Wadcutter Seat Deapth?

[LtFrankDrebbin]

Just a question out of interest, I've been loading and shooting the Lyman 150gn WC,BB
(358091) for a while now in my Colt Diamondback 4" 38spec.
No matter what powder type or charge it will only produce dismal groups when seated to the crimp groove. 3-4inch @ 25 meters off a bench.
But once seated and crimped to the top lube groove, charged with a starting load of AS30
( clays, red dot type burn rate) three shot clovers and two just off are the norm.
This load chrono's @ 650fps.
They require slight thumb presure to seat in the cylinders.
Have also tryed hollow base wadcutters and had the same outcome.
Any one else out there having to do the same to get good groups out of WC's?

[uscra112]

Y'know, when I started with my Colt O.M., I seated out so that a good part of the wadcutter was in the throat,, thinking that if it worked for rifles, it oughta work for revolvers. I was wrong. I now seat flush, like the old-timers used to do. Why you are getting the opposite results intrigues me. But I can't explain it. Are your throats a bit large, maybe? Are you using brass that's sizing the base of the boolit down when you seat it deep? I know that when I found a sizing die that just barely shrank the fired cases my results improved. I no longer need an expander, just a slight belling of the mouth to avoid shaving. I can seat my wadcutters flush with just thumb pressure now, which tells me that I'm not sizing the boolit at all when I seat. Uster be that I had to use the press to get 'em to go in all the way. I also only use cases with the cannelure that's about 7/16" down from the mouth.

I've read that the reason for the cannelures on .38 brass was to identify how deeply the wall thickness was held constant, so that seating the boolit didn't bulge the case or size the boolit. And wadcutter cases were not the same as semi-wadcutter cases. Haven't ever done any careful measuring to see if it's true, but it seems to help me.

[MSD MIke]

I think USCRA is right in that you might be swaging the bullet down in the brass. While I have never had a problem with hollow base wad cutters I have a had a similar problem with Lee TLWC’s sized to .358. When seated flush in Starline brass and loaded with the standard 2.8 grains of Bulleseye I always got mediocre accuracy and leading in my model 19’s and my Blackhawk. I decided to seat the bullets out far enough to enter the throat on the .357 revolvers and the leading went away and accuracy improved. Initially I thought it had something to with aligning the bullet in the longer .357 chambers. It should be noted that these could only be seated in revolvers that have the throats reamed to .358. Can’t get them in a .357 throat when they are sized to .358. Anyway, I pulled some flush seated bullets from the Starline brass and measured them only to find that they were swaged down to .356 at the bottom of the bullet. Hmmmm, undersize bullets always lead. So, I dig around and find some true R-P wadcutter brass with the two cannalures and tried them. They did not swage the bullet undersize and my accuracy returned and leading disappeared with flush seated bullets. For the record, all bullets were cast out of straight clip on WW’s.
Of course it also worth measuring your throats to make sure they arent oversized.

Thanks
Mike

[dverna]

I also seat WC bullets flush. 3" groups at 50 yards.

[Forrest r]

I'm the opposite & like to have my wc seated out further. If for no other reason it will move the carbon ring that builds up in the cylinder out further. A lot of shooters will use/shoot some flush wc's & then when they switch to another boolit profile they have to force them into the cylinders.

[palmettosunshine]

http://i237.photobucket.com/albums/ff1/palmettosunshine/IMG_20130101_165910.jpg

Both are Lee 148 WC. The one on the left is reversed and seated flush. The one on the right is seated to the crimp groove.

[williamwaco]

I use the Lee conventional wad cutter and crimp it into the crimp groove. This leaves about 1/8 inch out of the case.
Lee 2-Cavity Bullet Mold 358-148-WC (http://www.midwayusa.com/product/623052/lee-2-cavity-bullet-mold-358-148-wc-38-special-357-magnum-38-colt-new-police-38-s-and-w-358-diameter-148-grain-wadcutter)


I have verified that they are NOT being swagged down in the seating step.

Surprisingly, I just returned from the range this afternoon. I fired a box and a half of these at 25 yards.
2.7 gr BullsEye
CCI 300
Sized .357
lubed with LLA.


Groups from my Thompson Contender ranged from .75 to 1.25 inches.
Groups from my M-19 ranged from 1.5 to 2.5 inches.

I strongly suspect, you are swagging your bullet diameter down at the base when they are seated in the cases.
Pull one and check the diameter at the base. Since the inside of the case is tapered, any swagging will occur first at the base of the bullet.