Fireforming .308 cal brass to .375 cal brass

[1stmarine]

I have used wood dowels and hot glue in the past but not sure how much powder would work for the WSM.
I guess you could work it out until it fully shapes but I don't think you need to fireform.
http://www.ebay.com/itm/5-16-x-1-1-...4114988&pid=100005&rk=1&rkt=6&sd=281862572405
You are going to need dies one way or another otherwise how are you going to properly neck size to reload?
One thing you could do is to neck size and seat with cut dies from the 378 wetherby...

https://s-media-cache-ak0.pinimg.com/736x/a0/8b/bf/a08bbf46598637ccc5d235efa3e7331c.jpg

 

[GooseGestapo]

I've formed .300Winmag to .375Ruger.
Simply run the .30 brass into the .375 die. A tapered expander easily expands the neck.
If you don't want to do that, you can use the COW method. (Cream of wheat)
We don't eat much COW in Georgia, BUT grits work the same.
I expanded the necks and fired a Lee 255gr cast bullet over 10gr of Unique. Load was surprisingly accurate! I also expanded the first one by loading an unsized case with 10gr Unique, grits to the neck, and topped with a wad of toilet paper. Worked about like just necking up in the .375 die. Still needed to be fireformed.
I don't think you'll find it too difficult. Hardest thing will be finding.300SAUM brass.

 

[Walkalong]

It's hard to send a Barnes 250gr TTSX or Swift A-Frame 300gr bullet into the berm just for fire forming.

No doubt.

 

[MCMXI]

Here's an update. I spoke with the head guy in Hornady's custom die shop and he was extremely helpful. He has a chamber drawing for the .375 SAM and has made one set so far. He's asked me to send him three fired cases and he'll make up two dies (sizer and seater) that will minimally resize the brass relative to the actual chamber dimensions. I'm on vacation between Christmas and New Years so will try to stuff a .375 cal bullet into three of the cases that I've formed thus far, shoot them and possibly repeat the process to obtain three nicely formed cases for Hornady. The other option is to shoot the seven loaded rounds that my gf has to get an accuracy baseline and send those cases in. Maybe I'll do both if I have time. Now I find myself wanting to have my own wildcat cartridge.

 

[Walkalong]

Hammer them and make sure the shoulders are formed well and fill the chamber well.

 

[1stmarine]

Nice to hear. Those guys are awesome people.
Some firearms companies could learn a thing or two from the reloading/brass companies in terms of customer service.
Keep us posted on the little beast.

 

[MCMXI]

Hammer them and make sure the shoulders are formed well and fill the chamber well.

Will do!

Keep us posted on the little beast.

I'll update the thread once the cases are shipped out and when the dies are delivered. It takes 8 to 10 weeks to get the custom dies so it won't be until sometime in late February or early March.

 

[MCMXI]

UPDATE: Yesterday I used a brass drift punch with a .368" shaft O.D. to open up and uniform the case mouths of the five cases shown below. These are the cases that I fireformed once using cream of wheat and 6.0gr of Trail Boss.

.300 Remington SAUM cases fireformed using 6.0gr of Trailboss and cream of wheat.

I then deburred the case mouths, pressed in a new primer, added 60.0gr of IMR 4895 followed by a 250gr Barnes TTSX bullet and shot them into a berm 125 yards away. I was shooting offhand at milk jugs and was pleasantly surprised with the accuracy. I used a .357 Mag seater die to seat the bullets. You can see the ring around the bullet ogive where the I.D. of the die made contact with the bullet i.e. not the seater plug.

First loading with a Barnes 250gr TTSX and 60.0gr of IMR 4895. COAL is 2.885".

Fired cases after shooing 60.0gr of IMR 4895 with a 250gr bullet.

I then repeated the process using another 250gr Barnes TTSX in each case but upped the charge to 61.0gr of IMR 4895. One of the cases had a neck that was so loose that I had to be careful loading and shooting that round. The five cases that have been fireformed with cream of wheat and shot twice using IMR 4895 powder and Barnes TTSX bullets are shown below. Recoil is similar to my Talkeetna .375 H&H with the Remington .375 SAM having the edge. I shoot the same bullet in my Talkeetna but use 75.1gr of VV N540 and have a MV of 2,800 fps. Obviously I'll chronograph .375 SAM loads when I do the load workup and I'll definitely be wearing a shoulder pad for this little beast that I'd call the .375 SAM for Short Action Mule!! So now I have five cases to send to Hornady and hopefully the three firings has formed cases that are close to the actual chamber dimensions. I'll update this thread when I have the dies. In the meantime I can buy cornmeal and fireform a bunch more brass before the dies get here in February/March. I can also measure the water volume/weight and run some numbers in QuickLOAD to see how different powders might work with the Barnes 250gr TTSX which has a velocity window of 1,850 fps to 2,750 fps.

Cases after fireforming with cream of wheat followed by two firings using a 250gr bullet (cases not deprimed)

Here's the rifle the my gf's ex built in .375 SAM. The bolt/action needs a lot of work to smooth it out since there's a thick layer of Cerakote on everything. I'm giong to have CDI install their bottom metal so that my gf can use AI AICS 5 round magazines and I'll probably paint the stock for her or get it dipped. The scope is way too far forward for me but that's an easy fix. Clearly it needs to be right for the gf so I'll get if figured out.

 

[Varminterror]

I've formed .300Winmag to .375Ruger.

And you did WHAT with the belt? And how many cases rupture when you doughnut the case body from the inside of the belt to the outside? I heard about someone doing this a couple years ago, and loading for both of them myself, I really don't see how it can work without leaving the case body above the web - former belt section, incredibly compromised. How much case capacity are you sacrificing to have the mass of the belt inside the case? Have you cut your cases to measure your case body wall cross-section against factory cases?

As for how to fireform them, thousands and thousands of wildcatters have been blowing out cases with Cream of Wheat for basically as long as there have been metallic cartridges. For necking up, I run powder, cream of wheat, then poly fill plug. I started blowing '06 cases out to 35W with CoW over 20yrs ago, did thousands of them - clean after forming and everything stays happy.

When blowing out shoulders, I either use a false shoulder or a jammed bullet, depending upon how I feel at the time, and whether I have the expanders I need for the false shoulder.

A time for every tool. Necking up, the tool I prefer is CoW.

 

[1stmarine]

Hi @GooseGestapo,
I think you got things mixed up here like @Varminterror already described.
You cannot form 375 Ruger from Winmag. There is a substantial difference in the case dimensions.
300 winmag diameter at the base above the belt is: .511"
375 Ruger diamter at the base is .532"
.532-.511=.021" This type of difference will leave the case unsupported and most likely will rupture the case creating head
separation and a potentially dangerous situation.

 

[Varminterror]

@1stmarine - this is the second time in ~3-4yrs I've heard someone say they've fireformed 375R brass from .300win mag, and I'm still wanting to know how it really works in practice. When I heard it the first time, I asked the gentleman to email me or post pics online of the fireformed brass, as he asserted the fireforming blew the case wall in front of the belt out to belt diameter - which I tend to assume would create a weak point, if it didn't cause immediate rupture, and would also leave a doughnut inside the case, creating some interesting combustion effects with a doughnut within the case near the base. If it really can be done, I'd love to see a case cut in half, but the gentleman a few years ago never did supply pics of the cases fireformed (meaning I've yet to see a pic of a case shaped like 375 Ruger with a 300win mag headstamp). But I do know, I won't be trying it myself until I've seen ample proof it can be done safely.

I've wondered about squishing the bejeezus out of some 300RUM brass (of which I have oodles on oodles) to form 375 & .416Ruger brass, but so far I've done ok to snag up Hornady brass for the Ruger Safari Magnums when they make runs, so I haven't needed to really try making it.

 

[1stmarine]

I know, one can try but it is not going to be me.
8x68 perhaps still ..ufff. 6-8 thousands is a lot of shoe left to fill. Also might not extract in all rifles due to the slight smaller rim.
The RUM imo is too much to overcome and twice the cost.

I guess the best and more cost effective donor for the 375 Ruger and other great cats is the 375 Ruger. lol.

Merry Christmas!

 

[GooseGestapo]

You do get a small amount of "coke bottle" effect from the case body not filling out ahead of the belt, but most dissapears upon first firing. The oal is correct for the .375Ruger, and the brass expands upon fire forming.
It's malleable and stretchable, you know?
I bought a Lee .375 255gr mold just for that purpose. 10gr of Unique was just right and actually was/is a good mild plinking load. POI roughly correlates to the bottom cross mark on my Burris FF2 ballistic reticle.

Don't tell me it can't be done because I have 50 I formed. These are my "hunting/working cases so as not to lose a $2 piece of brass in the woods.

I'm not at home or I'd post a photo of the "used", reformed cases.
For range use I have ~150 Hornady .375Ruger cases.
BTW, I tried some 7mmRemMag, but they are too short.

re: internal case capacity. Due to the beefy internal construction of the Hornady, there is little discernible capacity between the two. (Winchester.300winmag cases) . Besides, I developed all my loads in the reformed cases, so they're safe, and intentionally below max, but are accuracy loads.
At 4,000+fpe, a bit extra speed is pointless.

And no, I ain't going to the trouble to whack 1/2" off my precious.300RUM cases to make fodder for the .375R.

 

[Elkins45]

10 grains of unique and the rest corn meal is what I've always used for fireforming.

 

[1stmarine]

@GooseGestapo,

Please don't take this the wrong way as we all know this is a free country and you can do what you want as soon as you do not hurt anyone else.
This is not about the typical pissing match to see who is right or wrong (I could care less about that) and as you said you know it can be done.

The issue here is that that this choice goes against all safety directives for forming brass so you are free to do it but we also owe to any readers to provide a
clear disclaimer so they know what kind of risks they might be taking.

Because something can be done it doesn't mean it is a good idea for everyone to try it. Eventually the brass will fail and aside from curiosity, experimental
purposes in a controlled environment, it is a risk not worth taking.

come on man, lets keep it real.

Merry Christmas.

 

[GooseGestapo]

BTW, the brass doesn't fill out because its tapered internally, strong enough to not expand under 60,000psi.
There IS a reason the die makers make special dies for loaders of the belted mags to eliminate the expansion of the cases immediately ahead of the belts that can make reloaded cases eventually not chamber easily as conventional dies don't eliminate it.
Not at all like the "Glock Smile".

If I didn't know it was safe, I wouldn't do it. I've been reloading for 46yrs, casting for 42, and still have all my fingers and both eyes!
Can't say so much for my hearing, but that was shot when I was 4yrs old by IV antibiotics, so nothing much to lose there...But I used hearing protection even before it was "cool", and LONG before it became the expected norm.

 

[MCMXI]

Another update:

Hornady received the five fire-formed pieces of brass that I sent off the first week of January. I tumbled them for an hour or two in stainless steel media so that they'd have nice clean cases to work with. The cases have already been measured and compared to the chamber drawing on file at Hornady with no issues. The dies have been designed and the design sent over to the "forge" for manufacturing. Hopefully I'll have them in about 8 weeks. I've started to look at potential powders and charge weights for a 250gr bullet using QuickLOAD but need to settle on a max pressure rating. Obviously it's somewhere between 62,000 psi and 65,000 psi. The parent case, a .300 Rem SAUM is a 65,000 psi cartridge just like the 300 WSM and 325 WSM, but the .375 H&H, .375 Ruger and .376 Steyr are 62,000 psi cartridges. VV N540, IMR 4895, and Reloder 15 all show potential with muzzle velocities in the 2,650 fps range, charge weights near compressed and pressures under 62,000 psi.

I'm not about to give up my .375 H&H for a .375 SAM given the ~200 fps differential with the same bullet, but I sure can see the appeal of a 300 yard bear/brush gun that has a short action, is lighter, should be faster to run and uses less powder. Is anyone aware of a "mainstream" cartridge that's similar to the size and performance of the .375 SAM?

 

[JimKirk]

MCMXI ... don't want to derail this thread ... but I think the 6.5/300 SAM would be an idea mid game caliber .... I went as far as gathering a few case of 300 WSM and 300 SAM to build a custom on a 700 Rem SA action ... I hesitated as the Rem SAM were falling out of favor fast and knew the supply of brass would dry up .... I still have everything for a 6.5 WSM on tap ... but sickness has put it on delay...

The 300 RSAM would hold slightly less at 69.4 grains of water compared to 76 grs. of water for the 300 WSM brass ...compared to the .264 Win Mag I already have holds 82 grs. of water ... the 6.5/300 RSAM would be about ideal for the caliber ... but the lack of brass killed that idea ...

If I had a 6.5 RSAUM already made ... I would consider reaming to the 6.5 WSM ...because there is plenty of WSM brass to use ...

 

[MCMXI]

MCMXI ... don't want to derail this thread ... but I think the 6.5/300 SAM would be an idea mid game caliber

No problem and it's been done. Here are some 6.5mm SAM (Short Alaskan Magnum) rounds. In addition to the .375 SAM that my girlfriend's ex came up with, he also built her a 6.5mm SAM rifle but I don't plan on doing much with that until she expresses an interest in it. He necked down .300 Rem SAUM cases to make brass for the 6.5mm SAM. I'm betting that this cartridge is a real barrel burner. I'm pushing a 140gr bullet out of my 6.5 Creedmoor at 2,900+ fps with around 40.0gr of powder. I would expect 3,200 fps or more from the 6.5mm SAM.

 

[Bart B.]

BTW, the brass doesn't fill out because its tapered internally, strong enough to not expand under 60,000psi.
There IS a reason the die makers make special dies for loaders of the belted mags to eliminate the expansion of the cases immediately ahead of the belts that can make reloaded cases eventually not chamber easily as conventional dies don't eliminate it.

I doubt anyone makes rifle cases thick enough anywhere forward of their inside base not to expand at internal pressures less than 60K psi. Most all modern magnum size commercial ammo can have peak pressures up to 69,000 psi, according to SAAMI specs. And some of us know folks often load "magnums" hotter because they think it's OK.

Nor do I believe any sizing die sizes belted cases that eliminates their expansion in the unsupported area from their belt to where the chamber body wall starts at the edge of the head spacing ridge. There are die's that squeeze that area down a ways that's used after a standard full length sizing die reduces case body diameter several thousandths short of the belt. But it gets expanded back out when fired. I use one and that's what happens.

Never heard of this before. Names of companies making cases and dies as you claim would be appreciated. Then I can verify what you claim and learn something.

 

[MCMXI]

If I had a 6.5 RSAUM already made ... I would consider reaming to the 6.5 WSM ...because there is plenty of WSM brass to use ...

It makes me wonder why Winchester didn't bracket the 270 WSM, 7mm WSM, 300 WSM and 325 WSM offerings with 6.5mm WSM, 350 WSM and 375 WSM. The 325 WSM has all but gone away so maybe 350 and 375 versions wouldn't have fared any better.

 

[JimKirk]

I'm betting that this cartridge is a real barrel burner.

If your 6.5 SAM is based off the 300 SAUM as you said then it would NOT be any more of a barrel burner than a .270 WSM and less so than the .264 Win Mag that I have now ... maybe you missed the amount of water each case holds(relates to the amount of powder that it can hold) ...any time a case is smaller in powder capacity ... it is less a barrel burner than one with more capacity ... with the correct powder there would be no problems for a hunting rifle in 6.5 SAM ...It would hold about four grains more powder than a .30/06 or a .270 Winchester ....

 

[MCMXI]

If your 6.5 SAM is based off the 300 SAUM as you said then it would NOT be any more of a barrel burner than a .270 WSM and less so than the .264 Win Mag that I have now ...

I measured the water weight of the .375 SAM fired case and the average was 77.84gr so the 6.5mm version might be close to 75gr. My point about it being a barrel burner is when compared to the 6.5 Creedmoor which supposedly has a barrel life of about 2,000 rounds and that's at fairly moderate velocities of around 2,800 fps. I realize that more case volume equates to more powder and I get your point that a 6.5mm SAM based off a .300 SAUM case would hold a bit more powder than the .30-06 Sprg and .270 Win. With the smaller bore and higher velocities of the 6.5mm I would expect shorter barrel life. That .264 Mag at over 80gr H20 must surely be a barrel burner compared to just about anything. I have to wonder why my girlfriend's ex didn't base the SAM off the WSM cases rather than the SAUM given the similarity of the two and very similar case capacity. As you mentioned, the WSM brass is much easier to find.

 

[Walkalong]

Nor do I believe any sizing die sizes belted cases that eliminates their expansion in the unsupported area from their belt to where the chamber body wall starts at the edge of the head spacing ridge. There are die's that squeeze that area down a ways that's used after a standard full length sizing die reduces case body diameter several thousandths short of the belt. But it gets expanded back out when fired. I use one and that's what happens.

He may be talking about these collet sizers for belted magnums. I reload .458 Win Mag and so far have not had any issues, or I would have tried one.

http://www.larrywillis.com/

 

[Bart B.]

Yes, I think he was.

Back in the '60's, some cut the top and bottom off belted case full length sizing die making a body die. It was used after normal full length sizing belted cases to size down the last several thousandths right in front of the belt to the belt. Otherwise that ridge there interfered with the case when fired; accuracy suffered. That's what I use.

Some military teams used new belted cases giving them away to civilians as once fired free cases. Their taxes paid for them in the first place. I gave away 99% of my once fired 7.62 match brass.