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View Full Version : is .360 too big?



Oldbrowngun
06-13-2018, 09:55 PM
hi i am fairly new to this stuff. lee claims the factory crimp die and with lee allox you dont need to resize. i have been shooting my cast boolits with 6 grns of unique in my 357 magnum. this load has been gicing superb accuracy with no leading. i just mic'd my boolits today and they are measuring at .360 after being ran through the factory crimp die. my question is , is this boolit too oversized to be shot safely? i am using water quenched wheel,weight alloy.

sigep1764
06-13-2018, 10:01 PM
How does the barrel look? Are the primers flattened or rounded? If they push through your cylinder with just light resistance, id say you were good to go.

Oldbrowngun
06-13-2018, 10:06 PM
ive tried to check the primers but its hard to tell my winchester primers look so flat becore being shot. barrel looks fine as far as i can tell and bullets drop in freely on most some drop 3/4 in freely then take a very slight push

Jayhawkhuntclub
06-13-2018, 10:10 PM
I wouldn't worry about diameter. Might consider backing off the powder a touch though. Especially, if you see any high pressure signs.

Oldbrowngun
06-13-2018, 10:11 PM
https://imgur.com/a/F9wcSj0

a collection of spent primers next to unfired. the primers were shot from 2 different smith and wesson 686's.222070222071

Outpost75
06-13-2018, 10:56 PM
Accurate cast bullet loads shot from.modern guns are safe.

jugulater
06-13-2018, 11:15 PM
That fired shell doesnt show any signs of excessive flattening. if the rounds chamber with out resistance you should be fine.

I think you should slug the barrel just to see what it measures, it will probably be spot-on standard, but it is possible that you have a oversized Bore/Groove diameter.

If accuracy is good,no leading, and the primers all look like that fired shell, id say you are safe.

tazman
06-13-2018, 11:52 PM
If you have good accuracy and no leading you should be home free. The powder charge you mention is not an issue as it isn't over max yet provided you are using 158-160 grain boolits in 357 magnum brass.
It is possible you might benefit from a slightly smaller boolit diameter but then again, you might not.
Stick with what works for you.

Grmps
06-14-2018, 03:38 AM
6.4 grains of unique is an old time standard load.
Is 360 too big? as previously stated only your gun can tell you that.
I suspect that if you go much harder on the alloy you might have an issue with the oversized boolit.

It also depends on the cylinder throat size, forcing cone size and bore diameter.

jmort
06-14-2018, 07:55 AM
With my .357s that is too big
Freedom Arms .357 cast bullets
Everything else I start at .358
Max has been .359

GhostHawk
06-14-2018, 09:06 AM
Let the gun do the talking.

"i have been shooting my cast boolits with 6 grns of unique in my 357 magnum. this load has been gicing superb accuracy with no leading."

Assuming you worked that load up correctly, watching for pressure signs and warnings.
Full stop, end of story.

I shoot .360 cast boolits unsized through my 9mm carbine and handi rifle and 9mm Pistol.
No pressure signs, no problems, better accuracy than factory loads. And it stopped keyholing in 2 of the 3 guns. The Hipoint carbine never did.

No, you don't have a problem.

mdi
06-14-2018, 11:38 AM
It all depends on the cylinder throats' diameters. "Push through", "Snug fit", "Drop through" aren't measurements and just slightly better than a WAG. Measure the cylinder throats, to the nearest .001" and size the bullets to the same dimension. If your cylinders are smaller than .360" the bullet will be sized as it passes through the throat. The worst case scenario I've encountered is lead spray on the front of the cylinder and on the frame, forcing cone from shooting bullets much over the cylinder throat diameter.

Primers are not a good indication of pressure. Here's a bunch of info.; https://www.google.com/search?q=pressure+signs+in+revolvers&rlz=1C1CHBF_enUS776US776&oq=pressure+signs+in+revolvers&aqs=chrome..69i57.8639j0j7&sourceid=chrome&ie=UTF-8

Oldbrowngun
06-14-2018, 10:49 PM
slugging cylinder throats showed between 358 and 359 i did notice there were some small lead deposits in the cylinders not sure if thats a bad sign or normal

mdi
06-15-2018, 01:26 PM
On two of my 38s the cylinder throats measure just like yours and the bbl groove diameter is .3565"-357". I size all my bullets to .358"+ (my "custom" sizing die runs .358"-.359" depending on alloy I push through it)...

Oldbrowngun
06-15-2018, 05:03 PM
I ordered a .359 sizing kit. If nothing else, just for consistancy, and the fact these bullets are fired through multiple guns. I hope to retain the accuracy with this slight down sizing that I was getting before. It is nothing to shoot a 7 shot cylinder in to one hole at normal handgun distances with the current load.

gwpercle
06-15-2018, 05:24 PM
From what I can see the primers look fine. An easy way to tell if a load is too hot is the extraction of fired cases. If the fired cases are hard to eject that's a sign something isn't right . If they extract easily...you OK.
The slight push to chamber is OK, the boolit is not too large. Your powder charge is not excessive , primers look normal.
So if the extraction of the fired cases is normal , no leading is occurring and good accuracy...then you have a good load ! It doesn't get any better than one ragged hole groups!
Gary

Oldbrowngun
06-15-2018, 05:54 PM
From what I can see the primers look fine. An easy way to tell if a load is too hot is the extraction of fired cases. If the fired cases are hard to eject that's a sign something isn't right . If they extract easily...you OK.
The slight push to chamber is OK, the boolit is not too large. Your powder charge is not excessive , primers look normal.
So if the extraction of the fired cases is normal , no leading is occurring and good accuracy...then you have a good load ! It doesn't get any better than one ragged hole groups!
Gary

Cases extract no problem, thanks for the info!

9.3X62AL
06-15-2018, 06:04 PM
It ain't broke. Don't fix it.

mdi
06-16-2018, 11:25 AM
I ordered a .359 sizing kit. If nothing else, just for consistancy, and the fact these bullets are fired through multiple guns. I hope to retain the accuracy with this slight down sizing that I was getting before. It is nothing to shoot a 7 shot cylinder in to one hole at normal handgun distances with the current load.


Hmmm. I might just leave them alone. Pressure ain't a problem, and accuracy is good. How do they work in your other guns?