[judaspriest]

I just got a new .40 (Sig 226) and will reload for it. However, it looks like it is very easy to convert to a 357 Sig - all I need is a new barrel. The advantage, to me, would be the cheaper 9mm bullets that I could use for practice. The problem is the brass (well and the cost of the extra barrel).

I looked at the specs and it looks like necking down a .40 could almost work, except for the rim thickness which is slightly larger for a 357 than for a 40. However, even there there is hope - if either a 40 or a 357 Sig can be handled by the same extractor, it would seem that a necked-down 40 would there work as well.

Has anyone actual tried this - does it work? Are there any issues? Are there conversion dies that work well and don't cost an arm and a leg?

Thanks,

JP

[ReloaderFred]

The issues are that the two cartridges work at different pressure levels, with the 357 Sig operating at higher pressure than the .40. The 357 Sig case has a thicker web, and is thicker at the junction of the wall and web of the case. The 357 Sig is also longer.

There are people who neck down .40 brass and use it, but it's not recommended for the reasons I've listed above. The 357 Sig case was engineered from the ground up for that caliber.

If you choose to do this, then you would have to keep your pressures low, and there will be a problem with the even shorter neck of the necked down .40 case. The 357 Sig neck is short enough as it is to cause some people problems with keeping the bullets from being set back during cycling of the action, and using even shorter necks would exacerbate that problem.

These days there is plenty of proper 357 Sig brass available, so my suggestion would be to just buy the proper brass, if you decide to do the conversion. I have two pistols in 357 Sig, and I've loaded about 15,000 rounds of it. This is one of those rounds that you don't want to cut corners on.

Hope this helps.

Fred

[judaspriest]

Fred,

Not the answer I was hoping for, but certainly does help - thanks!

JP

[Harley Quinn]

Hi,
I figure the 400 Corbon is a similar issue. Or can you make the Corbon out of 45 brass, and not have to buy the 400 brass? Just bought some more 45 brass to do the changing to it.

I have a G 21 in 45 cal, have the 10 mm barrel and just got a 400 Corbon barrel for it, 6" it is a barrel that will be used soon. Some have mentioned the stronger spring (have) .

I also have a 400 Corbon barrel for the 1911 Colt Gov model.

I have the 357 Sig barrel for my mdl 22 Glock shoot it a lot. The cartridge I have been using a lot of is 140 grain made by Lellier and Bellot. I have never had a problem with it. I have shot a lot of it and am down to my last 2 boxes.
Any recommendations?

HQ

[ReloaderFred]

I regularly make .400 Cor-Bon brass from .45 acp brass. For this, I prefer new Winchester brass, since it's thicker and seems to form better. If I use new brass, I don't get any wrinkled necks when forming, but If I use once fired, I'll get a couple of wrinkled necks out of a hundred cases. With thinner brass, I get more ruined cases, too.

Hope this helps.

Fred

[Harley Quinn]

New they aren't. Been fired.
I was going to anneal (heat and drop in water) them and see how that goes. I'll shoot some to get a good group and chrono. Then I was going to make up a few hundred and shoot them?

[ReloaderFred]

I've found that it's not necessary to anneal .45 brass before necking it down to .400 Cor-Bon. Just make sure the case mouths are straight, with no dings, before you size them down. Any dings at all will usually result in a wrinkled neck and ruined case. Be sure to lube them well, also.

You may lose a few to wrinkles, but we're only talking about .45 acp brass, which is plentiful. The new Starline .400 Cor-Bon brass uses small pistol primers, but I'm not real happy with them when using 135 grain bullets. They tend to flow at regular loads, whereas the large pistol primers won't with the same load.

I don't do anything special when necking the .45 brass down, other than making sure I've sprayed a liberal amount of case lube on them before running through the .400 Cor-Bon sizing die. It's a really simple process.

You may have to adjust your sizing die for your chamber, as they vary a little. You're adding a shoulder to the case, and the shoulder is what your new cartridge will headspace on, just like a bottleneck rifle cartridge.

Hope this helps.

Fred

[Jim Watson]

The first .357 SIG ammunition I ever saw for sale here was some fly by night outfit's stuff in necked down .40 brass. It shot ok for the people who just had to have the first one on their block.

I suggest you do the arithmetic. How many .40 bullets will the price of a new barrel and loading dies pay for? Not the entire cost of .40 bullets, just the extra over 9mm bullets.

[Harley Quinn]

ReloaderFred
Thanks for the information and your experience.
I'll do like you are mentioning.

The primers is an interesting story. It points out how important it is not to mix up various componets.

I like the idea of the necked case for the 400 Corbon. Why I like the 357 Sig also.
Bullet design is an important reason I have chosen the 357 Sig, malfunction is not something I want, nor a bad bullet design either.

I was going to order some of the starline brass (midway) but will wait on it now. I have their 30th catalog and have been in touch with them, regarding other items.


HQ

[Harley Quinn]

Jim Watson
Boy to buy just anyones reloads is scary to me. I see guys doing it at a gunshow:eek: NOT.
As much as I am going to shoot this round it is and will be pretty expensive for all the goofing around I am doing. Could buy a box of 20 Corbon or two and be done with it :uhoh:


:D

[ReloaderFred]

I have a thing about some of the oddball calibers. I've got 9x21, 9x23, 357 Sig, .400 Cor-Bon and .38 Super as some of my oddball "favorites". I've worked on a conversion off and on for the last couple of years for the 9x25 Dillon, which is the 10mm necked down to 9mm. It's a screamer when loaded to capacity. I'll get back on it one of these days.

As for the 357 Sig, I like it because it's such a flat shooting round. At 100 yards, it's no problem hitting a silhouette target in the scoring rings with a 4" barrel Springfield XD. At 50 yards, it shoots to point of aim.

The .400 Cor-Bon isn't as flat shooting, but it's still fun to mess with.

Hope this helps.

Fred

PS: Semper Fi 1965-1971

[Harley Quinn]

As for the 357 Sig, I like it because it's such a flat shooting round. At 100 yards, it's no problem hitting a silhouette target in the scoring rings with a 4" barrel Springfield XD. At 50 yards, it shoots to point of aim.

I have found that to be the case also. I have a 6.5 " barrel and it is really accurate (barrel) I have shot some of the best groups ever with that one.

For carry I use a the 4.5" in my Mdl 22. I have been known to carry the 6.5" at times also. I feel it is one of the very best out there for my money.

The 400 is a fluke and will probably be a home gun. Mdl 21 is bulky and the long barrel is compensated. It is one I am looking to shoot today with Corbon ammo. :D I'll bet it will show some flame :D One of those that would ruin your night vision ;)

I have an old "Astra" that shoots 9mm Largo. It is very accurate. Not very good sights though.