Touching the lands or .001 to .050 off?

[Deserthunter]

I've just finished breaking in my McGowen 6.5x47Lapua barrel with 50rnds of 120gr Sierra 120 gr BTHP's, Very t ime consuming, considering that I didn't get any copper after about the 5th round....

Anyway, does anyone know how much if any space should I start with between the ogive and the lands, .001-.050", touching, more? Just any experience either with the 6.5x47L or McGowen barrels in general?

Thanks,
Desert

[Dennis]

A load of 39.3gr RL15 with the Cauterucio 120 produced a .17" group with four in one hole, at a velocity of 3068 fps. This was still with CCI 450 primers, and bullets seated about .015" into the lands. This info is in the article below along with other great info. In fact 6mmbr has about the only/best info on the 6.5x47L.

I am currently building a 6.5x47L, should have it ready in about two weeks!

This is one of the best articles I have found concerning the 6.5x47L, read it, it will answer just about all your questions. Do a search on 6mmbr and you will find more, but this one is the best IMO.

http://www.6mmbr.com/gunweek072.html

[Dennis]

PS: PM me or email and let me know how your loads work. It might give me a head start as soon as I finish my 6.5x47L.

I will definetly share my info as soon as I start testing!

RCBS Gold Medal bushing dies are about the best, again IMO!

[Budweiser360]

IMO i would either be .005+ jump or jammed. Things start to get iffy when you try to just kiss the lands/try to load everything a couple thou off. Since not all of your reloaded rounds are going to be perfectly the same length, it is good idea to follow this "rule of thumb" so you are not getting into pressure issues in the differences between jumping and jamming.

FWIW Berger even states on their website that their VLD's may like a jump of up to .120 and it just depends what your rifle likes.

[Uncle Jack]

As a matter of safety and consistency, I start all of my load development at -.010 to -.012 off the lands. I never "Jam" a bullet until I've fired enough to have a general idea of the pressures being generated.

The first thing I do with any new chamber is to make a full length dummy round that just engages the lands. That round becomes my master dummy. From there it is easy to adjust seating depth either plus or minus. If you do not have a micrometer seating die, it is easy to come close with any seating die. For instance, the threads on the seating stem on my RCBS dies are 28TPI and that works out to .036" per turn or .018" per half turn or .009" per quarter turn etc. etc. Just measure the TPI on your individual seating die either with a gauge or just count them.

It's not exact, but with a little practice you can come within a .001" or two. As with everything else in reloading, start out on the conservative side.

uj

[Deserthunter]

I loaded up 50rnds of Sierra 120gr BTHP Match -- started with 40gr of Ramshot Hunter, up .5 gr every 5rnds to 44grs. -- the best group (OR string) was .4" Center to center, but I was still adjusting the Leupy scope (one click up for 3 shots,{should have been .75" not .664", but that's close}), when I shot it, If I had not been adjusting scope the group would have been a ragged hole.... So for now I'm stopping at 42grs. of the Ramshot Hunter and going to adjust the oal a little to see if thing get even better.... The wind was blowing about 5mph, on and off...

I'm very happy with the 6.5-47L and the McGowan Barrel (match SS 28"). Very happy....

http://i12.photobucket.com/albums/a230/UtahMike/MY%20Guns%20and%20Camping%20Trips/String-65x47L120grSierraBTHPa.jpg

[davemuzz]

I don't load Sierra's. Not that they aren't good bullets....it's just that I have excellent results with Hornady's, or Nosler, or Berger's.

But to answer your original question, I start with the seating at 50-thousands off the lands. Why? Because that's just what I do. I will try different powder amounts first, and then OAL's second.

Seems to work.

Dave

[pdog06]

As a matter of safety and consistency, I start all of my load development at -.010 to -.012 off the lands. I never "Jam" a bullet until I've fired enough to have a general idea of the pressures being generated.

The first thing I do with any new chamber is to make a full length dummy round that just engages the lands. That round becomes my master dummy.


I do the same thing as this, except i always start at .015" off, and for the same reason.

[Tightgroups]

I agree with Dave and U.J. above, and start out .050 or more. In fact I have a 308 that shoots under .5" @ 100 with Fed. Gold Metal Match, and it has a .100 jump. And my 308 reloads have shot in the mid .2s @ 100 with the same jump, plus they still fit in the detachable mag. So dont write off trying a jump, some rifles like it. I do jamb my 6BR, .010. And im still working on my 22 BR loads. But I dont start with a Jam.
Mike.

[Dennis]

I will post my pictures as soon as I get my camera back:

120 SMK's touching the lands produced a .213 5 shot group. Four of the shots were probably .175! All @ 100yds using a crosshair reticle. I believe I could have done better with a dot target reticle.

I loaded Bergers, SMK's, and some 140 JLK's. As the article I mentioned above stated, SMK's with RL 15 was the trick for my 6.5x47L also! NOTE: I did try 5 SMK 120gr rounds .010 in the lands, but mine likes it touching the lands. Bergers grouped better .010 in!

When I was breaking in the barrel and used the book COAL, app .030 off the lands, I was shooting some pretty impressive groups. I wasn't trying as I was more interested in breaking in the barrel. I finally recieved my COAL case this week and measured the chamber to get the correct depth! A few thousandths makes a difference.

[davemuzz]

I finally got my COAL dummy case this week and measured to get the correct depth!


Hey......my reloading friends say "I am the reloading dummy case!" And then they go on to say "I have no depth!" Hey.....I'm starting to smell something funny here!!!

Dave

[Deserthunter]

I had to give up shooting the 6.5 for a while.... SSS has it, T and T, Comp. Trigger, Muzzle Brake, Bead Blast the SS Barrel to remove shine.... I hope it comes home soon.....

[Scott Evans]

Putting them into the lands seems to very sensitive to neck tension, you got fully prepped neck turned brass it works fine, but for instance 800 Win 22-250 cases going thru first and second fireforming for 6XC and having neck wall thicknesses all over the place I try putting them close or jammed they shoot all over, back off .025"-.085" depending on bullet they shoot bugholes, even with the large variation in neck tension.