6SLR questions

[Kevin1990]

Looking to get a 6mm for deer and target. I stumbled upon the 6SLR on here a couple weeks ago and have been researching it as much as I can, yet still have a few of questions that don't seem to have definitive answers.

I'd like to use small rifle primer Lapua or Peterson brass, from what I see I'll have to neck turn, which is no biggie, but I'm seeing threads about people having to neck turn and ream the insides of the neck, not once but throughout the brass's life. Is that actually the case with this cartridge? That would be the deal breaker for me I think.

What's the ease of reloading this cartridge, is it finicky or pretty easy to find a good load? I see reports of better barrel life with this cartridge than the 6 creed or 243 win and the like. I like the idea of getting a little bit better barrel life and still having the velocity.

 

[Bob3700]

Been using the SLR since it came out. When u order ur reamer, just speck the neck diameter for the brass u are going to use. Originally, Robert Whitley spec’ed his no turn neck reamers for Win n REM brass . If u used Lapua, u had to turn the necks with his reamers.
Does Peterson make SRP 243 brass? I strictly use Win LRP brass so don’t know.
Powders: H4831sc was the initial go-to powder but VV160/165 work as well.
Brass is super easy to make, just run a 243 into the 6SLR fl sizing die and viola’.
I think any of the larger case capacity 6 mm don’t enjoy extended bbl life. But if this is a hunting rifle/ occasional target it will serve u well.

 

[Laurie]

Does Peterson make SRP 243 brass?

But it seems to be out of production / unavailable most of the time these days. I have seen comments on this forum that some of the slower-burners, notably Hodgdon H1000 won't perform in SRP 243 Win brass. If so, this'll likely apply equally to the SLR.

I have the 50 cases in the above pic for my 6SLR, but have yet to reform / try them. As @Bob3700 says I'll use Viht N160 and 165 when I get my SLR run-in and get around to load development. (I used N160 in SRP 308 Win Lapua Palma brass reformed to 7mm-08 with heavy bullets successfully.)

 

[One Eye Pete]

Been there done that.
I have used both Peterson and Lapua (308 Palma before small primer 243 was available) small primer brass to make the 6mm SLR. The problem with both of these is the brass in the shoulder is somewhat thicker than the brass in the neck and I ended up with very big doughnuts. Neck turning didn’t eliminate the problem and neck reaming was required. Neck reaming is a royal pain and it’s difficult to do properly so as to get a nice smooth finish on the inside of the neck. I just don’t like doughnuts in my brass even if I seat above the neck shoulder junction. I put a lot of work into making this brass and quickly came to the conclusion that it just wasn’t worth it. The small primer brass just didn’t shoot any better than the large primer brass. The SLR has plenty of case capacity for a 6mm bullet and you don’t have to push it to its limits to get good velocity and accuracy. In fact pushing it hard to the point where you will loosen up primer pockets will also result in poor barrel life.
The best brass I have found to form the SLR case is Sig Sauer 243 brass. It’s excellent uniform brass at a very reasonable price. You just size it with the SLR die to push back the shoulder and you get a nice case with no doughnuts. It makes life a lot easier and shoots just as well. The SLR is a really good cartridge especially if you want to shoot heavy 115gn bullets.
Another note is that I did get poor SDs when using H1000 in the small primer brass. I would recommend 4831SC or VV N160.

 

[Evlshnngns]

I'd wager the brand of barrel would effect the # of shots more than the difference between 6slr and 6creed. 6xc or 6x47L would cut some powder with plenty of shelf dies and brass.

I like ackleys and odd balls, just add up the cost/problems before you take the leap.

 

[idahoorion]

Kevin, I used my 6 slr for Prs shooting. it was accurate, easy to load, easy to form cases for. and I have plenty of speed. I picked it because I want to use H 1000, so that was my go to powder, I want to use the H 1000 cause it's supposed to be cooler burning. I'd did try some H 4831 cause some of the long range target shooters were using it. but saw no advantage for my use. I used WW cases, I went thru the investigation as you are doing now. I was really happy with the choice to stay WW. the srp brass was not available yet anyway. my first barrel I was 1500 rounds in and had a few matches to go so I switched over to Dtac 115's from Berger 105's. Tubb supposed to have designed them to seal better in a worn barrel. I did get 700 round's out of the barrel and it is still accurate. If you choose to go the SLR route I have new old stock WW brass and a reamer for the 105 class bullets you may be interested in. My new barrel is a Krieger, same reamer. I just plugged and played with the same loading as the ole barrel. I did have to change the seating die back from the 115's, as they are a little longer. Brass life has been very good, the case has a easy life running at 3080fps or so and annealing every 4th firing. I have lost very few cases to split necks or primers.

Best
Idahoorion

 

[NZ_Fclass]

My comments from another thread:

Post in thread '6.5SLR and Starline brass'

Jun 4, 2025

Just a footnote - I wouldn't build another 6mm SLR. Whilst it seemed a good idea at the time, it's not one of the most efficient cartridges out there - achieving very little over the smaller cased 6mm's and using a lot of powder to do it. Sure, it's "better" than a 243 - longer neck, nicer shoulder angle -ticks the boxes and barrel life should exceed the 6mm Creedmoor- and it's fast -3000+fps fast. But only a little faster than a Dasher for 25% (ish) more powder. Proof of of the Law of Diminishing Returns.

It was built in the heady days before COVID, when powder was plentiful and...

• NZ_Fclass

• 

 

[Kevin1990]

Been there done that.
I have used both Peterson and Lapua (308 Palma before small primer 243 was available) small primer brass to make the 6mm SLR. The problem with both of these is the brass in the shoulder is somewhat thicker than the brass in the neck and I ended up with very big doughnuts. Neck turning didn’t eliminate the problem and neck reaming was required. Neck reaming is a royal pain and it’s difficult to do properly so as to get a nice smooth finish on the inside of the neck. I just don’t like doughnuts in my brass even if I seat above the neck shoulder junction. I put a lot of work into making this brass and quickly came to the conclusion that it just wasn’t worth it. The small primer brass just didn’t shoot any better than the large primer brass. The SLR has plenty of case capacity for a 6mm bullet and you don’t have to push it to its limits to get good velocity and accuracy. In fact pushing it hard to the point where you will loosen up primer pockets will also result in poor barrel life.
The best brass I have found to form the SLR case is Sig Sauer 243 brass. It’s excellent uniform brass at a very reasonable price. You just size it with the SLR die to push back the shoulder and you get a nice case with no doughnuts. It makes life a lot easier and shoots just as well. The SLR is a really good cartridge especially if you want to shoot heavy 115gn bullets.
Another note is that I did get poor SDs when using H1000 in the small primer brass. I would recommend 4831SC or VV N160.

Never reamed inside of necks but I'd be willing to try, I have a ton of SRP's that I'd like to use up or I'd go for the sig brass or somthing else. That being said it does sound like a pain. Was it one and done though?

 

[One Eye Pete]

Never reamed inside of necks but I'd be willing to try, I have a ton of SRP's that I'd like to use up or I'd go for the sig brass or somthing else. That being said it does sound like a pain. Was it one and done though?

I ruined a lot of cases before I figured out how to ream the inside of the necks without scratching them all up. Basically what I came up with is using a K&M carbide cutting pilot to cut out the doughnut. I haven’t done it in a while but the trick was to use an expander mandrel and the correct bushing size in a sizing die to get the neck ID to the point where the cutting pilot just barely slid into the neck and only cut the doughnut. Also I used a lot of lube (STP and oil). Once you ream them they are OK for quite a few firings but eventually the doughnuts will come back.
If you want to use small primers in a 6mm it might be easier to go with a dasher. There is a lot of good dasher brass available, while not quite as potent as the SLR you can still hit a good velocity with a heavy bullet and it’s super accurate. Also since it uses less powder it’s easier on barrels.

 

[Bob3700]

Kevin, I used my 6 slr for Prs shooting. it was accurate, easy to load, easy to form cases for. and I have plenty of speed. I picked it because I want to use H 1000, so that was my go to powder, I want to use the H 1000 cause it's supposed to be cooler burning. I'd did try some H 4831 cause some of the long range target shooters were using it. but saw no advantage for my use. I used WW cases, I went thru the investigation as you are doing now. I was really happy with the choice to stay WW. the srp brass was not available yet anyway. my first barrel I was 1500 rounds in and had a few matches to go so I switched over to Dtac 115's from Berger 105's. Tubb supposed to have designed them to seal better in a worn barrel. I did get 700 round's out of the barrel and it is still accurate. If you choose to go the SLR route I have new old stock WW brass and a reamer for the 105 class bullets you may be interested in. My new barrel is a Krieger, same reamer. I just plugged and played with the same loading as the ole barrel. I did have to change the seating die back from the 115's, as they are a little longer. Brass life has been very good, the case has a easy life running at 3080fps or so and annealing every 4th firing. I have lost very few cases to split necks or primers.

Best
Idahoorion

The 115 DTAC is an excellent bullet. They shoot small round groups and have yet to get a box that doesn’t. 3050-3080 seems to be a sweet spot for them. You can drive faster, it just depends on ur bbl and what it likes. If ur a 105B junkie, u need the speed to match the high bc of the DTACs n the SLR does that easily. I like the 105B for 600 yds and the DTACs for 1K.

 

[Kevin1990]

I ruined a lot of cases before I figured out how to ream the inside of the necks without scratching them all up. Basically what I came up with is using a K&M carbide cutting pilot to cut out the doughnut. I haven’t done it in a while but the trick was to use an expander mandrel and the correct bushing size in a sizing die to get the neck ID to the point where the cutting pilot just barely slid into the neck and only cut the doughnut. Also I used a lot of lube (STP and oil). Once you ream them they are OK for quite a few firings but eventually the doughnuts will come back.
If you want to use small primers in a 6mm it might be easier to go with a dasher. There is a lot of good dasher brass available, while not quite as potent as the SLR you can still hit a good velocity with a heavy bullet and it’s super accurate. Also since it uses less powder it’s easier on barrels.

Thanks for all the info. To me, the juice isn't quite worth the squeeze. If it was one and done I'd probably go for it, but that puts a damper on things for me. I've been looking at the dasher, GT, 6xc. Just heard a lot about the 6SLR being easy to tune, and I really liked the velocity.

 

[Rubberduckie]

When I wear out my 6slr barrel I won't do another mainly do to brass. Sig sauer and winchester brass has been the easiest route. Maybe look at the 6xc. Tubb has plenty of good priced brass and the difference between 6slr and 6xc is .110 in case length. Or go dasher or 6gt. Plenty of great 6mm options out there.

 

[Kevin1990]

When I wear out my 6slr barrel I won't do another mainly do to brass. Sig sauer and winchester brass has been the easiest route. Maybe look at the 6xc. Tubb has plenty of good priced brass and the difference between 6slr and 6xc is .110 in case length. Or go dasher or 6gt. Plenty of great 6mm options out there.

Been looking into the 6xc a bit as well. Honestly, don't even plan on launching any heavies like the 115s or 110s. I'd like to hunt with the sierra 85 bthp or the 95 classic hunter and get some velocity behind them and shoot the berger 90bt for target.

 

[1shot]

Been using the SLR since it came out. When u order ur reamer, just speck the neck diameter for the brass u are going to use. Originally, Robert Whitley spec’ed his no turn neck reamers for Win n REM brass . If u used Lapua, u had to turn the necks with his reamers.
Does Peterson make SRP 243 brass? I strictly use Win LRP brass so don’t know.
Powders: H4831sc was the initial go-to powder but VV160/165 work as well.
Brass is super easy to make, just run a 243 into the 6SLR fl sizing die and viola’.
I think any of the larger case capacity 6 mm don’t enjoy extended bbl life. But if this is a hunting rifle/ occasional target it will serve u well.

^^^^^^^^^^^^^^THIS^^^^^^^^^^^^^^^
I've been shooting one since Robert introduced it as well. I started with W-W brass, but switched to Lapua brass years ago, and never looked back. If you want to run a slower node and get great bbl. life shoot heavy bullets on top of H-1000. If velocity is your game, move to H-4831sc. N-160, N-165 or RL-23 with 105 class bullets.

 

[Hoser]

I have been shooting a 6 Comp Match for 25+ years. It is basically the same thing as the SLR.

I am using H-1000, Lapua brass, Federal Large Rifle Primers and 115 DTACs. No complaints. Barrels go over 4,000 rounds and brass is good for 10-15 reloads. Maybe more, I quit keeping track.

 

[10XSHOOTER]

If your going to be hunting in Cold Temps. DON'T us SRP's
Stick with LRP's.
To much powder in that case for SRP's in Cold Weather

 

[Varminterror]

I played around with the SLR before the Creed came about - I had shot 243win and AI for years, wanted better barrel life, so pushing BACK instead of blowing forward seemed like it made sense.

I can't fathom how someone would expect better barrel life from the SLR, inherently, than the Creed. The two are nearly doppelgangers, with the 6 SLR being the larger, more powder hungry, faster cartridge of the two. "There's no replacement for displacement" when pressure is the same, so the only way the SLR could have longer barrel life than a Creed would be running lower speeds and lower powder charges - but even then, the same could be done with the Creed, and at that point, both are becoming less efficient and still burning barrels faster than would a smaller case (like my 6 creed I only ran at 2800fps, which still burned 40grn powder and was toast long before my Dashers at the same speed).

I made all of my 308win family cartridges from Lapua Palma brass for years, I don't mind SRP's even in cold weather, but I am REALLY hard pressed to believe I should spend time seeking less available brass and case forming SLR's instead of simply buying 6 creed.

 

[Bob3700]

The 6 Creed and the 6 XC are twins from a different mother. Minor variations in the brass but same performance out the muzzle. U can make 6 XC by running a Creed into a n XC fl die. Both those cartridges are ideal if u are running 105 gr or lighter bullets.
No need for the extra boiler room the SLR provides if u are not interested in 110-115 gr bullets.
Barrel life with the XC or Creed with the 105 gr bullets is in the 2200-2400 rounds bracket. Less powder = better bbl life.
If u use the slower/ cooler powders (H1000, VV165) with the SLR bbl life will approach 2000 rds.

 

[Gunnut26]

I always used Peterson 260 SRP brass, neck turned and loaded bullet above where the doughnut would be at, easy to load for and accurate also. Brass would go 15 loadings no problem and I was pushing it. VV N160 was the best powder I tried and I tried a few, if you get one and want some load data msg me and I’ll get my folder out from last barrel.