boring a .45 out to .50?

[aviator_2]

Hi folks. I am a new member and have owned a Thompson Center Seneca for 24 years. I have never felt that it shot all that good and have tried another Seneca with similar results. Recently a gunsmith looked down the barrel and said the rifling looked quite shallow and the corners of the lands were not very sharp. I am considering building another barrel if I can find some barrel stock which has a turn in 28 inch rifling. The problem is that I can't find 13/16 barrel stock with this rifling. Another option may be to re-line the existing barrel if I can find someone who can do the job with the desired twist. The final option is to see if it is possible to rebore it to .50 caliber and get it re-rifled, again 1 in 28". Obviously I want to shoot sabots. I'm open to all inputs at this time. I am expecially interested in opinions regarding the concept of boring or reaming it out to .50 caliber using the existing 13/16 across the flats barrel. Is that safe? Know your target. Hank

 

[GregK]

I would think you could sell that Seneca and have enough to buy two Thompson Center Renegades in 50 cal. Or one Renegade and a Green Mountain barrel, with cash to spare.
You can get the Green Mountain barrel in a fast twist for your sabots.
http://www.gmriflebarrel.com/catalog.aspx?catid=1516Long-RangeHunter

How attached are you to the Seneca?

 

[aviator_2]

Greg: Thanks for your response. I really like the Seneca, just don't like the way it shoots. I'm not married to the idea of making it a .50 cal, it's only one option, maybe. I have talked to the GM folks on the telephone and they do not make and will not make a .45 fast twist in 13/16". Know your target, Hank

 

[flaming canvas]

Seems to me that boring a 13/16 barrel to 50 cal would be getting pretty thin on the metal. Even if it handles the pressure, that would get kind of springy during recoil. :m2c:

 

[sniper68]

I HAD the same problem with a senica I bought years ago. the barrel, sorry to say was junk (36 cal)! The styling is(was) the best of any comercial rifle out there :imo: I also didn't like the bbl length. I pulled the breech plug, and made a new drop in bbl myself using a douglas 45 cal 36" bbl. Just matched everything up and away I went. Of course mine is round ball only. It shouldn't take much to do the same with yours, you could have any sights, length and twist you want. The key is to KEEP the breech plug and get a bbl blank, I don't remember what the thread size was so you would need that before you ordered a bbl. I'm sure there ary many on this site that would do this for you. If not I have A good source. If I could find another breech plug or old bbl I would make another bbl in 36 or 40 cal! :hmm: If this sounds like to much of a hassel, how much ya want for that non shootun thing? :: By the way 13/16hts = 32,36,38,40 & 45 cal, too small for 50 cal. Hope this helps you good luck,Jim :thumbsup:

 

Speaking of senecas, I have one in .36. It's in mint shape and shoots very well. However, it sits in the safe collecting dust because it's a bear to clean. I can't use a regular jag as it will ALWAYS get stuck at the breech. the only way to clean the thing is to use a bronze brush and put the patch on that. There seems to be some kind of shoulder of some sort that grbs the patch. I've had someone tell me that on some Senecas, TC used .45 cal breech plugs on .36cal barrels. That would explain the problem but I have a bity of a hard time seeing TC doing that. tried to pull the plug and the thing wouldn't budge. even tried heat, no go. Anyone have similar experience??

Cody

 

[aviator_2]

To Flaming Canvass and Jim, I too have a concern regarding the thinness of the metal if I go to .50 cal. with that 13/16 barrel. Thank you for your input. Does anyone else have experience or ideas about that option? Jim, I think there are at least two sources of hooked breechplugs for the seneca. Check with Track of the Wolf. They have both a 5/8-18 and a 9/16-18 for the 13/16 barrel. Also, Tip Curtis of the Frontier Shop says he has Seneca breechplugs. His number is 615-654-4445. Now Jim, maybe you could help me with the barrel blank search. I would like a 13/16, .45 cal., 1 in 28 twist (and while I'm wishing, round bottom cut rifling) barrel blank. As I said earlier, GM can't/won't/doesn't make one like that. Cody, I too have noticed that feature in my .45 Seneca. There seems to be a tendency for the patch to get stuck in the breech area. I have had to shoot the patch out more than once. Now I just use a regular rifle cleaning rod with the type of attachment that holds the patch like a needle holds thread. I suppose this doesn't get all the way to the bottom of the barrel but since I usually submerge the breech end of the barrel in a coffee can full of hot soapy water and pump the rod, I think it gets pretty clean.
You folks are coming up with some good stuff for me. Keep it coming. Boring to .50 cal, re-lining or build a new barrel? What are your thoughts? Know your target, Hank.

 

[Rat]

If you use a LONG patch on a slotted tip, (like an inch wide, but three, four, five inches long, depending on bore size) and get creative on how you bunch it up, you can get into the breech quite well. Put it through the tip and try folding it different ways, and also you can get most of the patch down the barrel first, so that the tip is pushing the whole deal down, but still twist it when it gets down there, and it will stay attached to the tip....oh well hard to explain but it works.

I have one rifle with which it is NOT a good idea to put any kind of jag down the barrel.

Rat

 

[Keith]

One option with the jag is to cut a small hole in the corner of the patch. Then when you thread the jag on the jag threads go through the hole in the patch. You would have to do this to each patch you use. The idea is the patch is stuck to the rod and can't get trapped down bore.

I would consider a new barrel for the gun. The reboring lining option seems to expensive. Barrels aren't that expensive. I not sure where you can get what you want though. I would forget .50 cal. to small a barrel.

 

[aviator_2]

Keith: Thank you for your reply. I read that trick about cutting a hole in a large patch and then screwing the jag on over it somewhere else. Maybe you posted it. Also, your observation regarding not boring the 13/16 barrel out to a .50 caliber seems to be of the main consensus. I really would like to have a new barrel built rather than reline the old one because then I would still have the lifetime warranty that TC has. The challange remains to find a barrel maker or barrel stock which is 13/16 across the flats, .45 caliber, fast twist. (1 in 28") Thanks again Keith. Know your target. Hank

 

[flaming canvas]

Some of the best barrels of all types are made by Getz Barrel Company. Getz barrels are a favorite for many of the best builders and I personally recommend them. The quality and finish is first rate. Getz provides the barrels for Jim Chambers' fine kits. Many suppliers stock Getz barrels. You can contact them directly at (570) 658-7263.

The above paragraph came from the American Longrifles website

 

[aviator_2]

Flaming canvas. Thank you. That's the kind of information I have been looking for. I'm not as "tapped in" to some of these things as many of the folks on this site are. Know your target. Hank