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Best 6mm cartridge*
- Thread starter sierracharlie338
- Start date
OOOOOHHHHH DAMN....where can I get a reamer...the range would look like Swiss cheese after a match with that!!
Dave in the the thread is shooting a GT. Marc @ Spartan Rifles delivers mine next week.. but I’ll finish my 6CM supplies before I worry to much about the GT..
Probably the route I’ll end up going for a change of pace. Gotta make my mind up soon so I can start prepping for some a match or two.
If you're a speed freak...go for the 243AI....the 6BR or 6XC are what I would suggest for accuracy...long barrel life...good/easy dies...excellent brass for either..I have a 12 twist 6BR and an 8 twist 6XC...yes Lapua still builds 243 brass.
I love my 6SLR, if id have to choose another cartridge it would be;
6 comp match
6 xc
6 creed
6x47
I look for velocity and barrel life. With the 6slr and 6comp you'll have good velocity and barrel life using h1000. 30/31 degree shoulders, long necks, cooler powders all suggest longer barrel life.
If you're in a cold climate then id stay clear of the small rifle primered cartridge, they can have ignition issues on larger cases.
The 6 creed is a great candidate but like mentioned previous you'll be using h4350 resulting is 1500 rounds or less and thats being easy on it.
Xdeano
6 comp match
6 xc
6 creed
6x47
I look for velocity and barrel life. With the 6slr and 6comp you'll have good velocity and barrel life using h1000. 30/31 degree shoulders, long necks, cooler powders all suggest longer barrel life.
If you're in a cold climate then id stay clear of the small rifle primered cartridge, they can have ignition issues on larger cases.
The 6 creed is a great candidate but like mentioned previous you'll be using h4350 resulting is 1500 rounds or less and thats being easy on it.
Xdeano
Yes so far so good. But I'm not killing it at matches or prairie dogs. I'm using it for actual hunting where the shot matters.
The cold weather thing, is a thing. I'm not talking 25 degrees, I'm talking in the negatives. Im sitting at -9F right now. Its happened to several people I know. I dont need a failure when I'm hunting.
Xdeano
Just for info, here is some velocity testing with varget and 109’s in 6gt
Interesting. Just picked up 3lbs of Varget about a month ago so looks like I’ll start there!
34.0 does really well for a break in load.
35.2 is likely where I will end up
Doesn't happen in the Gay Toger though as it's FLAMMMMMIN' and always on fire and hot!
Come on Rob.. you’re so cruel. Spartan is just spinning up my 6GT~
I already found my new lucky match underwear.
and by UNDERwear you mean ONLYwear? cause if you wear pants on top thats an insult to the gt
I was sooo close to going Gay Tiger but someone who I thought was a friend couldn't give me the common courtesy to answer a couple facebook messages I sent him with questions so screw it I will stick with my 6 Creed.
That sounds a bit sensitive.. cough gay.. I think you should just come out of the closet..
Soon we’ll all be shooting matches in just our underwear..
Might as well talk about that. Cause why not?
Anyone ever had consistent and documented issues with SRP in cold weather?
I personally haven’t and have gotten my ammo down to freezing and some below for testing without issue.
Anyone ever had consistent and documented issues with SRP in cold weather?
I personally haven’t and have gotten my ammo down to freezing and some below for testing without issue.
242AI
Because Creedmoor isn't as cool as any AI (improved is improved, right?).
Brx/bra for barrel life, 6 Creed/xc/243 for speed.
Because Creedmoor isn't as cool as any AI (improved is improved, right?).
Brx/bra for barrel life, 6 Creed/xc/243 for speed.
I’ve had ignition problems with a 6x47 Lapua in Montana. I’ve never had problems above -10. I’ve never had problems with magnum primers at any temp. But I have had problems below -10 with GM 205s with 4831sc and 7828ssc type powders.
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I'm on my third Criterion Savage prefit in 243AI. Both went over 2500 rounds before going over 1/2-5/8 moa. They did not get to 3k rounds. I document every round. I am not guessing. Both were running 105 @ 3150-3175 and 115 @ 2950-3075. 100% was with H1000 and CCI 250. It works for added barrel life but there are some idiosyncratic drawbacks.
At what point did you:
Adjust powder charge to maintain velocity
or
Notice velocity decrease
Many of use consider a barrel done for competition once it starts losing velocity/needs monitoring for powder increase. Which is a distinction most don’t make when talking barrel life.
Barrels have two points:
Where velocity starts to get finicky
Where accuracy starts to get finicky
Both have their uses as far as barrel life. Sometimes they coincide with another and other times not. I’ve had barrels slow down and remain accurate and other barrels totally burn out and lose accuracy and velocity at the same time.
I live and shoot at almost 7000ft elevation and have shot in the low teens a few times with my 6x47L but quite a bit in the 30's. I've never had an ignition problem probably because I always used powders with high load density like H4350 and H4831SC, CCI450 mag primers, and warm loads. The H4831 loads were compressed which I bet helped???
I think a lot of people like the UW Precision Rifle guys out of Laramie who's Range (hunting is higher) is at about 7500 and without wind chill, was -7 the other day. They might consider 30° balmy when the coldest temps have be lower than -30°. I am sure other parts of the country are similar.
My son and his roommates first duck hunt in super cold a couple years ago laid down in the ground blinds and when the tried to jump up to shoot, their jackets were frozen to the ground.. they’ve learned a lot scene then....like their semi-autos need to run dry in that kind of cold as well —
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If I were to shoot a 6mm (haven't, don't, likely won't), it would be the .243 Win.
I do shoot the .260 Rem, and do it because of the commonalities inherent in the .308 source cartridge. I set my headspace for the 260 and 308 using the same H/S gauge, and use the same case length gauge. I even make my 260 brass by necking down 7-08; which reduces vulnerability to 260 brass shortages, and actually costs less per case, to boot. Much of this is quite the same for the 243.
It's enough gun, and capable of running decent velocities without requiring higher pressures and temps. Being somewhat overbore, it can convert this configuration into a longer barrel, slower powder 'loafer round' that still delivers good velocities, with all this offering a possibility for longer bore/throat life.
OK, it's not the flavor of the day. It's old (Eeewww...), and not sexy. So's the 260 (imagine that, calling the .260 old, but I've been shooting it for going on two decades).
If there's a plan to develop even more new 6mm bullet styles, I suspect there's not a lot of room left for innovation on that score. This is not exactly terrible news.
Just pointing out the obvious. Some folks probably could use the reminder...
Greg
I do shoot the .260 Rem, and do it because of the commonalities inherent in the .308 source cartridge. I set my headspace for the 260 and 308 using the same H/S gauge, and use the same case length gauge. I even make my 260 brass by necking down 7-08; which reduces vulnerability to 260 brass shortages, and actually costs less per case, to boot. Much of this is quite the same for the 243.
It's enough gun, and capable of running decent velocities without requiring higher pressures and temps. Being somewhat overbore, it can convert this configuration into a longer barrel, slower powder 'loafer round' that still delivers good velocities, with all this offering a possibility for longer bore/throat life.
OK, it's not the flavor of the day. It's old (Eeewww...), and not sexy. So's the 260 (imagine that, calling the .260 old, but I've been shooting it for going on two decades).
If there's a plan to develop even more new 6mm bullet styles, I suspect there's not a lot of room left for innovation on that score. This is not exactly terrible news.
Just pointing out the obvious. Some folks probably could use the reminder...
Greg
I don't have enough experience with it to tell you for sure. I have two more barrels to shoot through, but my wife just got a 6 dasher. We'll see if I continue to shoot 243ai or switch to a Dasher. There are things I like about both.
The first barrel was my foray into long range shooting. I shot 105 AMAX for around 700 rounds and then developed a load with 115 DTACs. I started shooting matches and finished burning up that barrel in less than a season. When I developed the load at 700 rounds I jumped the bullets .040". That load shot lights out until the barrel gave up. I didn't have a magnetospeed at that time, but I didn't notice a change in dope until after 2000 rounds through the barrel. The barrel was cleaned every 200 rounds with gunslik foaming cleaner and JB borepaste in the throat. It would no longer hold vertical at distance at 2600 rounds.
The second barrel I tried a whole bunch of stupid shit with. I still cleaned and JBed the throat every 200 rounds, but I also shot 2 TMS bullets every 200 rounds after I cleaned the barrel, and then cleaned again to clean out the garbage from the TMS bullets. On the first barrel I did not measure the throat or check velocity. On the second barrel I measured the throat every time the velocity dropped and after every cleaning I shot dots for 15 rounds and then shot 10 over the magnetospeed. At 800 rounds I lost 40 fps and the throat had shot forward quite a ways (would have to look at my notes). The load with the second barrel was only .010" off the lands. I chased the lands and added powder and the thing shot for another 800. At 1600 I had lost about 40 fps again and the throat had grown a ton. I stopped shooting TMS bullets at that point. I chased the lands and added powder and that load shot and chronoed the same until around 2500 rounds. At that point everything went to hell. I had chronoed at 2400 rds, but I didn't rechrono when the accuracy went to shit at 2500 rounds. I just called it dead.
I'm just under 200 rounds into the third barrel and ready to get into serious load development. I'm going to try jumping .040"+ and see if the load will hold longer on this barrel. I also switched from a Savage action to a TL3 and started loctiting the barrel nuts, so I can switch barrels easily and maintain the same headspace. I'm going pull the barrel and clean the throat on this barrel with CLR and use a borescope instead of using abrasives and see how it goes. I honestly think the way you clean and the distance to the lands when you develop the load has some bearing on how long the load holds. I'm only 2 barrels in, so until I have 8-10 barrels burned out with the same caliber, reamer, load, and cleaning routine I don't think we can draw a lot of solid conclusions.
I just cleaned the wife's dasher at 220 rds and the throat has not moved a measurable amount using the Wheeler method to find the lands. She's running 32.0 gr Varget under a 105 at 2880, so not pushing it hard. Even then, there isn't a lot more wind to hold than my 243 AI and it was stupid easy to find a load that shot under 1/2 moa. If the barrel life is a lot longer, and there is less fussing with chasing the lands, etc., I may have my next barrel chambered in 6 Dasher. The only real drawback I can see is that a 115 DTAC going 3050 hits targets noticeably harder and is easier to spot misses with than the 105 at 2880. I even notice the 115 at 3050 is easier to spot misses with than the 105 at 3150 out of my 243AI when I switch back and forth.
The big 6mm cartridges definitely have drawbacks, but so do the little ones. I was simply stating that there are ways to extend the barrel life beyond the 1200-1800 rounds that has become the expectation for 6 Creed running 4350 while still getting the same velocities. It would be nice if barrels were free, and then I would just shoot them in matches from 200 rounds to 1200 rounds and switch and use the barrel with over 1200 rounds on it to practice. Until then I'm going to use 223 to train and save the barrel burners for matches and hunting.
It will be an interesting experiment to run the 243ai with H1000 next to the wife's 6 dasher for several barrels and compare them. It will be a while before there's been enough shooting for a real comparison as we only shoot around 3000 rounds/year through our match guns.
D
Deleted member 121493
Guest
Downloading 6cm to Bra levels, ie 105gr @3000fps I can not see any reason for increased barrel wear.. throat erosion is a function of heat whic is a function of pressure... There is no reason to think an extra 20% powder makes a significant difference with regards to erosion independently of heat/pressure...
that's not downloading a 6CM...that's not hotrodding it
factory Berger is a 105 at 2950 ish
33-42 grains is a wee bit more than 20% extra burning
lol, we doin math the same way?
33 divided by 42 equals .78XXX. 100% - 78% equals 22%
Now, i reserve the right to say, im pretty sure i passed my math classes simply b/c my teachers hated my guts and didnt want me another year. Math and people with ADHD and Dyslexia dont mix well. I.E. Me.
BRA/dasher uses 22% LESS than a 6CM.
the 6CM uses 27% MORE than a BRA/dasher
42/33=127%
or
9/33 = 27%
