The AirGun Guild

General Category => Airgun Ammo => Topic started by: Nicesurprice on November 08, 2019, 07:50:49 AM

Title: .258 texan
Post by: Nicesurprice on November 08, 2019, 07:50:49 AM
Question.
What speed would be the best for an .258 texan using 85 grain SP slugs?
The Arsenal 257388  slugs so to say.

Greets
Title: Re: .258 texan
Post by: rsterne on November 08, 2019, 10:34:49 AM
I understand that Doug Noble, an AirForce expert, prefers this bullet to the 257388, although he does use both....

(http://arsenalmolds.com/image/cache/catalog/Noble%20257%2092%20Gr%20LFN%20drawing-500x500.JPG)

http://arsenalmolds.com/products?product_id=93&limit=99999999999

Bob
Title: Re: .258 texan
Post by: Nicesurprice on November 08, 2019, 11:47:32 AM
Ok.
Think we can get those slugs for testing.
Just need some speed advise.
Title: Re: .258 texan
Post by: rsterne on November 08, 2019, 11:52:33 AM
Doug Noble is the go to guy for all AirForce guns.... He makes the best hi-flow valves available for them as well.... He goes by dyotat100 on the GTA Forum.... One thing you may want to do is machine a proper leade in the breech of the barrel on a Texan.... I don't have one, but I understand you cannot load slugs far enough forward in the stock chamber, it needs to be lengthened or tapered more.... Ask Doug about that too....

Bob
Title: Re: .258 texan
Post by: steveoh on November 08, 2019, 07:03:39 PM
I size 257420 and the Noe boat tail equivalent to .257.

I can’t find my notes but I think I was shooting around 1040 - 980 fps. Think is the keyword here. Notes, where are you?
Title: Re: .258 texan
Post by: steveoh on November 08, 2019, 08:36:29 PM
Just got some sample bullets from Loren on the GTA.  These range from 60grains to 64 grains I believe.

Can’t wait to give them a go.

First bullet on the left is my home cast 257420 which drops out around 74 grains.

Title: Re: .258 texan
Post by: steveoh on November 08, 2019, 08:51:21 PM
Eh, went back out to shop to retrieve the Noe 70 grain BT and a Lyman 257312 which drops out at 94 grains.

Title: Re: .258 texan
Post by: Nicesurprice on November 08, 2019, 11:36:45 PM
Eh, went back out to shop to retrieve the Noe 70 grain BT and a Lyman 257312 which drops out at 94 grains.

Know the feeling about notes.
Needed the advice for someone else.
To get him started.

Will test some other designs later on.
Title: Re: .258 texan
Post by: steveoh on November 09, 2019, 06:16:00 AM
Eh, went back out to shop to retrieve the Noe 70 grain BT and a Lyman 257312 which drops out at 94 grains.

Know the feeling about notes.
Needed the advice for someone else.
To get him started.

Will test some other designs later on.

The two marked in red are the de facto .257 bullets. I think anyone with a .257 should start out with the 257420. On my Texan at 1/4 power setting on power wheel I get a curve instead of a cliff.

Lyman 257420
Arsenal 257420
Noe 258-75-FN-BQ6 - latest that is performing very well indeed. (Thanks Bob!)

Title: Re: .258 texan
Post by: Nicesurprice on November 09, 2019, 07:32:36 AM
Eh, went back out to shop to retrieve the Noe 70 grain BT and a Lyman 257312 which drops out at 94 grains.

Know the feeling about notes.
Needed the advice for someone else.
To get him started.

Will test some other designs later on.

The two marked in red are the de facto .257 bullets. I think anyone with a .257 should start out with the 257420. On my Texan at 1/4 power setting on power wheel I get a curve instead of a cliff.

Lyman 257420
Arsenal 257420
Noe 258-75-FN-BQ6 - latest that is performing very well indeed. (Thanks Bob!)

Nice.
Wil copy this info and share with shooter.

This is all about a good forum.
Thanks for all info.
Title: Re: .258 texan
Post by: steveoh on November 14, 2019, 01:14:16 PM
Updated photo with approximate weights of .257 bullets against a .25" Grid.

As requested by John Bowman.