Barrel contour advice needed on new build

[dolomite_supafly]

I am in the process of building a Savage in 45 ACP. It is going to be used mainly to deal with problem animals. I will mostly use handloads but still have the ability to use factory ammo. I didn't plan un using a flash suppresser or muzzle brake.

I will be starting with a blank that is 1.25" in diameter. The muzzle will be .920 so I can use Tech Sights for the front sights. I have contacted various sight manufactures with my specs for the rear sights so that is being worked out. The rear of the barrel just ahead of the receiver needs to stay 1" for about 4" but I can't decide what diameter the area between the Tech Sights and just forward of the chamber should be.

The barrel will be 17" long with approximately 15.5" hanging out of the receiver. Question I have is on which contour looks best. I am torn between all three choices but am leading towards choice A. I would just like to get some other input from others.

I have been thinking of three options and whatever I choose it will be a straight taper.

Choice A:
.920 from the muzzle to the area just ahead of the chamber.

Choice B:
Straight 1" taper except the muzzle which is .920 for the Tech Sights

Choice C:
1" just ahead of the chamber, .920 at the muzzle for the Tech Sights and .75" in the are between.

Here is a rough drawing to kind of illustrate how it may look. It is not to scale but hopefully it will give some idea of how it will look when completed.

[img width=600 height=407]http://img.photobucket.com/albums/v446/Adyth/Savage/45acpbarrelcomparison.jpg[/img]

Thanks for your thoughts on this
Dolomite

[Cycler]

A or B but not C. Just for appearance in my opinion.

[dcloco]

I like B. Any time there is a sharp step in a barrel, it tends to collect things...like lint/snags/etc......or is the object of scrapes/dents/scratches.

[1Shot]

...B... 8)

[johndoe3]

I vote 44 Magnum because it has greater versatility, and 16.25" barrel length to knock off a little more weight. Both 45 ACP and 44 Magnum pistol rounds won't increase velocity after about 12" of barrel. So the only reason for 16" is to meet the Federal law about SBR (Short Barreled Rifles) which requires a $200 BATFE fee for those less than 16".

I vote B with flutes to lighten further.

[pdog06]

B here also...

[dolomite_supafly]

OK, thanks guys I think I will side with everyone's choices. Keeping it 1" the length of the barrel probably will look better than having steps.

I have numerous reasons for giong with 45 ACP versus anything else:
1. I am already setup to reload 45 ACP and have a ton of brass
2. There is no need for a custom bolt head, the bolt head for a 308 Win will work fine
3. Making it magazine fed will be easier with a rimless cartridge
4. Factory 45 ACP ammo is still mild, a plus for my wife
5. 45 ACP should be quieter making night shots easier on the neighbors

Next question:
Barrel nut or not?

I can have it headspaced using the barrel nut or setup to use a shoulder on the barrel. I am thinking if I have it headspaced using a shoulder on the barrel then swapping barrels would be a no brainer, just tighten down and I am done. I don't plan on doing a lot of swapping but I like the idea of being able to headspace by just tightening the barrel down.

The barrel will be blastd then blued to give it the appearance of a parkerized finish. The Tech Sights come parked so I will try to match those as close as I can. If I dont like it then I will just coat it.

One last question:
Do you think truing the receiver face would be worth it on this setup? If I do then I will get an aftermarket recoil lug to go with it.

Thanks for all the advice guys
Dolomite

[johndoe3]

dolomite,
Actually, 45 ACP has a lot of versatility.

I have a 1911 pistol with an extra barrel for 460 Rowland. In it with the 460 Rowland barrel installed, I shoot 460 Rowland ammo with 185gr bullets at 1550 fps (990 ftlbs) and 230gr bullets at 1350 fps. I also have a Mech-Tech carbine chambered for the 460 Rowland with a 16" barrel. I use the lower from my 1911 on it and favor 10 round magazines, which you can rip off fast if you want. In the 16" barrel the 185gr bullets go ~2100fps and the 230gr ~1800fps. I can and do also shoot 45 Super and 45 ACP in both my 16" carbine and 1911 pistol.

The 460 Rowland brass is 1/16" longer than 45 ACP and the OAL cartridge length is the same as 45 ACP. They use the same reloading dies for 45 ACP, 45 Super and 460 Rowland. If your barrel were chambered for 460 Rowland then you could shoot all 3 if you desired.

45 ACP chamber pressure is only 21,000psi
45 ACP +P is 23,000 psi
45 Super is 29,000 psi
460 Rowland is 40,000 psi

So...the chamber pressure is not that high and you could gain versatility by chambering your barrel for 460 Rowland and be able to shoot 45 Super loads and 45 ACP loads too. OAL length of cartridges is the same for all three. 45 Super brass has slightly thicker webbing of the brass but is the same as 45 ACP overall. Something to think about. Starline Brass makes the 45 Super and 460 Rowland brass. It would just be a matter of different loads with the same dies.

460 Rowland load info: http://www.clarkcustomguns.com/460loadchart.htm

Starline Brass http://www.starlinebrass.com/index.php?cPath=1

Mech-Tech carbine upper for 1911's and Glocks with 16" barrel. A simple blowback design.
http://www.mechtechsys.com/

I call the Mech-Tech carbine my "Frankengun". :)

[dolomite_supafly]

Just out of curiosity, if the 45 ACP headspaces off the case edge and the 460 is 1/16" longer how is it possible to fire them from the same 460 Rowland chamber?

I understand the OAL is the same but it would seem like the 45 ACP would fall too far into the 460 Rowland chamber to fire.

You don't have a link to the cartridge drawing for the 460 Rowland?

Thanks
Dolomite

[johndoe3]

OK, I'll try to post images for both. First is 45 ACP (and 45 Super)


Second is 460 Rowland
[img width=600 height=389]http://ad2004.com/460Rowland.gif[/img]

Johnny Rowland told me that the only reason they made the 460 Rowland brass 1/16" longer was so that it would not work in a regular 45 ACP chambered barrel in a 1911, because it might fail. The barrel for 460 Rowland is slightly beefed up in the chamber area as compared to the regular 45 ACP barrel. You can actually use 45 Super brass and load it to 460 Rowland levels, since the 460 Rowland brass is no stronger than 45 Super brass in any way. So...just chamber your rifle for 45 ACP and you can actually shoot 45 Super and 460 Rowland level if you want to. No need to use the 460 Rowland brass if you use 45 Super brass for both Super and 460 Rowland level loads.

BTW for full power 460 Rowland loads in a 16" carbine, they are:
185gr, 2100 fps, 1809 ft.lbs.
230gr, 1800 fps, 1653 ft.lbs.

regular 45 ACP gains about 50-250 fps in a 16" carbine as compared to 5" pistol (1911).