Fairly new to 300 BLK and have a question about compressed loads with A1680.
I got a deal on some Hornady 212 ELD-X projectiles and loaded some up with my preferred ogive seating depth. But these bullets are huge due to the polymer tip and they weren't even close to fitting in the magazine. So I seated them deeper until they fit the magazine. But now the powder is compressed.
I'm not worried about dangerous pressures because these are subs with 11.2gn of A1680. But is there anything else to be aware of with compressing this powder before I shoot these?
Hornady 212gn ELD-X and A1680 compressed
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Re: Hornady 212gn ELD-X and A1680 compressed
In general 1680 works well compressed. A magnum primer is helpful. Anything can be taken too far.
How far did you compress the powder, and did you use a drop tube?
You don’t mention barrel length, it it might be worth shooting a couple at you normal length single Fed to get an idea of velocity. It might turn out you want less powder anyway.
As far as jump, the ELD bullet is very forgiving. Probably won’t notice much of an accuracy difference.
How far did you compress the powder, and did you use a drop tube?
You don’t mention barrel length, it it might be worth shooting a couple at you normal length single Fed to get an idea of velocity. It might turn out you want less powder anyway.
As far as jump, the ELD bullet is very forgiving. Probably won’t notice much of an accuracy difference.
300 Blackout, not just for sub-sonics.
Re: Hornady 212gn ELD-X and A1680 compressed
Barrel length is 8.5" AR. I didn't use a drop tube, but once I realized I needed to seat a lot deeper, I vibrated the case before seating to settle the powder.
I'm not sure exactly how compressed the powder is, but I can feel some resistance with seating. I also pulled one of the bullets and used a micrometer to measure to the top of powder vs how much of the bullet is in the case. I don't have those measurements in front of me as they are on a scratch pad in my shop. But the bullet is definitely in the powder.
To your point about possibly wanting a smaller charge...I did exactly that. I loaded up 10 with 10.5gn vs 11.2gn in case the velocity is too high when I test. I'm hoping to get out with the chronograph this weekend. But the more I thought about it, the more I got in my own head about shooting these, lol. I typically don't make compressed loads, and since I'm new to this round and this powder, I just want to make sure there are no worries shooting these.
I don't think these bullets are even meant for 300blk since I couldn't find any load data, not even hornady has load data for these for 300blk...which added to my nervousness.
I'm not sure exactly how compressed the powder is, but I can feel some resistance with seating. I also pulled one of the bullets and used a micrometer to measure to the top of powder vs how much of the bullet is in the case. I don't have those measurements in front of me as they are on a scratch pad in my shop. But the bullet is definitely in the powder.
To your point about possibly wanting a smaller charge...I did exactly that. I loaded up 10 with 10.5gn vs 11.2gn in case the velocity is too high when I test. I'm hoping to get out with the chronograph this weekend. But the more I thought about it, the more I got in my own head about shooting these, lol. I typically don't make compressed loads, and since I'm new to this round and this powder, I just want to make sure there are no worries shooting these.
I don't think these bullets are even meant for 300blk since I couldn't find any load data, not even hornady has load data for these for 300blk...which added to my nervousness.
Last edited by FreeTacos on Tue Jan 31, 2023 12:30 pm, edited 2 times in total.
Re: Hornady 212gn ELD-X and A1680 compressed
Depending on whose data you are using, you can’t count on compressed loads being flagged. Take a look at Sierra data for the 240 SMK. The bullet is .040” shorter than the 212 ELD. Their loaded length is 2.230”, so basically you are seated about .010” deeper.
Sierra is good data to reference as well as Hornady because they load to max pressure. Not 1050 fps. A max load is 14 grains, 1300 fps. Compression is not indicated. A lot of people shoot compressed
Loads and don’t know it.
I have good luck compressing 1680 .010-.020”. Take a fired case or one that the neck is loose
Enough to slip a bullet in. Drop your powder charge and then insert the bullet and measure. That’s really the only way to know if you’re compressing the powder and will also tell you how much compression.
The only thing to watch out for compressing 1680 is since it’s a fine ball powder. If you use a drop tube or. I rate to settle, it can pack tightly enough that it is hard to compress. A good press with a lot of leverage will deform the bullet before you feel it.
https://sierrabullets.files.wordpress.c ... 052018.pdf
Sierra is good data to reference as well as Hornady because they load to max pressure. Not 1050 fps. A max load is 14 grains, 1300 fps. Compression is not indicated. A lot of people shoot compressed
Loads and don’t know it.
I have good luck compressing 1680 .010-.020”. Take a fired case or one that the neck is loose
Enough to slip a bullet in. Drop your powder charge and then insert the bullet and measure. That’s really the only way to know if you’re compressing the powder and will also tell you how much compression.
The only thing to watch out for compressing 1680 is since it’s a fine ball powder. If you use a drop tube or. I rate to settle, it can pack tightly enough that it is hard to compress. A good press with a lot of leverage will deform the bullet before you feel it.
https://sierrabullets.files.wordpress.c ... 052018.pdf
300 Blackout, not just for sub-sonics.
Re: Hornady 212gn ELD-X and A1680 compressed
Thank you! Great idea about dropping a bullet into an expanded neck case. I'm going to do that as soon as I get home.
Here is an idea of how much longer these are compared to 220gn Sierra, which I use quite a bit.
Here is an idea of how much longer these are compared to 220gn Sierra, which I use quite a bit.
Re: Hornady 212gn ELD-X and A1680 compressed
This might be helpful at times if you are not aware of it
https://www.jbmballistics.com/ballistic ... ml#Hornady
https://www.jbmballistics.com/ballistic ... ml#Hornady
300 Blackout, not just for sub-sonics.
Re: Hornady 212gn ELD-X and A1680 compressed
On a side note, you won’t find another bullet that works like a Matchking. The chamber was designed so that a 220/240 would be .010” off the lands at mag length.
300 Blackout, not just for sub-sonics.
Re: Hornady 212gn ELD-X and A1680 compressed
I really like the Matchkings. The only reason I bought these 212 ELD-X is because a buddy sold his .308 bolt gun and he had these left over. He sold me 200 for 40 bucks. Figured it was too good a deal to pass up...then when I couldn't find any published load data I kinda figured these are not meant to be used for 300BLK or in an AR platform.
I had to obviously seat these way off the lands, but if the bullet is forgiving like you mentioned, they may work out ok. I typically only measure to be as close as possible to the lands in my bolt guns anyway. For an AR I only use ogive to base for consistent pressure.
I guess I'll see. I'll report back once I get to the range in case my data can help anyone else who wants to use these.
I had to obviously seat these way off the lands, but if the bullet is forgiving like you mentioned, they may work out ok. I typically only measure to be as close as possible to the lands in my bolt guns anyway. For an AR I only use ogive to base for consistent pressure.
I guess I'll see. I'll report back once I get to the range in case my data can help anyone else who wants to use these.
Re: Hornady 212gn ELD-X and A1680 compressed
300 Blackout, not just for sub-sonics.
Re: Hornady 212gn ELD-X and A1680 compressed
Damn, that's a great group. So do you typically seat by COL or CBTO? I get inconsistent results seating by COL as I've found that hardly any bullets are exactly the same length, but the ogive is very consistent.
I noticed you listed 1.515 as your CBTO...were you compressed at that depth? (also wondering how you got a low cbto like that with max COL). Anyway, reason I'm asking is I was shooting for 1.579 when they wouldn't fit the mag, and ended up at 1.532 to fit the mag. And I confirmed this evening that I'm compressed. I did like you said and used a loose neck case to push a bullet in by hand. I hit powder to the point I can't push it in anymore at about 1.533 or so.
I noticed you listed 1.515 as your CBTO...were you compressed at that depth? (also wondering how you got a low cbto like that with max COL). Anyway, reason I'm asking is I was shooting for 1.579 when they wouldn't fit the mag, and ended up at 1.532 to fit the mag. And I confirmed this evening that I'm compressed. I did like you said and used a loose neck case to push a bullet in by hand. I hit powder to the point I can't push it in anymore at about 1.533 or so.
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