Pretty easy to rechamber by hand - a lot here have done it with good results. I'm guessing you may qualify to use the reamer that the forum has - but that is up to Tim. There are instructions in the stickies if I remember correctly.

 

I have an uncle that did his and had a reamer but he hasn't had it in a long time. I believe I have been around here long enough to use the rental reamer, was just wondering on the different views of those who might experience with either way or both.

 

I reamed one using the Graybeard reamer several years ago. I still have that barrel and would not part with it. It shoots plenty good for me and I would not hesitate to do it all over again.

 

If your a little handy. You can probably do the job. It isn't difficult.
Couple big things about the job.

1) NEVER EVER rotate a reamer backwards.

2) OIL reamer, 1-3 turns remove and clean reamer and the hole. Repeat.

3) NEVER ROTATE REAMER BACKWARDS!

I like to dykem ( magic marker works) the existing rim cut.
Do your reaming under very good brite lights. Stop reaming, when the MAXI reamer cut touches the existing 357 MAG Rim cut.

DO NOT CUT DEEPER.

This is the head space, cutting deeper, would ruin your barrel.

Go slow... You will be done in under 30 Minutes.

CW

 

I am fairly confident in my ability to ream the chamber and I like to build things. Just didn't know how much difference if any seen between standard reamers and how Bellm cuts the chambers. I bought a Contender 357 mag barrel last year intending to chamber it to Maxi, then I shot it and couldn't modify the chamber, shot to good. I just happened to find this Handi over the weekend, so I figured it was a sign since I have been trying to find a 357 mag/Maxi rifle for about 8 years.

 

I had my rifles done, but if you are confident in your skills and take care it should not be an issue. I would definitely not assume and check headspace after, even if nothing “should have” changed. “Should have” is the enemy of safety (and eyes, and fingers).

 

I have hand reamed a number of barrels in different calibers including the max. If you want the best possible chamber and throat, send it to Bellm. I have two .357 maxi's, one I reamed using the forum reamer and one that was reamed and throated by Bellm. They both shoot accurately. The Bellm chambered rifle seems to be a little more accurate. It is also a heavier profile and easier to hold steady.

If you ever want to sell your barrel, having it reamed by Bellm will make it more valuable to a prospective buyer vs a barrel reamed by hand by a novice gunsmith.

If you do send it to Bellm, consider having it reamed to 360 Buckhammer. It has much more power than the maxi and uses factory ammo. Provided you have an SB2 Rifle Receiver. If you have an SB1 Cas Iron Receiver, stick to the .357 Max.

My $0.02

 

Buy a 375 win and quit Dickin around...

 

While 360 Buckhammer is more powerful and is popular at this time, the only caliber that can be fired in a 360 is the 360 ammo. Staying with the 357 Max does still offer the capability of shooting 38 special ans 357 mag in the rifle as well as 357 max.

 

I've bought a handful of reamed 357 barrels from members here and every one was a shooter. Follow CW's instructions and use the money you saved to buy Maxi components.

 

I don't know the SB1 action on this Handi would tolerate the 360 Buckhammer for an extended time. I have bigger 35's in the Contender and Encore if I need more power than the Maxi.

 

At 50kpsi MAP the 360 BH would be a bit excessive for an SB1, IMO.

Tim

 

Hey Tim,,,,,,or anybody else! I used to know but can't seem to remember.
On a 357-barrel rechambered to 357 max(with the GB reamer, thanks again) what would be a safe pressure (in PSI) with an SB1 receiver ?
I've been thinking 40,000 is about the top even though I have not gone there yet.

 

That is what I was thinking about the pressure levels. If I had a short carbine barrel for the Encore I would probably have Bellm chamber it for the 360. The Maxi will do well for me as we still have straight wall restrictions in areas of Indiana for deer.

 

I use shortened 35 Remington or .358 WSSM for public land hunting. We do not have straight-wall restrictions in Indiana. We have caliber and case-length restrictions.

 

Dave hit the nail on the head. Bellm will cut a superior throat, but sometimes we need to be a perfect handloader and a sharpshooter to see the difference.

I've been studying under Bellm for about the last year or so. I cut my chambers then I throat them separately.

If the GBO reamer would only be used to rechamber existing 357 Magnum chambers (IF), I would make the recommendation to dull the reamer flutes that cut the rim counterbore. They could be used as a depth stop then. (Something else that Bellm taught me)

I'm in Indiana too. 30 minutes south of Indy.

Thanks, Dinny

 

If the GBO reamer would only be used to rechamber existing 357 Magnum chambers (IF), I would make the recommendation to dull the reamer flutes that cut the rim counterbore. They could be used as a depth stop then.

That's been discussed before, the Maxi reamers have been rented by several members for cutting new barrels, so I've never done it.

Tim

 

Hi dinny, I messaged you a while back about the Fury bullets in my Whelen and 35 Rem. Thank you for the input. I have the gb reamer coming to me at this time. Have to take the wife shooting this weekend and work Saturday, but hope to have the chamber done before next week. The member's input is always appreciated.

 

I get a pretty particular with my loading, but unfortunately I sometimes my shooting isn't what it used to be. Eye injuries are starting to catch up with me. I figured it should be better than minute of Indiana deer hunting range at any rate. I grew up bow hunting and still like them close.

 

Yes let Mike Bellm recut the chamber and he will possibly recrown the bbl you will be pleased with the results!!

 

I used the forum reamer and had great results following CW's instructions. Literally took less than 30 min doing it by hand. I am not sure about the lead and throat design or difference between the rental and MB but I am able to load 200gr gas checked hollow points all the way out past the crimp grove before engaging the rifling.

 

Throat geometry is a college level course. There's alot more to it than length.

 

So no Dremel??????

 

Yes, no straight wall restrictions. The length is the issue with any cartridge not originally for handgun use. I have used 458 x 1.8 (cut down 458 x 2 cartridge) on public as well as 45-70 on a TC Contender handgun which can be cut to 1.8" as well. If one doesn't reload, it can be hard to find rounds that fit the requirements unless you go with the standard straight wall cartridges.

 

I remember reading about the rifle throat vs revolver throat in discussions about 357max reamers

which is preferred?

which does the GBO reamer have?

was there an older reamer with a different style than the current one?

 

GBO Maxi reamer is a PT&G rifle finish reamer, we used to have a Clymer which likely didin't even touch the rifling.

Tim

 

Maxi at 40kpsi and case head at .379" is fine, 30-30 at 42kpsi and a bit bigger case head (.422"} is fine, going to higher pressure or larger case head is where the ductile platform becomes less than optimum, 44 mag with a .457" case head but at just 36kpsi. The 445 Super Mag has always been questioned as safe on a ductile frame partly because it isn't a SAAMI round, there is no SAAMI pressure standard, just pressures shown in published data which list it over 43kcup, for comparison old 44 Mag SAAMI pressure max was a little over 40kcup.

Tim

 

What is the correlation between case head and pressure? Also what is considered acceptable case head expansion on a 357 mag/max?

 

Thanks a bunch. I had forgotten how variable it is depending on case dia.

 

PJ, good question.

Force (lbs) = Pressure (lbs/square in) x Area (square in)

That is how much force is exerted onto the breech face of the receiver by the case head.

Case Diam(in)^2 *3.14/4= Area

Area for 357 case is .379 x .379 x 3.14 /4 = 0.113 in^2

Force for .357 case is 0.113 x 40,000 = 4,520 lbs

Tim compared this to the 30-30 case head which has been a standard factory chamber for the cast iron topper receiver for many years. The 30-30 case is 0.506 in diameter at 42,000 psi which exerts 8,450 lbs of force on the receiver at the case head.

Other factors for safety are a concern also such as shear strength of the breech face and tensile strength of the brass. Comparatively the .357 exerts much less force at equal pressure as the 30-30 because the case head has a smaller diameter.

 

The 30-30 case is 0.506 in diameter...

Um...the 30-30 case head is .422", the .506" rim diameter is not a factor in breech thrust. Ball park breech thrust based on external case head diameter for comparison purposes is 5874 PSI, Maxi is 4513 PSI

https://en.wikipedia.org/wiki/.30-30_Winchester

Bolt Thrust
Bolt thrust is easy to calculate. Only two inputs are required. They are peak chamber pressure in PSI and as mentioned, the inside area of the case head that the gas pressure can work on. The formula then is:

THRUST=AREA*CPSI Where:

AREA=3.1416*(HS/2)^2

HS=the diameter of the inside of the case head.

I sectioned some cases and measured the inside diameters and found that they were as follows:

CARTRIDGE CASE	INSIDE DIAMETER (HS)
222	.300″
PPC	.370″
308	.385″
MAGNUM	.420″
378 WBY MAG	.500″
50 BMG	.680″

The thrust is measured in pounds per square inch.

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