357 Magnum revolver problems

[Bruce Mc]

I wasn't familiar with that revolver so I had to do some research. Odd number of groves makes using a micrometer on the muzzle difficult and not have a round barrel further complicates measurements. Slug the barrel.

 

[salmonchaser]

Sell it!

 

[FOTIS]

Sell it!

That would be the easy/painless way out, and we all know what a masochist I am!

 

[grry10]

Have you measured the rifling?

 

[Vince]

Fotis,

Have you tried a different chronograph?
Just trying to rule out variables.

Vince

 

[PJGunner]

"Check groove diameter"
Not that easy with a Smith & Wesson. Unless there' been a chage I haven't heard about, they're still using barrels with 5 lands and grooves. Best you can do is a semi-educated guess without having a special mirometer. A standard micrometer won't work. My best guess it will be .358". If you know a machinist that might have the proper "mike" to measure that type slug from the barrel all you can get is an estimate. FWIW, I usually run bullets I cast for the .38 Spl. and .357 Mag at .359" and they've worked just fine.
Frankly matching the cylinder mouths vs the bore is more important. If the barrel has a groove diameter of .358" and the cylinder at the mouth is say 356" or 357" the bullet will be squeezed down to the smaller size and will most likely badly lead the barrel.

An easy way of doing this???
Other than driving a soft lead fishing sinker or soft slightly over sized lead ball or bullet from the muzzle and then measuring the bullet ot whatever you used I see no really simple answer.
Paul B.

 

[reflex264]

That is a wide cylinder gap. My son and I shot two identical Blackhawks side by side with the same load over the chrony. One had a .006" gap and the other .002". The gun with the .006" gap was about 150 fps slower than the .002" gun. Chamber dimensions? Large chambers are detrimental when squeezing the most of of a revolver. 4227 is way too slow for that set up. I have never got close the advertised velocities with it in a handgun but it does great from a .357 Rifle. A powder I am growing to love in several revolvers is Enforcer. It has been very accurate in nearly everything all the way up to .475 Linebaugh and velocities are good. Here are a couple of loads to try.

 

[Guy Miner]

Good info there 'Flex. Thanks.

 

[filmjunkie4ever]

Reflex264 -

+1 on Enforcer. Once I saw that it had a nearly identical burn rate with 2400, I began loading it in .357! It shoots great out of my Bisley Blackhawk with the 158 grain XTP!

The best part is, Ramshot powders are still priced at about $30 per pound versus the $60-$75 price tags we see on practically everything else.

 

[filmjunkie4ever]

Reflex264 -

+1 on Enforcer. Once I saw that it had a nearly identical burn rate with 2400, I began loading it in .357! It shoots great out of my Bisley Blackhawk with the 158 grain XTP!

The best part is, Ramshot powders are still priced at about $30 per pound versus the $60-$75 price tags we see on practically everything else.

I even load it in my .25-20! It shoots great in that too!

 

[FOTIS]

I loaded up some enforcer with hard 165 gr cast bullets I will check on Velocity/accuracy.

 

[FOTIS]

Tried a couple of more loads last weekend.

165 (.359") Matts bullet cast 14 gr Enforcer I got 1088 fps....should have been 1350 or so.
125 XTP 22.5 MP 3000. I got 1250 fps....should have been around 1500.
165 Matts cast bullet with MP3000 I got 1110 fps should have been in the 1300's.

After thinking on it a while I decided to measure the cylinder gap again. It measured .006.
I pulled my SW 686 out and I could BARELY fit a .003 gap gauge through it.
The 327 has a removable/adjustable barrel like the Dan Wesson pistol kits so I can change the gap.


Can this be the issue?

 

[Slimfinn]

The 327 has a removable/adjustable barrel like the Dan Wesson pistol kits so I can change the gap.

I would say this is definitely worth trying, and see if S&W gives you a recommended gap

 

[FOTIS]

They said .004 to .008. Mine is .006 but the 686 SW 357 has .002" or so

 

[JD338]

It sure seems like the gap is the culprit.

JD338

 

[FOTIS]

I minimized the gap to .003. That helped a little but no joy.
I started to work up beyond the max of 14 gr Enforcer 165 gr Matts cast.
14 gr 1100 fps
14.5 gr 1151 fps
15 gr 1218 fps
15.3 gr 1235 fps.


With the 125 XTPs

20.5 H110 gave me 1450 fps.
No visible pressure signs at all, no issues. Go figure

 

[Slimfinn]

That's frustrating, cutting losses yet, or going to continue working on it?
How is it to shoot?

 

[FOTIS]

No idea. The velocity conundrum took up all my attention thus far .

 

[JD338]

No idea. The velocity conundrum took up all my attention thus far .

Might be worth sending it down the road and starting out fresh with a new one buddy.

JD338

 

[FOTIS]

I will probably in time. For now it is keeping me busy. Gun learning can be so frustrating! LOL