.38spl tumbling

DavidAGO · April 27, 2009, 05:10 PM

I took out my Ruger GP100 and S&W 686 Saturday. Shooting a 158 gr SWC driven by 3.2 gr of Bullseye. The 686 shot beautifully, at 50 yds 1.5" group using a red Dot sight. The Ruger would not hit the target. At 50 ft, the 686 beautifull groups, the Ruger would hit, but all shots were tumbling. At 30 ft, still tumbling. I had some loads with 158 gr SWC but with 3.4 gr Bullseye, same result. Both guns were newly cleaned, no leading. Getting frustrated, went home and loaded a few 148 gr wadcutters, 3.2 & 3.4 gr Bullseye. The 686 shot beautifully, the Ruger better, but some obvious ovalling of the holes. Both the 158 gr and the 148 gr bullets are my casts, Lee tumble lubed. Both have shot well before in the Ruger.

I am not sure what to do next. Obviously, with the 686, nothing. for the Ruger, would you load up hotter loads, same bullet, or go to lighter loads, same bullet? I have examined the gun, no signs of lead collecting on the forcing cone, no unusual buildup in the barrel. The only new variable in the reloading process is I am using a heavier roll crimp with the Lee Factory crimp die than I have been using in the past, but nothing too excessive. My roll crimp still does not look as rolled as the factory crimp on commercial loads.

Thanks for any help

DavidAGO

**Mal H** · April 27, 2009, 05:21 PM

What is the diameter of the bullets, and what are the barrel lengths of the two revolvers?

My intuitive answer, more Bullseye and a better crimp. Can you chrono the loads you're using?

wncchester · April 27, 2009, 05:32 PM

Your bullets are not now filling the Ruger bore is my guess. It's frequently good to have bullets ONE thousanth larger than bore diameter. If you're casting your own, I'd suggest sizing them another couple of thou larger to see if you get a better fit.

I'd be reluctant to try driving .38 Specials hard enough to insure obturation but Rugers may be strong enough for it to work safely. Carefully bumping up the load may make your present bullets work. If it does, keep the ammo for the two seperated, you don't want to stretch the frame on the excellant Smith.

James R. Burke · April 27, 2009, 05:37 PM

I think what Wncchester said makes sense. I would give that a try.

DavidAGO · April 27, 2009, 09:39 PM

Should have posted this information with the original post. the S&W has an 8" barrel, the Ruger a 6". I went out to the shop just now to measure the last few bullets I have of this batch. Of the 7 158 gr SWC bullets I have left, one miked at .359, 6 miked between .357 and .358, and one miked at .357. I didn't have any of the 148 gr WC left from the last batch of them to measure.

I have been using the tumble lube bullets unsized.

I don't have a chronograph; that is high on my wish list.

David

**Mal H** · April 27, 2009, 11:53 PM

Good, now we can make a judgment on the fit of the bullets. Sounds to me like a good percentage of your bullets are undersized for lead bullets. The .359 ones should be good, but those that are less than .358 may do exactly what you are experiencing. With the not-so-tight bullets, a relatively light load, and 2" inches of barrel less, it's not much wonder that the Ruger could keyhole before the S&W with those rounds.

DavidAGO · April 28, 2009, 01:04 PM

Yeah, it was disheartening to find the wide variance. those cast bullets were the rejects from the last castings I made up, but they were rejected because of incomplete fill, not because I measured each one.

Now I gotta go back and review my casting technique and do more measuring. It's a bit ironic; the 230 gr rd nose bullets I cast for the .45 I was a bit anal and measured probably the first 5 or 6 batches I cast, but with the .38's being tumble lube, I assumed the literature was right and could be shot as cast. teach me to believe what I read.

DavidAGO

April 27, 2009, 05:10 PM	#1
DavidAGO Senior Member Join Date: October 7, 2008 Location: Magnolia, AR Posts: 340	.38spl tumbling I took out my Ruger GP100 and S&W 686 Saturday. Shooting a 158 gr SWC driven by 3.2 gr of Bullseye. The 686 shot beautifully, at 50 yds 1.5" group using a red Dot sight. The Ruger would not hit the target. At 50 ft, the 686 beautifull groups, the Ruger would hit, but all shots were tumbling. At 30 ft, still tumbling. I had some loads with 158 gr SWC but with 3.4 gr Bullseye, same result. Both guns were newly cleaned, no leading. Getting frustrated, went home and loaded a few 148 gr wadcutters, 3.2 & 3.4 gr Bullseye. The 686 shot beautifully, the Ruger better, but some obvious ovalling of the holes. Both the 158 gr and the 148 gr bullets are my casts, Lee tumble lubed. Both have shot well before in the Ruger. I am not sure what to do next. Obviously, with the 686, nothing. for the Ruger, would you load up hotter loads, same bullet, or go to lighter loads, same bullet? I have examined the gun, no signs of lead collecting on the forcing cone, no unusual buildup in the barrel. The only new variable in the reloading process is I am using a heavier roll crimp with the Lee Factory crimp die than I have been using in the past, but nothing too excessive. My roll crimp still does not look as rolled as the factory crimp on commercial loads. Thanks for any help DavidAGO

April 27, 2009, 05:32 PM	#3
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	Your bullets are not now filling the Ruger bore is my guess. It's frequently good to have bullets ONE thousanth larger than bore diameter. If you're casting your own, I'd suggest sizing them another couple of thou larger to see if you get a better fit. I'd be reluctant to try driving .38 Specials hard enough to insure obturation but Rugers may be strong enough for it to work safely. Carefully bumping up the load may make your present bullets work. If it does, keep the ammo for the two seperated, you don't want to stretch the frame on the excellant Smith. Last edited by wncchester; April 27, 2009 at 05:39 PM.

April 27, 2009, 05:21 PM	#2
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 17,066	What is the diameter of the bullets, and what are the barrel lengths of the two revolvers? My intuitive answer, more Bullseye and a better crimp. Can you chrono the loads you're using?

April 27, 2009, 05:37 PM	#4
James R. Burke Senior Member Join Date: January 3, 2009 Location: U.P. of Mich/Quinnesec Posts: 1,897	I think what Wncchester said makes sense. I would give that a try.

April 27, 2009, 09:39 PM	#5
DavidAGO Senior Member Join Date: October 7, 2008 Location: Magnolia, AR Posts: 340	Should have posted this information with the original post. the S&W has an 8" barrel, the Ruger a 6". I went out to the shop just now to measure the last few bullets I have of this batch. Of the 7 158 gr SWC bullets I have left, one miked at .359, 6 miked between .357 and .358, and one miked at .357. I didn't have any of the 148 gr WC left from the last batch of them to measure. I have been using the tumble lube bullets unsized. I don't have a chronograph; that is high on my wish list. David

April 27, 2009, 11:53 PM	#6
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 17,066	Good, now we can make a judgment on the fit of the bullets. Sounds to me like a good percentage of your bullets are undersized for lead bullets. The .359 ones should be good, but those that are less than .358 may do exactly what you are experiencing. With the not-so-tight bullets, a relatively light load, and 2" inches of barrel less, it's not much wonder that the Ruger could keyhole before the S&W with those rounds.

April 28, 2009, 01:04 PM	#7
DavidAGO Senior Member Join Date: October 7, 2008 Location: Magnolia, AR Posts: 340	Yeah, it was disheartening to find the wide variance. those cast bullets were the rejects from the last castings I made up, but they were rejected because of incomplete fill, not because I measured each one. Now I gotta go back and review my casting technique and do more measuring. It's a bit ironic; the 230 gr rd nose bullets I cast for the .45 I was a bit anal and measured probably the first 5 or 6 batches I cast, but with the .38's being tumble lube, I assumed the literature was right and could be shot as cast. teach me to believe what I read. DavidAGO