Cloning Mk262 - Winchester 748 & 760
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- čas přidán 12. 09. 2024
- The 12th entry in our Mk 262 cloning series. This series seeks to find accuracy and high velocity with the 77gr Sierra Match King in .223 Remington.
UPDATED 09/27/2018 - All links have been removed to comply with CZcams content policies.
www.patreon.com/reloading
Your mrk 262 cloning series is the standard for reloading videos. There isnt anything i have seen that remotely comes close to how well you cover the variables and interpret data. Well done!! Hornady Sierra Berger Hodgdon and Alliant should be funding your channel.
The pursuit of Perfection never ends does it. Carry on, good luck, and may the force be with you.
I would like to see a another test with W760 at 25.2, 25.4 (confirm) and 25.6. That was an awesome group at 25.4! TY, keep up the great videos!
Yes! If I saw groups like that I’d probably just load another batch to confirm and then run with it!
Damn, been waiting for a new installment. Love this series.
Great Vid JRB, Looking forward to the follow up. 760 might just get there. Keep up the great work.
You are filling my brain with so much useful knowledge and data I think I'm approaching max load. ;-)
This was the last video in the series 3 months ago but im still checking back for the results of that cold weather testing you were talking about.. hope you you got something man!.. this is what peaked my attention
Johnny - Found your Utube channel recently and have watched the entire Mk262 cloning series over the past week or so ... yea I fast forwarded some. Great series. Keep it up!
Not meaning to question you capabilities as a rifleman ... you make shooting sub-MOA groups look easy. But after watching all of the videos in this series I've noticed that when your groups go bad they seem to string out to the right (I'm watching the shot progression and the final result). I don't think I've seen but 1 or 2 groups that string out to the left and a few that threw flyers high or low. Watching the background and the target I'm not seeing a lot of wind, so unless there is a wind tunnel somewhere between you and the target that blows predominately from 9 o'clock I don't think the issue is wind.
When I shot rimfire benchrest in a previous life, we employed tuners to eliminate the effect of barrel harmonics. It was interesting to watch group size and shape change as we "tuned" the barrel to the ammo. Of course in cernterfire the ammo is tuned to the rifle. So I'm wondering if you are having a problem with harmonics. As a suggestion you could revisit one of the loads that was strung out to the right and shoot it again with and without the can and chrono attached. Yes this would be a repeat of a test you ran many videos ago.
Just thinking out loud.
Jack
Oh and I am a big fan of your channel and keep up. The good work it just seems to get better all the time. So we'll catch ya in the next video
Just found out about the mk262, found your channel and wondered about my load with same bullet, brass and 760. Glad to see you had good results too. Love the 760 easy to measure accurately with the spherical shape. Clean enough shooting. Primer change could help with higher charges. But I understand what your doing. Thanks for all the work.
Oh yeah my favorite serial is back !
I had real good luck with Win 748 and 73g ELD in a 1-9 Savage Axis. It actually stabilized it!!!
It seems like 24-2500 FPS is an accuracy node on that barrel -- in nearly all of these videos, if I'm remembering correctly, some of the best groups are in that velocity range. Once you get to around 2600, even today, the groups started to open up and move to the right.
Another great vid Johnny, our whole team loves this MK262 series and the 55gr FMJBT vids.
GREAT series my friend, Keep it up, there are a group of 4 guys meeting at a local range in OR doing similar load developments and this series is always influencing what we try. I would like to revisit the H4895, with the Nosler CC and Match kings. There was limited data on that powder.
I'm buying one of those barrels. I've been impressed more times than I can count.
Aaron Anderson u can not go wrong buying a white oak barrel
I've got one of their varmint barrels but need the SPR for another gun. WOA is awesome.
I think we just learned why Hodgdon didn't bother to list data for 748. :-)
I think your right.
BC it’s Winchester?
@@autom8ed Winchester, Hodgdon, and IMR are all owned by Hodgdon.
Thanks for continuing this series.
IMR 8208 @ 23.8 @ 2750 fps with 77gr MK with CCI 41
23.3 provided the best accuracy with tad less velocity
IMR 8208 loaded by Australia for MK 262 Ammo
Johnny, please would you do a video just concentrating on working up a competition bolt action rifle load? Go through the stages from start to finish please. Find the accuracy node, tweak the charge and then tweak up the distance off the lands to squeeze the minimum possible dispersion out of the combo?
In this gun we are limited by magazine length, but I will be doing exactly what you suggest over in my 6.5 Creedmoor series!
Great video! I have some W760 left over from a work up I did on my 6.5 Creedmoor. I ended up settling on H4350 so I have 2 leftover cans of W760 might as well use it on my AR and see what happens
Just ran across 8 pounds of Winchester 748 and 16 pounds of 760, I think I’ll pass. Great videos Johnny
love your channel ! would like to see a shoot out of your most accurate loads , bullets etc
What about cloning other military rounds? SS109 would be cheap getting it accurate would be a challenge. MK318 would be fun as well.
I've used W748 for decades with 50gr-62gr bullet with great results. I have also found with bullets above 62gr it doesn't show the same accuracy as it does with the lighter bullets.
I'm thinking it's about time for the next video.
760 looks like a good candidate for .223 cast bullets
Sure wish you would give us an "up to date best results" duplicating the top load, Please.
I just watched one of your older vids and you said something that caught my ear lol. "let's get vack to the bench" I think that should be your slogan for your tee shirts or your bench mats or whatever your put a slogan on to sell. I think that would sell buddy I really do hope you put out something soon
Johnny do you ever retest the loads without the Magneeto on the muzzle ? I find my groups improve a lot without it . Great videos , I can watch these for days !!!
760/H414 is slow enough that you could probably go 27 grains without seeing pressure problems.
"Everything went to crap!" lol
You cant talk about pressure signs when you have a suppressor choking the barrel.
Thank god for fast forward!!!
I had the same experience with W/748 and 77 Sierra's. I was able to get the velocity but accuracy was in the 1.5-2" range. W/748 works great for me with other bullets, just a bad combination.
Johnny I have found that W748 works better with 50,52,55, gr bullets. 25.4 Gr's of W760 is a load that you want to keep.
With a ball powder I can get 27.8 grains of powder in a Lake city case, so you have room to work. If this were my horse to ride, I would start at 26.1 in 0.1 grain increments until I saw pressure and hope for something as good as that 25.4 group.
This is off topic, but have you thought of trying the Oregon Trail hard cast 308 bullets through your 300 BO's? They are supposed to be a harder alloy that can be pushed faster without leading barrels. Also, I've watched all your videos and have had very good results from some of your load data.
Awesome video and data Johnny!! One question: Are you running the factory Palmetto State Armory bolt and carrier? If not, what BCG are you using? Do you think the standard PSA or a high end BCG would have a significant difference in accuracy? Thanks.
For this video I had a Rainier BCG in there. I have used at least 3 different BCGs in this series and they've all shot really good groups. One of them is a generic $75 semi-auto BCG that I don't remember where it came from! Every BCG I've owned has shot really well. Maybe I've been lucky, or maybe it doesn't matter that much. Either way...I will not buy another expensive BCG. My experience so far points to it being a waste of money.
I've got plenty of lake city brass I'll send you if you want it all once fired
How do you guys feel about using cerma bryte for cleaning brass? Cleans em quick and good. But, I'm just not sure if the chemicals are going to be making the cases brittle. Great video Johnny! I'm wondering if 760 will work in my gun. So far it hasn't cared for the slower powders like 2000mr or aa 2520. Trying to get those nice high velocities but unsuccessful so far. Back to the bench! Take it easy everyone.
Just used the Brownells link to order my Hornady Lock n load shell plate and 6.5 creedmoor custom grade new dimension 2 die set the dies had to be backordered but that's ok I have 80 rounds of Hornady 129 grain interlock factory ammo and 20 rounds of Federal gold medal Berger in 130 grain so I have 100 rounds factory ammo to get started with while I wait on equipment
I have had good results in my AR using 748 with Nosler 55gr Varmagedons.
At some point would you mind pulling the suppressor and running both the mk262 and one of the clones? I’d like to see what the shift in velocity is on your rifle.
I know this is an older video, but I was curious if you explored using some sort of primer sealant, to really duplicate the loads for long term storage.
I’m sure you’ve seen but midway has a sale on lapua 6.5 brass
After the results of my hang fire tests, I am seriously considering a batch of Starline large primer next. I am still thinking over the situation. We'll get at least a few more firings out of the current batch so I've got time to ponder the situation.
Maybe test the new batch of bullets with an older load that have good velocity and accuracy. Make sure it's not the new bullets going crazy at higher speed.
I meant to add it to the video... I did measure the new batch of bullets for overall length and length from the bullet base to ogive. They were right on the money with the last batch! I like the way you're thinking, though. I've still got a handful of the old batch so I can test side by side if these don't shoot well in the next video.
I’d like to see how Ramshot big game would work out
Interesting video, how much do you think the wind moving the target impacted the one bad W760 load performed?
love this channel. I recently started reloading and this channel has taught me alot, both the vids and comments. keep up the great work and when will you return to 300blk
I haven't abandoned 300 blackout. Just taking a little break. The majority of my videos over the last 2 1/2 years have been on 300 blackout and I got a little burned out, to be honest. It will be back soon! I've got a bunch of bullets in the queue that need tested.
Looks to me that the target is moving due to wind, which can effect group size. I use a pallet with 2x4 legs at an angle and a piece of alumilite to tape targets to.
try H380, its a tad warmer than Win760 but is small grain
I'm really thinking about trying to work-up a similar load using 77 SMKs w/o cannelures and maybe some wolf magnum small rifle primers ... although I do have a couple of thousand prepped and CCI 41 primed LC cases I was saving for something else in the 68 grain range. Now I don't know what to do next. Decisions decisions. I have no AA2250 remaining but I do have 11 pounds of Leverevolution and plenty of all the others in this series .... a preponderance of choices leaves me with some load work-ups to get busy doing.
Hey Johnny, check out Diamond K Brass. I’ve bought never fired, pulled LC brass and it’s beautiful. Such a great deal considering it’s already primed. Sign up for email advertisement, they have a deal every week it seems
Winchester loading data from my older manuals always states that 748 needs a magnum primer because the graphite coating makes it harder to ignite. I've shot a lot of 0.5 moa groups with 748 in 222Rem and 223. Rem 7-1/2 primers have always worked well for me or CCI 450. I could never get groups with CCI 400s and 748.
Chris, I believe the CCI-41 is equivalent to the CCI-450, which is a magnum small rifle primer.
Would you go back and use rl15?.. please
Is the Mk262 Mod2/Black Hills primer crimped? If so, does this allow them to push a hard primer to higher PSI before worrying about popping primers?
I think you should try some different brass. LC has way too much Case capacity and for what you are striving for between velocity and accuracy requires a properly compressed load. You examined the factory load but never examined the factory case. I’d say pick up some Starline and go back and redo some of the older loadings that were 90ish fill that showed ok accuracy and zero pressure signs.. with lower case cap you’ll get compressed load which equals better SD and accuracy, as well as room for pressure sign examination. You’ll also likely get some additional velocity from some that were close but not quite enough.
I personally would start by cracking open an existing round like you did but then reload it with the exact same parts and powder to get a better feel for exactly how it was loaded from the start. I’m betting it’s a smaller case fill with a pretty compressed load. To be as hot as it is with the pressure it’s at with the deviation and accuracy it has it has to be very compressed.
Johnny, I have a question about interpreting your shot groups. Have you considered looking primarily at vertical spread? You mentioned wind during testing and I was wondering if that may have been affecting some of your W748 groups. My understanding is that when conducting OCW tests that the focus on finding nodes through vertical groups and less emphasis is placed on horizontal spread. It appeared your flyers were mostly to the right. Could that have been wind down range?
I really don't think the wind had much effect on the groups in this video. I just don't buy that there's enough influence at 100 yards to ignore horizon spread. The articles you've read are really more about long range load development methods.
This barrel in particular is prone to horizontal double grouping and spread when the loads are bad, and I have other guns that like to do the same thing. I've never bought that concept of focusing on vertical spread and ignoring horizontal. There are a lot of great and successful shooters that do, though...so I'm not claiming they're full of it. I'm probably misunderstanding some basic concepts of their methods.
Thanks for the reply, you made a great point that those who concentrate on vertical spread are typically shooting 300 or farther. I was excited when I saw you were testing W748 because I have had good luck with consistent weights through my Dillon powder measure. I swapped to TAC for faster speeds which also measures well. Thanks again for all your hard work, don't blow your face off!
I use W748 for my M193 loads. My problem with it is the temperature sensitivity. My current load I reach 3200 fps average in 50 degree weather, but when it comes summer time at 90+ degrees it jumps to 3290 fps.
What's your M193 load? Any pressure signs in the 90+ degree days?
Something I thought of. LC brass has a lower capacity than most other brass. BHA (Black Hills) brass is the same as Winchester brass. Maybe we're fighting an uphill battle due to the case capacity difference given the BHA stuff is so hot/fast.
Aaron Anderson i'm may be wrong, but in his first vidéo he show us lake city brass from the factory box off bha.
The factory Black Hills MK 262 uses both lake city brass or WCC NATO brass.
Cool. Happy to be corrected!
I did'nt know that black hills use both brand off brass, are the performance identical?
That should be interesting, i've never found any bha in my country ( like a lot off nice toys and components you can have, or at stellar price).
All of the BHA I've shot has had wcc brass. I actually asked about this a while back.
Good save that 748 for me LOL
40 grain vmax 748win 44grains cover with a dime
Hornadys 9th addition shows VARGET with 23.7 will give 2700fps with a 75 gr. A-MAX. have you tried that?? That's only 2 grs less than your trying and that's with the 5.56 mm NATO load data which is basically what LC brass is.
We shot Varget in episode 5. Check it out here: czcams.com/video/KwwLj7bG2-U/video.html
Increased velocity may have affected stability- also, ball powders seem to like mag primers. Early loads in development in the '60s w/ ball powder left many M16 inoperable
They had a heavy graphite coating it was reduced long long ago. So if your above 80% load u don’t need magnum primers. Long legs on that old story.
Where do you get your new LC brass?
How dare you spend 6 seconds promoting your channel's primary source of income! Kidding of course. I donate monthly. You're my favorite gun channel, and second overall only to AvE.
Have you given any thought to going another route with your AR platforms again? .22Nosler was hot garbage, but you were debating that versus .277WLV way back then. I'm happy to report my WLV is up and running, grouping .6-.8MOA with Accurate 2200 and 1680 with 110gr VMAX.
Just got a box of BH and the bullets were not cannelure?
I know it's expensive but have you tried Norma or Lapua cases? It may save you some time and money to eliminate that variable. Lapua brass also lasts a long time. You just may need to sell a kidney to get an ample supply for the amount you shoot.
That would defeat the purpose of this series.
LC brass has a really great reputation. I just happened to get a hold of some that comes from a crappy source.
wind was bad.
if you increase the OAL to 2.26 full mag length, how much more W748 and/or W760 can you get in the cartridge? I know this doesn't match what the OAL was for the BH MK262 ammo, but keeping things at full mag length just may help those slightly slower powders. Thoughts?
how much powder do i use for my 223 55 grain bullet i have 760 powder
I always heard 748 and BL-C2 are the same. Do you think they shoot the same.
I'd have to go back and compare the velocities. I do remember that BL-C2 shot horrible, and so did 748, so they definitely have that in common! haha They are certainly close...right next to one another on the burn rate chart.
have you tried any hornady 75gr bthp?
I've shot a few back in my White Oak barrel break-in video, but I need to do some standalone videos on the bullet. I have two boxes on hand, so I'll do some soon! They've been awesome shooting bullets for me so far.
Johnny's Reloading Bench cool I'll check it out. I was thinking about getting them instead of the 77gr Sierra's because they're a bit cheaper
How do you like that magnetic chronograph? If you had your money back in your pocket, would you buy it again or something else?
If the money was back in my pocket I would have to look REALLY hard at the LabRadar. I would probably still end up going with the Magnetospeed, but the convenience of the LabRadar is pretty awesome. That price tag sucks, though! The Magnetospeed is really dependable and has given me a couple years of almost constant use without a single problem. It was absolutely money well spent! I have found the Magnetospeed effect on groups to be very minimal, but be prepared for every jackass at the range to come up and tell you how it's screwing up your barrel harmonics.
BTW...nice car. I was a hard core DSMer back in the day. Had a 90 Laser, a 94 TSI AWD, then an 05 EVO. Some chick high on pills ran a red light and I totaled my EVO. I decided to move on to other hobbies. I miss the feel of a spooling turbo!
Where are the final results?!
What about n140 I know that it's expensive but and my Sierra manual it is notated as the most accurate powder for the 77 grain Sierra Match King.
I just want to know, after all the testing is over and done, what's the closest and overall best MK 262 clone load?
You stated your scope to be 6-24, link says 6-24 but link goes to 5-25, did you mis-speak or go to wrong scope?
My Vortex PST isn't made any more. They came out with a new "Gen 2" a while back and switched to a 5-25 magnification. Sorry for the confusion!
How about the NEW 224 Valkyrie. That would be nice.
czcams.com/video/vhXBrjBZtqQ/video.html
Damn, Johnny...you gotta update your plywood placard for your sub count...maybe put some fancy spray paint or aluminum foil to "church it up" a bit? Just...dont blow your face off!
sorry 223 28 grains748winchester
How far are these bullets off the lands?
I would have to go back to video 1 to be sure. We're off the lands a decent amount. I think it might have been .090".
Johnny's Reloading Bench wow mine jump 120 thou from 2.260
Looks like there QUALITY CONTROL has gone to crap on that batch of crimps.
Johnny- I emailed you an offer, if you would like to accept. Keep up the good work! Thanks!
I've never been first before. .
ItsDburch congratulations