Barrel indexing vs muzzle jump

[Macropod]

Indexing, to control recoil, is important for pistols too, but they're much easier to index. Here's a snapshot from some recent Olympics precision 300 meter pistol trials. The team is from California, in anticipation of California becoming its own country.

The woman on the right, with the pink hearing protection, is competing in the new Transgender Class. The Olympian on the left, without hearing protection, is nicknamed "huh?".

View attachment 1024343

Crotch grab must be mandatory with this shooting style.

 

[dmoran]

@fgregorio -
My own testing has proven to me that indexing a bore's curvature is effective (particularly at distance/LR).
With what I call my "spin chassis" (pictured below), I have came to the conclusion, for myself any way, that there is more to optimal index/timing then just "clocking the high" to 12 or 6-o'clock. Each barrel having its own unique optimal position(s). For barrels that I haven't or won't spin test to final fit/chamber, at 12-o'clock is my preference.
Donovan

 

[jds holler]

Until just now, I had no clue that our barrels were banana shaped, or that indexing them to compensate for this shape was even "a thing".

I don't know whether to thank you or curse you for educating me. jd

 

[Ledd Slinger]

Barrel indexing is very important and the OP is correct in stating that no barrel is straight. I dont see the confusion? He simply asked from the start whether to index at 12 o'clock or 6 o'clock. For those who dont understand, thats the bore pointing up or down. Sad to see such few helpful replies on a precision shooting website. Getting worse all the time. Tho dmoran's post was great

fgregorio,
I would also recommend sending a PM to member 'Alex Wheeler'. He indexes all of his barrels and I bet he could shed some more light on this subject for you.

 

[Metal God]

Since so many of us aren't familiar with indexing a barrel .

Can someone explain why the barrels are bent ?

When do the barrels bend , before or after rifling is cut ?

Does it matter if it's hammer forged ?

I assume if you're concerned about barrel indexing you are buying high end barrels . Why doesn't the barrel maker straighten the barrel before delivery ?

 

[savagedasher]

Since so many of us aren't familiar with indexing a barrel .

Can someone explain why the barrels are bent ?

When do the barrels bend , before or after rifling is cut ?

Does it matter if it's hammer forged ?

I assume if you're concerned about barrel indexing you are buying high end barrels . Why doesn't the barrel maker straighten the barrel before delivery ?

So far we have not been able to drill a straight hole .
Some manufacturers are honing
The straight .
The reason for timeng straight up or down You should be able to adjust the scope in one direction for different distance
Larry

 

[mysticplayer]

This may seem like a silly question at a first glance.
In your opinion, what would be the best barrel index in order to minimize muzzle jump? 6 o'clock or 12 o'clock?
I'm interested only in the inertia (internal ballistic) aspect if it. Not interested in the gas release aspect of it, suppressors, muzzle breaks etc, because those devices are not allowed in palma shooting.
I'm thinking 6 o'clock because since the recoil pivots beneath the bore line, a 6 o'clock index would impart more of a compression force rather thank bending force.
Thoughts?

Surprised at the range of "silly" responses. Yes, indexing can help with barrel tuning... just ask the rimfire shooters BUT with centerfire, I would just adjust my loading to resolve.

Over the years, we have played with clocking the barrel and typically go 12 oclock with a rare occasion at 6oclock. With load tuning, the effects, if any, were negated.

With prefits and no chance to index, same thing. Load tune to get the barrel is its happy place.

If you have to use supplied ammo, I would put on a barrel tuner and adjust onsite.

We have looked at cold bore location vs indexing. it was not 100% in the direction of the clocking so that too has proven to be not a hard rule.

ultimately, there is an effect. It is small, it can be dealt with ammo tuning. I wouldn't loose sleep over it.

WRT to recoil and muzzle rise, nothing to do with the barrel and everything to do with the stock.

Jerry

 

[Metal God]

What about Savage actions . How do you index the barrel on them ? Don't you just screw the barrel in until the headspace is correct ? What if your index point is a 1/2 turn either way ? I'd assume you would want to remove material rather then add shims ?

 

[Shynloco]

View attachment 1024430

Thats actually for the Boys in the Hood who can't figure out what's up and what's down. They BAD!

 

[338 Mollett]

View attachment 1029315

LMAO Tom you have too much time on your hands finding this chit.

 

[IdahoSharpshooter]

hmmmmmmmmmmmmmm...

 

[Metal God]

What if I added more then just lipstick ? Would longer eyelashes and maybe a little blush help ? oh and a six pack

 

[tn noshooter]

I will have to say I have no good answer to you're question but I think if you could talk to Alex Wheeler he could shine some light on the this topic

 

[Metal God]

What if I added more then just lipstick ? Would longer eyelashes and maybe a little blush help ? oh and a six pack

I will have to say I have no good answer to you're question but I think if you could talk to Alex Wheeler he could shine some light on the this topic

Why is he some sort of cross dresser

 

[Dans40X]

OP,
P.M. inbound

 

[jbhotrod]

Try not to take the silly replies to heart. alinwa responded in the thread earlier, shoot him a PM.. he does a TON of testing of this stuff. I also think what Mr Lambert mentions has merit, that it may be better to think of the barrel as more of "twisted banana" or spiral to it than just a one dimensional curvature... dmoran also Id bet has useful insight on the subject.. Benchrest central honestly might give you better responses

 

[butchlambert]

So far we have not been able to drill a straight hole .
Some manufacturers are honing
The straight .
The reason for timeng straight up or down You should be able to adjust the scope in one direction for different distance
Larry

Larry,
The Sunnen Hone will not straighten a crooked bore. There are advantages to it, but bore straightening is not one of them.

 

[savagedasher]

Larry,
The Sunnen Hone will not straighten a crooked bore. There are advantages to it, but bore straightening is not one of them.

Ok how do we straighten cam bore and main on race motors
Sunken home
The problem with cam you then have to get over size od bearings
Main bearings you can cut the caps and then you don’t need oversized od bearing
Yes it will straighten the bore .

 

[JRS]

Ok how do we straighten cam bore and main on race motors
Sunken home
The problem with cam you then have to get over size od bearings
Main bearings you can cut the caps and then you don’t need oversized od bearing
Yes it will straighten the bore .

 

[sdean]

Larry where do get your oversize bullets?