What bullet jump to expect from a new barrel?
 

I just had a 'smith rebarrel my 22-250 with a Lilja heavy barrel. Even after careful break-in, it shot terribly (2" at 100 yds). I got out the Stoney Point gauge, and it shows 0.15" of bullet jump. My understanding is that 0.02-0.04" is more the norm, but the 'smith said there's nothing he can do for me.

I've already checked the usual suspects (free floated barrel, scope screws, ammo, etc.), and I think the culprit is excessively long bullet jump. For this I paid $700???

I returned the rifle to him tonight. He said he'd "look at it," but I didn't leave his shop with much of a warm and fuzzy feeling.

Am I getting hosed?

RE: What bullet jump to expect from a new barrel?
 

Are you talking about headspace???

RE: What bullet jump to expect from a new barrel?
 

How many loads have you tried?

RE: What bullet jump to expect from a new barrel?
 

I think your talking about freebore, all I know is that a bullet which has to travel an excessive distance before engaging the rifling can become slightly upset and accuracy goes south. Also a bullet which is seated to contact the rifling will make chamber pressure rise sharply. Might you seat your bullets further out of the case and minimise the jump, if your magazine will allow it. Also isn't that deminsion machined into the barrel by the manufactuer.? If so would you go to the gunsmith for a solution or to the Mfgr. Just thinking a little over my head, Glenn.

RE: What bullet jump to expect from a new barrel?
 

Since the rifle has a Lilja barrel, andthe rebarrel job ranyou $700.00 the rifle should shoot very well. Don't let the gunsmith get away with it.

The same thing happened to a friend of mine; the best his rifle would group is 2.5", but he did not pressure the gunsmith, and he is stuck with a unaccurate rifle. Good luck.

RE: What bullet jump to expect from a new barrel?
 

Fifteen thousandths doesn't sound like a whole lot of free-bore. If I remember correctly, Weatherby rifles have much more than that, right from the factory. How does the crown on the muzzle look? A poorly machined or damaged crown can ruin accuracy in a hurry. The good news is that recrowning the barrel should be inexpensive and easy to do.

After you've exhausted all other possible solutions (ammo, bullet seating depth, scope, crown, etc.), and if your current gunsmith is unable/unwilling to help you, another gunsmith should be able to turn down the back of the barrel and recut the chamber. In effect, you can start over, without having to buy a new barrel or spend another $700.

Good luck.

RE: What bullet jump to expect from a new barrel?
 

Thanks for the replies so far, gentlemen.

Re.seating the bullet out further, the cartridge OAL is already a hair above max; any further lengthening and the cartridges wouldn't fit in the magazine.

I'm not talking about headspace or freebore, I'm talking about bullet jump, which is the word Stoney Point uses to describe the term. Headspace is not a problem, since the round seats firmly against the shoulder of the chamber.

I've tried two loads: My reloads that always shot well in the previous factory barrel, plus some factory Winchesters. Both shoot poorly.

If the crown is bad on a new barrel, then I assume it's the gunsmiths problem and something he should fix.

Keep the comments coming, guys!

RE: What bullet jump to expect from a new barrel?
 

one hundred fifty thousandhs (.150) is excessive if that is the distance from the riflling to the ogive of the bullet... therefore you have a deep throat in that barrel.... but you don't say what you are shooting from it, which bullet, if you are handloading and what your COL is....

when that barrel was chambered, a reamer was used to cut it... that reamer has a set throat length on it... which is pretty much "standard"... to change the throat length you'd have to custom grind a reamer (or find one with a shorter throat already) to shorten the throat...

so, in order to correct the length of bullet ogive to rifling you'll have no other option than to either A) seat the bullet out further or B) find a longer bullet.

even if you found a reamer with a shorter throat you'd have to remove the barrel, face off the end to shorten up the chamber (short chamber the barrel) and run the new reamer in to depth and then reset headspace....

btw, i am not of the school where just a barrel will transform a gun into a cloverleaf generator... has to be right from the recoil pad to the crown IMHO.... that includes the ammunition in the chamber... and that can be the most frustrating part as the combinations of bullets, powders, primers, cases and reloading methods for 22 caliber are endless...

JR

RE: What bullet jump to expect from a new barrel?
 

The cover on a book of matches is .020, so .150 is a hell of alot.Which ever way the bullet prints on the rifling, it's the way it's going to come out!

RE: What bullet jump to expect from a new barrel?
 

The distance the bullet has to travel before it contacts the rifling has to do with how much Free Bore the barrel has.

RE: What bullet jump to expect from a new barrel?
 

It's hard to believe that .150 of an inch is the Free bore on a Lilja barrel.

RE: What bullet jump to expect from a new barrel?
 

Yes, 150 thousandths IS a lot of freebore, not 15 thousandths like I mentioned before. Those pesky decimal points..... [:@]

Sorry for the mistake on my part.

RE: What bullet jump to expect from a new barrel?
 

You may have got hosed. .15" is alot but depends on your situation. If your shooting factory ammo, could be the ammo is deep as most is. If your handloading and you cannot reach the rifleing, then his reamer is causing the issue.

Thats why when I have a gun rebarreled, I specify the freebore wanted with a certain type of bullet. My gunsmith can customize it with a two stage ream to my specifications.If he used a off the shelf clymer reamer, and you are using factory ammo, you might have to change ammo to find one without all the jump. There is no telling what off the shelf factory reamers are cutting.

I had a 300RUM rebarreled. Max COL I could load was 3.65", and my freebore was so long, you had to load out to 3.85" to hit the rifling. I was upset, but with a magnum like that, I found out, you really need some freebore, maybe not that much. But it still shot subMOA easily.

RE: What bullet jump to expect from a new barrel?
 

Barrel twist is 1:14".

Factory loads are 55 grain Winchesters.

Reloads are 55 grain Ballistic Tips in front of 37 grains of Varget; this load always shot great in the previous pipe. This is what I based the 0.15" measurement on. (The factory rounds had even more jump.)

As far as the terms "freebore" or "bullet jump", I'm a little unclear on them myself. I used bullet jump based on the diagram in the Stoney Point gauge. Here's what I did: Using the SP gauge, I measured the distance to where the bullet just touched the rifling, then subtracted the length of my cartridge. This yielded the 0.15".

I don't remember what the jump was on my previous barrel, but I know it was a LOT less than 0.15". As mentioned earlier, my reloads are already a little long; any further lengthening would put the bullets too high in the neck, plus the rounds would no longer fit in the magazine.

I appreciate your feedback, gentlemen. Please keep 'em coming!

RE: What bullet jump to expect from a new barrel?
 

One thing you can do, is take back to the gunsmith and have him set the barrel back, and recut. But if it was me, I would take to a different smith.

RE: What bullet jump to expect from a new barrel?
 

No two barrels are the same. Can't you load some ammo up that has the bulletds seated out more? This will tell you if there's too much throat length. If there is, the only remedy is to set the barrel back one thread and recut the chamberwith a shorterthroat. Or seat all bullets out farther, and use it as a single-shot, if the rounds turn out to be too long for the magazine....

RE: What bullet jump to expect from a new barrel?
 

Sound advice!;)