"How Well Do Prechambered/Threaded Barrels Shoot?"

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Mystic Precision

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A very common question I get asked. Follow the link to my blog and you see how my new Shilen 260AI is doing. Other articles on the same page that might also be of interest.

http://www.mysticprecision.com/htm/rifle.php#barrels2

Box stock Savage action - started life as a 7RM package rifle, headspaced the barrel and dropped into the stock and went shooting.

Spent more time sighting in the scope then actually working up the load.:D

Weather has turned lousy, cold, wet with snow so not sure how much more testing I will get to this year. Maybe it will warm up in Nov.

The 300m results have been really nice and this rig definitely has the ability to shoot 1" or better at that distance. Grouping around 1/4min with a drop in barrel is pretty decent performance.

Have put it into my F class barrel block stock and was going to do some more testing but we will see what the weather allows.

I have had many successful rifle builds using drop in barrels. As long as the chamber is cut true and the barrel of good quality, these Savages will shoot very well indeed.

Now to see if I can get similar products for the Rem;)

Jerry
 
I can attest to the fact that these barrels can shoot. I bought a 260AI Shilen 30" with the Savage bull barrel profile. I have been fireforming brass until now.. I used 49gr of IMR 7828SSC behind a 123 Lapua scenar with 210M primers in 243 lapua brass.

I was at the Lande Memorial Tactical Competition with this load and shot a 0.55" 100 yard 5 shot group. Rick from ATR was there to witness it. As I said this was my fireforming load and nothing more.

I now have all my brass fireformed and am currently working up loads again. So far my tightest group is a three shot 100 yard group that measured 0.147 MOA. I measured this with the OnTarget soft ware.. I tested groups between 49 and 50.2 gr and 49.6 is what it liked best so far. I do have to add that only two of the weights measured over 0.5 inches and the rest were under.

I do now have to shoot thirty rounds at 300 or 400 yards to get an idea if the load is going to be tight enough for competition as Mutt, Dave and Chad are dying for some competition next year, I think, at the ALRC.
 
Blygy said:
I can attest to the fact that these barrels can shoot. I bought a 260AI Shilen 30" with the Savage bull barrel profile. I have been fireforming brass until now.. I used 49gr of IMR 7828SSC behind a 123 Lapua scenar with 210M primers in 243 lapua brass.

I was at the Lande Memorial Tactical Competition with this load and shot a 0.55" 100 yard 5 shot group. Rick from ATR was there to witness it. As I said this was my fireforming load and nothing more.

I now have all my brass fireformed and am currently working up loads again. So far my tightest group is a three shot 100 yard group that measured 0.147 MOA. I measured this with the OnTarget soft ware.. I tested groups between 49 and 50.2 gr and 49.6 is what it liked best so far. I do have to add that only two of the weights measured over 0.5 inches and the rest were under.

I do now have to shoot thirty rounds at 300 or 400 yards to get an idea if the load is going to be tight enough for competition as Mutt, Dave and Chad are dying for some competition next year, I think, at the ALRC.
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I was impressed by what you did, you certainly deserved to win given your performance.:D
 
There is no accuracy benefit with a pre threaded pre chambered barrel just because it is pre threaded and pre chambered.

The benefit of pre threaded pre chambered barrels is if you have the equipment, you can change the barrel or adjust the head gap yourself.

If the chamber and threads are not concentric with the bore it does not matter when it was threaded and chambered; it will not be delivering the best accuracy.

Converting a 700 to a barrel nut configuration and using pre threaded and pre chambered barrels will not in itself increase or give you the best accuracy.

Just my thoughts...
 
GT, as always, you info is bang on. The issue is that there is a vocal group that say a prethreaded/chambered barrel CANNOT be accurate or at least as accurate as a shoulder headspaced install.

You have certainly made me barrels that used the barrel nut install that were superbly accurate and those from other quality manf's offer similar performance.

The key points are QUALITY BARREL AND CHAMBERING WORK. Then the useage of a Savage or Stevens actions which reduces the need for a whole bunch of set up. Shilen and McGowen are certainly machining their barrels well and many shooters have reported excellent groups.

These prepped barrels do offer top shooting potential to a host of shooters who neither have the opportunity or budget or desire to use other forms of install. As has been shown many many times, these barrels will certainly shoot to the potential of the action/stock/load/shooter.

There is no disadvantage to this form of headspacing/installation especially if used with a Savage/Stevens.

Still working on the Rem/nut set up and waiting for feedback from various suppliers on whether they are going to pursue this form of barrel work. They are presently making stuff for Savage but still wonder if Rem shooters will embrace a process many vocal Rem shooters have derided over many years.

As is well documented, the Rem 700 action typically needs some machine work to get things true so the full potential of a prethreaded/chambered barrel may not be realised using this action. However, they will certainly shoot a whole lot better then the factory barrel.

I can see handling elevated pressures as being one shortfall. Most Rems need some lapping to get the lugs to have ideal contact with the receiver. A user could certainly do this BEFORE final headspacing but all the other set up will be left to chance.

Since I have built several Rems that have shot in the 2's and 3's without action work, I can say this level of accuracy is certainly achieveable.

As was mentioned before, these premade barrels will appeal more to the sporting/varminting/tactical shooter who wants to try various chambers or goes through barrels quickly.

If I can supply the parts, we will see what the demand is like.....

Blygy, very happy that the barrel is shooting so well for you. My Shilen really likes Bergers and shoots them a bit better then the Lapua. Was around 1/4 to 1/2" better at 300m. For F class, that is quite a big difference.

IMR7827 is an interesting powder choice. I am using H4831SC.
Jerry
 
guntech said:
There is no accuracy benefit with a pre threaded pre chambered barrel just because it is pre threaded and pre chambered.

The benefit of pre threaded pre chambered barrels is if you have the equipment, you can change the barrel or adjust the head gap yourself.

If the chamber and threads are not concentric with the bore it does not matter when it was threaded and chambered; it will not be delivering the best accuracy.

Converting a 700 to a barrel nut configuration and using pre threaded and pre chambered barrels will not in itself increase or give you the best accuracy.

Just my thoughts...
Click to expand...

Dennis I could not agree more!! Having a hand fitted barrel that is properly mated to an action would be my choice too.
I was surprised at how well the 1 that Blygly had shot, but the fact remains it shoots very well for something genericly produced.
 
This sounds like a great option for self-directed tinkerers!

Pardon an ignorant carpenter's question, but when you went from a 7RM to 260AI, wasn't the bolt face too big?
 
Well, the same care and attention Shilen puts to making their barrels is also put in their manf of these prechambered/threaded barrels. Having a background in building BR winning rifles for several decades in the US puts them pretty high up the 'generic' food chain.

[Sorry, this service is not available outside the US]

But then aren't Ferraris, Porsche's and Lambo's generically produced too?

Jerry

PS McGowen does a great job as well.
 
Silverado said:
This sounds like a great option for self-directed tinkerers!

Pardon an ignorant carpenter's question, but when you went from a 7RM to 260AI, wasn't the bolt face too big?
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5 minutes (or 10 if you repeatedly put the bolt handle on wrong like me) and some hand tools rectify's that inconvenience. Another reason to love the Savage/Stevens platform.
 
I bought pre-chambered barrels in .223 and .17 rem from Pac-Nor and reamers / head space gauges from Brownells in the days when it was relatively easy to import such items. Both barrels shoot better than I can, but it does need a degree of care and you need to read up on the topic before considering the DIY approach.

I read an article in a recent Varmint Hunter magazine where a chap used a custom Savage nut setup from Pac-Nor on a 700. Looked pretty interesting I have to say.
 
These barrels are simply an affordable option for me.. If I had the funds I would have Rick or another one of the excellent smiths on here do the work.. How ever with mortgage, truck and support payments this is an excellent way for me to continue in the sport..

I have only had the one prefit so far and am working on a second currently.. I believe the Savages are a compromise. A floating bolt head, like a floating barrel, is not as consistently accurate as a properly machined rigid bolt, like a floated barrel isn't as accurate as a properly supported and bedded barrel... But floating bolt heads and floated barrels allow us to achieve acceptable accuracy with a minimum of work.

Just my opinion but there it is...
 
Blygy said:
A floating bolt head, like a floating barrel, is not as consistently accurate as a properly machined rigid bolt, like a floated barrel isn't as accurate as a properly supported and bedded barrel... But floating bolt heads and floated barrels allow us to achieve acceptable accuracy with a minimum of work.

Just my opinion but there it is...
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....then I guess I have to differ with your opinion. :)

Free-floating a barrel is indeed an important step in accurization. The exception to that rule is the use of a barrel block that free-floats the action and the distal portion of the barrel, but otherwise, free floating is an essential part in minimizing/eliminating harmonic interference.
 
Blygy, I will also add that the floating bolt head is one of the best things offered in a factory action. This is the reason we can get such great results even when pressures are run up.

The floating bolt head ensures that there is full lug contact with the receiver. They simply must make contact. Any bolt put into any like sized action WILL have similar contact- this without any lapping or mucking about. Yep, done the swaps.

Please note, this doesn't mean the headspace is identical!!!! Just that any correct length bolt can be used in another action without machining. Adjust headspace accordingly.

Just as importantly, the bolt head is now suspended from the bolt body and all the bouncing and moving it does during the firing process. The bolt head is not moved during the firing process common to ALL solid front locking bolts that have not had the bolt body properly bushed.

If you look at the steps taken by a BR smith when they tune a Rem (or another front locking solid lug action) or look at the points that a Custom action resolves, you will quickly see why I am so excited about the Savage design.

So many of the issues affecting the Rem are simply not a problem in a Savage. Is the Savage perfect? Of course not. But a box stock Savage can give you amazing accuracy with a barrel swap simply because of all these free floating parts.

It is a feature that is working for thousands of shooters and many, many, many barrels so this is not a fluke.

The potential for 1/4 min accuracy with a box stock action and a simple barrel swap is pretty exciting stuff. Except for maybe the new Marlin, I can't think of another action where this is possible on a wide scale or without the need for a bunch of custom machining to set up.

Oh, in case you were wondering, the level of accuracy that you are experiencing with your barrel/action can be duplicated on another action just by installing your barrel and shooting your ammo. That is pretty neat stuff too.

Yep, I have tested this by swapping one barrel between 4 actions of various models (Savage and Stevens) and years of production (put into the same stock/bedding).

Just make sure the barrel is free floated :)

Fun, fun, fun...

Jerry
 
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