Finally playing with seating depth in the 6.5 PRC
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- เผยแพร่เมื่อ 14 พ.ย. 2024
- After a little over a year of testing loads we are finally playing with seating depth in the 6.5 PRC. Will our groups improve? There is only one way to find out...let's watch.
Halfmilesniper Merch can be found at: halfmilesniper...
Guntubers, please take and pass a statistics course. 3 shot groups can tell you you have a problem, but for 4 of the 5 groups you shot, there's no statistical significance between them. Until you shoot at least 10 rounds and better yet, 30 (central limit theorem), the uncertainty from a small number of shots in a group is too large to definitively state which seating depth is the best. In the end, most of the seating depths tested likely don't matter, what you may have found is the distance you want to avoid seating bullets at, which is helpful.
Statisticians, please under stand that some calibers have a very short barrel life and components, when assembling your ammo are not free. Running 3 or 5 round groups looking for a load that groups well stretches the life of the barrel and allows more ammo to be tested before the barrel is toast. 3 round groups gives me tem times the number of groups to test than your 30 round central limit theorem, or in other words, shooting 3 and 5 round group have my barrel at close to the halfway point in barrel life while using your preferred amount I would likely be on my 3rd possibly 4th barrel. So, hopefully you see there is a reason behind my 3 or 5 round groups.
My 6.5 PRC shoots the factory match loads under .75” consistently. Reloads with the same bullets and H-4831 shoot .5-.75” groups when loaded to that same length. When I tested for seating length it opened up to 1” to 1.5” at .025 longer than the factory loads and .050 longer than the factory loads, but when I got to .20 off the lands it tightened back up. You might want to consider bigger steps…maybe .010 to .020 at a time. You might find another range that shoots even better than your longest test.
There is still a lot of testing to do. One factor I have to keep an eye on is the magazine...talking with the folks at MDT, because the mag is so long, they recommend loading as close to 3 inches OAL as possible for reliable feeding and at my longest, just off jam, I am at 2.995" OAL. 2.975" was still feeding reliably so I might have a little room to go shorter.
When you say jam do you mean where the bullet sticks in the bore or where the bullet touches the lands?
👍👍Thanks Halfmile, I always enjoy your videos.
Glad you like them! I do enjoy making them, any range time is good time...even the bad range days, lol
Great video
Thanks! Glad you enjoyed that.
He can do his business for sure ,he has forgotten more than I'll ever know, John from Oklahoma
Thank you for the video hated I missed the live .
Next time! No worries Carbon, I understand that not everyone can make it everytime...good thing we have the reruns, lol. I really do appreciate you watching.
👍Halfmilesniper
Thanks!
Great information and presentation 👏 👍 😎
Thank you! 👍Peter, good to see you here.
Im surprised you're loading so long. Everything I've seen said start at 20 thou off the lands. That's how ive done all my initial load development except my 6.5prc which is limited to factory mag length. I load that to the factory 147 eldm length that shoots well for me. Have you checked out eric cortina's videos chasing the lands is stupid part 1 and 2? Definitely some nice es/sd numbers you're getting. Looking forward to the next one
Hey there Eggbert, yes I have watched Erik's videos, I think they help explain why I had consitent groups across the 4 seatings...can't claim the 5th yet...not sure if that was due to the seating or due to heat as I was shooting way faster/hotter than I normally do. My mag length for that AICS magazine I am running is 3.175"...it is a very long mag so I can long long.
Liked the video. Sorry I missed the live.
All good, no worries...that's what the reruns are for, lol.
Pretty much any of these with maybe the 0.22 the exception. Good results overall. Thank you.
I honestly expected to see more difference, not sure why I did but I did expect more difference in group sizes, lol. The last group sure did, lol...but that could have been heat too as I was running it hot.
@@Halfmilesniper Likely hotter barrel. Thank you.
Good video
Glad you enjoyed
I’ve never had to adjust seating depth. I get great accuracy by loading them to the load data’s tested COAL.
Due to the magzine I am running, which is an ACIS 3.175" magazine the folks at MDT advised that I load as close to 3 inches as possible to ensure proper feeding. The book OAL is pretty short compared to what I have been running.
@@Halfmilesniper I load 6.5 PRC for a buddy’s couple of rifles. They’re all book COAL. It’s worked well in both rifles. Everything from 120 ttsx, 140 Accubonds, and 143 eldx bullets have been accurate. Good luck with your search.
Just tell em the woobly table keeps your coffee stirred...lol
LOL, it does do that...and acts like a slider.
Oops I meant exstreem spread an standard deviation
Always being curious how much difference will there be at 500yds & farther? It would be too easy to multiple by 5 since fps is slowing & other factors 🤔. Nice groups to help get a venison roast. Thanks. 👍🙏🇺🇸🎯
I did another 200 yard group and drop test this year...plus shots at 600 yards and beyond 1100 yards.
@@Halfmilesniper👍🎯
What did you measure your jam as? On my howa 6.5 prc with 147gr eldm, I got 2.997" using the hornady oal tool.
Edit: i just saw on another comment you said 2.995, so lines up with my result.
I actually only measured the OAL once after someone inquired...I have not been measuring by OAL for seating, or checking jam I have been measuring from the ogive to base for my measurement, which is 2.381". OAL measures out at 2.995" but can vary a lot based on bullet tip deformity etc.
Why don't you dial down the elevation knob a few clicks?
You shouldn't look at just group size, but also the trend looking at all the groups. You first group was lower and had vertical stinging, the next three were all higher on the same waterline and the last group strung again. I think .007 to .012 would be the node.
I tend to agree with you, and will likely give those two another try. For the next few tests I kept seating depth where it was though. I appreciate the input, thanks.
What camera are you using for the target camera ? Wonder if you were to put up a tripod with an umbrella blocking the sun on the camera if that wouldn't buy you a few more minutes?
Just a thought as you seemed in more of a rush and not your normal relaxed enjoy myself at the range video
My target camera is a GoPro Hero7, usually directly in front of the target, an umbrella might get in the way. I might have to consider a small pop up, maybe that won't block or interfere with the target. I was definitely in a rush shooting this one, trying not to overheat the cameras. Heat and cold are murder on the cameras and batteries.
@@Halfmilesniper on the heat thats killing camera batteries my thought was if you had a tall enough bipod and umbrella you could have it 5 to 10 feet behind and off to the side now that also limits your time frame of the day when you can shoot as the middle of the day you wouldn't be able to use this idea unless it was in the way or pretty big or tall.
If you are always using the same range you might get them to allow you to put up a sun shade down range as a permanent thing but almost doubt it though as government owned and operated facility most likely won't allow that as there is way to much red tape.
Anyways just random thoughts keep up the good work
@@JeRKII all good ideas, but as you said gov't property I won't be able to make changes like that. Good thing the sun and heat only affect like 9 months out of the year, lol. I'm sure I'll figure out something.
I would go with better group and lowest SD.
I think you're right.
What primer are you using in your loads? I’ve found BR4 to give me my best groups with a 2.955 col and that is with the 140 grain Berger Elite Hunting VLD. Lapua brass as well as Winchester brass seemed soft to me! I’m using 55.5 grains of H4831sc. Just got my garmin chronograph so I’ll see what velocity I’m getting but it’s so accurate.
Most of the time I am running some standard CCI large rifle, but I do have some Winchester large rifle and Federal large rifle magnum primers. I've never tried the BR4...I might have to though, hmmm.
Too much heat in the gun
That last group might have been affected by heat a little...I was running the gun hot trying to get this shot before the ambient heat killed my camera batteries.
Time for an umbrella over your camera for shade @Halfmilesniper
@@eggbert191 umbrella might block the target as my camera is usually directly in front of the target. I might try a pop up though.