Any one loading .357 Maximum for straight wall rifle cartridge deer hunting? I'm having JES rebore a TCR barrel to .357 Max and have not found any load data yet.

I shoot the Max in a contender barrel, data from the Sierra manual...

I shoot a Max in a Martini (plenty strong for whatever the Max can throw at it). Whaddaya wanna know? Load data is everywhere. The Lyman Cast Bullet manual is the tits, lots-o-loads for the Maxi in it.

200 grain bullets shine, jacketed or cast doesn't matter - same velocities, same performance - so save yourself some money and shoot cast if you can. 1680 powder is your huckleberry. Li'l Gun is good too but it seems like 1680 was custom tailored for the Maxi..

I loaded XTP's for the 357 that I Maxi'ed for
a young relative. I took it out to prove it up
before handing it off for hunting. It's a great
deer cartridge. I'd been reading about the
success others had with it before I decided to
go Maxi with it. I didn't have any to use, but
others have used some of the 35 rem projectiles
with success. Dinny has done more with it
than I have and can tell you more about it.
It'll serve you well

I do. For both my daughters. TC encores. 26” barrels. One likes 26 gr lil gun 180 hornady SSP. The other likes same charge but a Speers 180 HCFP. They hammer deer.

I have one in a 14" Van Horn Contender barrel, typically load 180's over H110/296.

The Hodgdon, Lyman, and Hornady manuals on my shelf all have 357 Max load data in the handgun and Contender sections. I'm getting 2075 fps with 180 Fury spitzers using 20.0 grains of Lil Gun in a 16.25" Contender carbine. I really like these Fury bullets for accuracy, too. Match Grade Machine has 357 Max load data on their website, using their barrels, but it seemed very hot so I've avoided it. I'm getting all the velocity I need to meet the 100 yard energy requirement in CO using the Hornady data. I may get a chance to try this load on a mulie doe next season.

And don't ignore the utter versatility offered by the .357 Maximum. Nothing says that one must detonate a full power balls-to-the-wall load with each pull of the trigger. (Such behavior has always made me wonder about some people.) You can load it down to .38 wadcutter levels and every level between there and full max - without bruising your wallet (but maybe bruising your ego), and with the same .35 diameter holes in the target paper and the same fun quotient (maybe more).

The maxi is great easy and fun cartridge to load for. For 180gr bullets 24gr of h-110 or w-296 is a max load so I would start out at 20gr and work up from there for the 180s. What projectile are going to be primarily loading with?

I had one in a Handi. The Barnes 140XPB over IMR4227 shot extremely well out of it. Velocity wasn't blazing vs some other powders, but still considerably better than you'd see out of a 357 Mag carbine.

It's one of the very few rifles I regret getting rid of.

What bullet are you thinking about? For a 158 gr bullet use H110, for 180 gr or 200 gr bullets use AA1680. Post up which bullet weight and I'll dig out my books.

I shot .357 maxi in a Super 14 contender for a while in the late 80s and again in an 18" custom shop contender carbine barrel around 2000 or 2005. Cool cartridge.

If you're not finding data you must not be trying very hard. There is a lot of data out there. Speer, Hornady .. etc. Try the Speer 180 grain flat point, Hornady 180 grain SSP, Nosler 180 grain Partition, and Hornady 180 grain XTP .. some of these are discontinued. As suggested, H110 or 296 for bullets 160 grains and under, AA1680 for 180s and up.

As a f**k around load try an 88 or 90 grain 9mm JHP with a case full of H110, sorta roll crimped over the bullet shoulder. Not extremely accurate but man will they tear up a ground squirrel if you get close enough.

I have been loading for it since 2008. Here are a few things I have learned along the way.

- don't let JES cut the chamber nor modify the extractor/ejector

- do let Mike Bellm cut the chamber and modify the extractor/ejector

- use small rifle primers

- use A1680 with all bullets 158 - 275 grain. 28-29gr with just about any suitable 180gr bullet works well.

- don't shoot any Barnes solid copper bullets. The 140gr XPB is too light and the various 180gr .35 cal bullets are built too tough

- Fury Bullets are tailor built for Maxi speeds

- experiment with crimping. Some of my rifles shot better with a firm roll crimp. Some did not

- Viht Tin Star (when found) is the single best low velocity powder for youth hunting loads

- test pistol bullets in wet newspaper or something similar before hunting deer or black bears. Some pistol bullets like the 158gr XTP-HP expand too quickly

My son and I have killed no less than 15 deer and 2 black bears with our 357 Maxi single shot rifles.

Let me guess, JES uses a revolver reamer which incorporates a loooong throat way too long for a normal ball seat in a rifle.

Yes, Gary, you are correct.

I appreciate all the responses. I did finally find .357 max load data in Speer Number 12. And Hodgon load data on line, just had to look at pistol data section.......

Gnoahh and Dinny, this is a rebore of a corroded .22 Hornet barrel, not a rechamber of a .357 magnum barrel. What issues can I expect from a JES extractor job? Seems like replacing the extractor after the reboring and before rechambering and using the chamber reamer (I'm assuming the chamber reamer also relieves the rim recess) to modify the extractor would work. Also not sure I understand the revolver reamer comment. Are you saying that JES uses a .357 max reamer designed to finish revolver cylinder chambers on rifle barrels? Or a revolver forcing cone reamer?

I do have somewhere another TCR extractor that was intended for an aftermarket TCR 20 gauge rifled barrel setup using a ?90% monobloc that was digitally copied from a TCR monobloc and CNC milled. But that's another story.

If the freebore is a bit long, what's the harm? This is new territory for me and I'm a rank novice compared to you guys. IIRC Weatherby rifles at one time had long freebore to reduce pressure, although those were much higher pressures than I saw in the Speer 13 manual for the .357 max. Also, would one be able to compensate by seating 158 0r 180 gr bullets out a bit?

4570fan, I found load data for 158 and 180 gr bullets but would appreciate any info on heavier bullets.
Thanks, Bill

4570fan, I found load data for 158 and 180 gr bullets but would appreciate any info on heavier bullets.
Thanks, Bill

His extractor jobs have been sloppy. It should be lathe bored separately, not cut by the chamber reamer. There's not adequate relief. The throat of any chamber is without doubt the most important factor in obtaining accuracy. It's not just freebore but a combination of freebore and throat geometry that supports the bullets transition to the rifling. You want a cylindrical throat and his reamer doesn't cut one.

No amount of compensation can overcome improper chambering besides (perhaps) rechambering to a larger cartridge like 358 Win.

https://bellmtcs.com/357maxchamberthroats

Well, this may be a case of getting too soon old and too late smart. I expect JES has completed the job by now. The TCR barrel and monobloc arrangement are not suited to setting the barrel back. The barrel is press fit into the monobloc and then pinned. I'm not aware of any currently operating gunsmiths who are willing to pull or install a barrel in the TCR monobloc.

Bellm's post was dated September 2023. Wonder if Dinny's guns were factory chambered or if they are rechambered .357 magnums and if so, when and who did the work. Very interesting that SAAMI specifications are a flawed design for .357 mag and max. I can understand the need for a forcing cone in a revolver where cartridge alignment with the barrel isn't perfect, but what would the purpose be in a gun where the chamber and barrel are integral? Are SAAMI revolver and pistol/rifle chamber specifications the same? I'll have to try my hand at chamber casting when the TCR barrel is returned.

Also interesting that, according to Bellm, other straight wall pistol cartridges have the same SAAMI chamber design issues. I have a TC Encore .460 S&W barrel that shoots longer 300 gr bullets better than shorter stuff. Might have to do a chamber cast on that too.

Call JES. If he hasn't cut the chamber then ask him to cut it to 357 Magnum. Some rifle chamber reamers (I prefer Clymer's 357 Max reamer) are available with cylindrical throats. All mine have been 357 Mag chambers that were either rechambered with a Clymer 357 Max rifle reamer or were properly throated with a cylindrical throating reamer.

Bellm has experience with monoblocs.

Am I mis-reading or are you confusing "forcing cone" with "throat"?

My understanding is that revolver barrels have a forcing cone that receives the bullet as it exits the cylinder. The portion of a rifle chamber between the mouth of the case and the rifling is the throat. The leade is the portion from the end of the throat where rifling tapers from throat or groove diameter to bore diameter.

Bellm's SAAMI chamber drawings in the post Dinny referred to show a tapered throat with a breech end ID the same as the case neck OD and tapering to ?groove diameter at the front end of the throat. I assumed this was the "long throat" you referred to above. If I understood his description correctly Bellm asserts that the rear of the throat with an ID greater than bullet OD allows the bullet to tilt before encountering the lands.

So in effect the SAAMI .357 max chamber has a throat with a forcing cone profile which does not fully support the bullet between exiting the case mouth and entering the rifled portion of the barrel. A long throat is not necessarily a tapered throat.

So, I was wondering why the SAAMI chamber throat was tapered. And ,if Bellm is correct about other SAAMI straight wall revolver cartridge chambers, why Thompson Center would use a tapered throat in their rifle barrels.

This has been an interesting and educational exercise....and just the sort of thing I appreciate participating in 'fire discussions.

I called JES and left a message asking him to cut the chamber to .357 Magnum if his .357 Maximun chamber reamer did not have a cylindrical throat.

Well, the rebored barrel arrived today so my call to JES is moot.

I'll chamber some spent .357 cases to check out the ejector. It might need kissing with some fine grit wet dry sandpaper but I 'll wait to pass judgement after checking with fired and unfired cases. IIRC my Springfield, MA factory TC .460 S&W barrel ejector needed the sharp edges taken off.


I have 158 gr and 180 gr bullets, primers and H110, IMR4227, and CFE BLK powder. When I scare up some .357 max cases I'll report how it shoots. The LGS had a bag of .357 Max Starline brass a year ago very reasonable and I'm kicking myself for not grabbing it.

I have enough Maxi brass to share.

Dinny, PM sent