartridge and you talk about reach out there. Barrel life will be the only issue, but as for killing power it should be awesome indeed. :grin: