1911 45ACP Lowering POI

[Jon]

My 1911 is shooting high 8" at 25yds. I have to aim below the black to get it somewhat ballpark. Right now, I'm using 4gr of Bullseye with Winchester Primers. If I go down to 3.5gr will that bring it down a bit? How low can I go with Bullseye?

My bullets weigh in at around 233gr using cast range scrap.

The max range seems to be all over the place from 5 to 6gr. Can anyone verify that for me?

Thanks

[44MAG#1]

My Springfield full size stainless with the higher more pronounced fixed sights did the same thing. I filed down the top of the rear and it still has a good notch depth left. About .056" should do it

[Jupiter7]

Up the charge, try again. 5-5.5grs bullseye is the classic GI load.

[Char-Gar]

I doubt very seriously if you can raise the POI 8" at 25 yards by messing with the powder charge. It will take a higher front sight or a lower rear sight.

[Char-Gar]

Up the charge, try again. 5-5.5grs bullseye is the classic GI load.

That is incorrect. The arsenal load was 4.7 to 5 grains of Bulleye depending on the lot. 5.5 grains of Bulleye is a red line load and should be avoided.

With cast bullets 4.5 grains of Bulleye will produce mil spec velocities with 225-230 grain bullets. 4.2 grains of Bulleye will produce excellent accuracy with very little loss in velocity.

[30calflash]

Lighter bullets than what you are using with a more potent but safe powder charge will definitely do it also. Try some 185 or 200 grain heads if you can.

[DougGuy]

It's been my experience that loading to a higher velocity will bring POI down. Less "dwell time" in the barrel = less muzzle flip before the boolit leaves the muzzle = lower POI.

[Jupiter7]

Per alliant, they show 5.7grs with 230gr TMJ producing 840fps from a 4.4" barrel. I'd hardly call .2 under that "redline", especially with cast. Personally I load 4.7grs, matches up with factory Springfield GI sights on mine.

[littlejack]

John:
It is well established, to lower the POI of a projectile, one has to speed said projectile up to reduce bullet in barrel time.
The bullets gets out of the barrel quicker, therefore, it has left the muzzle sooner, before the muzzle has time to rise up.
If you slow it down, the bullet stays in the barrel while the barrel is rising, therefore shooting high.
It is plain old physics.
And yes, it works.
Regards
Jack

[44MAG#1]

Eight inches at 25 yards is a lot to expect to move impact with a given bullet.
Some people, myself included, doesn't want to use light piddling bullets just to move impact.
He may be a fan of the 230 gr bullets.

[Win94ae]

John:
It is well established, to lower the POI of a projectile, one has to speed said projectile up to reduce bullet in barrel time.
The bullets gets out of the barrel quicker, therefore, it has left the muzzle sooner, before the muzzle has time to rise up.
If you slow it down, the bullet stays in the barrel while the barrel is rising, therefore shooting high.
It is plain old physics.
And yes, it works.
Regards
Jack

I have demonstrated time and time again that this is a wives tale.
Every physicist I've talked to scoffs at the notion.
Also, thousands if not 10s of thousands of ladder tests debunk the notion beyond any doubt.

There are only 3 ways you can get a lower POI from more powder.
1. If the higher powder charge was traveling at just above subsonic and the lower charge is just below supersonic.
2. If the Harmonic effect happens to whip the bullet lower.
3. If you strap the firearm down as solidly as possible.

Here is where it has been most extensively hashed-out.
http://www.thefirearmsforum.com/showthread.php?t=100867&page=2
Start at comment 37...
Rap, is a physicist.
There are numerous experiments in the thread. But by all means, post your own results from your own experiments.

[375RUGER]

what kind of sights do you have? if the front sight is dovetailed, $15 will get you a sight blank that you can file to suit your needs.

[Jon]

what kind of sights do you have? if the front sight is dovetailed, $15 will get you a sight blank that you can file to suit your needs.

Unfortunately, it's a pinned front sight.

I'll try bumping the charge up to 5ish grains, and make a few with less to see what happens. I guess it's time to finally get that adjustable charge bar for my Lee powder measure.

[35remington]

Try a lighter bullet.....say of of the HG 68 clones that weigh in the vicinity of 190 grains (longnose SWC) if you want to see if you can adjust the POI without any filing. If you have a 200 try that to see if any improvement occurs.

That is, if a lighter bullet is acceptable to you. If it is not, then it's time to go after the sights.

[DougGuy]

There are only 3 ways you can get a lower POI from more powder.

There are numerous experiments in the thread. But by all means, post your own results from your own experiments.

This has been totally opposite of my findings in developing loads for a short barreled Ruger Vaquero chambered in .45 Colt.

First, a single action revolver with the plowshare or birdshead grip will inherently incorporate the movement of the pistol in the shooter's hands into the point of impact.

In this process, I have one specific boolit that struck the target at 4" below point of aim with a charge of 19.0gr of A2400 powder. The same boolit struck 2" below point of aim with 18.0gr, and 1" to 1/2" below point of aim with 17.0gr of powder. Climbing up a treestand and shooting straight down (removing the horizontal pull of gravity from the equation) the boolit shot directly to the point of aim with 17.0gr of 2400 powder.

This represented a 4" change in the point of impact, in roughly half the distance the OP is shooting his 1911.

There are many variables which combine to render the point of impact for a given gun, load, and shooter. All things considered, if one factor of that given equation is altered significantly, then the outcome responds in like fashion.

This being true for a single action revolver in achieving an elevated point of impact by reducing the powder charge, and leaving all other factors the same, would seem likely to be able to be duplicated with a 1911, and furthermore reversed causing a lower point of impact by increasing the powder charge rather than decreasing it.

To rigidly adhere to a theory that states that changing one factor (which is in part responsible for an outcome) within an equation involving momentum and inertia would have no effect on the outcome, is simply trying to nullify one law of physics.

If that were possible, there would be no need for adjustable sights, and all boolit weights would shoot to the same point of impact over a single given charge weight of powder, and we all know this is simply not a valid statement.

Therefore, changing powder charge, or lightening boolit weight in the 1911 in question, should by all means alter it's final point of impact.

[bobthenailer]

First i would see where your gun hits with factory 230 gr load or equivlent hand load at 800 to 850 fps.
the front sight if not dovetailed in is actually staked in , a tool is made to do this from Brownells its called a front sight staking tool. measure the height of your orgional front sight and get the tallest front sight avalible and install it on the slide, and then after determing where you gun now hits with the new taller front sight file it to the height needed for correct bullet impact.

Another thought ! if you have acess to another barrel bushing and or barrel assy ? install them in your pistol and test for POI
Your factory barrel or bushing may not be fitted correctly.

[gray wolf]

Some 1911 have a staked front sight----some have a dove tail
and some like my 1911-A1 loaded Springfield are dove tail and roll pinned from the top.

[jakharath]

Another thing to try would be to change out the barrel link to a 'taller' one.

[Char-Gar]

Another thing to try would be to change out the barrel link to a 'taller' one.

The purpose of the barrel link on a 1911 pistol, is to raise and lock the barrel lugs into the recesses in the slide. That is a critical point for accuracy. A properly fitted link will give full engagement of the barrel lugs and the recesses without bottoming out.

I don't think I would be messing with the height of a barrel link to try and change the point of impact.

[pipehand]

I have demonstrated time and time again that this is a wives tale.
Every physicist I've talked to scoffs at the notion.
Also, thousands if not 10s of thousands of ladder tests debunk the notion beyond any doubt.

There are only 3 ways you can get a lower POI from more powder.
1. If the higher powder charge was traveling at just above subsonic and the lower charge is just below supersonic.
2. If the Harmonic effect happens to whip the bullet lower.
3. If you strap the firearm down as solidly as possible.

Here is where it has been most extensively hashed-out.
http://www.thefirearmsforum.com/showthread.php?t=100867&page=2
Start at comment 37...
Rap, is a physicist.
There are numerous experiments in the thread. But by all means, post your own results from your own experiments.

Win94ae, what you are saying is very true for rifles, where the weight of the boolit is small compared to the weight of the firearm, and the barrel is long and whippy. Also, the speed of most rifle boolits is way up there compared to pistols. There is a reason why most bullseye boolits for the 45ACP are 185 to 200 grains. It allows the sights to work with lower velocities.

I always get a kick out of guys at the range trying different brand loads that swear one is shooting faster than the other because the group is higher on the target, and therefore dropped less. I quit trying to explain barrel harmonics to them. Waste of breath.

The harmonics involved in a 5" 1911 barrel is insignificant compared to projectile weight difference.

[Char-Gar]

Win94ae, what you are saying is very true for rifles, where the weight of the boolit is small compared to the weight of the firearm, and the barrel is long and whippy. Also, the speed of most rifle boolits is way up there compared to pistols. There is a reason why most bullseye boolits for the 45ACP are 185 to 200 grains. It allows the sights to work with lower velocities.

The reason Bullsye shooters use lighter weight bullets in their pistol is recoil reduction. That coupled with powder puff loads and a lighter recoil spring for function, makes the 45 auto easier to shoot for high score.

They use adjustable sights, so the pistol can be precisely sighted for weight/velocity of the bullets and the range.

[pipehand]

Char-Gar, you are correct.. In order to use powder puff loads, and have them strike reasonably to point of aim, the bullet weight would be reduced. I do believe there was a "Hardball" stage requiring 230 grain ball, and an "any centerfire" stage. I could be very wrong, as I've never shot 2700 bullseye competition.

I do know that I sent a very nice S&W 25-7 down the road because the front sight was too short to allow 285 grain boolits to print low enough at 25 yards as fast as I felt comfortable shooting them in an N frame. Worked great with H&G 68's, but that's not what I wanted a 45 Colt for. A lot of the Ruger Single Actions converted to 5 shot configuration have higher front sights to enable their use with 300+ grain boolits.

Most factory fixed sight S&W 38 specials are sighted in with the standard 158 grain round nose boolit. The use of the 125 grain rounds will make them shoot low. Primer powered wax bullets will shoot lower still.

General rule is this:

Keep velocity the same, and increase boolit weight and the POI will rise. Decrease Boolit weight and POI will lower. Keep boolit weight the same, and increase velocity, and POI will lower. Decrease velocity and POI will rise.

There's some left and right impact differences due to weight and rifling twist, grip on the pistol etc.

[Char-Gar]

With handguns, POI of impact will determined by bullet "dwell time" in the barrel. As the handgun archs upward in recoil, the bullet exits at some point in the arc.

A faster bullet will leave the bullet sooner than a slower bullet and hence hit lower. The slower bullet will leave the muzzle later and hit higher.

A heavier bullet will produce a higher recoil arch and therefore hit higher, than a lighter bullets if they leave the muzzle at the same velocity.

Thusly, the point of bullet strike is a combination of bullet weight and velocity and these factors can combine in many ways, but the above is a blue print from which to work.

Most fixed sight handguns can be made to hit dead on the POI, with some manipulation of sights and loading, but it will be a one load proposition. The best results will most often be found with standard factory bullet weight and velocity.

A good example is a 1913 vintage Smith and Wesson Hand Ejector (38 Special) in my collection. With 3.5/Bulleye and a Lyman 358311 RN, it will hit exactly right at 25 yards. I mean exactly right. The sights are small and my eyes are 71 years old, but it is hard to miss with that handgun and load.

[375RUGER]

The purpose of the barrel link on a 1911 pistol, is to raise and lock the barrel lugs into the recesses in the slide. That is a critical point for accuracy. A properly fitted link will give full engagement of the barrel lugs and the recesses without bottoming out.

I don't think I would be messing with the height of a barrel link to try and change the point of impact.

That, and if the barrel wasn't fit properly or had wrong link he'd be shooting patterns instead of groups.

[MtGun44]

Link will change POI, but you very likely cannot put in a longer link and
make the gun work. The link length required is set by slide and frame
dimensions.

You need a taller front sight or shorter rear sight, no other fixes are
going to work.

Bill