7 twist 3.50" COL 270 winchester quickload request

[assasinator]

im new to the forum, but i been reloading since 1987.
im experimenting with how far i can take a long 270 winchester.
59 grain case
3.50" COL
magpro AA4350 and 24n41
cci 200
27" barrel 7 twist
bullet touches up at 3.89" COL,so .390" freebore
150 ablr and 170 ablr

what i have loaded so far. 150 ablr with 62 grains of magpro. 2898 fps average. no case stretch measured everywhere comparing
55 grains to 62 grains.

i am going to shoot 170 EOL, 170 ablr, 175 TGK, 155 barnes, and 150 ablr using the 24N41 primarily. i intend to add .010 more throat for a full caliber and a half freebore. its my standard for barrels i oreder in all calibers.

thank you.

 

[assasinator]

oh BTW 62 grains of magpro was just touching the bullet base.

if i cant get the heavies where i want them i am going to cut the throat longer for the 170 to 175 bullets, and then get it rechambered to 270-338 with the neck cut longer to match 2.49" .30-03 case length, so my brass are 416 rem for resizing and cutting the longer neck. mt COL with the 270-338mag will be the same as now. 3.5-3.55"

i have dies for 270-338, and i have also used 270 weatherby sized to knock back the shoulder. i will fire form them after the chamber gets resized, IF i do. planned for this all along. wanna murder 6.8 western. that's actually the whole point of this. i like playing with what can be done.

i have fired a 3.55" COL using a 175 TGK and just a 3.69" touch up. .140" jump using 24n41 cant remember the load. its on another old computer. think it was 55gr. chrono didnt read it. pressure was over my limit and i stopped. gonna work up better bullets. i called sierra and talked to a engineer, that bullet was designed specifically fo the 6.8 western and really has too long of a bearing for 270 win. it drags and raises pressures.

-bill

 

[assasinator]

bump. no comments on quickload using 24n41 and 170 ABLR with my 270 win specs?

hope i get a response, but i can do it. my start will be 53 grains.

 

[Calvin45]

Welcome to LRH! Ain't got quickload….do have a .270 haha.

Interesting approach with the long throat/freebore. Is this about realizing higher velocity or just about being able to seat long bullets way out there?

 

[assasinator]

Welcome to LRH! Ain't got quickload….do have a .270 haha.

Interesting approach with the long throat/freebore. Is this about realizing higher velocity or just about being able to seat long bullets way out there?

its about maximizing velocity for 150ABLR, 170ABLR, 170EOL, AND 175 TGK. Long seating is for saving case capacity, and freebore is my chamber spec for all barrels. so far it works better for belted mags, but all wide/short cases benefit.

 

[Leaf Litter]

No such thing as a 170gr ABLR in .277, they're 165gr.

 

[nksmfamjp]

QuickLoad Ballistic Prediction Software – Neconos.com

www.neconos.com

It's $155….pay the man. Sometimes I offer help, but a guy playing with a 7 twist 270 win long throat needs to buy their own copy. Every change to your load will require touching up your model!

 

[assasinator]

No such thing as a 170gr ABLR in .277, they're 165gr.

ty. lol.

i stand corrected kind of.... they are just plain nosler ballistic tipped.....170 grains never the less lol.

and the point of doing this is adding case capacity like MILLIONS OF OTHER wildcatters do. long COl is as old as reloading. adding freebore for hotter loads started in the 1930 to 1940s.

i just wanted a quickload post as many others have in this forum. i can surely do it myself like i have done for decades. it just saves me powder and primers. thanks anyway forum. later.

 

[assasinator]

QuickLoad Ballistic Prediction Software – Neconos.com

www.neconos.com

It's $155….pay the man. Sometimes I offer help, but a guy playing with a 7 twist 270 win long throat needs to buy their own copy. Every change to your load will require touching up your model!

thanks anyway.

 

[assasinator]

Welcome to LRH! Ain't got quickload….do have a .270 haha.

Interesting approach with the long throat/freebore. Is this about realizing higher velocity or just about being able to seat long bullets way out there?

yes, the concept is the same i use for all of my barrels. i want to ty to see if i can approach 6.8 western ballistics with a long 27 win. if i cant i have everything i need for 270-338 mag. i wanted to try. im not getting a lot of help, but i guess i really dont need any. i expected other 270 win enthusiasts to show interest. so far its kinda like the engine building forums where the feedback is what cannot be done.

longer bullet seating, slower powders, more capacity, and faster twist for heavier bullets. i own elephant guns. this is for fun.

 

[can1010]

24n41 is way to slow for that case. you will never get enough in the case to even come close to working pressure. there was a tread a year or so ago about long throated fast twist 270 try a search for the 270 Thor i believe is what he called it.

 

[Calvin45]

24n41 is way to slow for that case. you will never get enough in the case to even come close to working pressure. there was a tread a year or so ago about long throated fast twist 270 try a search for the 270 Thor i believe is what he called it.

Holy smokes you ain't kidding. I just consulted a handy burn rate chart…that's one above H50BMG!!!!!

I agree therefore. Way too slow. Not useless. But expect nowhere near top velocity realized with heavily compressed loads that burn FILTHY! I know this because I've done similar things, H50bmg in a .300 Winnie, h870 in a .270.

And I'm a big believer that the 270 data out there doesn't seem to want to include slower burning powder THAT DO GREAT! Imr 7828 and rl25 have proven to be some awesome powders in my 270, even with a 22 inch pipe. But that bmg burn rate is just waaaay to slow, even for me!

 

[jjmp]

Welcome to the forum , I'm and 270 fan but have no Quick load machine lol ,I'm sure someone will help you out ,many 270 fans on board it's early times on your post stay tuned, Happy to have to join us . Build it ,mor with follow,cheers

 

[can1010]

Holy smokes you ain't kidding. I just consulted a handy burn rate chart…that's one above H50BMG!!!!!

I agree therefore. Way too slow. Not useless. But expect nowhere near top velocity realized with heavily compressed loads that burn FILTHY! I know this because I've done similar things, H50bmg in a .300 Winnie, h870 in a .270.

And I'm a big believer that the 270 data out there doesn't seem to want to include slower burning powder THAT DO GREAT! Imr 7828 and rl25 have proven to be some awesome powders in my 270, even with a 22 inch pipe. But that bmg burn rate is just waaaay to slow, even for me!

i ran some numbers and even at 106% case fill you barely make 45000 psi and your right will burn extremely dirty.