Throating a throatless lever chamber?

[Canuck Bob]

I have a couple of levers, Win 94 32 Special and a Winoku 92 32-20.
they have the SAAMI throatless chambers. I am wondering if anyone has throated such a chamber and their evaluation of such?

Also has anyone ever cut a leade ramp of a degree or two and dispensed with the cylindrical throat (freebore). I recently waded through some long threads elsewhere were folks I respect argued about the definition and names of the throat parts. So for this discussion the throat is both freebore and leade.

Ed Harris answered this question and his advice is what I'm considering.

http://www.castbulletassoc.org/forum/thread/6375-best-chance-for-a-tack-driving-32-20-rifle-load/

 

[Pistolero]

I think Brad has done this, check with him.

 

[Brad]

I have not done that but do have a couple rifles that could use it. My Marlin 32-20 shoots quite well as is. My 357, 44 mag, and 444 Marlin all suffer a bit from that steep leade angle.
Listening to Ed Harris is never a bad idea. I would recut the throats in a minute of the cost of the reamer wasn't an issue. I get kinda cheap some times.
I don't think the freebore is a huge issue unless it gets too large in diameter or way too long. Look at a revolver cylinder throat, it is essentially a long freebore. Make the bullet the size of the freebore and it can't really expand under pressure, can it?

Go for it. It can't really hurt but sure could help.

 

[300BLK]

Unlike Brad, My Marlin 32-20 (1894CL) had a tight spot ahead of the chamber. I made a short attempt to lap it from the muzzle end and decided that (likely) wearing the muzzle wouldn't be good. I used LBT bore lap, old stuff from 25+ years ago, instead of lube and fire lapped it. The constriction was removed, and it shoots rather excellently.

 

[freebullet]

Zero experience with that caliber, myself. I have throated numerous barrels from 22-45.

You can mess up a barrel quite easily but, careful application of the throating reamer is usually helpful. I ask a few questions before I do it, like-

Can I get/afford to replace the barrel?
Can I load to standard seating depths and get accurate fire the way it is?
Are there other issues with the barrel?

Freebore to me is the space between the end of the chamber step to the point the rifling starts. If the bullet has any jump between the chamber and rifling that is the freebore. You can make this area too large and/or long. Once that happens it's the same as having a shot out barrel. Patterns will be your reward at the target.

The throat is the size/angle of the same area minus the jump. A proper throat gives a gentle taper from chamber to rifling without room for the bullet to jump unsupported.

Tons of guns get sold today with zero throat.

Now, after giving a double warning, I'll say throating is easy.

Make up dummy rounds with the bullets seated where standard length for caliber or, longer if you have a reason(some folks go long to decrease pressure in small cals..ie, 9mm major guys, non magazine fed guns, guys loading heavy for caliber exclusive loads) to do so.

Use oil as thick as 30w or slightly thicker. Too thin is very bad & imo tranny fluid is no good for this.

On a lever & some other guns you'll need an extra long tap handle that fits your reamer to get it in there past the receiver. Lube it make no more than 3 turns(clockwise for most reamers & don't turn it backwards) with almost zero pressure. Clean, inspect, test dummy round for fit. Rinse repeat till they fit. It's that easy.

Stainless barrel will take twice as much reaming.

 

[Eutectic]

I have a couple of levers, Win 94 32 Special and a Winoku 92 32-20.
they have the SAAMI throatless chambers. I am wondering if anyone has throated such a chamber and their evaluation of such?

Whatever you decide Canuck Bob....... I would make sure my reamer pilot was a snug fit. Especially the .32 Special as barrels vary in dimensions. Each gun will require its own reamer as dimensions are different between calibers as well.

I have modified two Savage Model 23's in .25-20 however...... The first one shot so well that I did the second.!! Here, I used a throating reamer leaving a .2585" freebore area .100" long, then a 1 1/2 degree taper onto the land tops. Both guns will shoot cast under MOA.

I also have two Savage Model 23's in .32-20..... NEITHER has been modified. I also have a Winchester Model 43 in .32-20. I have thought long and hard on these three for throat work. First I would need a special throating reamer made. It would need to have the bushing type pilots as the 'bore' diameters are different. Not to mention they shoot so well now.

But you could approach this from the other direction.... My high speed varmint bullet for the .32-20's I designed myself. It is Accurate 31-105E. It has a short bore ride section that centers things up quite well. Sadly, there is no crimp groove as it is bolt action designed...... BUT........

My grouse load for the Savage .32-20 uses another bullet cast in a Magma mold. This design has a wide crimp groove area and then the ogive starts at a large enough diameter to 'act' like a bore rider and this bullet could be crimped as well. These are also available from Oregon Trail or Meister where you could try them before buying the mold from Magma... The Meister bullet will shoot under MOA in my grouse load @ 1200fps. Of course they are weight sorted, inspected, and I have to re-lube them with my 4Q lube! This could help your .32-20 with no gun modifications. Your .32 Win. Special would need its own bullet designed or a throating reamer designed.... Some cost to get you there...

Pete

 

[Pistolero]

K31s have no throat, and the GP11 ammo uses a .299 bullet ahead of the cannelure, .307 behind the cannelure.
Same basic thing with Rem 405 Jbullet, two diam bullet to work in Win 1886 chambers. Doesn't hurt in other
guns.

Bill

 

[fiver]

the 32 specials were designed around a 321 diameter bullet with a fairly long ogival taper to a rounded nose.
unfortunately Winchester wasn't always so good at cutting chambers and such and this lead many to believe they had a larger more tapered throat when they just had a slightly larger 30-30 shaped one.

in mine I went down the same design path as the 30-30 uses but ended up going to 324 in diameter to deal with the issue.
this meant a two diameter parallel sided design where the bore rider engraved the rifling and I needed a crimp groove to jerk the bullet back out of the rifling after chambering it.

now the 45-70 throats Miroku put In the 86 rifles are correct to saami specifications, and they cause all kinds of problems because nobody else did.
they do benefit from some throat reaming, but that is so they are compatible with the bullet offerings from the rest of the industry not because they are cut wrong.

I mention this because your 32 special could be cut to the correct dimensions and,,,,, well,, tolerance stacking from the rest of the world is just messing you up.