357 Throat Improvement?

[gcrank1]

Just thinking back to an article I read by Ed Harris regarding his days with Ruger and throating improvements he discovered for the No.1s in .357Mag. Seems it was not unusual to have them not group well and he and a friend came up with a throating reamer that greatly improved things. I dont remeber who made the reamer in question or the change(s) in profile that worked out, perhaps someone does.
Im speculatin' that the 357Max reamer may have just such an 'improved' throat and that by just touching it slightly upbore may result in much the same, without going the full Max treatment (some just want to stay at Maggie's).
The next time somebody gets the reamer maybe try just rethroating first and shoot some groups and report what you find? Then do Max if thats what you want, of course, and do comparison groups with the same Mag load.
BTW, if I had one Id do it, but not my good fortune as yet.

[gendoc]

blake, when we did the max to the #1 ss barrel several months ago, it improved its overall
stability and accuracy with the projectiles we wanted to use 180gr ssp's and 200gr lapua
of course it took some developing but it turned out excellent.
thats why my dad sold all but 1 max in h&r. this #1 barrel was his for over 17 years.
it could not hit the broad side of barn accurately thats why he said MAX,
and that turned out to be one of the best ream/throat jobs i have done in 15 years.
J2
USMC armorer
1994- to date
yes sir, still active and damn proud

[Antietamgw]

I "suspect" that the rental max reamer cuts a rifle type leade and throat meant to support the bullet as it starts on it's way. It would be great if someone who has used the reamer could do a throat slug (ala Verl) and provide the measurements. I'm lazy and have not made a throat slug of my 357 Mag barrel or even shot it all that much in load development. It gets the same plinking load I use in my levergun and revolvers. If I do go to the Max chambering, there will be some serious before and after load development done.  Better accuracy after the rechambering would likely come from a throat better suited to the bullet being used.

[Antietamgw]

I got to wondering about this so went out to the shop and did a quick throat slug. When I started measuring I thought for a minute that the barrel had already been rechambered to Max as it was so long. It hasn't,  a Max case will show slight resistance about 3/16" before closing. Looks like my chamber is long and the throat just tapers from the end of that long chamber down to bore diameter. My throat slug wasn't long enough to find the point where that happens but it's waaay down there somewhere! There's no reason for a factory chamber to be that darn long, no brass will ever "grow" long enough to get anywhere near the throat.  I'd sure like to see what the throat from the Maximum reamer looks like but I don't think just rethroating would really do that much good. I didn't calculate the angle but it's pretty mild and without any sharp transitions. If the Max reamer cuts a throat with a short .359 ball seat and a slight taper to bore diameter I'd guess that the best accuracy will come from rechambering and using Maximum brass. What I wonder is if the sharp transition from case diameter to ball seat would cause troubles with cast bullets when shot from shorter cases. If the reamer cuts a throat that looks like the factory I would think that any increase in accuracy with the Max brass came from elimination of the overly long chamber and the bullet being started directly into the tapered throat. I believe that accuracy differences would be more pronounced with cast bullets than jacketed. That's just a guess as I very rarely shoot jacketed.

[quickdtoo]

Previous discussion on 357 Mag throats...

http://www.gboreloaded.com/forums/index.php/topic,125780.msg1098446320.html#msg1098446320

From the 357 Max reamer sticky...

After reading the review at Midway, I think it may work just fine, worth a try, the price is right!! 

Tim

http://www.midwayusa.com/viewProduct/?productNumber=734226

Excellent reamer will easily re-chamber a 357 Mag to a Maximum. True 6 deg ramp. You can chamber completely or stop when your target / hunting load touches the bore. I have re-chambered 3 Handi Rifles with this reamer and all three shoot excellent groups.

[Slowhanddd]

Don't know how or why the reamed out 357's that I've done,three of them,all shoot better after.Mine shot ok as a mag,but now shoots the maggies real well.One of my buddies guns wouldn't group but patterned like a shot gun.Now it shoots great too.The other shot good to begin with and just got better.Don't know what it does,but it worked for me.