Fire form 7-30 Waters

B

burrhead

New member
Bear with me as I’m a 45+ year hand loader but I’ve never fire formed before. I recently bought a Contender in 7-30 Waters and today finished fire forming 100 new Winchester cases. Or so I thought. I was using 130gr Speers and H335 at about 1.5gr under max. The measurement from datum to head varies over a range of 6-7 thousandths. I suppose I’ll have to take another whack at it to get the brass to really fill out.

My plan is to partially neck size without touching the shoulder and try again. I have 7mm bullets ranging from 120gr to 150gr and the only appropriate powders I have are H4895, Varget and H335 and maybe IMR4350.

So, should I use light or heavy bullets to generate the most pressure? A powder suggestion using one of the four I have would also be appreciated.

TIA
 
Lead bullets seated into the lands gave me the best results fire forming for my 357 Herrett. For contenders, you want the cases to be exactly chamber length, so you have to slam it to get it to shut.
 
Waters

I fire-form using COW and a minimal powder charge followed by a resizing and cartridge AOL trim if necessary.

The shoulder will not be perfectly formed at this stage.

Load with desired components and off to the range.

Clean, resize and trim if necessary and now get down to serious reloading.

OAL is around 2.788 to 2.870.

I load bullet weights 139-140gr for both hunting and target shooting.

My best results have been with H332 and H335 along with Nosler 140gr BTS and Hornady 139gr SST with velocity in the range of 2350ft/sec and a light crimp.

Consistently, 5-shot groups at 100yds are covered by a dime all day.

As a hunting cartridge, I recently took a 330-pound running boar with a shoulder hit that put him down instantly.
 
Thanks for the help. Looks like at this point I'm going to neck size and start working up some loads. I got this pistol for hunting small Texas Hill Country whitetails and axis does. Figured 120gr Nosler BTs or Sierra Pro Hunters at 2400 fps or so. I've also got some 140 Partitions I'm going to try.

Thanks again.
 
For my FF loads I sized just enough to give a false shoulder. I used RL15 for powder and 139gr Hornady and some Rem 150gr bullets. I never seated into the lands to avoid pressure issues. From the medium loads up the cases usually filled out fine. Accuracy was easily good enough to hunt with.

Once I had formed cases, I switched to the 140gr Nosler Ballistic Tip and my accuracy was outstanding. From a solid rest, I've shot plenty of 1", and some less than that, groups at 100yds and even out to 200yds they weren't much bigger.

Good luck with yours, I hope you get as good of performance as I have outta mine.
 
You should have got it in one firing with that amount of pressure. I still buy my 7-30 brass. Federal make a seasonal run of it before deer season.
 
Burrhead,

What are the exact load details (charge, primer, bullet length and COL and distance off the lands) and what is your measured case water overflow capacity? That variation in shoulder position could be due to failing to reach enough pressure to stretch the head back at the pressure ring in all instances. Overpressure stretching the breech back from the chamber could also do it, but that seems unlikely unless your case capacity is really small or you got too close to the lands (I would be at least 0.030" off the lands for a starting point.

Assuming you had no other possible pressure signs, your plan for re-fireforming is fine. If the pressure is marginal for brass stretching, it may take a little bit heavier charge to get there. The heavier bullet will allow the case to dwell a bit longer at the pressure peak and should burn the powder more completely.
 
Unclenick, I used 130gr Speer Hot Cores, Winchester primers, and 33.5gr H335 in virgin Win. 30-30 cases. COAL was 2.750. I don't know how far off the lands but imagine it's not particularly close. Since doing this I read a good article by Zediker on case forming and he says to use a max load. I was 1.1gr under max according to the Sierra manual using their bullets.

As it is, I intend to neck size without touching the shoulder and load up some 120s. Hopefully that will push the shoulders the rest of the way forward. Never formed cases before, and it's a learning experience, but I'm still in the weeds a little feeling my way forward.
 
Uncle, just re-read your post. I think you're right about heavier bullets. I have a stash of unknown brand 150gr spire points. I think I'll run some through a few cases and see what happens. Thanks for the advice.
 
I have a stash of unknown brand 150gr spire points.
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That's basically what I did. Found a sale on Midway years ago on the 150 Win bullets and they worked fine for forming. I never tried them for hunting though as I didn't feel that they would expand at the lower level velocity. The 140gr BT however loaded up to the upper end did work well out to 100yds, but after that started to fall off pretty quick.
 
Burrhead,

If you haven't done it before, to get case water overflow capacity, take a fired case with the spent primer still in it and weigh it. Get a caliper measurement of its length at the same time. Fill it with water just level with the case mouth (no meniscus) and weigh it again. The difference in the two weights is the case water overflow capacity. For cartridges that work at over 30,000 psi, doing it as-fired rather than as-resized gives you the number that is going determine peak pressure volume.
 
Mike/TX gave a good suggestion. Form the 30-30 brass so there is a step fro 30 cal to 7mm tha holds yr cartridge against the breech.

Do use the bent paperclip test for stretch rings . In my experience,they can be a problem with a 7-30 Contender.

I fire-form using COW and a minimal powder charge followed by a resizing and cartridge AOL trim if necessary.
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Ammocrafter: Its likely you know what you are dong,but for those who may read your post, : I have formed a lot of cases using Cream of Wheat.(COW)
For some applications,it works retty good.

The part to be very clear about is you DO NOT use a bullet.

If someone needs to know more,ask
 
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