Boolit for .38 Colt Diamondback

[LtFrankDrebbin]

G'day all,
I am a proud owner of a Colt Diamondback .38 4" barrel. Been going through the phase of finding out what boolit it likes. So far after trying just about everything I can get my hands on the only thing that will group @ 25meters off the bench is a 158gn RN.
WC's SWC's regardless of weight just seem to shotgun pattern when the 158gn RN will pop into a sub 2" goup no drama.
The only powders I've been able to try are Trail Boss, W231 and ADI-AP50N all of wich seem to be on par.
Taken the gamble and orderd a Lee TL 358-158RN mould anyway.
Was just interested if others have had the same thing, a fussy gun?

[rintinglen]

Very nice gun. I had one briefly back in the seventies that I sold to get a Python, but it shot well with everything, especially WC's. It would put round after round into 2 inch groups, sometimes less. I am a little surprised that yours is so finicky.
Good luck with the Lee TL.

[PacMan]

Very nice Colt. I tried to buy one a while back but the price was ro high.
Very Nice

[Kraschenbirn]

My wife has one just like yours. Either 3.8 gr. 700X under the Lyman 358156 SWC (w/o gascheck) or 3.2 Bullseye under the RCBS 38-148-WC (full wadcutter) will hold 2"-3" groups off sandbags. Both cast from 50/50 WW/Pb and sized .358.

Bill

[catboat]

How about a 148 grain HBWC over low dosages of Bullseye or W231? Speer or Hornady are great.

For a cast bullet, I've had excellent results from the Lee 148 grain tumble lube wadcutter (6 cavity)in my model 14 S&W 38 special over 2.5 grains of Bullseye. You can order some of the bullets from a vendor on this board, called Carolina Bullets (or Carolina Cast bullets). Excellent quality, service and very fair price.

My next bullet mold (Christmas is coming) is a six cavity Lee 158 grain tumble lube SWC.


Size the bullets 0.001-0.002" over your cylinder throat diameter. I use a .360" diameter sizing die on my SAECO lubrisizer on all of my 38 special/357 mag cast bullets This doesn't size them, but really just lubes them. My cylinder throats run .357-.358", depending on the revolver. I'm guessing the bullet diameters run in the .359" range.

[9.3X62AL]

You might have the revolver checked by a knowledgeable gunsmith concerning its "ranging", or how closely the charge holes are clocking with the line of bore. If there is any significant variance in clocking, it will show up more prominently with square-fronted bullet shapes like SWCs and WCs. The shoulderless RN designs tend to self-center in bores of misaligned revolvers more readily than their square-shouldered counterparts.

Diamondbacks have a STRONG rep for superb accuracy with all bullet types. Jewels, really.

[shooting on a shoestring]

LtFrankD...Welcome aboard. Nice revolver, going to be a good time working up loads for that machine.

I have several .38s, meaning both moulds and revolvers. The one single wins everytime in every gun I've tried is the lowly Lee 158 SWC Tumble Lube. I have 358156, 358477, 358091 and 358087 and the Lee 140 SWC, all of which see lots of use, but that darn 158 SWC TL just plain works, provided its not driven over 800 or 850 fps. It has very little shoulder, lots of barrel to boolit surface area, and it works.

I would suggest you branch out in powders to try Bullseye, 700X, Unique, Herco some of the old standbys.

I do think you will be happy with the RN 158 TL, just don't use too much lube. Most people do and it gums up your dies. I thin mine with mineral spirits way down, then use a toaster oven to warm the boolits before lubing, and toast them after lubing to drive off the solvents and dry them quickly. I find 200F to be plenty of heat, takes about 10 to 15 minutes, cool and load.

Enjoy sir. PS shoot soft lead too.

[MtGun44]

Recommend 359477 or Lee 358-158-RF conventional lube. TL is likely to work OK at
.38 Spl pressures and vel, less likely at .357 Mag pressures and velocities. GCs are NOT
needed in pistol calibers with properly fitted boolits of a good design with a good lube.
Use NRA formula 50-50 with the above two, size to .357 or .358 and you should have a
very accurate load. For a nice warm .357 mag load with either boolit above cast in
air cooled wheel weight alloy, try about 16.3 gr of H110 or W296. This is a ~1" load at
25yds in several of my .357 mags with zero leading.

Bill

[LtFrankDrebbin]

Wow, thanks for the feed back. I will not give up on trying with the WC boolits will just settle on the RN for now.
Interesting pointer about the clocking of the cylinders thanks 9.3x62AL, I will follow up on that in the future. Just gunsmiths are a long way from me plus the time turn around will require a lot of patience.
Thank you all for the info, not to mention the compliments.

[x101airborne]

I know all about Colt Diamondback's and Python's reputation for accuracy. I bought a python from my dad and the thing wont shoot anywhere near my smiths. Wonder if we just got lemons?

The Lee 158 RF is what I settled on for 90% of my 38 / 357 loading. 9 bhn for 38's and 16 bhn for 357's. Like was said, that round shoulder really helps center the transition from cylinder to bore. And the flat point is really effective on game. I have even shot some hogs up close with the 38 load from a model 67 smith 38 using bullseye. My 357 loads for my 66 smith use unique. For a handgun giving only marginal results, try using as soft an alloy as you can. Maybe I just got lucky, but a buddies taurus was shooting bout like your diamondback with 12 bhn boolits. Ran out of that alloy and just to try it, I used some near straight range scrap boolits that I was using to slug throats. Cut the groups in half. This is my guess, but I think that the boolit was choking down in the throats then was soft enough to slug up once inside the bore. Stopped some of the leading issues also.

[x101airborne]

By the way, if you would like, I will make you some of those Lee RF's if you have not tried them yet. PM me if interested.