What the heck???

[fecmech]

I been playing around with my Rossi single shot .357 rifle the past couple of days shooting mostly .38 specials out of it, rn's and wadcutters. It's a nice plinker that shoots 1.5-2" 50 yd groups all day long with the specials. My .38 loads are H&G 158 rn over 4.2 of Bullseye or 4.9/231 with the BE being only slightly more accurate by a whisker out of my hand guns. Some time ago I loaded some Lee cowboy 158 gr rnfp's ahead of 4.9/231 and I took them out to shoot out of the rifle. I could not believe it, they were going thru the target sideways and of course hitting all over the place! I went downstairs and loaded some ahead of the 4.2 BE load and fired 2-10 shot groups. Both groups were under 2" for 9 shots with 1 tumbler each about 2" away from the main group. The Rossi is a 1 in 16 twist rifle and I've never seen a Keyholed bullet from my RN's or even Keith's. Any of you gents have any idea whats going on here? I took the same shells that were keyholing and grouping well over 1 1/2 FEET at 50 yds out of the rifle and shot 18 rounds into a 3.5" 50 yd group out of my K-38??? I could not put 2 rounds within 6" of each other out of the rifle. I fired about 20 more H&G rn's out of the rifle and it shot like it always did so I don't think there is anything wrong with the gun. It sure does not seem to like that rnfp and 231 though. Any ideas out there?

[Bass Ackward]

The rifle shoots with other bullets. The load shoots in a handgun. So that eliminates a lot of things.

If I had to place a guess, I would probably go with lube break down in the longer barrel even if the velocity isn't that much higher. That bullet doesn't carry a lot of lube. Was the keyhole at one particular shot in the string like towards the end?

[Leftoverdj]

Have you checked the diameter on the Lee bullets? That's always my suspicion when I hear "Lee".

[44man]

Try a 180 gr boolit and see what it does. Someone should have a few to send you.
Boolits that keyhole have a drive band length problem. Either that or they are stripping and not taking the twist.

[fecmech]

If I had to place a guess, I would probably go with lube break down in the longer barrel even if the velocity isn't that much higher. That bullet doesn't carry a lot of lube. Was the keyhole at one particular shot in the string like towards the end?

Bass--There were only 1 kehole each in the BE groups , both somewhere in the middle of the 10 shot string. The 231 loads were keholing practicaly every shot imo cause even when they went thru the target point on they were scattered all over 6,8, even 10 inches apart. Somehow the 231 seems to aggravate the situation.I don't know about the lube, the muzzel end of the barrel was dark, not light grey and there was no leading visable to me.
I have several 10 shot groups (with this bullet)that are less than 2"@50 with 12 grs of AA9 (approx 1400FPS) and a couple @ 100 yds of about 3-4". Also with 2400 at 12 grs in the 3-4" range at 100 yds. Those were mag loads in mag cases. Do you think this could be some kind of a throat thing where the longer jump from the .38 case is aggravating the situation, although it does not seem to bother the H&G rn or wadcutters out of .38 cases??

Leftoverdj--They drop from the mold .359 and were sized .358 same as my RN's and SWC's in my Star sizer.

44 man--The H&G rn and the 358429 and wadcutters all shoot good so I don't lack for bullets for this gun, I'm just curious why such a strange result with this combination.

[drinks]

It seems a case of a fast powder being the problem.
I have found the slowest powder that will give me the velocity I want is almost always the most accurate.
I would think it is the base being deformed that is causing the shotgun patterns.

[LarryM]

It may be a genetic thing with me but I can't get BE to do worth a darn in my Ruger Vaquero I always end up with a hideously leaded barrel with any load of bullseye with any bullet, my 1894C eats up the same loads that try to turn my revolver into a smooth bore and prints ragged holes at 25 yards I can cover with my thumb.
The Lee bullet is a bevel base and you may be experiencing some gas cutting, are you getting much leading in your rifle barrel? Any chance you can recover the fired slugs from your backstop? If that is possible you may be able to get a bettter idea on what is happening to your boolits.

[Bass Ackward]

I have several 10 shot groups (with this bullet)that are less than 2"@50 with 12 grs of AA9 (approx 1400FPS) and a couple @ 100 yds of about 3-4". Also with 2400 at 12 grs in the 3-4" range at 100 yds. Those were mag loads in mag cases. Do you think this could be some kind of a throat thing where the longer jump from the .38 case is aggravating the situation.

Fecmech,

Well, I am just guessing. It's great to play the guessing game, when it is someone else's problem. When these things happen to us, they just bug hell out of ya. I see enough of that. Here, I type a few key strokes and my life goes on. :grin:

Very easy to tell. Just use 231 in Mag cases and repeat the string. I wouldn't raise the powder charge. See what happens. If it shoots, then you know it is a jump thing. Or a seal thing. Won't hurt to run a brush and see if you get any lead. Even key holed, you should get better groups than 1 1/2 feet at 50 .... if you don't lead.

Let us know what you find out.

[44man]

Twist versus velocity is tricky. I had a 30-30 TC Contender that would hit a nickel at 100 yd's with a gas checked boolit. If I left off the check, every boolit would keyhole at 50 yd's due to the lack of a drive band. Your 231 load is not matching the twist rate because the velocity is off. The boolit is very borderline.

[fecmech]

Fecmech,


Very easy to tell. Just use 231 in Mag cases and repeat the string. I wouldn't raise the powder charge. See what happens. If it shoots, then you know it is a jump thing. Or a seal thing. Won't hurt to run a brush and see if you get any lead. Even key holed, you should get better groups than 1 1/2 feet at 50 .... if you don't lead.

Let us know what you find out.

That was kind of my thought Bass. The weather has turned to crap here for a few days but first chance next week I'm going to load them in .357 cases to the same oal as the .38 with the same charge of 231 and see what happens. That should give me pretty much the same ballistics but case support for another 1/8 ". Don't know that it will change anything but will only take a few minutes to try. Sure is nice having a range in your back yard!

[fecmech]

Came back from shooting sporting clays and the weather was still nice so I went down to my basement and loaded some rnfp's in some mag cases to the same oal as they were in the spl cases. Same powder charge of 4.9/231 and went back and shot them. What a difference!! I fired 12 shots, 10 went into 2 1/2 inches at 50 yds and 2 were leaving the group and that took all 12 to 5". The 2 flyers were starting to tip as the holes were oval and marked on one side, also 1 in the group had tipped and just got lucky. Big difference from 1 1/2 foot group with 80% going thru sideways! Evidently the jump from the 38 case to the throat with this bullet and load does some bad things. Just for the hell of it I loaded 10 more to an oal that set the bullet just into the rifleing and bumped up the powder .5 gr to try and keep the ballistics close. In that group 8 went into 2 1/2" again with 2 outside taking it to 3 1/2" for the 10 shots. There was also evidence of tipping on 4 of those bullets. So much for rnfp's, 231 and my Rossi, the JuJu is just not right. I will just continue with the H&G RN+ Bullseye or wadcutters with BE when I want to shoot .38's out of the gun.