throating , the one I couldn't pass up part 2

here is part 1 on this rifle .
viewtopic.php?f=9&t=32610


I received the throating reamer from 4D Wednesday . I was disgusted when I got it , I thought I would get the "T" handle to turn the reamer since it's pictured with the set on 4D's website , but I didn't . so I thought about it and went to the hardware store and bought a bolt and a few nuts that fit the reamer #12 x 24 machine screw . with this hex nut on the screw I can run the reamer with a socket . the alignment sleeve seems to keep things centered up pretty good . I do know that the targets will tell the true story , and this rifle did shoot good before . I'm probably nuts for doing this . I bought a bunch of different bullets to use for measuring . I want to reach the lands , and not exceed the mag box length . the rifle will be primarily a hunting rifle so I'm more interested in how the hunting bullets work out . if I decide to use the long slick VLD type bullets I can single load them if I need to . I lengthened the throat a fair amount , and things seemed to work out well from what I can tell without shooting it . I have measurements off the bullet tips and also off the ogive I used both while I did this . I would keep loading a few different bullets and keep making them longer as I cut the throat , so I could watch my progress . I'm glad I did this the different style bullets changed at different amounts as I cut . it would have been a lot easier to just throat it for one bullet , but I didn't want to pin myself down to just one bullet . I wanted a happy medium that would work for many bullets . I'll post some bullet lengths and put up a few pics .

length off the bullet tip to touch lands.

bullet ........................ before length .........................after length
140 B-tip ....................2.779 ..................................2.933
120 B-tip ....................2.780...................................2.933
130 A-bond..................2.799...................................2.954
Horn 129 SP.................2.741...................................2.813
125 Partition ...............2.770...................................2.905
129 ABLR ...................2.893....................................3.012
143 ELD x...................2.882....................................3.044
140 berger VLD h.... ....2.888....................................3.044














more pics coming .

Nicely done and you have the makings of a bush Alaskan with that handle improv!

thanks gbflyer , it looks good to me , but I'm anxious to get it out and shoot it to see how it does . it looks like the weather is going to turn mild for a few days , maybe I can get it out .

Looks great Jim. Can’t wait to see how it shoots.

I’m no expert on peering with a bore scope but to me that looks quite smooth. I’ve taken to what I call a “pre-break in” on the throat area with the chambers I’ve been reaming by carefully polishing the throat area with JB Bore on a patch wrapped bore brush while still in the lathe. Only the throat. I borrowed this from one of the real gunsmiths that is willing to share publicly. I think it helps the throat not copper up as much with the initial couple of shots.

The point of my sharing this is that your barrel might want to foul for a bit after the fresh throating job. Or that baby might just go along like nothing ever happened.

SJB358":s4wymo2y said:

Looks great Jim. Can’t wait to see how it shoots.

Click to expand...

I'm anxious too . I have a ladder loaded up and a few 3 round groups to check seating .

gbflyer":1ukl9ik7 said:

I’m no expert on peering with a bore scope but to me that looks quite smooth. I’ve taken to what I call a “pre-break in” on the throat area with the chambers I’ve been reaming by carefully polishing the throat area with JB Bore on a patch wrapped bore brush while still in the lathe. Only the throat. I borrowed this from one of the real gunsmiths that is willing to share publicly. I think it helps the throat not copper up as much with the initial couple of shots.

The point of my sharing this is that your barrel might want to foul for a bit after the fresh throating job. Or that baby might just go along like nothing ever happened.

Click to expand...

it does look to be a pretty smooth finish .looks to be a fair amount smoother than the original . I'll keep the JB's tip in mind . I've heard of guys JB-polishing the throats as a maintenance . I've never done this . thanks for the tip .

I put a few rounds through the rifle yesterday . it is producing great velocity and didn't copper up much at all . I have a 3 round group about an inch at 100 yards, man am I rusty . I need to start loading 4 or 5 to be able to get 3 good ones on target .the range was busy , I didn't get to walk out and number my ladder shots . I really just wanted to get some rounds through it , and check for copper and velocity . it looks like things are going to work out .

Wow that new throat is clean. Nice work!

That’s some great speed. 46/46.5 look might close on speed. That’s hoofing for a 260... darned thing thinks it’s a 270.

thanks guys . I didn't show pressure yet , but according to quickload this is over max by 1 or 1.5 grains . the velocity is also plenty fast . I thought I'd be working with the 120 - 130 class bullets for decent velocity , but I'm thinking a 140 B-tip should still be in the 2900 - 2950 FPS range . that's fast enough to keep me interested . I'm anxious to get working up a load watching accuracy now .

I haven't been shooting much at all this year , helping my son with some home remodeling . I'm rusty and I caught a cold . shakes and jitters , you bet I am . I took it out again today . I was testing seating at a minimum powder charge . quickload looks to be 42.8 min at 2850 FPS . I've done this before and there was always a group that was noticeably better than the others , this time things are not so easy to read . a couple of these groups look like I could start increasing the powder charge and see how it shoots . I have a couple groups marked 1 pulled , I actually touched it off before I was ready . I have a hard time shooting from the bench with my bag set up . it seems I don't have room for my trigger hand unless I have it all twisted around trying to fit in there . gotta be something better out there for me . all that said , the rifle looks like it'll shoot .


this is at 100 yards .

Interesting project Jim and always good to see improvements. Looks like a job well done to me.

thanks Shade Tree . I got some ammo loaded today , I'm anxious to get it out again .

got out again today . the rifle shoots well . I'm very pleased . here's a couple of targets from today . I'm starting to see why you guys like the 260 rem's .

final load with the 125 gr Partition . I think all the info is on the target , if not I'll add it . the lower shot was a cold , clean bore .

3 shots from 100 yards .




started a seating depth test with the 140 B-tips with a starting load of RL26 . I felt sloppy on the .010 jump and the .015 jump targets . I think I'll shoot them again . the .005 jump is 3 shots , the others are 4 .

from 100 yards .

got out yesterday after work . the rifle seems to shoot well with anything I try . I had a seating depth test loaded up at jumps of .010 , .050 , .090 , .130 . but after I shot 3 rounds to foul the clean bbl at .035 jump I decided I need to work in around that area . all shot from 100 yards .


cold clean bbl , .035 jump , new brass .




.010 jump



.050 jump .

Nice shooting Jim, have you taken it out to a further distance and see what different seating depths will show?
The ABLR bullet had been fussy in my 7mm Mag and I gave up on it. Good to see it worked good for ya.

And for the Partition, its a solid hunting load as the picture shows.

Nice work. I have always though the .260 Rem is way Underestimated !

thanks guys , I'm really liking this rifle . it shoots everything pretty good , that I've tried so far . fast and accurate , what more could a guy ask for . Mark , I haven't tried it out at longer distances , I have to get the powder charge nailed down before I shoot it far .