Any interest in a 1:14 twist .22 barrel?

[BillG]

I have a client that really wants to have a 1:14 twist barrel in .22 cal. Everything would be the same as what has been used in the War rifles. It's the same TJ barrel that has been distributed by Marmont Malitia / Wicked Air Rifle. The faster twist will be the only change. Before I invest in the mandrel, I'd like to have an idea of demand.

 

[steve123]

Depending on cost I might be interested.

 

[Heavyopp]

What .22 cal projectile would this be optimized for?
These are barrel blanks or are they finished?

 

[UCChris]

What diameter/length would the barrel blank be?

 

[Motorhead]

Just helping .. no affiliation
WAR rifles ... used .500" or 1/2" diameter.
If TJ is making them, should be able to pick your length out too IIRC 36" max ?

Cost WAG .. figure about $7 or so an inch

 

[Airgun-hobbyist]

The geoffry-kolbe twist rate calculator indicates that twist would probably work well. If you made them to drop into a few popular guns, like an FX Impact they may sell pretty well. I don't have a .22 barrel for mine, so I'd be interested in going this route.

Barrel Twist form

 

[Airgun-hobbyist]

Bill, if making a mandrel for .216 airgun and slug use (small i.d. for polishing to size), here's an image and link to a proven land and groove design that prevents leading, brought to us by valued AGN and Gateway member Bob @rsterne. As the images and link shows, the mandrel was made for 7mm projects, hammered by TJ's as well.

The 7mm / .284, 18" twist barrel from TJ's - Airguns & Guns Forum

The 7mm / .284, 18" twist barrel from TJ's, Air guns, Airgun Forum

www.gatewaytoairguns.org

 

[mercado]

I would buy one 9/16 thick... 26 1/2 to be used in a condor.. I could send you a airforce barrel so you could have all the measurements..

 

[SupremaRatio]

If you are able to make one for my Prophet mk1 with bridged TP and at least 24" length+ shipping to EU, i'm all in

 

[jdanvers]

^^ what @SupremaRatio above said - except I'm in Upstate, NY. ;-)

 

[Rallyshark]

If I remember correctly, those WAR barrels were great for pellets, but were an extremely tight bore. I can dig the 14" twist, but not the tight bore... That super tight bore is what prevents so many folks from doing builds with the TJ's .22 barrels. I LOVE my 16" twist .300 barrel, and it's a laser with almost every slug I put in it. I wish they would offer a .22 barrel with a twist in the 14-16" rang(I'd pick 15") with a bore more like .212/.217-.218 bore. I'd buy that blank in a heartbeat

 

[SupremaRatio]

If I remember correctly, those WAR barrels were great for pellets, but were an extremely tight bore. I can dig the 14" twist, but not the tight bore... That super tight bore is what prevents so many folks from doing builds with the TJ's .22 barrels. I LOVE my 16" twist .300 barrel, and it's a laser with almost every slug I put in it. I wish they would offer a .22 barrel with a twist in the 14-16" rang(I'd pick 15") with a bore more like .212/.217-.218 bore. I'd buy that blank in a heartbeat

Right, but you have Green Mountain 25 (25 is not the caliber) blank barrels that work great!
Can't order from EU, unfortunately

 

[BillG]

Sorry folks.
I'll try to address some of these posts as I read through them.
The available diameters would be .561 down to .437. At least that's how I've been getting them for the past year. The .561 is what I use for the impact. for the .25cal and .30cal, I've gotten as large as .591. I've had some clients inquire about using the .22LR blanks because of the 1:16 rate. I'm just not sure about procuring proper fitting lead for those without rolling your own. One fella ordered one with only crown, choke, threaded muzzle. He wanted to cut the throat and lead himself. Unfortunately, he wasn't happy with it. Turns out, he was shooting a .217 slug and that groove diameter is like .222. I tried to convey my concerns, but we suffered a language barrier, and he wasn't having it. I have no idea what he was doing for throat and lead. As far as I know, he has procured bigger pills for it. He did order another barrel tonight though. This makes his 9th or 10th. So, this guy is the one who compelled me to ponder the question. I haven't done any Kolbe work on it yet, just been too covered up with work in and outside my shop. Some of you have sent PMs and I haven't been getting the e-mail notifications. I'll try to get back to you ASAP. Thank you all for your replies and suggestions. I'll post the availability here if I decide to try this out. I just don't have time to shoot much anymore which hinders R&D a bit.

 

[BillG]

I would buy one 9/16 thick... 26 1/2 to be used in a condor.. I could send you a airforce barrel so you could have all the measurements..

Marcado, I'll keep that as a note on my white board. I've been wanting to venture into the Air Force realm. I would definitely need something to reverse engineer. They look to be a really straight forward design.

 

[BillG]

What .22 cal projectile would this be optimized for?
These are barrel blanks or are they finished?

You can have them either way. I procure and finish them for those who desire such a service. There are few folks on here that probably do their own work. As for the projectile question, I have yet to dive into that. I was approached about developing it and I wanted to kind of take the pulse of the people that might be interested, before I make the investment in the mandrels.

 

[BillG]

If I remember correctly, those WAR barrels were great for pellets, but were an extremely tight bore. I can dig the 14" twist, but not the tight bore... That super tight bore is what prevents so many folks from doing builds with the TJ's .22 barrels. I LOVE my 16" twist .300 barrel, and it's a laser with almost every slug I put in it. I wish they would offer a .22 barrel with a twist in the 14-16" rang(I'd pick 15") with a bore more like .212/.217-.218 bore. I'd buy that blank in a heartbeat

Interesting, Is that 1:16 .30cal a TJ's? I don't see it on his list.

Depending on cost I might be interested.

I'll need to put some deeper thought into it but as a SWAG maybe $0.35-$0.50 per inch more than what Tj's charges for standard offerings. That would put recoup for the mandrel at maybe 35ish, typical length barrels. Maybe $6 to $6.25/in. Assuming you do the machine work, that'd be somewhere around $130 plus tax and S&H. For a crowned, choked, ported, and chamber cut, probably north of double the DIY price.

 

[steve123]

Interesting, Is that 1:16 .30cal a TJ's? I don't see it on his list.

I'll need to put some deeper thought into it but as a SWAG maybe $0.35-$0.50 per inch more than what Tj's charges for standard offerings. That would put recoup for the mandrel at maybe 35ish, typical length barrels. Maybe $6 to $6.25/in. Assuming you do the machine work, that'd be somewhere around $130 plus tax and S&H. For a crowned, choked, ported, and chamber cut, probably north of double the DIY price.

Thanks. Keep us posted.

 

[Rallyshark]

Sorry for the slow reply, I forgot to check the notification box... The 16" twist .30 barrel is a TJs barrel that is not on the list. I found out they had it, because I messaged them a while back wanting a .30 barrel with a faster twist. That's when they informed me that they had a 16" twist .300 barrel. Of course, I jumped on it! That barrel has been one of the best barrels I've ever done for my uses.

 

[lbc_PSI]

The geoffry-kolbe twist rate calculator indicates that twist would probably work well. If you made them to drop into a few popular guns, like an FX Impact they may sell pretty well. I don't have a .22 barrel for mine, so I'd be interested in going this route.

Barrel Twist form

View attachment 322066

Where does the above graph show optimal velocity for rate of twist? At the vertical spike around 1100 fps?

 

[Scotchmo]

Where does the above graph show optimal velocity for rate of twist? At the vertical spike around 1100 fps?

The graph does not show “optimal velocity” for rate of twist.

The left side vertical axis of the graph indicates the twist rate needed by that slug to have a stability factor of 1.5, vs velocity.

At slower twist rates (above the curve), the stability factor will be lower than 1.5. At faster twist rates (below the curve), the stability factor will be higher than 1.5.

Optimal velocity is up to you to decide. i.e. acceptable accuracy, fpe, drop, drift, at the distances that you plan on shooting.