Uberti 66 carbine sight picture.

[greyhawk]

Generally, a heavier bullet has lower velocity, hence more time in the barrel. It also generates more recoil, so the muzzle rises more. Thus there is more muzzle rise before the bullet exits the barrel, leading to a higher point of impact. Bullet drop may be a factor at longer distances.

CC Griff

I am bamboozled but unconvinced 

only way to change that is shoot it out meself -----------------
Rifle recoils before boolit leaves barrel ? really !!!

[Coffinmaker]

Hey Greyhawk 

  Yepper.  Simple Physics.  For every action there be an equal but opposite reaction.  Recoil begins the instant the projectile begins its' forward travel.

Hide and Watch   

[Coal Creek Griff]

Rifle recoils before boolit leaves barrel ? really !!!

Remember that it only has to begin to recoil. It takes a very small amount of movement to affect the point of impact by a few inches...

CC Griff

[Sir Charles deMouton-Black]

Generally, a heavier bullet has lower velocity, hence more time in the barrel. It also generates more recoil, so the muzzle rises more. Thus there is more muzzle rise before the bullet exits the barrel, leading to a higher point of impact. Bullet drop may be a factor at longer distances.
CC Griff

I have found that with pistols, either revolvers or semi-autos, that velocity is neutral in predicting POI, but that weight of bullet does change POI by raising it with heavier projectiles and dropping POI when a lighter projectile is fired.

Long guns are a different matter, each one a law to itself. In my experience with Winchester style leverguns the the POI changes with a more powerful load. If anyone uses one for both hunting loads and "pop-ting" shooting the difference can be disconcerting. The heavy loads shoot LOWER!

NOTE:I corrected my post.

[greyhawk]

Remember that it only has to begin to recoil. It takes a very small amount of movement to affect the point of impact by a few inches...

CC Griff

you guys are trickin with me
every rifle I ever shot put a heavier boolit lower with equal charge behind it

more bamboozled ----less convinced
only cure is gonna be powder smoke
need an excuse so thats all good

[Coffinmaker]

Not neither!! 

Bamboozle is not (necessarily) in my Lexicon.  I make no claims about up or down with projectile weight.  I'm just sharing the information that Recoil begins the instant the projectile begins to move. 

After the projectile begins it's movement, you guys are on yer own.

Hyde and Watch

[greyhawk]

Not neither!! 

Bamboozle is not (necessarily) in my Lexicon.  I make no claims about up or down with projectile weight.  I'm just sharing the information that Recoil begins the instant the projectile begins to move. 

After the projectile begins it's movement, you guys are on yer own.

Hyde and Watch

I shall make smoke and report back in doo course
Easily bamboozeled these days (twas never much of a challenge anyway)

[Coal Creek Griff]

It is true that I am most familiar with the phenomenon as it relates to revolvers. That has been well-established, but I am less certain that it transfers to pistol caliber rifles. I would love to see the results of your experimentation.

CC Griff

[Speedballalice]

A recent trip to Wyoming and having to go back to work this week has kept me from persuing this problem. I have made up some varying reloads to experiment with the next time I get to the range.
464190 lyman bullet over 30gr 2f OE in Schofield case
424230 nei bullet over same.
454190 over Red dot in a colt case
454190 over unique in a colt case.
I have yet to try the lyman bullet I just bought the mold right before my trip.
The bullet profile is nearly identical to the NEI without the hollow base.it also casts out 10gr heavier.
Hoping to get these to the range within the next couple weeks.

I also tried removing the front barrel band screw. Like coffinmaker stated it's in pretty tight. Although I didnt crank on it super hard as my screwdriver was not a perfect fit.
Anyhow, I'm hoping to find a sight picture and  load that shoots acceptable in this carbine at some point. Keeping my finger crossed that I can find a combo that will work without using the fold up peep sight. And hopefully it's a blackpowder load too.

[Montana Slim]

Ok, I just read your other post (I had to know what was special about this carbine). Rather than hash about removing stubborn Uberti screws or intimacies of bullet weight, velocity & POI.

Noted the barrel length is 20", rather than the 19" they've made for quite some time.

If I read that correctly, here's my take. The barrel band/ front sight is very likely the same as used on the standard 19". The juncture of the barrel & mag tube will put pressure on the barrel (thus causing a noticeable impact shift) In other words they should ( my opinion) have designed a new mag tube/sight band for the different barrel length.

Regards,
Slim

[greyhawk]

I shall make smoke and report back in doo course
Easily bamboozeled these days (twas never much of a challenge anyway)

Mr Coffinmaker ...here 'tis ....my effort to prove a point ....think we should call this one a draw - the house got all our bet money !
You reckoned heavy boolit would shoot higher - I bet it would go lower

Loaded 20 rounds Remmy brass, Federal Large Rifle primers, all with 37.5 grains of BP, no wads no grease cookie,

10 got the Cast Boolit Engineering 225 grain Flatnose 10 got the LEE 429 x200 which at my place weighs in around 205 to 208 grains depending on what I had for breakfast on that casting day.

Shooting at 50 yards,  fired alternately onto two targets side by side CBE- 1,3,5,7,9 on LH ----LEE - 2,4,6,8,10 on RH
1 and 2 cold barrel shots low  - the CBE shots are strung vertical (could be my eyes - sights are not ideal and I dont see em real well anymore) , LEE 4.6.8.10 makes a better group - but center it all and there looks no appreciable difference in height of the strike at 50 yards - between the two different boolit weights


Then I went and fired five more of the LEE, walked up and checked, back, fired five more of the CBE so that made 20 all up - neither of these boolits hold near enough lube for BP and that shows clear on this target - the first ten went ok - but the last five was more of a buckshot splatter than anything else.

This is a 66 Uberti 24" rifle - - its my "how fast can ya go gun" -- run it hard and I can get 15 to 18 shots at 25 yards using the CBE boolit without fouling bad - this is a one minute event - we start standing clear, gun empty, load and fire as many as you can, no race guns have appeared yet, 20 guys on the line at once firing full throttle black loads was kinda fun. (we got old! down to about ten these days)       
ooops - the cardboard is two feet wide  - ignore the big hole in the middle

[Tuolumne Lawman]

Check my post.  I trimmed a tad over 0.1" inch off the front sight and brought it up to POI being about 1.5" above POA at 20 yards. The rear notch was still wide enough for a good sight picture.