44 Mag Throat Diameter

[fredj338]

my current loads do drop in the cylinder fine, they are tight to exit though. Based on your comments, do you agree I should try and resize the bullets to .429? My main concern here is to reduce the crazy leading I'm getting. Am I following the right path? I'm not currently looking to mod the gun at all if I can help it.

Thanks,

Dan

IMO, a 0.429" bullet is likely to lead early in the bbl. It matters little if you size it to that size, the throat will size it for you on firing. An undersize bullet entering the bbl is just that, regardless of how it gets there.
I would rather open the cyl up. Any good grinding outfit can do it. A buddy of mine has such an business & showed me how to run his machine & I did my own on a RBH in 45colt. The cyl throats were very tight, like 0.450" or a bit less. I opened them them to 0.4515" for a .0452" bullet. Accuracy got better & leading was reduce. I am a believer.

 

[M29since14]

Dan, don't go smaller with your bullets. If necessary, open the exit bores of your cylinder to 0.4300 - 0.4305". The correct way to do this is with a honing machine. Remember to keep your bullets the same size as the exit bores, or a bit larger.

I have not used Blue Dot in .44 Magnums but you might try some other powder before you ship your cylinder off for honing. I am very partial to #2400, though I will begrudgingly admit it is not the only powder for .44s. Give 18.0-19.0 grs. of #2400 a try (standard primers) and see if your leading situation changes. I'd think it would be worth the cost of a pound of powder.

 

[BLUEDOT37]

Measure throats

We then took a look at the throat dimensions and I was surprised to find the throat was so tight... my current loads do drop in the cylinder fine, they are tight to exit though.

You didn't say exactly what they measured & tight to exit isn't very specific. If you can measure the throats & post it that would be helpful.

My 29-2 has .4325" throats & has always been very accurate with .430" cast lead & 17gr/2400 for some reason. Wish my SRH 454 was as good.

 

[fredj338]

You didn't say exactly what they measured & tight to exit isn't very specific. If you can measure the throats & post it that would be helpful.

My 29-2 has .4325" throats & has always been very accurate with .430" cast lead & 17gr/2400 for some reason. Wish my SRH 454 was as good.

SLightly larger throats are often not an issue. IT's the smaller throats sizing the bullet down before it gets to the bbl. Really excessive throats, like some of the M25s @ 0.455", won't do as well with cast. I size all my 44s to 0.431" for several guns. Better slightly large than slightly small.

 

[catfish_dan]

thanks for all the info, sorry for not including the throat diameter.

I measured .428 by running one of my cast bullets through the throat. There was some rebound since I still can't easily push the bullet through the throat but I measured .428 with a micrometer so it's probably slightly smaller yet.

I ordered a .427 sizing die as a trial to see what the effect would be of matching the bullet closer to the throat. I figured that would be a simple test before considering to have the cylinder modified.

Also, another question. I reviewed the SAMI spec and was not sure I read it right but it looked as though the spec was .4325, wouldn't that mean my cylinders were out of spec?

Thanks,

dan

 

[M29since14]

IMO, a 0.429" bullet is likely to lead early in the bbl. It matters little if you size it to that size, the throat will size it for you on firing. An undersize bullet entering the bbl is just that, regardless of how it gets there.

Exactly right, IMO. If your exit bores measure 0.428" I would sure consider opening them to 0.430" for use with 0.430" bullets.

Matching the bullet size to the exit bores is generally helpful as long as the exit bores are larger than your groove diameter. If smaller, the bullet is going to rattle around going down the barrel with the usual problems.

 

[catfish_dan]

M29,

My plan is to get the exit bores opened up. I ordered the .427 sizing die to satisfy my curiosity since that should leave the cast rounds close to the exit bore but larger than the groove diameter.

I will also try some 2400 with the test loads if i can find any.

Thanks for the info/advice.

Dan

 

[fredj338]

M29,

My plan is to get the exit bores opened up. I ordered the .427 sizing die to satisfy my curiosity since that should leave the cast rounds close to the exit bore but larger than the groove diameter.

I will also try some 2400 with the test loads if i can find any.

Thanks for the info/advice.

Dan

How? I doubt the groove dia is less than 0.429", so sizing the bulelts smaller will play havoc on accuracy & leading. You are going the wrong way. As noted before, if the cyl throats are smaller, that is the size the bullet will be, regardless of what it starts at. The result, it then has to bump bacl up as it hits the rifling. If it's soft enough, it bumps early & you may get decent accuracy w/ a little leading. If it's too hard, they may not bump at all & accuiracy will suffer & you should get leading for the first half of the bbl.
Undersized bullets just do not shoot well in anything IME. SO intentiopnally sizing smaller, why? Fix the gun or don't shoot lead. It won;t matter as much with jacketed, but you'll never get realyl good accuracy shooting an undersized bullel.

 

[M29since14]

...since that should leave the cast rounds close to the exit bore but larger than the groove diameter.

Dan, no, you've got it backwards. It is almost certainly going to leave them SMALLER than groove diameter (as Fred points out) so you want to go the other way with both exit bore size AND the size of your cast bullets. I'd increase both at least to 0.430", always keeping the bullets as large or a bit larger than your exit bores. But don't get carried away! Remember, you can always make them larger - pretty tough to make them smaller.

 

[DGNY]

Don't have too much experience with enlarging chamber mouths, but had two tight-chamber mouth S&Ws done by a professional 'smith. My 696 no dash 3" and 629-4 4" both ran .4280 -.4285 and were at best 2.5" @ 25 yd guns. Now under 2" with lead and factory jacketed, after both relieved to .430.

My .44 mags that are around .430 are definitely more accurate than the one or two that are .432 or .433 in chambers [e.g., Ruger SBH 4.625" @ .433]. [Of course, realize that if bores huge, that is another issue - as with my .41 Ruger BH OM with .410 chambers and .412 bore...].

Regards,

Dyson

 

[fredj338]

My 29-2 is .430 on all cylinders. 8 3/8 scoped & magna ported. I have owned since the early 80s. It shoots lead ok but jacketed bullets with a close to max loads it is a star @ 100 yards. I never measured it until yesterday when I saw this post

I imagine it would depend on the size of the lead bullets you are using. FOr me, nothing a proper lead bullet won't do in a big bore as well or better than jacketed, at any handgun vel. My RBHB scoped will do 3" or slightly better from a rest @ 100yds using a 2x scope with good lead bullet loads. FWIW, your Magnaporting may be the issue w/ lead bullets.

 

[catfish_dan]

great info, thanks. I'm just waiting on a reply from S&W before I look to get the throats opened to .430. I emailed S&W asking why the throats are so close to being out of spec relative to SAAMI. In the SAAMI docs, the throat is listed as .4325 +/- .004 which leaves a throat of .428 just barely within. After a reply, I'll be looking to find someone reputable to do the honing.

I am so glad I found this forum because before this I never considered reviewing the specs on my gun. I thought my leading issues were a result of too soft lead. I even went so far as to start electroplating my cast rounds. Came out pretty good too, I was plating 50 rounds at a time with a nice hard shiny coating. I was shocked when I tested the rounds and they leaded horribly too. Live and learn

 

[M29since14]

Getting your bullets the right size for your gun (and/or adjusting the gun to properly sync exit bore size with groove diameter) will make a believer out of you. Small exit bores may work fine with jacketed, I wouldn't know, but I do know they are miserable with lead. "Soft" cast bullets are usually not a problem with most handgun loads unless the barrel is exceptionally rough or the metal has been contaminated.

 

[catfish_dan]

last S&W I'll ever own. PERIOD. Just got off the phone with customer service and they are the worst I've ever experienced bar none. I may just use this piece as a boat anchor just in spite. I've dealt with other manufacturers and this was my worst experience. Good luck to everyone else on here you have all been most helpful and I really appreciate the advice and assistance.

 

[C17]

last S&W I'll ever own. PERIOD. Just got off the phone with customer service and they are the worst I've ever experienced bar none. I may just use this piece as a boat anchor just in spite. I've dealt with other manufacturers and this was my worst experience. Good luck to everyone else on here you have all been most helpful and I really appreciate the advice and assistance.

That sucks. S&W just replaced my cylinder because the throats were too small. I have. 625-8 and they only had it a week. Granted I had to fight with them to send it back, but they eventually did. Not all customer service guys are created equal. I had one guy from S&w tell me to shoot smaller bullets! I told him I wanted to shoot the caliber bullet stamped on my barrel. Call back and ask to talk to a supervisor. They will fix your gun, but if you let a non S&W smith screw with it, your warranty will be void.

 

[BLUEDOT37]

I'd try again

last S&W I'll ever own. PERIOD. Just got off the phone with customer service and they are the worst I've ever experienced bar none. I've dealt with other manufacturers and this was my worst experience.

I too would suggest you call again & talk to someone different. When I had to deal with CS for my 325NGs problem, some people were helpful & informative and some were jerks & you just wanted to smack them, but it got repaired. Try again.

 

[fredj338]

last S&W I'll ever own. PERIOD. Just got off the phone with customer service and they are the worst I've ever experienced bar none. I may just use this piece as a boat anchor just in spite. I've dealt with other manufacturers and this was my worst experience. Good luck to everyone else on here you have all been most helpful and I really appreciate the advice and assistance.

ANY good polishing/grinding shop can do this job. All that is require is an ID honer. I did mine @ my friends grinding shop in about 20min after he set it all up & showed me how. A set of pin gages or ID micrometer are the ONLY way to accurately measure cyl throat ID, a caliper won't get it done.

 

[catfish_dan]

yah, now that I've cooled down a bit, I might call CS back an try again. I am looking for a shop with a honing machine now in the event that S&W fails.

I verified the throat dimensions with a mic(pushing a lead round through) and gauge pins so I know where I'm starting. I'll try and get the throats to .430. When I manage to get the mods done I'll come back and let everyone know how I made out and the results.

Thanks again folks

 

[jepp2]

I am looking for a shop with a honing machine now in the event that S&W fails.

You can't go wrong with Bowen Classic link

 

[M29since14]

You can't go wrong with Bowen Classic link

True enough. Last I knew Mr. Bowen was still doing the work for a reasonable sum. Once the right mandrel is in the machine and trued up, this is such a simple procedure that it is probably one of the "best bang for the bucks" jobs a gunsmith can do. Might check with him. I seriously doubt S&W will do anything with your cylinder as long as it is within the range of the factory's tolerances.