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Discussion Starter · #1 ·
I just bought some AA2200 and Hornady 120gr SSTs. Hoping to use it to develop a hunting load for my 6.8spc rifle. It's just an AR with a 16" ARP scout barrel.

I've got a good mix of 1x fired brass on hand, it's a mix of Hornady, Federal, and Remington cases.

My Hornady and Sierra manuals don't have any AA2200 data for 120gr projectiles, but the Hodgdon data and Western data sources online cite a max of 27.2gr using a Remington case (and marked it as a compressed load). I've noticed numerous people here have used 27.5gr charge (not sure which case though). Anyone have any suggestions of loads they use using Federal, Remington, or Hornady brass?

I haven't reloaded for 6.8spc in probably 10 years, but I do a ton of reloading for 223, and 308 though. Just haven't messed with this caliber in quite some time.

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Couple of things off the top of my head:

You probably know this but the Rem is large primers and the others small.

Most spc2 loaders go to at least 2 285". This will allow more powder/less crunch. This is dependent on your mags...some allow a little longer and I think Barrett are shorter (may be wrong). Some people "load long" and cut the front off the mag.

I don't think you necessarily need to drop 10% from 27.5 but there will be differences between the brass brands. You've probably been down this road before with other calibers.
 

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Weigh your cases or look on line for volume charts and notice the difference in them . What is good in one can be hot in another . Also Hornady will sometimes throw you a curve . Some Hornady are made by Hornady and some were made by S&B . The ones made by S&B are lighter and have more volume . Depending on which case you have the most of may make a difference . You can work up a load with the heavier cases ( less volume) and be comfortable it will not be hot in the lighter (more spacious ) if it shoots satisfactory out of the different cases. Note the velocities will be a little different depending on difference in volume . The 120 SST is my wife's favorite and her arp16" shoots them tighter than any other gun we own of any caliber . If all your Hornady brass weight the same then look at the head stamp . I believe the Hornady say 6.8 where as the S&B has 6,8 . If in doubt post the weight and one of us can tell you .

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Discussion Starter · #4 ·
Thanks for the info.

Yes, I'm very aware of the Rem brass being large primer brass. I have large and small primers on hand though.

That's a good point about loading slightly long. I load a little long in 1 of my 308s as it not only minimizes bullet jump, but also slightly lowers chamber pressure. I'll have to measure to see what I can get away with in my magazines. I just have 2 10 round mags by ASC (my state limits hunting guns to 10 rounds).

I'll probably start off at 26.5gr and work up to 27.5gr with each brand of brass, and make note of group sizes and velocities.

For me this is a hunting round, so my goal is to develop a load and load up my brass and have a couple hundred on hand for the future.

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Others may not agree with me on this but I would start by looking for your pressure limit with a 0.2-0.3 grain increases with single rounds. Your 26.5 is a good start point. If you load 3-5 rounds in each brass type, in a ladder, you may have a lot of loads over pressure you have to pull. Once you find this point, then look for accuracy.

I wasted a lot of components trying to get over the 27 gr target. My hog load now is 26.6 A2200, 120SST, Hornady S&B brass, 2.295". Anything over 26.6 does a lot of damage to the case head. Anyone with suggestions on what to look at or tweek where I could go higher, I am open. I tried different buffer weights, Geissele H2 buffer and spring system, double/triple checked headspace, rounded the ejector face,...
16" ARP, ARP bolt, SLR adj gas block, vel? (would have to pull my notes). My 12.5" ARP is also about the same. I disassembled the 12.5" and rebuilt and am starting back with development now.
 

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Discussion Starter · #6 ·
Makes sense to me. Thanks for your input.

I'm only able to go to the rifle range once every couple of months (young kids keep me busy) but can go to an indoor range more often. Guess I could do pressure testing there so I'm not wasting a trip to the rifle range.

Wish I had a suggestion for your issue of not being able to go over 27gr, except maybe dial your gas down, but I'm sure you've already tried that.

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You might want to look at the Satterlee Method. It's the method I've been using for a couple of years now. It saves on components. Most of the loads that I've developed for several different rifles have been sub MOA.
 

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Others may not agree with me on this but I would start by looking for your pressure limit with a 0.2-0.3 grain increases with single rounds. Your 26.5 is a good start point. If you load 3-5 rounds in each brass type, in a ladder, you may have a lot of loads over pressure you have to pull. Once you find this point, then look for accuracy.

I wasted a lot of components trying to get over the 27 gr target. My hog load now is 26.6 A2200, 120SST, Hornady S&B brass, 2.295". Anything over 26.6 does a lot of damage to the case head. Anyone with suggestions on what to look at or tweek where I could go higher, I am open. I tried different buffer weights, Geissele H2 buffer and spring system, double/triple checked headspace, rounded the ejector face,...
16" ARP, ARP bolt, SLR adj gas block, vel? (would have to pull my notes). My 12.5" ARP is also about the same. I disassembled the 12.5" and rebuilt and am starting back with development now.
My rifle seems to be finikey in the extreme. Ben there done that with everything. Works great with factory loads anything I load is a jam . My next outing I’m going to 27.5 gr. AA2200 and 120 gr. Sat Hornady bullet. I believe all my issues are from under charge loads . Tried everything else so I give up. I have reworked magazines, reworked feed ramps reworked gas system, tried 3 different buffer weights. I have $2800 invested in this and I want it to work but I’m going over what all the so called experts say.I would like to know what goes into factory loads but they won’t let that be known?
 

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27.5 is too hot in my 12" and 16" ARP. I'm using 27.2 with SSA brass.

Gascan, did you say everything you load jams? Does you resizing die have an integrated crimp feature? If it is touching your case neck, even the slightest, it can put a slight bulge in the neck that you can't even see that will cause jams.

A handload that is slightly over-pressure can also cause jams by holding the case wall against the chamber wall, delaying extraction, and causing failure to feed/jamming the next round.
 

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27.5 is too hot in my 12" and 16" ARP. I'm using 27.2 with SSA brass.

Gascan, did you say everything you load jams? Does you resizing die have an integrated crimp feature? If it is touching your case neck, even the slightest, it can put a slight bulge in the neck that you can't even see that will cause jams.

A handload that is slightly over-pressure can also cause jams by holding the case wall against the chamber wall, delaying extraction, and causing failure to feed/jamming the next round.
At first everything jammed that’s how I started reworking everything. Now I can get factory loads to work flawlessly, now I’m trying to replicate my own loads to work. My opinion is that the Ar is a pos.
No rifle should be this finicky but I have to much invested to give up on now . I’m going to keep increasing my loads until it kills me.
 

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At first everything jammed that’s how I started reworking everything. Now I can get factory loads to work flawlessly, now I’m trying to replicate my own loads to work. My opinion is that the Ar is a pos.
No rifle should be this finicky but I have to much invested to give up on now . I’m going to keep increasing my loads until it kills me.
You need to start over from scratch and regroup or it may just kill you . Go back to square one and do it like you should have the first time . If factory loads are working and your loads are not then it's not the gun it's your loads . Don't listen to what everyone who thinks they are experts tell you . Find one or two that tell you like it is and ignore the " have you tried this thing I saw on the internet " people . Safety first so in a secure area with muzzle pointed in a safe direction start over and run a few factory through manually and see if when mag empties the bolt locks back . If that doesn't work don't go farther until you fix that . Now run a mag of your loads through manually and see if all comes out well and bolt locks . Check cases for unusual scratches or marks . X man made a good suggestion about the crimp feature on your die . It's my opinion the sizing die should be backed off enough it doesn't crimp any and all crimping be done with Lee crimp die . Only after the loads feed and eject manually should you fire a shot , then it should be one shot with an empty mag and mark where the case lands and if the bolt locks . The process of determining the problem is easy if you don't jump back and forth and skip steps .

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You need to start over from scratch and regroup or it may just kill you . Go back to square one and do it like you should have the first time . If factory loads are working and your loads are not then it's not the gun it's your loads . Don't listen to what everyone who thinks they are experts tell you . Find one or two that tell you like it is and ignore the " have you tried this thing I saw on the internet " people . Safety first so in a secure area with muzzle pointed in a safe direction start over and run a few factory through manually and see if when mag empties the bolt locks back . If that doesn't work don't go farther until you fix that . Now run a mag of your loads through manually and see if all comes out well and bolt locks . Check cases for unusual scratches or marks . X man made a good suggestion about the crimp feature on your die . It's my opinion the sizing die should be backed off enough it doesn't crimp any and all crimping be done with Lee crimp die . Only after the loads feed and eject manually should you fire a shot , then it should be one shot with an empty mag and mark where the case lands and if the bolt locks . The process of determining the problem is easy if you don't jump back and forth and skip steps .

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Like I said, been there done that ? Wondering what the difference is from a 115 gr. Seller & Beloit and Hornady sst 120 gr could make ? The sst is almost 5/16 longer and takes up more space for case capacity? The Hornady 270/6.8 sst is not a 6.8 specific bullet it’s more generic for either one. I don’t know where all my issues come from ?
 

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While it isn't necessary, doing load development with a chronograph may help. Factory Hornady 120SST gave me 2400 fps in my 16 inch Rec 7. I was never able to get over 2350 with A2200 without the SSA case heads showing extractor marks, The deer never notice the difference in fps and A2200 is still my go to powder for the 6.8 and 120 SSTs.
 

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Like I said, been there done that ? Wondering what the difference is from a 115 gr. Seller & Beloit and Hornady sst 120 gr could make ? The sst is almost 5/16 longer and takes up more space for case capacity? The Hornady 270/6.8 sst is not a 6.8 specific bullet it’s more generic for either one. I don’t know where all my issues come from ?
Then do it again until you see what you missed . Does all loads factory and reloads work manually ? Do both factory and reloads lock back on empty mag ? If yes to both questions then you can go forward if not then why don't they. It is simple diagnosis if you take one step at a time ,its not rocket science .

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I just bought some AA2200 and Hornady 120gr SSTs. Hoping to use it to develop a hunting load for my 6.8spc rifle. It's just an AR with a 16" ARP scout barrel.

I've got a good mix of 1x fired brass on hand, it's a mix of Hornady, Federal, and Remington cases.

My Hornady and Sierra manuals don't have any AA2200 data for 120gr projectiles, but the Hodgdon data and Western data sources online cite a max of 27.2gr using a Remington case (and marked it as a compressed load). I've noticed numerous people here have used 27.5gr charge (not sure which case though). Anyone have any suggestions of loads they use using Federal, Remington, or Hornady brass?

I haven't reloaded for 6.8spc in probably 10 years, but I do a ton of reloading for 223, and 308 though. Just haven't messed with this caliber in quite some time.

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I was able to safely get to 27.5 gr A2200 under a 120 SST but the accuracy at that point was noticeably worse than at 27.0 gr.

For my rifle with a 16” ARP barrel, 27.0 gr of A2200 is the best trade off between accuracy and velocity.

obviously your rifle barrel may be different. However, just because sone reloaders report certain loads are good in their barrels doesn’t mean I accept that as the absolute truth for all barrels.
 

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Resurrecting a necro-thread, apparently, but did you ever get it figured out? I have some AA2200 and 120gr SST pills that I want to load for deer this fall.
His results were the exception not the norm so don’t stress on it . As others have noted 26.5 to 27.5 is the area most find works in their barrels with 27.5 being a little hot in some . If you start around the lower and work up .2 at a time you will probably find your sweet spot somewhere in the middle . Of course stop at pressure signs which will defer depending on case volume and barrel .


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Discussion Starter · #18 ·
Sorry, just saw this. I did a ladder back in January. Didn't get to the range until mid July. Fired my ladder over a chronograph. 27.1gr and 27.3 grains were tight velocities and grouped decently. I loaded a 2nd ladder with those 2 steps again to make sure it's repeatable, but haven't made it back to the range. 27.5gr for me was showing some pressure signs. Below 27gr, and the velocities were low, and it felt like the rifle barely cycled.
 
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