Best Boolit Alignment Technique in Revolvers

[ejcrist]

Up to this point in my life I've worked up some decent loads in my revolvers using both off-the-shelf boolit molds and semi-custom molds from Accurate. In an effort to squeeze every bit of accuracy out of my revolvers I'm curious about two things that might tighten up accuracy even more but I haven't found much written on the subject. One thing is to only neck size brass so the cartridges have a tighter fit, and the other thing is to order a mold with a longer front driving band for the SWC's I shoot so that they enter the throats by a few thousandths of an inch. I think either of these steps would improve accuracy to some degree.

The only downside I can think of using either option is in heavy recoiling revolvers where I'd worry the cartridges might be pushed back ever so slightly causing the cylinder to lock up when attempting to re-cock (SA's). Has anyone used either of these methods to improve accuracy? If so did you have any problems seating cartridges or with the cylinder binding? I'd appreciate any info or opinions.

[tazman]

I did something similar with full wadcutters in my 38 special. I sized the wadcutters to a light press fit in the cylinder throats. Luckily all my cylinder throats were the same size on the revolver I used for testing. I them seated the wadcutters long so that the boolit was just inside the cylinder when chambered.
This made the loading of the cylinder considerably more time consuming since each case must be pushed into position.
It did work quite well and accuracy was noticeably improved but the extra effort and time to reload the cylinder was too much for the games I play. Definitely didn't work for timed or rapid fire.
There also wasn't enough difference in accuracy to make it worth my time since I am not a competitive target shooter. It did work though, and might be worthwhile for a long range, un-timed event where accuracy is everything.
For heavier recoil, you would need to use a strong, roll crimp to hold the boolit in place.

[jcren]

Common practice now is to use lfn or wfn style bullets without driving hand shoulders. The idea is that the long taper of the bullet will self center more smoothly. Also, if you haven't had the cone done, get in touch with Dougguy.

[Groo]

Groo here
Having the forcing cone cut to about 11 deg helps with some guns.
The true Keith has a larger driving band in front , when fit to the gun it works well.
But they need fit to each gun.
The LFN , WFM, rnfp. or tc seems to be more tolerant .
Making sure there is no thread choke, and the chambers are not smaller than the bore makes the biggest difference.

[ejcrist]

I did something similar with full wadcutters in my 38 special. I sized the wadcutters to a light press fit in the cylinder throats. Luckily all my cylinder throats were the same size on the revolver I used for testing. I them seated the wadcutters long so that the boolit was just inside the cylinder when chambered.
This made the loading of the cylinder considerably more time consuming since each case must be pushed into position.
It did work quite well and accuracy was noticeably improved but the extra effort and time to reload the cylinder was too much for the games I play. Definitely didn't work for timed or rapid fire.
There also wasn't enough difference in accuracy to make it worth my time since I am not a competitive target shooter. It did work though, and might be worthwhile for a long range, un-timed event where accuracy is everything.
For heavier recoil, you would need to use a strong, roll crimp to hold the boolit in place.

Thanks for the info Tazman. That's very interesting. I figured it would improve accuracy but never talked to anyone that did it first hand.

[ejcrist]

Common practice now is to use lfn or wfn style bullets without driving hand shoulders. The idea is that the long taper of the bullet will self center more smoothly. Also, if you haven't had the cone done, get in touch with Dougguy.

Roger that on the WFN/LFN. Another one of the reasons I was asking is because I'm planning on going on a guided bear hunt in AK, black bear mind you not brown, and so I ordered the 45 caliber (for 45 Colt) 300 grain WFN mold from LBT just for the task. I was reading Veral's book again and remember him saying the same thing about the smoother transition into the throats. The only reason I didn't cast any WFN's in the past was I was worried about accuracy beyond 50 yards and I figured the SWC design might work better due to less resistance. Up till recently though I didn't consider bear hunting where the WFN would probably do a little better. Also I don't plan on shooting past 50 yards. It'll be interesting to compare the two designs accuracy-wise but as long as the WFN is close to the SWC I'll go with it. The SWC does an excellent job on hogs so I'll stick with it for that and NRA/IHMSA silhouette and everything less than bear unless the WFN does better out to 100 yards. Thanks for the input - much appreciated.

[ejcrist]

Groo here
Having the forcing cone cut to about 11 deg helps with some guns.
The true Keith has a larger driving band in front , when fit to the gun it works well.
But they need fit to each gun.
The LFN , WFM, rnfp. or tc seems to be more tolerant .
Making sure there is no thread choke, and the chambers are not smaller than the bore makes the biggest difference.

Do you know if the Keith driving band was large enough to seat the boolit into the throat? I'd think if it did it'd be the cat's meow. I don't remember reading if it did or not. By any chance do you know if the Keith's exact dimensions are available somewhere? I haven't tried to look it up but it'd be nice to know for both the 44 and 45 boolit, or at least one (the 44) and if it fit into the throat of a particular revolver that I know the dimensions of I can figure out if it'll work in the couple I have. Do you know the forcing cone angle in Ruger's? I think it's 5 degrees. Is the purpose of 11 degrees to give it a smoother transition (with less deformation) into the barrel? I'd imagine that would help quite a bit for anything even slightly misaligned.

I see where the WFN/LFN would probably tolerate the transition to the throat a lot better. I should've tried them when I was first developing loads but I never did because the 429421 and 45-270-SAA did so well, even not being "in" the throat when loaded. I've already worked on the 45's I have, except for a model 83 FA which didn't need any work. I still checked everything over but all checked ok and it shoots 45 Colts really well in the 45 Colt cylinder. The Rugers I have all needed the throats opened and equal but thankfully didn't have any choke issues that I could detect. I also used lighter Wolf trigger springs and smoothed out the trigger mill marks which made a heck of a difference. I also put Belt Mountain base pins in all except the FA. I've read fire lapping helps too so I might try that on one of the Rugers that shoots 1.5" groups out of a Ransom Rest at 25 yards - that's the best I've been able to get that particular revolver to do with the 45-270-SAA. I'm hoping the WFN or seating a longer front driving band boolit will improve it some. If not I might try fire lapping it to see if that helps; don't think it would hurt.

Anyway thanks much for the input, really appreciate it.

[Good Cheer]

Best way to go about it depends upon the diameter of the throat, rifling geometry and the bore diameter.
A bore rider design boolit can be a real winner.
This one is from 1981, expressly for a five groove wide land blued Security Six.

[DougGuy]

It totally comes down to fitment. They (we) say Fitment is KING and it is. That's really the bottom line!

You are right on track with seating the boolits into the cylinder throats, they are an alignment tool to guide the boolit to the bore and so they should be used as such. DO have your cylinder throats reamed .0005" to .001" over boolit diameter if the boolits don't slide into the throats with finger pressure and make sure they are all even.

I do agree with having boolits with an ogival profile more parallel to the forcing cone and less of a sharp shouldered driving band (which btw, WILL work as an effective alignment feature when seated out long enough to chamber with the band well into the throats).

If you are using a hard alloy, you will get by with a firm roll crimp and it will keep heavies from pulling crimp and moving forward under recoil. If you are using a softer alloy, these require more crimp as the boolit itself can swage and pull even though the part held by the crimp doesn't move. In this case the crimp will hold the middle of the boolit in place but the base of the boolit can creep forward which really messes with groups in a revolver something terrible. And if it moves enough, can lock up the gun if the front of the boolit hits the forcing cone.

I use a specially modded collet crimp die that cures all the ills in shooting a heavyweight boolit cast in softer alloy. I find ES to be less using this crimp also, as it provides a consistent resistance against bullet pull from primer ignition and gives slow burning powder just a few more nanoseconds to begin to burn before boolit movement occurs. (If you have ever tried to pull one of these boolits with a kinetic puller you will understand why this works)!

Details of the modded crimp die can be found here: http://castboolits.gunloads.com/show...=1#post2239315

Photos of the crimp, as you can see the crimp grooves in the Lee C452-300-RF boolit is not large enough to allow a decent crimp, the collet crimp will force a groove in the boolit where there is none, or it will force the existing crimp groove to open up enough to accept the crimp. Either way works great, and if you are in an area where your life could depend on the reliability of ammo and gun, I wouldn't use anything BUT this style of crimp. It just WORKS.

[Hickok]

Ejcrist, just passing this along. A 250 gr Keith, ACWW @ 1250-1300 fps from a .44 mag will completely penetrate a 200 to 350 pound black bear from most angles, both shoulders, or from head to tail. Consistantly. This is with a close range shot, with dogs, on the ground. Others may have different views, but this is just a small sampling from 4 kills from a bear hunting friend who uses my Keith boolits.

Just for sake of comparison, so you can gauge other calibers and boolits.