It's the first load I tried, I wouldn't quite describe it as driving it to that point so much as inadvertently starting there
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It's the first load I tried, I wouldn't quite describe it as driving it to that point so much as inadvertently starting there
ADI max for a .260 using 140's and 2217 is 50.5 getting 2700ish in a 24" barrel.
I just went 54.5 compressed in my .260Ai and got 2850 in a 24" barrel. No pressure signs. I can't get much more in so had flag any idea of using it as I get way better fizz out of RL-17 for 7 gr less.
That was using fed mag primers and newly formed Lapua brass.
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Ive found the current adi data for 223 to be pretty much bang on
Nb max for 70gr in current data is 25gr. I found velocity etc for 69gr with 2206h to correlate perfectly (in my rifle) my other rifles in lother calibres always need extra to get close to the stated velocitys
Ive used 2209 and backed of .5 from pressure to get exact same speed same primers and brassQuote:
Originally Posted by R93
Yeah I was having a play because of advice given on a standard .260 that reached good speeds with 2217.
No where near it in my AI so will stick with RL-17 as it works.
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It's got fuck all to do with the ADI data, it's the fact you are fitting a VLD into a AR mag
seated to a normal length ie out a heap, and the pressure will plummet
I think his point is he plugged mid-range ADI data into Quickload and found that Quickload suggests the pressure is through the roof. His real world observations seem to back this up. This is completely against the commonly held belief that ADI data is anemic and well below SAMMI recommendations.
And my point is he has what would be considered an abnormal seating depth for that projectile in a 223 and thus why the pressure is high and predicted high.
His overall cartridge length is 0.03" longer than SAAMI specs for 223 and 5.56 Nato so I don't see how that could be a factor. Unless he has a short throat, but you cant account for that in Quickload.
It's loaded longer than the COL in the ADI data. I think. Going shooting now, will look later. This isn't a serious criticism of ADI or whatever
It is a hilariously compressed load. My only point would be that book data can be fairly meaningless
You're almost comparing apples and bananas and saying they are the same because they hang from trees :D
From what I have here at this time:
The Berger 70 gr VLD is 0.976" long.
The Sierra 69 gr SMK is 0.898".
(I dont have the HPBT Sierra, but from memory it is shorter again)
Given the same OAL, you're looking at an effective seating depth change back into the case of about 0.078" or close to 2mm
If the HPBT is shorter, you have increased that further again.
Seat the VLD out 2mm.. QL will tell you what you want (and expect) to see, and when fired (single load or bolt gun) the case will too.
Same same but different :pacman::thumbsup::ORLY:
Quote:
Originally Posted by Spanners
Still over 72,000psi... 10,000 more than spec max.
It is also worth noting that your 69gr SMK at spec OAL and 25.5gr 2206H comes out over pressure (~72,000psi)
Interestingly I just checked out the online ADI data and for 2206H they suggest a max of 26gr for the 69gr (Sierra HPBT spefcically), and only 25gr for a 70gr Speer SP.
I just don't think OAL has much effect on pressure unless it is extreme or touching the lands.
Also, QL was pretty good at predicting the speed (only 14fps difference) and that the charge gimp was testing would be over pressure....
Quote:
Originally Posted by Wildman
Take a factory Rem with 6+mm to the lands so they are out of the equation and go 3mm either side of SAAMI spec and tell me what you see - my RUM was about 4gr (from memory) MORE powder to get speed back after seating out
Ive found that depth makes a difference - from Pistol cals through to my big guns. I'm not concerned about where the rifling is as long is its far enough away. My 1st and only attempt at it resulted in a action full of powder and I lost interest in chasing them and in my guns, doesnt matter
2mm in a 9mm case can increase pressures to blow up levels
ADIs data is measured in CUP.. QL in psi...
ADIs data is in 223 Winchester cases, not 5.56 Mil cases...
ADIs data is for a proj that takes up 2mm less case space...
ADIs data is for a proj with a softer jacket
Fruit salad :D
A 2 min search online suggests all those shooting ARs using 2206H (which is 4895) with 70gr VLD are seeing max loads of around the 24gr mark
Whats QL say to that?
I'm shooting 68gr Hornady's in front of 26gr of 2206H, ADI brass. Goes mint. Plug that into QL?