[DougE]

I was at the range trying out some 38 loads this morning .......... shot at 15 yards from a rest. I loaded some 158 gr. lrnfp ( lyman 358665 ) over 4.0 to 4.3 gr. of unique. I loaded 10 each at 4.0, 4.1, 4.2 and 4.3 gns. All charges were weighed so they were as near as possible to the charge weight as my scales allow. Every group I shot had four holes pretty close to the POA and one way over there away from the group. 4.0 and 4.3 yielded the tightest groups, but still had one hole outta the 5 shots quite a bit off from the others.

 

[Geoff40]

Doug, what model of gun? Is this the first time you ever fired this gun? Is it possible the flyers are coming from one chamber?
Do you have any of these bullets left? I would weigh several, and I would also take the calipers out and measure the diameter of several to check for consistantcy in those 2 aspects. Did you cast them and were they all cast at the same sitting? Tell us about the sizing and the lead you used, if you did the casting.
Post this info and someone here will come up with some ideas.

 

[xtimberman]

greatpost

Next time, mark that cylinder with a grease pencil and try to figure out what's off with it.

xtm

 

[Sebago Son]

In addition to the good info supplied by our friends Geoff and xtm, I would inquire if you had all of your cases trimmed to the same length?

Short cases means less crimp and random case lengths mean inconsistent crimp.

Usually this inconsistency is manifested in vertical stringing of your group.

Lastly, case lead bullets are sensitive to seating. Your cases should be sufficiently bell sized to eliminate any shaving of the bullet's base during insertion and seating to length.

When I am trying to work up a good load with a new combination, I use new brass of all the same head stamp wherever possible and check the bases of each bullet carefully.

Good Luck,

Drew

 

[c pierce]

My guess is you have one cylinder thats out of spec.

 

[carl418_resigned]

You're getting excellent suggestions from everyone. But, it does sound to me like a cylinder problem. Or, more specifically, one charge hole has a problem.

Let us know what you find out..

 

[DougE]

Thanks for the input guys.
In answer to your questions ............

The revolver I was shooting was not a S&W .

Rossi m851 which I bought somewhere around 20 years ago

I didn't cast the bullets myself. I bought 1000 of them from Kempf's gun shop. I was ordering a few other things from them and the price was pretty good. The bullets are all pretty uniform ........ all the ones I miked were .358 dia. and what ones I have weighed so far were all within a few tenths of a grain of each other.

The brass I used was all federal once fired. I did not trim the brass since all of it was pretty close in length anyhow. Cases were belled just enough to prevent shaving during bullet seating and I also seat and crimp as 2 separate operations.

4.0 gr. unique
There's only 4 holes ........ not sure where the other one went on this group.

4.3 gr. unique
4 grouped fairly well while one flew off to the side in this one.

4.0 gr. seemed to do best out of the loads I tried so I guess I'll load some more of them up and hit the range when it warms up again later this week to try and figure out what's going on.

 

[Guest]

Clean the heck out of the cylinder until it's spotless. Take out your micrometer and find 6 bullets that mike the same diameter. Drop them down each chamber and see if one of them protrudes significantly different then the rest. I had a 629 cylinder that had one chamber a couple of thousands larger then the rest...

I'd also check the forcing cone to see if there is not some sign of erosion to put it out of round.

giz

 

[Geoff40]

As Giz says, clean it beyond what you normally do. Way beyond! Then I'd grease pencil the cylinder at 1 chamber as the first chamber to fire off in at least 2 cylinders full of ammo. Fire a shot, check for the flyer, fire again, check for the flyer, etc, and I think you'll ID it pretty quick as 1 of the chambers being the issue. Post your results.

 

[DougE]

That I shall do. It should be warm enough for another range trip toward the end of the week.
As an aside, this revolver has been mainly used as a plinker since I've owned it .............. shooting beer cans and the like ......... I never punched much paper with it until recently. It always seemed to hit what I was pointing at though.