I'm a Savage guy, so fitting a new barrel is a simple DIY job for any enthusiast with half a brain.

But now my Howa-1500 "fun gun" is starting to lose accuracy after nearly 7000 rounds down the barrel. It still averages better than 1/2 MOA but I no longer achieve those occasional 1/4 MOA five-shot groups which I used to enjoy on nearly every trip to the 100 yd range.

I'm going to order a pre-fit barrel, but unlike a Savage "drop-in", my Howa replacement will require some machine work to set the head space and I'm told I have two choices.

I'm no gunsmith, but my understanding is that I can chose a fully chambered barrel with a short threaded shank.  By trimming a bit off the chamber-end shoulder I can adjust the headspace, but this job requires a lathe. A friend has a suitable lathe.  He a shooter and accomplished machinist but he isn't a "real" gunsmith either.

The other choice is to order a short-chambered barrel, in which case I would adjust the headspace with a finish reamer.  This method requires buying a finish reamer.

Is one method better than the other; i.e. short threaded shank vs short chambered?.

What are you talking about; "half ass"?  How do you think replacement barrels get fitted?

He meant nothing personal.  There is a learning curve involved.  It is not simple plug and play.  I interview gunsmiths to leave work with and I don't trust very many of them at all.  I'm not very proud of the first couple - or maybe 3 barrels I've installed.

You said you never installed a barrel before, and I assume you don't have much machine work under your belt, either.

BTW, a sub-half MOA rifle is better than 95% of the rifles out there.  You won't see much of a gain - if anything - with a mass market short chambered barrel.

Yes, those Howa 1500 rifles are supremely underrated.  Only thing wrong with them is metric threads.

Unless you buy a premium barrel, Krieger, Bartlin, Brux or the like, and blueprint it and the action, I seriously doubt you will see anything but disappointment. And as far as I know, none of the premium barrels are offered as a pre-fit, so you are almost guaranteed to buy a lesser barrel than you already have.

I built a Mauser with a budget ER SHAW barrel trued the action, the bolt face the shoulder and was VERY happy to end up with a sub MOA gun. It has never shot a 1/4 inch group.

There is a learning curve, and you need to be able to deal with such issues as tolerance stacking, and action truing.

I would be exceedingly surprised to see a 1/4 moa rifle come out of a first timers effort.

If you forge ahead, buying a short chambered barrel and  reaming to a good headspace would be the method of choice.

Much harder to screw up.

And you can rent most reamers Here

Have you considered sending it to someone and having it set back?

Have you been inside of it with a borescope to see if you can figure out the issue?

Given the round count, the throat is the most likely suspect,setting the barrel back and cleaning up the chamber and throat, and maybe a re-crown while your at it might be an option, allowing you to keep your very good barrel. .

Spend your money on a good smith instead of a cheap barrel.

ETA: No one here, especially not me, is trying to discourage you from learning to rebarrel a rifle, or develop your smithing skills. I am a rank amateur compared to most here, and certainly the only way to learn is to get experience.

The point is; you already have an exceptional rifle, and improving what you have is a very tricky proposition best undertaken by an experienced and highly skilled smith. I, and I expect most here would be thrilled if I ever turned out a 1/2 moa rifle. I would dance a jig and call everybody I know.

If you want to work on your skills, start with a rifle that really needs improvement.  Building a 1/4 moa rifle is the field of a very few masters.

If you want to practice, buy any-1500 rifle out of a pawn shop.  They are all the same, S&W1500, Howa 1500, Vanguard, etc.  If it looks like a Howa 1500, it probably is.  There is NO collector interest in them, so you can get them really cheap if there is a bit of finish wear on them.

I had a thing, still do, about 1903 Springfields.  I used to cruise pawnshops during lunch and buy any decent Springfield I could find under $100 for project work.

Here is an update which DIY enthusiasts who like to play the part of a gunsmith out in their garage may find interesting.  I decided to purchase a short threaded barrel and cut back the shoulder to set the headspace.  A friend who is a shooter and a trained machinist has a lathe passed down from his grandfather from before the dawn of the industrial revolution, leather drive belts and all.  It doesn't have all the bells and whistles of a modern gunsmithing lathe, but it's plenty accurate to set headspace.  The procedure was dead simple.  The factory barrels on Howas are notorious for being either very difficult or impossible to remove and mine was no exception.  A relief cut just ahead of the receiver took care of that problem, but the inability to remove the barrel without damage makes the suggestions to simply rechamber the factory barrel a moot point.

From there it was a simple matter of making a couple of careful measurements, centering up the barrel, and cutting the shoulder.  The headspace came out perfect, which is to say the bolt closes on a go gauge but won't close on the gauge plus .001".  It took us a while because our goal was to hit the measurement precisely.  If we were doing it for a living, we'd quickly go broke.  On the other hand, I didn't have to pay a gunsmith a wad of money and get back a job which "meets SAAMI specs".  

Preliminary testing shows that the new barrel has restored the accuracy of this gun.  Since I use a different .223 for competition use, this gun will continue be a simple "fun gun" for training and punching paper mostly at 100 yards.  As I hoped, the Sierra Match King 69 grain bullets seem to work best so far.  Testing at a promising charge weight using IMR 8308 XBR shows that five shot groups at 100 yards average .325" with a best group of .255" out of the first test session.  That is with a default seating depth of .010".  I expect that experimenting with seating depths and perhaps a little fine tuning of the charge weight will improve on those figures.  

It looks like this new barrel will shoot as well as the previous one and, since it's 4" longer, it looks like the best accuracy is occurring at a MV about 350fps faster than before without getting into the "hot" load neighborhood. That's a nice bonus even for a plinking gun.  Best accuracy with the factory barrel occurred at a charge weight not far above the recommended minimum.

So, in spite of some negative responses to this thread, I'm happy with the procedure I used to fit this new barrel and I'm quite happy with the preliminary results .  

More than one barrel has had problems even when you have done hundreds (I have on REM700s).

I have a Panda action.

I still pay Kelbly to make new barrels for it when I need one.

I will get a barrel that fits (by serial # of the action) and has a high chance of shooting with painful accuracy.

The .22-250 AI shoots one inch lower and 1 inch left of the 6 mm REM AI.

I can swap back and forth and the POI repeats.

I use the 6 mm at over 500 yards for groundhogs.
The .22 at less than 500.

My 'personal best' is a single shot on a grundhog at 350 yards.

One shot.  Dead groundhog.

A whole lot of parts.

The farmer was watching in my spotting scope.
He was yelling more than I was.

That is spectacular.  What barrel, what reamer, how bedded, any action work, etc.?  I know this is a sample size of one, but I've never gotten this level of results.  Do tell more.

My Howa 1500 in 223 Improved is probably a true sub MOA rifle, but .325" is a whole 'nother level.  My other best efforts come close to MOA, but the rifle (221-300 FB) that should have been my shining star is a 2 moa rifle at best.

Very impressive.