Browning A-bolt Bullet Jump To Rifling

So I've got a Browning A-bolt in 22-250 that is a fairly good shooter. All I have done is a trigger job (home done job). It can shoot most factory ammo well within MOA. But.. I'm a hand-loader... I've figured out the length of my cases using a comparator to be 2.568"... What that means is using the #10-35 comparator, with a zero'ed caliper, my cases measure 2.568" to be a perfect fit... 2.571" the bolt will not close.. 2.570" it is a snug fit... 2.568" the action will close with little, to no, resistance.. Which means I can bump the shoulder back to this measurement and not overly stress the brass. Keep in mind a comparator is measuring off the case shoulder, or where it necks down.. However... When seating the Hornady V-max 55 grain bullet, I have to leave it at a 2.540" which is well over the published 2.350" COAL for this caliber. My magazine can accept the longer rounds, and even at this seating depth it is not jammed into the rifling.. what can I, or should I, expect to happen with accuracy, and pressure, putting the bullet closer to the lands? I have not measured where the bullet would need to be seated to be pressed into the lands.. the seating depth I am at now leaves just about the same bullet diameter seated into the case so I don't think I can seat it any farther out..

Questions:
1. Should I turn the rifle over to a gunsmith to have the barrel set back?
2. Should I attempt to seat the bullets farther out to be closer to the rifling? I DO NOT load to max... In fact I like to load to about the mid-range between minimum load and maximum load just to save on powder, and to slow throat erosion...
3. Understanding that I am seating the bullet farther out of the case than factory, should I slightly increase the powder charge to account for this loss of pressure?

I LOVE this rifle.. I use it for varmint extermination out to about 250 yards and it is like a laser with this load, and bullet, that I am currently using. I did not have to do any leg work.. I just looked at the label on the Varget cannister of 8 Lbs. and it lists 36.5 grains for this bullet and it has been working superbly... I am willing to do a ladder test with the rifle if necessary but feel like I have been handed the golden goose already as this load, with this bullet, has been phenomenal on long, and close, distance shots. To say that it is explosive on smaller varmints would be an understatement.

Published lengths have nothing to do with YOUR chamber. Load your ammo to fit your chamber as you see fit. OAL pertains to SAAMI, not hand loaders. And free-bore in barrels is a huge variation from barrel to barrel.

Seat the bullet where you want to.

Work up a powder charge on that seating depth as you see fit. Seating longer does produce powder space. You may see more powder begin to shoot better.

I have the same rifle, it’s a tack driver with factory ammo.

I have a ruger M77 in 22-250 that has a wonky chamber or throat. You can load light bullets with no problem but if you try using 55 grain bullets they get shoved right into the lands unless you sink them really far into the case. That could possibly be a me problem and not the rifle problem because I suspect it was intended to be used with light bullets.

It has nothing to do with the weight of the bullets, it's just the profile or shape of the bullet. Try some other 55-grainers and you will find one that has a profile that won't present that problem (which isn't really a problem at all in the first place, if performance is acceptable). There are a multitude to choose from.

I'm waiting on throating reamers to come in. They will be hand operated. So, the barrel can stay in the action, and hand turn a deeper throat. First time I've heard of a factory barrel with so little free bore.

I was under the impression that Ruger used hammer forged barrels on this model and the chamber and throat were formed and not cut. It hasn't been a problem but I grabbed some factoy ammo at Walmart 8 or 10 years ago and it pulled the bullet when I unloaded an unfired cartridge. I think it was a mid 60s bullet weight.

You’re way overthinking this. If you’re concerned about an optimal jump to the lands, use the CBTO measurement.

I don’t bother with bumping cases (or much else in the way of measurements). Most of my rifles produce sub 1/2 moa groups and a couple .1 groups consistently. Whatever the die sizes to is what I use. Of course I trim when it’s needed.

I’m of the opinion most hand loaders get lost in the weeds with measuring and end up unnecessarily stressed.

With what rifle , caliber and bullet are you getting .1 groups ? Also what type rest and wind flags and gauges are you using ?

Browning ABolt I had in 7mm-08 was a little short in the throat.

I've shot some of my current reloads and they seem to be more accurate than the other rounds I've put through this gun. I have a feeling being closer to the lands has produced better accuracy but I need to be set up on a dedicated shooting bench so I can have better back to back data to compare. It's either better accuracy or the placebo effect.

For now, I will leave the barrel alone and just focus on seating the bullets a little further out.

2 are .223 AR’s I assembled using LaRue Stealth barrels. The other is a Bergara 7-08 with a Geissele Super 700 trigger.

69 SMK N140
55 BT CFE223
160 SGK (#1925 version)

I use a Caldwell tripod front rest and leather sandbag (can’t remember the brand) to shoot off of.

You should go to bench rest matches and clean up . All the national ranked shooters there with their custom barrels on bench rest actions , with hand made match bullets , 1 oz triggers , 40x scopes , $1000 rests , 3 wind flags , would all bet you $1000 each that .1 would not happen . You could make them look like fools and much poorer . I am going to hit the Indy 500 this year with my 2003 Taurus .

And you should go view my previous posts where I’ve provided photographic documentation.

I actually got a .0-something group one time that I didn’t mention.

Buy you one of these



And one of these




Then use it with your particular bullet and measure your CBTO where you touch the lands using your comparator. I like to take 5 measurements and make sure I am getting a consistent value.

I would start off seating your bullets with a CBTO .050 less than what you measured when you contacted the lands.

OAL doesn’t really matter you want to measure CBTO.

That is why I gave you the big tip on how to make a bunch of money .

You were being facetious, not supportive.

My overall point is that hand loading isn’t inherently complicated. People make it that way and companies want to sell stuff.

That’s the only performance-oriented measurement I take. I start at .02 though.

I read an interesting article on the subject. Depends on the caliber but on things like a 6 creed you can expect the lands at throat to erode 0.004 to 0.007 per hundred rounds. According to the article and extensive testing the closer you are to the lands the more sensitive precision is to slight changes in the bullet jump. When close to the lands it said that changes in bullet jump as little as 0.002 to 0.005 can significantly impact precision. The conclusion was 0.040 or more off the lands was least sensitive to changes in jump. The article did state that seating close to the lands can certainly produce great precision but that to maintain it you would need to closely monitor and adjust your seating depth every 100 rounds or so.

Here is the article if you want to read it.

Bullet jump

Will definitely read that. I’m starting to run low on some of my loaded ammo, so testing at .05 is not too much trouble.

Sounds like a good idea . You may be able to get your groups smaller than .0 .