Finally - some .44 slug & bbl measurements

[ghh3rd]

Now that I have a micrometer (used Starret), I have slugged the cylinder and barrel on my Ruger SBH .44

The cylinder throats are .432, barrel is .430. and the three types of cast boolits I've been casting are .433 .432 and .429.

The .429 is the Lee 310gr which I've been using the most of. I can literally drop the 310gr boolits through the cylinder without it slowing down. Even as such, the last four targets with them last weekend had 4's and 5's of 6 rounds in the 2" ring at 50 yards. Perhaps the gas check helps it somehow?

Is .002 to big a difference between cylinder and barrel? Is boolit diameter that's same size as cylinder throats OK?

Since my cylinder throats are all .432, the only molds I should be using are those that provide at least .432 boolits - correct?

I think that perhaps it's time to investigage lapping or beagling my 310gr mold.

Thanks - Randy

[462]

Those dimensions are the same as mine S&W Models 624 and 24. I cast and size a Lyman 429421 to .433".

[44man]

That seems awful small for the Lee 310. What kind of lead are you using?

[RobS]

Your cylinder throat to groove diameter is fine.............in fact most people would love it for cast boolits. Sizing to cylinder throats is good as it leaves the front drive band of the bullet at a diameter that will give it the least about of slump. What I mean is if you have a smaller bullet then it will be able to move around more in that cylinder throat prior to shooting which leaves for a bullet that isn't directly centered up where as a bullet that fits the cylinder throats as it should will not have this issue. Now is this a huge issue...........no not terribly at all..........but less variables means more accuracy (or at least in theory of the prefect world we live in). I usually let my guns determine what works best.

Some people have great success actually sizing a bit over the cylinder throat diameters as well. As to one way and one way to another for it has worked well in all directions for a variety of individuals. If it were me............I would say to size to the cylinder throats or a bit over. If you are planning on using harder alloy then size to the cylinder throats and if you are planning on shooting softer lead (12 BHN or lower) then I would size at or a bit over as many times a softer bullet such as this will size down a bit during the seating and crimping stage of reloading.

The gas check most definately helped you out on the .429 bullet but it does amaze me that is is only dropping out at that diameter. Lee 310 grain 44 cal bullet usually drops out a bit larger say......... .431-.432 from wheel weights. If you are using an aloy similar then, you have to love Lee's quality control

[Edubya]

Now that I have a micrometer (used Starret), I have slugged the cylinder and barrel on my Ruger SBH .44

The cylinder throats are .432, barrel is .430. and the three types of cast boolits I've been casting are .433 .432 and .429.

The .429 is the Lee 310gr which I've been using the most of. I can literally drop the 310gr boolits through the cylinder without it slowing down. Even as such, the last four targets with them last weekend had 4's and 5's of 6 rounds in the 2" ring at 50 yards. Perhaps the gas check helps it somehow?

Is .002 to big a difference between cylinder and barrel? Is boolit diameter that's same size as cylinder throats OK?

Since my cylinder throats are all .432, the only molds I should be using are those that provide at least .432 boolits - correct?

I think that perhaps it's time to investigage lapping or beagling my 310gr mold.

Thanks - Randy

Now why in hades would a fella want to fix something that is not broken?

EW

[ghh3rd]

Now why in hades would a fella want to fix something that is not broken?

Cause I want 5/5 :-) (or 4-5 of 6 at 100 yds)

[cbrick]

Now why in hades would a fella want to fix something that is not broken? EW

Because "broken" is a relative term. What is braggin groups for one person is back to the drawing board for another. It all depends on what your willing to settle for, what your attempting to acheive and how much your willing to learn.


The cylinder throats are .432, barrel is .430. and the three types of cast boolits I've been casting are .433 .432 and .429.

Is .002 to big a difference between cylinder and barrel? Is boolit diameter that's same size as cylinder throats OK?

Since my cylinder throats are all .432, the only molds I should be using are those that provide at least .432 boolits - correct?

I think that perhaps it's time to investigage lapping or beagling my 310gr mold. Thanks - Randy

No, .002" isn't too large a difference. It would be if the measurements were reversed, ie, larger bore than throats.

You didn't mention your load or your alloy but were it me I would test each diameter boolit at 50 yards or preferably at 100 (I test revolver loads at 150 and 200) and keep careful notes. I would do this testing before doing any lapping or beagling so that you can learn what the effects of different diameters might be causing.

From an accuracy view normally a mild snug fit in the throats with a boolit that's long enough to be chambered with the front driving band seated inside the throat will give the best accuracy at longer distances. If they are hard to chamber you should size down in increments of .001" until they chamber easily.

Rick

[MtGun44]

Sounds like you are in pretty good shape. Try .432 at first (beagle the mold if necessary)
and shoot enough to KNOW how it works. Then try .433 and see if it is better. I usually
have found about .001 is more accurate in my S&Ws, but some do just fine at throat diameter.
Actually a few do OK at -.001 on throat diam, but that is not the norm.

I need at least 3 sessions of 2-3 groups each time with a load before I am SURE what it is doing,
given the differences in conditions and the jerk behind the trigger from day to day.

Bill

[ghh3rd]

That seems awful small for the Lee 310. What kind of lead are you using?
WW +2-3% tin. I've had same results now with the 6 cav and 2 cav. I have decided that I will lap the 2 cav. It will be a learning process.


I would test each diameter boolit at 50 yards or preferably at 100 (I test revolver loads at 150 and 200)
Unfortunately, no scope on this gun yet, just an ultradot set at the smallest dot, so 50 is plenty far for me.


Try .432 at first (beagle the mold if necessary)

I tried to beagle the mold which worked, sort of. My tape turned out to be .0015 (minus the glue), so I had to use two layers. I was seeing a ridge line on the boolits, but no fins. However, when I sized them to .431 parts of the grooves were being swaged off. I have lapped my Lyman sizer from .431 to .4325 tonight, so perhaps I'll try beagling again before lapping the mold.

[Bret4207]

Okay, this part can get confusing for some folks. Your measurements and groups indicate you have a load that works in your gun or at least that wants to. In this particular instance it would be nice if your 310 boolit was a couple thou fatter, yes. BUT- remember that you have a big long heavy boolit and if memory serves there's a very good chance that your boolits leading edge is striking the forcing cone when part of the boolit is still well within the chamber, if not the case. With an adequate powder charge you'll get some obturation at this point and I'd hazzard a guess that's fitting the boolit to your barrel.

Back to the confusing part- Yes a fatter boolit would be "better". Fit is King, no doubt. But in this case you're getting by using obturation to at least somewhat fit the boolit. While it's best (IMO) to fit the boolit prior to firing many people find success by booting the boolit hard enough to obturate or swell the boolit. You have a case where it works, with a lighter or shorter boolit in your alloy it might not work at all.

Your 4/6 groups might tighten with a fatter boolit or a different load. You have lots of room to play here. Have at it.