6.5 STW case and load development.

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04-08-2016, 10:58 PM
257weatherby

2 Attachment(s)

6.5 STW case and load development.

Started comment on my 6.5 STW development in another thread, but the 6.5 Saum guys felt violated, so starting a different thread for a real 6.5 powerhouse:P

Got my hands on a 6.5 STW, Remington 700 action, GRS stock and 3 groove Lilja 28" barrel.
300 Weatherby cases and a canister of 50BMG to get started, did the math to work out a start load to fireform the cases, necked my first 10 and went down to the range. 80gns of 50BMG got me 3050fps average with 130gn Sierra Gameking HP's.
Attachment 53359

Was only bore sighted so it cost me two rounds to get on the paper to get an idea how it might go for grouping accuracy
Attachment 53360
Rather happy with the start, considering I don't normally use bench rests front and rear, normally only ever shoot wrapped through the sling and over a daybag even on the range, so found the shooting off rests really unnatural. Have necked the rest of my cases and loaded then in 5 round sets at +1 grain per set, the last set will run at 88gns of 50BMG, assuming I don't run into pressure problems first, was able to get more in the pre fireformed cases than I thought, will go high 90's in the formed cases. Decent sort of a bang then I think.
04-08-2016, 11:13 PM
R93

Looking good.

Is rifle like an SF GPMG and you have 5 quick change barrels? 😆

80gr of 50BMG giving 3050fps?
Or did I read that wrong?

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04-08-2016, 11:29 PM
257weatherby

Quote:

Originally Posted by R93

Looking good.

Is rifle like an SF GPMG and you have 5 quick change barrels? ��

80gr of 50BMG giving 3050fps?
Or did I read that wrong?

Sent from my SM-G935F using Tapatalk

Now that would be a handy Tahr gun, but prefer someone to carry it for me, getting old, apparently.
Yep 80gns, Seems slow on first look, but the Sierra HP Gameking usually runs anywhere from 50-100 fps slower than it's equivalent weight projectile in most calibres, likely it's the bearing surface and heavy wall, and a lot of energy goes into blowing out the case, it's a bit more than blowing out an Ackley, leaves a really short neck.
05-08-2016, 12:47 AM
300_BLK

Pics of the fired cases?

Seems real slow to me... Mighty 264 WM nets 3300 with considerably less powder...
05-08-2016, 08:30 AM
Gibo

Pics of rifle too :D
05-08-2016, 10:02 AM
Uplandstalker

From what I've read, in you 28" inch barrel, it could be possible to get to 3500fps with the 140gn with around 87-88gn of 50cal powder before the pressure turns to shit.

Maybe, just maybe, you could try some Matrix bullets in this bad boy
05-08-2016, 08:25 PM
257weatherby

Quote:

Originally Posted by 300_BLK

Pics of the fired cases?

Seems real slow to me... Mighty 264 WM nets 3300 with considerably less powder...

Well I suppose I could just fill the case to the top and pull the trigger and see what happens........... am fire forming and inventing load data at the same time.
My .264 Win Mag gets 3300fps with 130gn Swifts easily, but there is a lot of published data for it.
05-08-2016, 08:30 PM
Kiwi Greg

Quote:

Originally Posted by 257weatherby

Well I suppose I could just fill the case to the top and pull the trigger and see what happens........... am fire forming and inventing load data at the same time.
My .264 Win Mag gets 3300fps with 130gn Swifts easily, but there is a lot of published data for it.

Bit of info here for you.

6.5mm STW @ www.reloadersnest.com
05-08-2016, 08:34 PM
257weatherby

Quote:

Originally Posted by Uplandstalker

From what I've read, in you 28" inch barrel, it could be possible to get to 3500fps with the 140gn with around 87-88gn of 50cal powder before the pressure turns to shit.

Maybe, just maybe, you could try some Matrix bullets in this bad boy

Worked up through the load increases and fire formed all the cases today, 86gns of 50BMG gets 3400fps, it stops there though, can't get any more in the preformed case at the given seating depth, should get to 3500fps with the finished case and the same bullet, will likely switch to the Berger for more velocity gain and may go to ADI2225 in search of 3600fps.
05-08-2016, 08:43 PM
257weatherby

Quote:

Originally Posted by Kiwi Greg

Bit of info here for you.

6.5mm STW @ www.reloadersnest.com

Cheers for that, trolled the net a bit looking for data, but elected to trust my own judgement/seat of the pants in the end and start safe but with plenty in the case,
05-08-2016, 08:52 PM
257weatherby

2 Attachment(s)

Quote:

Originally Posted by Gibo

Pics of rifle too :D

I think you've seen this one already, but I wiped off the stains so you could do it, oops, I meant see it again! Bloody gun porn!
Attachment 53398
300 Weatherby cases, standard, necked and formed, the faster loads formed the case better, this is the start load.
Attachment 53400
06-08-2016, 12:04 AM
Friwi

Shit with a short neck like that you are going to burn your throat in not time. I would have gone with a 6.5-300 weatherby,a bit more neck to hold those bullets and to postpone the burial day of your tomato stake.
06-08-2016, 12:13 PM
257weatherby

Quote:

Originally Posted by Friwi

Shit with a short neck like that you are going to burn your throat in not time. I would have gone with a 6.5-300 weatherby,a bit more neck to hold those bullets and to postpone the burial day of your tomato stake.

7mm Mag has a short neck, doesn't burn out throats in short order. Neck length isn't a factor in throat degradation, fast loads, faster hot powders and strings that allow high continuous throat temperature are the main culprits. I think people make too much out of "short throat/barrel life". They are still making barrels. You are hereby invited to build a 6.5 300 Weatherby and race me to barrel life endex.

Maybe Kiwi Greg could comment on that.
06-08-2016, 12:24 PM
7mmsaum

Quote:

Originally Posted by 257weatherby

7mm Mag has a short neck, doesn't burn out throats in short order. Neck length isn't a factor in throat degradation, fast loads, faster hot powders and strings that allow high continuous throat temperature are the main culprits. I think people make too much out of "short throat/barrel life". They are still making barrels. You are hereby invited to build a 6.5 300 Weatherby and race me to barrel life endex.

Maybe Kiwi Greg could comment on that.

All true
06-08-2016, 12:30 PM
R93

Quote:

Originally Posted by 257weatherby

7mm Mag has a short neck, doesn't burn out throats in short order. Neck length isn't a factor in throat degradation, fast loads, faster hot powders and strings that allow high continuous throat temperature are the main culprits. I think people make too much out of "short throat/barrel life". They are still making barrels. You are hereby invited to build a 6.5 300 Weatherby and race me to barrel life endex.

Maybe Kiwi Greg could comment on that.

+1

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06-08-2016, 01:10 PM
ANTSMAN

80 grains powder, wow !
06-08-2016, 02:11 PM
Kiwi Greg

Quote:

Originally Posted by 257weatherby

7mm Mag has a short neck, doesn't burn out throats in short order. Neck length isn't a factor in throat degradation, fast loads, faster hot powders and strings that allow high continuous throat temperature are the main culprits. I think people make too much out of "short throat/barrel life". They are still making barrels. You are hereby invited to build a 6.5 300 Weatherby and race me to barrel life endex.

Maybe Kiwi Greg could comment on that.

Absolutely :)

Just say you have a hunting rifle that has a big case behind a small calibre burning 80-100 grains of powder :cool:

Just say it has a 500 round life which is really pretty short, most would be much longer if looked after.

If you use 100 to get it going that leaves you 400, if you fire 40 rounds per year hunting, (which is more than most would) that should be 20-30 animals a year & 10 years of hunting.

Most guys wouldn't keep a rifle for 10 years ????

A re-barrel is only costs about the same as filling the Hilux 12 times :thumbsup:
06-08-2016, 09:40 PM
MSL

What are you filling your hilux with?
06-08-2016, 09:46 PM
Kiwi Greg

Quote:

Originally Posted by MSL

What are you filling your hilux with?

Smelly old Diesel :)
10-08-2016, 09:12 PM
257weatherby

1 Attachment(s)

Cases all blown out and now the real work begins! 90gns of 50BMG gets just over 3400fps from the formed case, but the plan was always to use the 50 powder to form and ADI2225 to chase outright speed, once I get hard bolt lift, then back it off a fraction and start chasing grouping at 110 via bullet selection and seating depth, the 130 GK was only to form the cases and pressure test.

The first 2225 test got me better than 3500fps with the Sierra
Attachment 53733
Not a bad start.