help with regulating loads to fixed sights

[scrapcan]

Well guys I need some help, or better yet a shooting buddy needs some help. We went out shooting 32 caliber colts (and others) yesterday evening. I took a little colt Police Positive in 32 S&W Long, he had a Colt Army Special in 32-20.

I have been shooting the Lyman 311252 and various powders. For particulars an this little guy you can refer to the gunsmith section for a thread tittle need a new barrel for a revolver. Nueces fixed me up with the barrel and it is working out pretty good. This is not the problem gun.

The problem gun is the 32-20. We shot several loads with 2 bullets. The 311252 and an RCBS 30-115SP with reformed nose to a flat point round nose both sized to .312 bore and throats slug at .310-3105. Main loads tested used unique at 3.7 grains under both bullets. Both loads grouped well but point of aim versus strike point was not good. Strike point for both boolits was about 4 - 6 inches left of aim point. No leading occurred and had lube star at muzzle. WE did not have factory or reloaded jacketed rounds to try. I gave him a box of 32 85 grn xtp bullets to try, but he has not loaded them yet.

Here are the big questions:
1) Would bringing the load up in velocity help this situation?
2) Is this a result of load or is something more drastic going to be required?
3) If more drastic measures what might they be and how might they be done?

All comments and criticisms welcome and allowed.

[scrapcan]

forgot to mention the point of aim vs point of impact was the same direction for both of us. Both off hand and off sand bags. Both of us are right handed and right eye dominant.

[Ricochet]

I wonder if the barrel (with the fixed front sight on it) may have become slightly misindexed?

[dubber123]

Changing velocity and or bullet weight may help to an extent, but 4-6 inches is awfully hard to make up. On the other hand, assuming right hand threads on the gun in question, turning the barrel in slightly will move point of impact to the right. Moving the front sight has the opposite effect of moving a rear sight. Moving the front sight to the left, will move impact to the right. A gunsmith should be able to do this fairly inexpensively. Hope this helps.

[scrapcan]

Thanks for the suggestions guys. I was worried about trying to turn the barrel due to age of the gun. Elevation adjustment is a no brainer, a small sharp file, and a way hold the revolter level, and patience will make a short job of it. I personally felt that there is no way that the load would cause that much shift after shooting the 115 RCBS. Then after 2 of us shooting the 311252 and the 115RCBS, I knew immediately something was up. Just thought I would verify with the rest of you.

Would it be best to have a gunsmith try to index the barrel?

Could a person file the rear sight notch to adjust point of impact? Any harm in doing so?

[Lloyd Smale]

for what a gunsmith will charge you to turn that barrel you can go to brownells and buy a barrel vise and do it yourself. Then either sell it to recoup your money or keep it for future use.

[joeb33050]

What range was the pistol shooting 4-6" left?
How was the vertical, too high, low or right on?
The 311252 is ~ 75 gr., is the RCBS bullet ~115 gr.?
Changing bullet wt. and/or velocity sometimes changes the impact point L or R, but I've not been able to figure out why or what causes L vs R.
If the range is 25 yards then the ratio sight to point of aim change is ~100:1, move the sights .040" and the bullet hole moves 4" on the target.
That's a lot for the sights to be off.
I'd try different bullet wts and loads before filing or turning anything.
I'd also have a left hander try the gun/loads to see if the POI changes.
Heavier/slower bullets = higher POI
Lighter/faster bullets= lower POI
at short ranges
Please keep us informed.
joe b.

[felix]

Joe, L to R and vice versa depends on the twist direction, accelleratin of boolit (powder speed and/or primer), weight of boolit. The torque generated, and its timing, in your hand. ... felix

[scrapcan]

Joe,

The 311252 is running about 80 gr in my alloy lubed and sized to 312. the RCBS 115SP is running about 118 gr lubed, checked, and sized to 312 in my alloy. the nose has been modified to flat round nose using a 311041 top punch. Both boolits are on the hard side (12-14 bhn uisng lee tester), but I did not have any staright lead to soften.

We were shooting at approx. 50 foot. I know why so close, well it was windy and it kept us well into the berm and out of the 22 mph left to right cross wind.

Both loads shot lower than POA, but expected that due to front sight height. Elevation is not a problem easily corrected.

We are planning to change charge and to try some jacketed to see if point of impact changes. He is finding out the curse of the thin 32-20 brass, but Mike learns fast only lost 2 cases out of a hundred learning the quirks of thin brass.

I am glad I am workign with the little 32 S&W long, it is just like the 38 special in that a one armed monkey can use about any recipe and get good results.

I will keep all of you updated. Hope to get out next week.

[mtngunr]

I was wondering the range, too......I NEVER advise messing with the gun until LOTS of shooting has been done.....simply pushing the trigger a little bit right can bring POI right in a dramatic way....I've lost track of how many guns I've owned that wouldn't group, or that grouped way off POA, that mysteriously got better with a lot of shooting.....I think it's a muscle memory thing where the body adjusts to adjust POI, by relaxing or tightening the grip, pushing the trigger one way or the other, etc etc.......benching the handgun MIGHT give you handle on grouping with a load, but will in no way give you a handle on POI compared to hand-held, so just throw out bench results for comparison in that regard......

[truckjohn]

On a Taurus 45 long colt revolver I am playing
with for the nephew.....

I found that seating depth, charge weight
and bullet would affect left to right impact
(shooting off bags)

For some reason, the ogive profile seems to shift
impact right and left.

Lowest charge fired today shot closest to aim point
(height just right, about 3" left at 25 yards.)
.2 grains heavier was 6" left at 25 yards.

Gonna try walking powder down .1 gr at a time
to see if it will center back up with decent accuracy
or not.

On your gun, if you have a pile of bullets
do 10 shot groups off bags:
1. Try backing off length in 0.01" increments from
your gun's max length for a given powder charge..
Do not do this with max charge, though.
or
2. Try adding/removing powder 0.1g at a time at the same
OAL to see if this makes any difference.

Good luck.

John

[44man]

Changing velocity will move impact back and forth.
Boolit design will also do it. I shoot four different boolits from my Vaquero that are very close in weight except one which is 12 gr's heavier. One hits left, one hits close to center and two hit right. This is all with the same powder charge.
Sometimes a powder change can move the POI. Sometimes boolit hardness too.
I would not fool with the barrel or sights until you exhaust loads and boolits. There is no way to predict it either, you have to hunt for it.

[9.3X62AL]

The 32-20 in a wheelgun can be an unholy bee otch to get shooting. The 32 SWL is genteel and polite.

I would get "spec loads"--115 grainers at about 850-900 FPS in the 32-20, and maybe leave the nose "as cast" to see what happens. SR-4756 is my "go-to" powder in this caliber for rollers, and many a shooter has found accuracy and consistency using unshouldered RN bullets in this application.

The 32 SWL ran 98 grain RN to about 750 FPS at the start of its life. Try that sort of load intensity and see what happens downrange. Shoot left-handed--GET OFF THE SANDBAGS--and keep plugging away until accuracy and consistency is found. EVERYTHING TOUCHING YOU AND THE SIDEARM INFLUENCES SHOT PLACEMENT, INCLUDING YOUR HANDS.

[32 20 Mike]

The 32-20 in a wheelgun can be an unholy bee otch to get shooting. The 32 SWL is genteel and polite.

I would get "spec loads"--115 grainers at about 850-900 FPS in the 32-20, and maybe leave the nose "as cast" to see what happens. SR-4756 is my "go-to" powder in this caliber for rollers, and many a shooter has found accuracy and consistency using unshouldered RN bullets in this application.

The 32 SWL ran 98 grain RN to about 750 FPS at the start of its life. Try that sort of load intensity and see what happens downrange. Shoot left-handed--GET OFF THE SANDBAGS--and keep plugging away until accuracy and consistency is found. EVERYTHING TOUCHING YOU AND THE SIDEARM INFLUENCES SHOT PLACEMENT, INCLUDING YOUR HANDS.

Al: I picked up a uberti P jr a few months ago in 32mag/ 32-20. It was dismal, shooting about 14 inches low and 10 to the right. I finally settled on 4.2 grs of Unique with a 115 gr blt. sized to .314. The "groups" went from 4 to 6 inches to about an inch at 50 ft. The bore was slugged at .310 so I started at .311, then .312. and still had problems hitting my hat. I then saw an art. by mike "vintura".He said that he had an original colt in 38-40 with the same problem, going to oversize blts. solved it. I then took my drill vice to the range and clamped it to the shooting bench. After about 200 rounds and s-l-o-w filing I have a fun tight shooting pistol. I also picked up an original Winchester, fixed cal., reloading tool in 32-20 (32WCF) ,on Ebay. It loads faster than a single stage press and only neck sizes to save the brass. Ps use a Lee trim die stem for the decapping pin. drops right in. Mike sjso, retired

[44man]

Even the bearing length of a boolit and how it is distributed across it's length will change POI. Too bad it can't be worked out on paper before choosing a boolit.
I just don't like fixed sight revolvers! I only have one, the Vaquero, but have made it shoot good enough to drop a deer in it's tracks a few seasons ago, at 100 yd's.
I even made this sight for it once. It slides over the front sight and is held by two tiny set screws. It is just brass pieces soldered together and can be shaped or offset any way you want. It held up to hundreds of very heavy boolits and loads without moving.