Lower POI .45 Colt question.

[AJ]

Have a kind of neat old hand cannon. I have a Colt New Service ,45 with a two inch barrel, With a load of 5.6 grains of Bullseye with a 250 grain cast RN bullet, it hits about 6 inches lower that POA at 7 yards, Looking for a loading that will hit closer to POA than that. Faster or slower I guess would be the question. Ideas welcome! TIA

 

[venomballistics]

usually we go to a heavier bullet and higher velocities to get more muzzle rise.
But what you describe sounds like some wild geometry with a lot of angle to make up. You might do well to read up on how the late Elmer Kieth used his sights. That might get you closer to a solution than loading alone

 

[Nevada Ed]

+1;

maybe try just half of the front sight blade,
set up in the rear sight,
and see if the bullet impact is closer to your wanted, POA ?

 

[alwslate]

Your Colt has been altered with a new front sight that is way too high. File it down until bullet impact is where you want it.

 

[StrawHat]

Where does it hit at twenty five yards?

Kevin

 

[ArchAngelCD]

A lighter bullet will raise the POI.

 

[AJ]

Where does it hit at twenty five yards?

Kevin

Kevin,

Don't know, with a 2 inch barrel wasn't going to try it. It was about 8-10 inches low at 15 yards.

AJ

 

[STORMINORMAN]

Your Colt has been altered with a new front sight that is way too high. File it down until bullet impact is where you want it.

Without a doubt lowering the front sight will raise the POI: the suggestion to "try about half" should get you closer vis-a-vis the POA. Whether it will be at 7 or 15 yards or longer is the BIG question. Fixed sights are almost always a compromise... That, and your intended use.

Looks like that has a hi tech refinish of some kind: any details?

Cheers!

P.S. If I'm reading the Alliant load data correctly you should have significant wiggle room vis-a-vis increasing the velocity (as in up to 7gr), but with such a short barrel... Have you tried more powder, AJ?

 

[ArchAngelCD]

IMO unless you are going to commit to using that 1 load and only that load I don't usually like modifying the front sight. Once you take off the material it is very difficult to build it back up again.

Above I said a lighter bullet will shoot higher. If you want to keep using the same bullet if you decrease the velocity it will also shoot higher. I'm thinking a charge of 5.0gr or 5.1gr instead of 5.6gr Bullseye might give you what you're looking for.

Bullet weight and bullet speeds are easier method to change the POI vs POA.
Good luck, be safe...

 

[alwslate]

Sorry but lighter bullets always impact lower on the target than heavier bullets. In my handloads with cast bullets in AR brass for .45 acp revolvers 185 gr bullets may impact as much as 8-10" below 255 gr SWCs at only 15 yds. It's a matter of recoil and time. Recoil is more with heavier bullets raising the muzzle more before the bullet exits the barrel. If you don't believe this try it yourself and find out.

 

[OFT II]

A lighter bullet will raise the POI.

I thought that a heavier slower bullet would raise the POI.

 

[glenwolde]

Sorry but lighter bullets always impact lower on the target than heavier bullets. In my handloads with cast bullets in AR brass for .45 acp revolvers 185 gr bullets may impact as much as 8-10" below 255 gr SWCs at only 15 yds. It's a matter of recoil and time. Recoil is more with heavier bullets raising the muzzle more before the bullet exits the barrel. If you don't believe this try it yourself and find out.

That's been my experience too. To raise the impact point I'll use a heavier bullet and/or reduce velocity.

I like to refer to it as "barrel time". If you increase the amount of time the bullet is in the barrel, the recoil has more time to raise the muzzle before the exit. It's harder with a 2" barrel, and he's already got a heavy bullet moving slow. But if he can find a heavier bullet, or reduce the velocity, he should try that first.

There's not much front sight to file down. The right way to fix this is to ditch the ramp and have an old-school blade put on it. That's hard to do too what with the refinish.

 

[alwslate]

I thought that a heavier slower bullet would raise the POI.

Yep, a common complaint with J frame S&Ws is that 125 gr JHPs shoot below the point of aim compared to factory 158 gr RN ammo.

 

[rockquarry]

I'm well aware of the claim that "heavier bullets will shoot higher" in handguns and have always found it to be valid. However, it's possible there could be an exception to the rule with such a very heavy bullet in a very short barrel. The original poster is probably getting such a low velocity (maybe 650 fps or so?) with this weird combination that the rule we all assume is correct doesn't apply.

I'd try different bullets (perhaps the same or similar weight as that already used but different design) and also lighter bullets and a variety of powder charges before I tampered with the front sight. Point of impact from a benchrest will be different than shooting offhand, perhaps significantly different, 6" or even more in elevation. Test at 25 yards to easily weed out loads providing poor accuracy, then test offhand in the preferred non-rested stance.

Yes, a lot of trouble that may only lead you back to the "heavy bullets shoot high" principle, but it would beat speculation. Then you go to work on the front sight, or have a good gunsmith do it.

 

[2152hq]

Unless it's just the picture playing tricks,,it looks to me like the top edge of the front sight is not parallel with the sight line. Nor is it slightly tipped downward towards the muzzle to give a good shadow pic of the front sight blade.

The front sight blade is tapered upwards like a small ramp towards the muzzle if I'm seeing it correctly.

So I expect that the shooter will use the front/forward edge of the front sight blade as the 'sight picture'.
That is somewhat higher than if the sight blade were filed straight on top or a slight downward taper towards the front and the shooter uses the rear face of the front blade in the sight picture.

That small difference my be enough to make the gun shoot to POA and would not make the front sight look unreasonably small in height on the ramp.

Hope I explained it OK.

 

[zeke]

The problem with commonly held beliefs', is the occasional exception. Am fond of 200 lrnfp in 45 colt, and most of the Rugers owned have the front sight filed down to accommodate the significantly lower poi at 25 yds.

However have found one exception to the lighter bullet always shoot lower than the heavier in a 44 mag Mt. Gun. At lest in my hands, and others certainly differ, a full on 180 jhp hit noticeably higher than a lightly loaded 250 grainer at 25 yds. Attributed this the significant difference in power in a lighter revolver, and others with better control may not see same results.

Good idea to check the poi at 25 yds, just because the sight radius is so short. Would also consider having another shoot the pistol to see if it still hits so low.

 

[BSA1]

AJ you have a franken gun monster.

Is this just a illusion but looking closely at the picture you posted it appears the muzzle has a slight outward bell shape?

I wonder if this is even the original barrel?

What does the bore look like?

Have you tried slugging the bore?

Have you measured the throats on the cylinder?

As commented the front sight sucks. There is not enough material to file it lower and still be able to see it.

If this is a gun I really like I would probably track down a original 4” barrel that the bore is in very good condition and install it. Of course this means refinishing the gun. It would be a fun rabbit hole project. (I know about rabbits. My current rabbit hole project is a Glock 43X). You could end up with a neat big bore self-defense home and belt gun.

 

[StrawHat]

…
I wonder if this is even the original barrel…

track down a original 4” barrel…

The nice thing about that type of revolver is any barrel blank can be used. Cut the correct threads and spin it in place. Not front lock up to worry over.

Kevin

 

[Drm50]

In very same gun “ unmolested “ I focused point of aim with bullet and powder charge at 25’. Mine had 5” barrel and was in mint shape, didn’t want to file on sight.
My experience has run into many more revolvers that shot high. Even those with adj. sights couldn’t go far enough. You can custom load most fixed sight guns to point of aim at a fixed distance. What is PIA is if the gun is shooting off horizontal.

 

[rockquarry]

In very same gun “ unmolested “ I focused point of aim with bullet and powder charge at 25’. Mine had 5” barrel and was in mint shape, didn’t want to file on sight.
My experience has run into many more revolvers that shot high. Even those with adj. sights couldn’t go far enough. You can custom load most fixed sight guns to point of aim at a fixed distance. What is PIA is if the gun is shooting off horizontal.

I can't offer an explanation, but sometimes with a good bit of load development, you can change the horizontal even if you didn't intend to do that. I've seen it often with rifle cartridge load development, but it occasionally happens with handgun loads as well.