bullet size for S&W 629

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  • Last Post 09 June 2016
TDW posted this 07 June 2016

Have been sizing my bullets at .432 for my rugers and getting good accuracy and no leading. Now that i have a new 629, my .432 bullets are giving me leading issues. ( using wheel weight lead ). The smith cyl. throats are .429 and the barrel is .430. Before i buy a .430 sizer, does anyone think this will solve the problem? I'm guessing reaming the throats to .432 would be the best choice, but looking for an easier choice. Thanks for any thoughts. Forgot to mention, these are powder coated bullets.

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Premod70 posted this 07 June 2016

I'd ream the throat, a lead bullet once squeezed to .429 will not spring back to seal a .430 groove and will lead like crazy.

Forrest Gump is my smarter brother.

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Ed Harris posted this 07 June 2016

My S&W Model 544 in .44-40 has .4285 cylinder throats and .429 barrel. I cast Accurate 43-230G in 1:30 alloy from Roto Metals and have no issues with loads as hot as the revolver will handle.   My bullets are NOT powder coated, but lubed with Lee Liquid Alox.   I expect that tight cylinder throats are scraping the powder coating off and that you are shooting naked lead down the bore, which is why you are getting leading.  I believe that conventional lubrication which maintains original bullet diameter is the answer in your case.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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M3 Mitch posted this 08 June 2016

While a soft enough bullet will slug up given a high enough pressure load, would it actually make more sense to have cylinder throats opened up to .0005 or so over barrel bore diameter? Wouldn't this give more consistent accuracy with cast?

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mtngun posted this 09 June 2016

I had (actually still have but it has been retired for some time) a Dirty Harry era M29 with 0.433” throats and a 0.430” barrel.   A 45 ACP bullet would drop into the forcing cone.  :D   I tried the full spectrum of BHN, from pure lead up to hardened wheelweight, and many different lubes, yet accuracy was never satisfactory with plain base bullets, and leading was always present in the forcing cone.

Switching to a GC design sized 0.432", and using at least a medium hard alloy, solved the leading problem, and made accuracy decent (3” 5-shot groups at 50 yards).

Later, just to see what would happen, I turned the necks on a few cases so that 0.434” plain base bullets could chamber.    Those heat treated 0.434” plain base bullets did not lead.    That was the one and only time plain base bullets did not lead in that sloppy M29.

I vote for reaming the OP's throats to 0.430"- 0.431” if he can find someone who has the proper tools to do a good job.

I assume the OP has also verified that there is no choke where the barrel screws into the frame.

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TDW posted this 09 June 2016

I'm back to give some more info on the handloads i am using. First let me say what i'm looking for in a load. Since i have a ruger flat top 44 special shooting a keith 250 scw at 950 fps and a SBH hunter for full power loads, i am looking for an in between load for the 629. I'm looking for a 240-250 gr. bullet at around 1100 fps. The load i was trying was 10.5 gr. of W231 with a lee 240 swc or the keith 250 swc. Velocity with either is around 1120 fps. The lee bullet is a gas check design but i powder coat my bullets and can usually shoot them without a gas check with no problem. The keith bullet is a flat base. The lee bullet was more a problem with leading than the keith. Going to try backing off the load a little and gas check the lee bullet and see what happens. I did try a lee bullet with lee alox(no powder coat and no gas check) and was able to recover two bullets. Very obvious that the hot gases got around the bullet. going to keep trying. Open to suggestions.

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M3 Mitch posted this 09 June 2016

Read through the Lee Handbook section on matching alloy hardness to cartridge pressure. A regular grease lubed bullet has at least a chance to slug up enough to give decent accuracy in your 629 as-is. The alloy strength just needs to be matched to pressure.

I think that if you want no-hassle accuracy, though, getting someone to ream the throats, make sure the fired brass will easily accept a .430 to .431 bullet, if not, the chambers need to be reamed some too.

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