6slr range report

[1000yardstare]

Started breaking in my new 6SLR. MacLennon 8 twist barrel, squared Rem 722 action, rebedded in a Fajen prone stock with JB Weld, Anschutz rail and butt pad, Timney trigger, Bushnell 4200 6-24 Tactical, Burris Z-rings with 10 moa inserts, Harris bipod.

Pushed the shoulder on Win .243 brass to 30 degrees with a 6 XC body die, seated a 107 SMK to desired depth and sent dummy round to PT&G. Resulting reamer is based on Kiff print 9857. Sent reamer and GO gauge to MacLennon.

Pushed the shoulders on 50 Win .243, primed Win LR, loaded 107 SMKs over 46.0 gr RL25, COAL 2.800. 2910 fps. Want 3000 fps. Will go up to 46.5 gr then 47.0 gr to check accuracy and velocity.

Cleaned after each shot for 10 shots. First five to sight in and chrono. Next five went into 1/2 inch at 100 metres. Not bad for a new barrel and getting up and down to clean barrel. Next 10 shots for sighting at 300 metres. Cleaned after every two shots.

Shots 21-25 for a group at 300 metres lying on the grass in front of the benches using a bipod (don`t like pedestals). Print my own International ICFRA F Class 5 ring targets used by Canucks, Brits and Aussies. Has a 0.8 moa 5 ring and 0.4 moa V-ring. Result was a 1 3/4 inch group (0.5 moa at 300 metres) scoring 25-2V. Kept pushing shots up and left because shooting on flat ground, not a mound. Was happy with the group out of a new barrel.

Target is shown below. Inner light circle V-ring, inner dark circle 5 ring, outer light circle ISU iron sight 10 ring, outer dark circle 4 ring.

 

[rcw3]

That long and detailed shoot and clean routine had to be tedious for sure. Maybe I am shorting myself in the process, but I do not do that and I have never noticed any difference from when I used to do it years ago. These days I kind of figure a good hand lapped barrel should not need all that - 5 rounds and clean, 5 more and clean, then just shoot 10 or 20 and clean, then just shoot it. I do a lot more shooting (which I enjoy) and a lot less cleaning (which I don't enjoy doing).

Enjoy the 6mm Super LR

Robert

 

[Dgd6mm]

I agree Robert.

 

[Bob3700]

Robert,

One thing that I have found with new bbls is that in the throat of a newly chambered bbl, there are slight tool marks from the reamer. Take a look with your bore scope.

I believe that the tedious bbl break-in routines originated in an effort to remove these tool marks by firing the rifle. Back in my benchrest days, new bbls would exhibit a lot of blue patches during the beginning of the bbl break-in process. Then as you approached a total of 20 shots or so, the blue would just stop.

This, I believe, was a result of the tooling marks (some refer to it as fraze) being worn off and this rough surface is no longer stripping jacket material from the bullet.

You can validate this using your borescope. Any reamer will leave perpendicular to the bore, cutting marks, some more than others.

To get around the bbl break-in process (now that we feel we know what the reason for the break-in is) try useing a mild diamond lapping paste (available from McMaster-Carr). Wrap a patch around an old worn out brush, spread the past on the patch and give the throat a half dozen passes. Now take the bore scope and look at the throat. She be smooth maan and you don't need the shoot-n-see method of bbl break in. You are ready to shoot Xs from the get go.

Just my experience.

Bob

 

[rcw3]

Hi Bob

To me the only purpose of doing any barrel "break in" is to get the barrel shooting well and to have it continue shooting well without accuracy declining as you shoot rounds through it and without the necessity of having to clean it continuously to retain accuracy. Once a barrel will shoot and continue to shoot, it does not bother me if there are some tooling marks in the throat. Now maybe I am choosing to ignore something I should pay attention to, I don't know, but I don't seem to be paying a price for it so I don't worry about it.

As a side note, I am most particular with the reamers I get to make sure the cutting surfaces in the throat area are very clean and sharp. I have had the cutting surfaces of the throat area of some brand new reamers re-stoned to get them where they need to be to make a clean cut and not leave a lot of tooling marks. Fred, who I work with, is very good that way, and is very fussy about the tooling, and can re-stone reamer cutting surfaces to clean them up if they are not right.

I am lucky because I have picked up a lot of information relating to "barrel break in" from my test firing of hundreds of the new premium barreled AR-15 uppers we have put together over the past few years for customers. These are set up with barrels like Krieger, Brux, Bartlein, Hart, PacNor, etc. Since the AR uppers need to be test fired for function (feeding and ejection, with magazine fed sequences) it is not unusual for me to run 3 to 5 sequences of 5 shots each (15 - 25 rounds) through a new upper to assure everything runs 100% with multiple magazines. With many new barrels I see the same thing over and over again that leads me to believe barrel "break in" is many times (not always) a waste of time. I never do any cleaning at the range when I test fire uppers - I just shoot them. What I see when I start out with a brand new barrel is that the first 5 shot group with it is typically loose (understandably - never had any rounds through the barrel and the first shot or two out of a new barrel is almost always out a bit), then the second five shot group is either still a little loose or maybe tightens up a little (and with some frequency the second group out of a new barrel zooms right in to .5 MOA or less), then by the third five shot group on some barrels the group is still a little loose or a little tighter, but if a barrel ran a tight second group it usually runs a tight third group as well, but on many of the barrels the third group really tightens up significantly (to .5 MOA or better), then by the fourth five shot group (if I do that) most of the barrels tighten up significantly and those that tightened up earlier stay tight. If I run another group (i.e. the fifth five shot group) it seems most all the barrels that shot good earlier groups all stay tight. What I see is it just takes some barrels a number of rounds down them for them to tighten up and shoot well, and once they get the rounds down them, they shoot tight and stay tight without the need for any cleaning at all, and if I take them back after test firing and look at them, most of them show no coppering at all.

Now some (not many) of the barrels do need shooting and cleaning, but not a lot typically. Sometimes I have taken an upper out for a test firing and fired 3 to 5 five shot test fire sequences out of it and all groups are loose (and with a bore scope you can sometimes see coppering in the barrel when you come back from the range). If I take that barrel and clean it, then take it back out and test fire it a second time the next day, many times it will shoot well right from the get go and hammer .5 MOA or better groups all the way (with the exception sometimes of the first shot out of the clean barrel may out a little - which is not unusual or unexpected).

What I also see with the new barrels is once a barrel starts shooting tight it typically stays tight. With some of the new barrels (mostly button rifled it seems) they will initially shoot a few shots tight then loosen up and won't shoot well until they are cleaned at least once (these are typically the ones that I have had to bring back for a second round of test firing). But typically after they have gone through the first round of test firing, then been cleaned, they will shoot well and stay tight without needing to be cleaned.

There are always exceptions, and I have seen some barrels that needed more shooting and cleaning and some that shot well right from the first round "down the pipe".

So that's why I do a minimum barrel "break in" - what the heck - why clean if you don't need to?

Robert

 

[1000yardstare]

Shooting is as much a head game as golf. By going through a set routine with a new rifle in my mind I think I have eliminated one more variable.

Doesn`t take much time to clean every shot for the first 10, then every two for 10, then every 10 for 50. After that the barrel is on its own.

Rob MacLennon himself says you don`t have to break in his barrels. I get very light blue for the first 5 shots then barely any after that. Same experience with a Shilen Select Match.

The F Class target has become very challenging with its 0.4 moa centre ring at 300 and 1/2 minute centre ring for all ranges beyond that. Call me a creature of habit but I don`t want to get a flyer at 1000 yds and think to myself "Geez, I skipped my usual break-in routine. Did that cause the flyer?" Common sense tells you "No" but sometimes the human brain is not very good in dealing with common sense. Especially on a hot humid Summer day after having shot 3 matches earlier in the day and sweat is dripping down into your eyes. Every competitive shooter has gone through those doubts about some aspect of their equipment. I hear it all the time on the firing line including practises.

Anyway, that has nothing to do with the 6SLR. Our next F Class practise is 900 in the morning, 1000 in the afternoon next Sunday. Would be nice to have a 600 in there first but it didn`t work out that way. With the 107 SMK zeroed at 300 yds at 3000 fps, my ballistics calculator says 20 minutes up for 900 and 24.5 minutes up to 1000. Will be interesting to see how close those comeups are.

Bill

 

[rcw3]

Shooting is as much a head game as golf. By going through a set routine with a new rifle in my mind I think I have eliminated one more variable.
. . . . . . .

Bill

I won't disagree there - - you have to have confidence - - and if that's what it takes, then that's as good a reason as any to do a break in routine.

Robert

 

[1shot]

Having shot the SLR since it's infancy, (6SX) my routine went like this. I like to get several things done at the same time while breaking in a bbl. especially if it is a caliber that I have no prior experience with. In the case of the SLR I will fire one shot and clean for a total of five shots. During that time I'm trying a different powder, changing a powder charge to reach a target velocity, and maby adjusting seat depth between each shot. After that is complete, I fire a total of five three shot groups each loaded with data from the previous group and the five single shots. By the time I have 20 rounds down the tube I'm seeing no copper, and generally very close to at least one load that really works really well for that cartridge. BTW, every round is fired through a chronograph, and I feel like I’m getting the most buck for my bang using this method. (pun intended) ;D As always, YMMV.
I hope this helps,
Lloyd

 

[1000yardstare]

Had a 900/1000 yd F Class practise 2 days ago, 36 shooters there, good turnout. Warm sunny day.

Backed the 107 SMK load off to 2900 fps in preparation for the Summer heat. Don`t want hard bolt lift under a blazing sun.

With a 300 zero comeup to 900 is 21.5 minutes. Comeup to 1000 is 27 minutes.

Hope this helps someone.

Bill

 

[Bob3700]

Bill,

What length bbl are you shooting? 2900 fps seems like a pretty low velocity for the SLR with a 105-107 gr bullet. My BRX will shoot the 107s at 3020 fps and that is my Summer loading. My bbl is 30 inches long.

I would have thought you would be looking at 3100-3200 fps with that large case to get some ballistic advantage. Are you having hard bolt lifts at velocities over 2900 fps?

Just curious as I have been shooting the SLR for going on a year now and shoot the 115 DTACs at 3050 with no pressure signs (using H4831sc).

Bob

 

[Bob3700]

Robert,

Years ago when I was shooting service rifle, I never broke in a bbl. Just load and shoot. Any difference in accuracy between a properly broken in bbl and just shooting was IMHO, a waste of time cause the aiming system was not all that precise and the distance not that great. Heck, I never even weighted a powder charge until I got back to the 600 yd line. One friend loaded on a Dillon progressive and didn't way powder at all. He shot exceptional scores XC all the time.

With a LR Match rifle, I have always prepared the throat of the bbl before serious shooting. Too much time and cash involved to do otherwise IMO, plus, all the small things seem to matter when shooting at 1K.

Like the one poster said, much of the game is in the head. Confidence in your equipment is as important as confidence in your ability.

Bob

 

[1000yardstare]

Bob3700......I have chronod a load at 3050 fps out of my 28 inch barrel with the 107 SMK and RL25 on a mild May day. Seemed accurate enough with no hard bolt lift.

I learned a bitter lesson in a 300 metre ISU match with a 6mm/250 some years ago. I had worked up max loads in the cool Spring and took them to a match on a blazing hot August day. Had to hammer the bolt open after the first two shots. Third shot the bolt was frozen closed. Had to withdraw from the match.

So now I find a max load in cool weather, back it off 150 fps as the heat approaches, use the load in hot humid weather and watch the bolt lift and primer flatening. If all appears OK I go up another 50 fps and watch the signs on another hot day. Repeat the process until I have a max load I am comfortable with in the dog days of August.

The 6SLR is a new cartridge for me and I am just starting the process of hot weather shooting with the rifle. I don`t want to be hammering bolts open again.

Bill

 

[bozo699]

Shooting is as much a head game as golf. By going through a set routine with a new rifle in my mind I think I have eliminated one more variable.
. . . . . . .

Bill

I won't disagree there - - you have to have confidence - - and if that's what it takes, then that's as good a reason as any to do a break in routine.

Robert

Bill,
I couldn't agree with Robert more, if you genuinely believe the break in helps the gun will shoot better for you, I have no doubt of that. I personally think breaking in the barrel does help, it helps smooth out the barrel and I learn what the barrel is likes, it only takes me a day to perform the task and I feel much better doing it

 

[frankgreen]

I do agree the break in is more of a head game/confidence thing for most people.

I've always said that the only thing you really break in, in a new barrel is the throat. The nicer the finish the chamber/throating reamer leaves the faster the throat will polish/break in, and it's because the reamer like was stated earlier cuts in the opposite direction of bullet travel.

I don't have a lot of time anymore and when I do go to the range with a new gun weather it's mine or say a new build for the police dept. I don't do a set break in anymore.

I might shoot 5 rounds thru it right away. Touch up the scope and clean the barrel than back shooting but that's it.

My last two barrels one was a .284win. on a F-class gun and I restored a '03 Springfield as a 1941 USMC sniper rifle with a Unertl scope on it. Neither gun had any type of break in. Just sat down and shot'em. The '03 is a honest 1/3 moa gun you do your part right. The .284win. will shoot in the .2's. The Springfield had 40 rounds thru it the first time and the .284win. was the same give or take a few rounds. Also the Springfield is a c.m. barrel and the .284win. is S.S.

I tell guys this. Shoot the gun and look to see what it tells you more than anything else.

Later, Frank
Bartlein Barrels

 

[Bob3700]

Bill,

One thing that I have found is the difficulity reading primers in a custom action. The bolt faces are so flat that all the primers apear flat and the only way to tell the pressure is to look at the edges with magnification. HP loads will be flat all the way out to the case. Normal pressure loads will still have a rounded edge.

With any action though, I keep the lugs greased after every cleaning. Keeps the bolt openings nice and easy.

Good luck with your SLR, I do like mine.

Bob

 

[HPMike800]

I just Love these 6SLR & 6CM threads, aren't wildcats great! (even easy ones)
1,000 - let me know where your velocity ends up with 105's and 107's. I just chambered my 1:8 6SLR for 105-108's. My stock is out of commission for a couple of weeks.

We have a guy here that shoots a "6SLR" with the shoulder pushed back 0.030" and uses H4350. He's running 3030-3050 with 115's.

My goal with 105's is a reliable 3150. We'll see.

As far as break in goes, I want to be productive with my rounds. I'll get on paper, clean. Shoot a couple of groups looking for pressure, clean. Get a zero on my irons and scope at the shortest distance the gun will be used for, maybe clean. Shoot a full group for fun and clean completely at home. Something like that anyway.

If I feel good the second outing will be a match. Third time out I will start looking for loads and chrono data. Out of 6 new barrels, I've had two that were screwy the first day. So I no longer look for hard data the first day.

just my 0.02

 

[coyotehunter]

I have been trying some reloader 17 with great results. My gunsmith has one also and has been having great results with the reloader 17. So far it has a lower extreme spread than other powders we have tried. I am shooting 107 sierras and with 42 grains of reloader 17 can get 3250 fps with no signs of pressure. We are however backing down on the load as there isn't much loss of velocity and it seem to shoot better around 3150 to 3180. We are jumping 25 to 30 thousandths. Dang I love this round. My smith shot a 5 inch group at 940 saturday morning with 4 of those rounds measuring 2.5 inches. He should have quit with 4 shots lol.

 

[Julien]

Hi guys I just chambered an slr about a week and a half ago and am doing some load development , I had some surplus powder made by nobel called 47N which is a 4350 type pwder I shot some beautifull little groups @100 fireforming.

Yesterday I tried some H4831 sc 44gr with 105 berger vld gave me an average speed of 3075 fps using lapua brass ,I tried win and rem brass also with the lapua giving less vertical by the looks of it.
This is a target I shot yesterday at 200m

 

[1000yardstare]

Julien......nice 200 metre target for a new barrel. I am making up my mind between H4350 and H4831sc with the 107SMK. Loading to 3050 fps with both and getting good accuracy.

For various reasons that I wont go into, I never used my 6SLR in competition this year, just a few F Class practises. So it will be a low usage barrel next year and I plan to develop it as my short range cartridge.

Good shooting
Bill

 

[Julien]

Next time out I was thinking of trying a slower powder I would like more speed out of 105 or 108's maybe some h1000 or some retumbo , seems to me I am at about max pressure with 44gr of 4831.

The 105 bergers I was shooting were jammed in about 7-10 thous the first time I shot it I had not measured the bullet to the lands as I was just fireforming I measured the lenght to ogive were a good .035" jump and they shot great.
Yesterday I only got it to group well when the bullets were jammed a bit I may try them again with a good jump like the first time.