Building a new 6 SLR

[Nvreloader]

OK Guys

I am gathering facts and info on my new build,
which will be a 6 SLR case, (have a ton of 243 brass available).

Primary use will be a hunting and semi target (informal use),
bullets used will be good hunting and target bullets brands,
from 80 thru 115gr weights, for their proper applications etc.

Bbl twist will a 1x8", used at 4000+ elevation or higher,
bbl length will be 18" +.

Need some questions answered by those who use this case only,
not really interested in any other case, at this time.

1. The first and major info needed is,
this case MUST feed reliably from a standard OEM magazine,
either a Rem or Savage action, (never owned a Savage before,
but would be willing to one).

I am not sure,
if I need a SA or LA for the longer bullet weights etc,
I would like to have the BT/shank junction right at the shoulder/neck junction,
of the case when loaded.

Which action length will work the best, for my application?

Tia,
Don

 

[XTR]

You don't need a long action for any SLR application. Even 115s will work in a short action.

As for bullets at the junction. You do realize you can do that for one but not all bullets. In 6mm the bullet length changes are large with weight changes.

I'd get more barrel, but that's me. Mine is a 25". I wouldn't go less than 22". I think a 308 is a better choice for a short barrel.

The case, like all 243 based cases is pretty overbore. It takes a while to get all that gas down a 6mm tube. More barrel length is going to give you more velocity. I'd say quite a bit more from 18 to 24, somewhat less from 24 to 30. Most of the other shooters here are running this round in a target rifle setup with 30" barrels. If you do go short be realistic with your velocity expectations. My hunting load with a 25" barrel and the 105VLD-H is a comfortable 3075FPS. Could go faster, but that was where it shot best. I'd guess you'd be in the 2800FPS range with an arseload of muzzle blast.

Set up for optimum loading in an internal mag with 105/107 class bullets is what I'd recommend. Your freebrore is important. If you are limited to 2.85 or so in a factory mag you probably want to have about a .075 freebore. My chamber has a .076 FB, my 105 VLD-H load is jammed 10 and measures 2.883OAL Load up a test and see if that will chamber in a factory mag. My rifle uses AICS pattern mags and is set up to feed from mags w/o the front plate. My rifle can feed about 2.95, I'd be better off with a 110 or a 115 FB. Single feed guys are loading 105s in chambers with 125FB so there is plenty in the neck, and we have a long neck to work with in this case, it's one of the features.

The 6mm 90 grain non-VLD bullets are supposed to be very jump tolerant, but if you are set up to reach the lands with mag length 105/107s you should be able to get there with 90s.

The 115s are probably a bit long for factory mag length feeding.

 

[XTR]

If you are building it why not put a Wyatt's extended mag box in it and utilize all the action can give you? Any smith I'd trust to chamber a barrel can install one?

They only cost $51 + the cost to mill the front of the feed ramp to feed long rounds, about $120 total.

http://wyattsoutdoor.com/product_info.php/cPath/1/products_id/37

 

[Nvreloader]

XTR

Thanks for that info,
I have never heard of that mag option before.
I will give it more study.

I do not own a SA Rem or Savage,
so I can not measure the mag box length, to know the lengths etc.
All I have are LA Ruger/Winchester's actions.

I have been playing around with QL to see what the OAL loaded lengths generally runs, at this time every thing is a SWAG on my end.

Still trying to find more info about the 6 SLR round.

Tia,
Don

 

[NickB1075]

It is a great cartridge. I am very happy with mine. No need for a long action. I use Sierra 107s at about 3040 fps and it shoots amazing. My reamer is .100 free ore and I have no issues with a normal short action magazine. It feeds great from a magazine.

I would absolutely go longer on the barrel. I would say minimum of 24. I personally would use a short action.

Nick

 

[rain164845]

I would advise a shorter case length than standard. When forming Winchester brass, it ends up way under normal trim length.

 

[Nvreloader]

Guys

Thanks for the info,

Questions,
What action are you running for the 6 SLR round?
What is the inside internal maximum length of the magazine?

Tia,
Don

 

[XTR]

Most are running a Remington 700. The internal mag on a R700 is about 2.850. The OAL of my load listed above with the Berger 105VLD is not really indicative of other bullets to reach the lands. That is a really long nosed bullet. The 107SMK and the 105H will be shorter due to the shape of the bullet nose. If you plan to run anything other than the 105VLD-H you will be great with about a .100 freebore and an internal mag.

Read my first post in this thread:

http://forum.accurateshooter.com/threads/my-new-6slr.3875511/

 

[Nvreloader]

XTR

Thanks for the info,
Here is what I am doing, see info for the designed pistol I am building.

http://bulletin.accurateshooter.com/2017/02/amazing-benchrest-pistol-ten-shots-in-0-289-moa/

This info is on my 284 SP pistol,
http://specialtypistols.infopop.cc/...46004005/m/4410087466?r=4410087466#4410087466

After fine tuning the loads,
I have several groups around the 1 1/2" range @ 300 yds,
when I do my part correctly, and changing to RL-26 powder etc.

I will have a 18" bbl?, unless QL shows a better option on the bbl length,
on either a SA or LA Rem or Savage action,
I want the best OEM action, for this wildcat case, with at least a 2-5 rd mag capacity.

I don't think, I will able to shoot at this level, in my OLD age,
but if I get close, I will be tickled pink to win some more free lunches.

This SP pistol will be built for hunting and Varmint (Rock chucks) shooting and informal target competing against the local rifle shooters that are giving me a hard time on using that "contraption" etc.

I have won several FREE Hamburger lunches, using my 284 SP hunting pistol,
out too 300+ yds , they don't have a clue, yet,
and I have also bought a couple of lunches.

I hope this info gives you a reason for all my questions,
to obtain the best info for my build etc, and not turn you off,
and Yes, I like doing things the hard way.

I know, there is at least one varmint thumper (ground hogs),
using this case on the site, from the East side of the US, (Ohio), I think,
but I can't remember his name etc.

So far, there does not seem to be much info on this case/caliber,
being used etc.

Tia,
Don

 

[Nvreloader]

Guys

In further research of this case, and so I can have in hand info,
I would like to buy the following, (at a reasonable price).

A half a dozen of fired cases, not sized,
for the correctly sized 6mm SLR chamber, suitable for bullet seating,
these cases will be used only for determining,
the overall cartridge loaded length of the following bullets.

.243 caliber (1 or 2 bullets only),

100, Nosler PART SP 35642
100, Nosler PART SPSemi 16316
105, Hornady A-MAX 24562,
105, Berger Hunt BTHP #24528,
107, Sierra HPBT MatchK 1570
115, Berger Hunt VLD #24430,
115, Berger VLD #24530,
115, DTAC HPBT,
115, JLK VLD #24115
117, DTAC HPBT

If you would be willing to help in this endeavor,
feel free to drop me a PM, or post the info here,
along with any other info on this case,
so I can have a reamer ground etc.

Thanks,
Don

 

[Milo 2.0]

Guys

Thanks for the info,

Questions,
What action are you running for the 6 SLR round?
What is the inside internal maximum length of the magazine?

Tia,
Don

Buy these, any M5 dbm, or PT&G style work, get the non binder, an oal of 2.990" will work:
http://store.accurate-mag.com/308winchester762x51mmboxmagazine.aspx

I have a 6slr on a Stiller, also a 6 comp match on a Mausingfield, they handle it all. An aw cut action(custom) with aw mags is the same.

 

[Nvreloader]

XTR

What's the matter,
did I scare you off, because of my build, I am planning?
I hope not..........

I am not finding much info for this case,
lots on the 6XC rd etc.

Is there another name for this case?
I may not be using the search function correctly.

Tia,
Don

 

[Nvreloader]

Milo-2

Thanks for the info,
I'll check it out.

Tia,
Don

 

[tonysnoo]

Hi Don,

I have plenty of fired cases. You could certainly have some. Im in Reno. Been shooting slr for about 4 years. We might even know each other???

 

[Rtheurer]

Don

I have a few old cases laying around if you want them? Send me a PM with shipping info and I can send you a few.

XTR gave you good info so far. I don't feel there is anything left to ask actually. .100 Free bore will handle any bullet in a Normal Magazine like the AI mags. (The exception may be the 115gr class bullets) Get a reamer that has .275 or .276 Neck and go to it.
Put 43.5gr H4831SC with a Large Primer of your choice. and go shoot.


Russel

 

[Nvreloader]

Thanks guys,

By any chance could I also buy 1-2 bullets,
of the following brands listed below,
if you have of them available.

.243/6mm caliber

100, Nosler PART SP 35642
100, Nosler PART SP Semi 16316
105, Hornady A-MAX 24562,
105, Berger Hunt BTHP #24528,
107, Sierra HPBT MatchK 1570
115, Berger Hunt VLD #24430,
115, Berger VLD #24530,
115, DTAC HPBT,
115, JLK VLD #24115
117, DTAC HPBT

I want to make sure I don't run into any problems,
using a stock Rem SA or Savage action and magazine,
and be able to seat these bullets to my spec's etc,
and not run into more expense, than needed.

I want to seat the BT of the bullet at the junction,
of the neck/shoulder etc.

Tia,
Don

 

[XTR]

Been away from the keyboard for a while.

I have my kit scattered from TN to NH and most of my reloading supplies for my SLR are still in TN (and I'm living in VT and typing from AZ). I don't have any fired brass or bullets laying about the house right now. All I have is about 100 rounds loaded with the 105 VLD-H which I would not recommend for your application.

 

[Nvreloader]

XTR

Thanks,
Sounds like you have busier than a Long tailed cat,
in a room full of rocking chairs.

You can just send your smoke pole my directions,
and I'll get some learning experience with her,
and I promise to treat her real nice........ LOL

Tia,
Don

 

[Nvreloader]

Guys
I have some questions on bbl twist rates,
my base altitude is 4500' and goes up from there.

I am attempting to find the best twist for these bullets,
for use in a 6mm SLR case,
80 to 90 gr weights
100 to 115 gr weights

For varmint and match bullet configurations,
to be used for varmints, hunting and informal target shooting etc.

I have found that the main choices are 7.5 and 8 twists,
but really don't have a clue which would be the BEST all round choice,
for the bullets weights listed above.

And then there is the .236 or .237 bore diameter choice?

I would normally lean to the fastest twist available,
then there is no doubt etc,
but this the first time with this 6mm SLR wildcat case.

Is there any thoughts or suggestions,
that you would care to provide?

Tia,
Don

 

[spclark]

In a 6SLR chambering, using bullets over such a wide weight (and length, accordingly) any choice of twist for one bullet at one end of the weight range will be a compromise with bullets at the other.

I shoot two 6's, nether have case capacity to equal the 6SLR. The smaller of the two uses a 26" barrel, the larger 30".

With them, and bullets from 90 to 107 grains, I've found 1:7.5 to be entirely satisfactory. I've tried 115's (Berger's in a 1:8 & they exploded, DTAC'S in a 1:7.8 & they didn't shoot any better than Berger's 105VLD) & for what I like to do they've not worked out too well.

Maybe Berger's 115 will work in a 1:7.5 for you as you can push 'em faster? I dunno, but 80's in that twist, at velocities easily reached with a 6SLR case capacity, suggest careful load development so as to avoid 'grey cloud' syndrom once launched.

At your altitude maybe 1:8'd work with 115's?

With your stated goals, perhaps barrel length will put a limit on how fast you can push anything? Hunting rifles generally don't handle well with 30" barrels.

I think I'd opt for 1:7.5 myself....