Fixed Sights and Point of Impact

[35Whelen]

I've just bought a little Rossi 68 38 Spec. with a 3" barrel and fixed sights. Not a bad shooting little pistol at all save for the fact that at 20 yds., loads hit about 6" above point of aim. The principles of physics don't seem to apply here either. My standard handload with a 148 gr. hollow base full wadcutter at 600-650 fps hit a full 6" high at 20 yds. Conversely, a handload driving a cast gas checked SWC weighing 167 grs. at 760 fps only strikes about 3" high. A 158 gr. commercially cast SWC at 900 fps strikes around 5" high. Many other loads give equally strange results. It seems that possibly handloads with the slower burning powders such as Blue Dot have a slightly lower point of impact than loads assembled with Unique....'though that makes no sense to me. The pistol has quite small grips and fairly ferocious recoil with some of the loads. Likely some of the problem is lack of recoil control is due to the small grips. Anybody dealt with this problem? I'd like to use the heavier SWC bullets. Any suggestions or simlar experiences?
  Thanks!!

[oso45-70]

35whelen,
Its been my experience that the heavier bullets will shoot higher than the lighter ones will. You can change the point of impact a bunch by trying different loads. On some of my fixed sighted gun i have a different load for each of them. You might try some 180 gr cast loads and see what happens. you may have to vary your loads to get the results you want.
Good Luck........Joe.........

[35Whelen]

Joe that's been my experience too, until now! One would think that a 148 gr. HBWC at 600-650 fps (low B.C., low velocity, low recoil) would shot much lower than, say a cast 150 gr. SWCHP at 855 fps (higher velocity, much more muzzle flip/recoil). 'Tain't so with this pistol. Maybe some of the other guys on this board will have experience with this. My next step is to try some larger grips and work up some loads using 2400 with the heavier SWC's.
  Thanks.

[unspellable]

You guys are dealing with a problem that us double rifle shooters deal with day in and day out.  With the typical double rifle you not only want the load to shoot to the sights but also both barrels to the same point.

First a term, "jump" which is that part of recoil which occurs before the bullet leaves the muzzle.  That part of recoil which occurs after the bullet leaves has no bearing on this problem.

There are several variables at work here.  All considerations are for short ranges say 15 to 25 yards.  At longer ranges bullet drop becomes significant.

A heavier bullet at a given velocity will tend to strike higher as it produces more jump.

A given bullet driven faster will tend to strike lower due to a shorter barrel time reducing the jump.

A given bullet driven at a given velocity will strike lower using a small amount of fast powder or will strike higher using a larger amount of slower powder.  Faster powder will reduce barrel time, larger amount of powder will increase jump.

Last but not least, there is rule number one.  Given the tightest conceivable control of all the pertinent variables, the gun will do as it damn well pleases.

[Mikey]

35Whelan:  The advice Unspellable provided is quite accurate and also quite true - the dang gun will do what it wants to do.  But, Oso45-70 is also right on.

I can tell you from experience that the little snubbies will jump on you and that will have a tendency to help throw off your point of impact.

I would find myself another pair of grips, ones that give you a bit more to hold onto between the rear of the trigger guard and the grip frmae - that has helped me.  Either Hogue or Pachmyers should help there.  Also, the is a gizzy out there called the Tyler T-Grip that just fills in that space I mentioned and helps with the grip.  

As for your different loads hitting in different places.  Sometimes the sights on fixed sight pistols are regulated for longer distances than 20 yds.  Some might even carry the old regulation of 50 yds.  If so, your poi should be high at 25 yds and dead on at 50, if you were going to shoot a snubbie at 50 yds.  You may have to play with it it find the load that hits where you want.  One of my favorite loads, in fact it is my favorite, is a 200 gn swc/rnfp over 3.8 of WW 231.  It lists 770'/sec but probably only gets about 700 from a snubbie.  Pretty accurate from my snubbies and a standard pressure load too, this is not a +P load.  HTH.  Mikey

[PA-Joe]

Once you get your bullet combination figured out try adding layers of electrical tape strips to the front sight to raise it a little at a time. When you figure out how much the front sight has to be raised to lower your point of impact this is the amount that you will have to file off of the rear sight. Once you lower the rear sight remove the tape! Go slowly and keep rechecking. I would not start filing until I am happy with the bullet combo and grips.

[Savage]

35Whelen,
Actually, unspellable put his finger on the problem. Your gun starts to recoil the instant the powder charge starts to burn. Slow heavy bullets take longer to exit the bore. All the while the gun is rising in recoil. On the other hand, a lighter bullet at the same velocity (or slightly greater)produces less recoil and remains in the bore a shorter period of time. All this ammounts to less muzzle rise durring the propellant burn = lower point of impact. No doubt, better grips would reduce the ammount of muzzle rise durring firing as well. With a corresponding loss of concealibility. I would be curious as to what load and distance Taurus requlates the sights on this snubbie.
Savage

[Savage]

35Whelen,
Just reread your initial post. You do indeed have a grasp of the laws of physics, and yes, they do apply. I'd try a good set of oversize rubber grips and give the gun another try with a good rest. Good luck!
Savage

[35Whelen]

Thanks for all the help guys. I feel silly as I've been reloading for 25 or so years now and feel like I oughta be able to lick this problem.
    Mikey, as for your load, I don't have any W231 anymore and really hate to buy a can for my burgeoning powder cabinet. I do have Bullseye and standard Clays. Would a comparable charge, 3.8 or so grains work? My heaviest bullet is 168 grs.; the Keith variety and the gaschecked Thompson type.
    Savage, the reason I said physics don't seem to apply is because my standard plinking load of 2.5 grs. of Clays behind a 148 gr. HBWC running 600-650 fps has about the highest point of impact. While a 167 gr. SWC @ 760 fps has the lowest POI. WEIRD!!! I fully understand the heavier bullet striking higher due to lower velocity (more time in the barrel), more muzzle flip, etc. Anyhow, I am going with my instincts and getting some larger grips.

[Mikey]

35 Whelan:  HP37 duplicates the WW231 charges, if you have any.  But, for the 168 gn Keith style swc, the book (Lyman) accuracy load is 8 gn of 2400 powder for 700'/sec (from a 6" revolver).  With Bullseye, 2/5-3.3 gn gives 660-788'/sec.  I'm sorry, but I don't have any charge loading data for Clays.  For Unique however, 3.0 - 5.0 gives you 585-913'/sec.  With 2400 you can go all the way to 10.5 gn for slightly better than 1000'/sec.

I think the process to follw would be as you specified - get some good grips on that gun first, and then see where your preferred load hits.  Once you have reached that point, I would follow the other advice to use some material to raise your front sight to bring your bullet to poi at your preferred distance.

You didn't mention if the revolver was blue steel or stainless.  If blue, you can use material such as the 'Cold Weld' compounds, and add a small bit to the top of your front sight, see where she hits and adjust accordingly.  HTH.  Let us know how it goes.  Mikey.

[Doc T]

To regulate point of aim with handguns follow these rules:  To raise bullet impact shoot heavier and/or slower bullets.  To lower bullet impact shoot lighter and/or faster bullets.  Hope this helps.

[oso45-70]

Doc T
Thats what i was trying to say, You got it said with a lot less words. Never was to sharp with words though. Have a good day Doc. and stay safe.........Joe..........

[bgjohn]

Once you get your bullet combination figured out try adding layers of electrical tape strips to the front sight to raise it a little at a time. When you figure out how much the front sight has to be raised to lower your point of impact this is the amount that you will have to file off of the rear sight. Once you lower the rear sight remove the tape! Go slowly and keep rechecking. I would not start filing until I am happy with the bullet combo and grips.

 :? Why not just solder something on the front sight instead? :wink:
JM