Rem 722 Rebarrel to 300 Blackout

S

Slughammer

Member
A couple of years ago I rebarreled my Rem 722 to 223. After initial testing I seem to have lost interest. I've finally accepted that I don't really have a desire to play with jacketed bullets and rifle powders. In fact, I really don't have a lot of rifle powders around, and what I do have I would like to conserve. However, I do have plenty of pistol powders and 30 caliber molds. So a 300BO bolt gun makes a lot of sense for me.

Last fall I ordered a chamber reamer from the Ukraine and I already had a 19" raw blank from Green Mountan. I started on turning the blank just after Christmas.

Instead of starting out by offsetting the tailstock I decided to take off most of the material by making stepped cuts. After most of the material was off, I could decide if I wanted to offset the tailstock or if I could just blend from where I was.

20240130_190132.jpg20240130_190149.jpg
 
Last edited:
S

Slughammer

Member
The steps didn't look that bad. They were .0255 per inch. I approximated the center of each of those and took an additional .010 off of half of each step. Then I picked up a file the size of a 2x4 and tried to see what it would take to smooth it out. After several progressively smoother files and then grades of sandpaper, the long taper was done. (1.00 - .72 over 11 inches).

20240130_190931.jpg

A few days later, I turned the barrel around and set the compound to cut the second taper. For this I calculated the angle, then adjusted it for exactly .100 taper over 2.5 inches of travel using my dial indicator.
20240130_191037.jpg20240130_191202.jpg

Enough posting for today, more tomorrow.
 
Last edited:
CWLONGSHOT

CWLONGSHOT

Well-Known Member
Nice project.

I really enjoy my Blk Out Bolt. It's so lite recoiling and accurate its simply a joy ta shoot.
I enjoy the AR's but the bolt is my "baby".

I don't shoot cast often at all in the AR's. Sans some (NOE 247g cast) subs that I regularly shoot.

CW
 
S

Slughammer

Member
CWLONGSHOT said:
Nice project.

I really enjoy my Blk Out Bolt. It's so lite recoiling and accurate its simply a joy ta shoot.
I enjoy the AR's but the bolt is my "baby".

I don't shoot cast often at all in the AR's. Sans some (NOE 247g cast) subs that I regularly shoot.

CW
Click to expand...
I have a CZ527 in 7.62x39 that I have thoroughly enjoyed. I think the 300 has several benefits for a 50-100 yard cast bullet paper puncher. Plus I wanted my own barrel profile to get the weight and balance point better for 50 yard offhand shooting.
 
Last edited:
S

Slughammer

Member
The barrel still has some extra on both ends at this point. Finished length is going to be 16-1/2". I looked a palma profiles for the inspiration. The profile is 1.20 straight section for 3 inches, then taper from 1.20 to 1.00 in 2.5 inches, then taper from 1.00 to .72 in 11 inches.

It was at this point I realized I needed to learn how to cut threads with my new lathe. My previous barrel I cut on a Logan 9B with a lantern tool post. I needed tooling and practice, so I started doing a few trial threads every day. Switching tooling, and process along the way. Even tried upside down feeding away from the chuck.
20240131_171028.jpg

I finally decided on conventional threading using a layflat insert. I was very pleased with the results on this test piece. 20240131_171111.jpg


20240131_171232.jpg
 
S

Slughammer

Member
I installed the 4 jaw again and dialed in the bore as deep as I could get. I turned the tenon, cut the threads and counterbored in this position.
20240131_171318.jpg

I then extended the barrel all the way out holding just the muzzle in the chuck. The steady rest gapped with an index card to loosely support the chamber end at the threads. The reamer held firmly in an ER32 collet in the tailstock would guide itself by its pilot. (SORRY, NO PICTURES IN THIS POSITION).

I ended up back in the chuck for some break edges and chamfers that I should have done earlier. I had cut my tenon length .8845 so I could depth mic across the counter bore to the headspace gage and direct read the headspace with no math involved at the lathe.

20240131_171356.jpg
 
Last edited:
S

Slughammer

Member
With the chamber end done, it was time to cut the extra inch off the front and cut my crown. I saw someone else make a tapered bushing for their barrel and I thought I should try the idea. (Anything to avoid using a cats head).

I drilled a piece of 1.5 inch dia aluminum and then I set my compound using a dial indicator again to cut my taper. It came out nice and smooth and I installed it with a single layer of paper between the barrel and the bushing. I put a tune over the barrel and gave the bushing an extra smack to make sure it was seated.

I then chucked the barrel up with a live center in the muzzle and turned the OD of the bushing to remove any runout.

20240131_182956.jpg

I then set up the steady rest at the bushing. I had marked the barrel for index at the chuck I removed it and cut an inch off the barrel with a band saw. I put it back in the lathe to face it and then work on the crown.

20240131_183020.jpg20240131_183045.jpg
 
S

Slughammer

Member
Spindrift said:
Interesting project, impressive skills!

I wonder, what is the rifling twist of your chosen barrel?
Click to expand...
Thank You

The barrel twist is 1:10. No plans on jacketed bullets. I have most of the Lyman 30 caliber molds, a couple of Saeco and 1 RCBS to get me from 125gr - 200gr. I'll be shooting powders like WC820, 2400 and H110. Maybe a few faster powders like Unique or AA7 and something slower like Reloader 7.
 
S

Slughammer

Member
With the barrel done I used my wrenches and connected it to the action. Checked the headspace with the Go-gage and then again with a piece of tape on the back of the gage. Smooth with the gage and then tight with the tape added.

I didn't have any loaded 300BO ammo and no real records of what I tried when I played briefly with an AR upper. This is a new thing to me, I looked at Hodgdon and decided the thing for me to try for the first time out was H110 at 14.0gr. I loaded some ammo and headed to the range.

20240201_164458.jpg
20240201_164630.jpg20240201_164644.jpg
20240201_164710.jpg

At home I looked in the chamber with a bore scope and saw lead just in front of the case mouth. Remembering that those bullets I loaded were all lubed and checked in my Lyman 450 last summer and using a .3135 die. The intent of those was to use the push through later and size to match the rifle. I've done a slug of the throat now and .311 is more appropriate and that's what we'll try next.

Overall I'm very pleased with the accuracy. I have lots of molds and powders to play with, but it's really nice to find some good loads right from the gitgo. I still need to blue the barrel and I'm gathering the stuff to do that after practicing.
 
CWLONGSHOT

CWLONGSHOT

Well-Known Member
Now, I'm even more interested. My surmised a while ago that a one and 10 twist in the blackout would be a better cast. Bullet twist. Interesting good work good shooting.!
 
Last edited:
K

kenton

New Member
I like the tapered bushing for the steady rest.

I have had good luck using 357 load data as a guide line for faster powders using the same bullet weight. I have a load using CFE Pistol and a 110 grain 30 carbine plated bullet that at 100 yard shoots just a few inches under my full house 125 jacketed hunting loads out of my RAR.

(I know, plated bullets. I have small kids, limited time and they were the cheapest bullets available at the time)
 
S

Slughammer

Member
kenton said:
I like the tapered bushing for the steady rest.

I have had good luck using 357 load data as a guide line for faster powders using the same bullet weight. I have a load using CFE Pistol and a 110 grain 30 carbine plated bullet that at 100 yard shoots just a few inches under my full house 125 jacketed hunting loads out of my RAR.

(I know, plated bullets. I have small kids, limited time and they were the cheapest bullets available at the time)
Click to expand...
That's a good idea with the 357 load data, I'll have to remember that for the Unique and AA7.

There is nothing wrong with plated bullets if they shoot well. I used plenty of the extreme 150FN meant for 30-30 in my CZ 7.62x39 (the 150 shot better than the fatter 123gr 7.62x39 bullet). If it's a choice between having no ammo and having ammo because you bought projectiles, I'll always choose to have ammo.
 
S

Slughammer

Member
The Saeco 301 is 199gr and its shooting those very well. They came out of a 4 cavity and the nose is just a little fat on some. I'll have to sort them if I'm going to continue shooting them without nose sizing.



I have the Lyman 311299 and they weigh 212gr according to my notes. I have some on the shelf. I'll check if the bore can handle the nose and if it does, then I'll probably try those next.



I also have the Lemon 311284, . I don't remember if I've completely finished that one for Lyman or if it needs another corrective session. They may weigh more, but I'd probably have to push it way back into the case to get it to chamber.
 
You must log in or register to reply here.