356 TSW Anmo

[PD5523]

I was searching for reloading data this evening and discovered Underwood Ammo appears to be loading 356 TSW and has it in stock in two different bullet weights. Just ordered a few boxes - here's hoping since Cor Bon also had it listed some time ago and never came through!!


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[BLUEDOT37]

Corbon's website shows they have some 356TSW in-stock.

356 TSW 115gr JHP[Handgun]

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[vigil617]

Some additional information in case you're interested:

Factory 356TSW ammo

 

[PD5523]

Thanks all. I actually placed orders for Cor Bon on two different occasions and, despite leaving several messages (and receiving a confirmation e-mail) never received any ammo. I wasn't charged so I assumed perhaps they were waiting to make a production run until they received sufficient orders.


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[s537]

356 TSW ammo and Glock conversion kit update

An update on the 356 TSW Glock 17 & Glock 19 Briley barrel conversion kits, Corbon 115 grain JHP and Underwood 115 grain JHP: during testing in June 2020 Corbon averaged about 1612 fps from the Glock 17 conversion kit and about 1569 fps from the Glock 19 conversion kit. Underwood averaged about 1570 fps from the Glock 17 conversion kit and about 1540 fps from the Glock 19 conversion kit. Accuracy and feeding were good, no anomalies were observed. Starline makes strong brass, Corbon and Underwood load great ammo, ISMI springs and LWD guide rods are first rate, and the Briley barrels are top notch. Glocks are....Glocks, and with 356 TSW they are that much better.

Ammo is available through Ammoseek, Corbon, Underwood, Selway, Midway.

356 TSW Glock conversion kits are available on Gunbroker.

Look for others to catch up at some point with even more options (Apex/Hornady)?

 

[Rock185]

s537, Those actual .356TSW chronographed velocities are very impressive, to say the least.. Years ago I experimented with Col. Cooper's "Super 9" cartridge, a .223 rifle cartridge case trimmed to .900". In a 5" barrel I got to 1625 FPS with a 115 grain bullet before calling it good. So given the .356TSW's smaller case capacity, those numbers are, WOW!

 

[s537]

s537, Those actual .356TSW chronographed velocities are very impressive, to say the least.. Years ago I experimented with Col. Cooper's "Super 9" cartridge, a .223 rifle cartridge case trimmed to .900". In a 5" barrel I got to 1625 FPS with a 115 grain bullet before calling it good. So given the .356TSW's smaller case capacity, those numbers are, WOW!

You could probably get even a little more with the modified 223 as it can handle a bit more pressure?

 

[Sevens]

A buddy of mine got a hold of a 3566 Limited just this August and promptly ran two different Underwood .356TS&W loads through it.

115gr clocked 1,606fps with a SD of 3fps
124gr clocked 1,407fps with a SD of 8fps

I was impressed!

 

[Rock185]

S537, Yes, I could have gone further with the Super Cooper, others did. I was using a standard unramped type barrel, that did not have the case head support of today's integrally ramped barrels. Even then, the .223 case heads did not seem to expand at all.

 

[505Gibbs]

Corbon's website shows they have some 356TSW in-stock.

356 TSW 115gr JHP[Handgun]

.

I question the viability of the new ownership which is now relocated to Ohio.
Maybe its just growing pains or they it off more than they can chew??

 

[oldman10mm]

The address shown in the link is the same as on my boxes of C.O.P.(copper only projectiles) ammo. General Arms & Ammunition. It seems the C.O.P. line no longer is made and they've taken over production of the CorBon line.

 

[Erocksmash]

I have a question and pardon my ignorance...

I am rather fascinated with the 356TSW round/cartridge. It is a shame it is not more prevalent today.

The question I present is, why/how can the "TSW" generate or have so much pressure 50k and function properly(without catastrophic failure)in the limited guns/Glock barrels and Jframe guns? Compared to say 9mm/.357/.40s&w or "standard" pressure rounds. Again pardon my ignorance as I do not know.

I am rather new to handloading and I understand not to exceed pressures in certain calibers and firearms...

Why is this so different? Is there a case anomaly or a different treatment process?

 

[the big guy]

Just ordered a case of Underwood 356TSW 124gr. 507.00 with shipping, 500 rounds. Direct from Underwood.

 

[Rock185]

Erocksmash, I don't know, but Colt used to sell the 9X23 Win. chambered in what appeared to be a regular Government model. I have used the same 55,000 PSI 9X23, though not extensively, in standard STI and Kimber pistols with no apparent issues. And as you mentioned, even the little J-frame "Pocket Rocket" revolvers have been factory chambered in .356TSW.

FWIW, Years ago I experimented with Col. Cooper's Super 9/Super Cooper pistol cartridge, made by trimming .223 cases to .38 Super length. I have little doubt pressures would be similar to those other high pressure loads. Using a Colt Government model, I reached 1625 FPS with a 115 grain bullet before deciding that was enough. Others went further, with no catastrophic failures reported that I'm aware of.