A1680 Load Check

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Wildkow
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Re: A1680 Load Check

Post by Wildkow »

Tothemax! wrote:According to the accurate chart I could possibly load up too 21.6 with a 150gr fmjbt.

If I'm reading the chart correctly that was posted above, the load I put together is close to max. Is that correct?
Shot two Sierra 155 gr Palma Match BTHP today with 19.5 grains A1680 and both blew the primers clean out. That was enough I'll restart around 18 grains.
DarkSoul
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Re: A1680 Load Check

Post by DarkSoul »

Tothemax! wrote:I talked to one of the guys at accurate today and he told me everything should be GTG if I follow that chart. He said go with the 150 data as it is the closest in weight. He also mentioned that A1680 was very compatible and that they compacted it 125%?
So they are loading compressed powder charge at a maximum of 25% compressed is what I take it they are doing/saying, If this is correct, at 18.6g there is only .176 g of room left in the case, if Accurate is saying you can go over by 25%, I hope they are just saying that as a general statement about the powder, and not specifically to the 300 Blackout, that would put, for the blackout, at 23.2g, which would be a massive over pressure, guaranteed to blow your gun and you up.

So that being said, I am going to ASSume that they are just stating that you are safe to compress that particular powder to 25% and it will still perform as intended, as a general statement about the powder, and NOT specifically to the 300blk round.

EDIT-

Just ran the 19.5g with a 155g bullet (just changed the weight of the 147g M80 since there is no listing for the Palma), and yea, overpressure for sure-

Image
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Tothemax!
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Re: A1680 Load Check

Post by Tothemax! »

DarkSoul wrote:
Tothemax! wrote:I talked to one of the guys at accurate today and he told me everything should be GTG if I follow that chart. He said go with the 150 data as it is the closest in weight. He also mentioned that A1680 was very compatible and that they compacted it 125%?
So they are loading compressed powder charge at a maximum of 25% compressed is what I take it they are doing/saying, If this is correct, at 18.6g there is only .176 g of room left in the case, if Accurate is saying you can go over by 25%, I hope they are just saying that as a general statement about the powder, and not specifically to the 300 Blackout, that would put, for the blackout, at 23.2g, which would be a massive over pressure, guaranteed to blow your gun and you up.

So that being said, I am going to ASSume that they are just stating that you are safe to compress that particular powder to 25% and it will still perform as intended, as a general statement about the powder, and NOT specifically to the 300blk round.

EDIT-

Just ran the 19.5g with a 155g bullet (just changed the weight of the 147g M80 since there is no listing for the Palma), and yea, overpressure for sure-

Image
Interesting. Did you see their load data listed on their site (and in this thread)

http://www.accuratepowder.com/wp-conten ... t_Data.pdf

According to Hornady you can load the wisper up to 22grains with a 155gr projectile.
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Tothemax!
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Re: A1680 Load Check

Post by Tothemax! »

Range report A1680 Experiment.

I set up this experiment after talking to Joel at Noveske Rifle Works about the issues I was having with my 300 Blackout. I have been trying to find a load that works with lil gun and 147gr pulls but no matter what I tried, I could not get the bolt to hold open consistently after each shot. In the last experiment I was using lil gun, this go around I am using A1680. I am running a 16” Noveske barrel on my AR with a Spikes Tactical H2 heavy buffer. During our discussion he concluded that LIL Gun may be burning off too fast and allowing my bolt Carrier Group (BCG) to outrun the magazine on the last round. He wanted me to try A1680 after the lil gun experiment did not work.

I tested 3 different magazines, a PMag, GI Mag w/Magpul Follower, and a Stock GI Mag w/ Green follower. I also tested each load suppressed (AAC 762SDN6) and unsuppressed. All loads were shot with my heavy buffer installed.

I don't have any chrono data as my buddy forgot to bring it out. I will be back on the range (hopefully soon) and will get some data of the rounds that work.

18.0gr Winchester Small Rifle Primer (WSR) 147gr Pulls
Unsuppressed: PMag-Closed Bolt
GI w/Magpul – Open Bolt
Stock GI- Open Bolt
Suppressed: PMag-Open Bolt
GI w/Magpul – Open Bolt
Stock GI- Open Bolt

18.5gr Winchester Small Rifle Primer (WSR) 147gr Pulls
Unsuppressed: PMag-Closed Bolt
GI w/Magpul – Open Bolt
Stock GI- Closed Bolt
Suppressed: PMag-Open Bolt
GI w/Magpul – Open Bolt
Stock GI- Closed Bolt

19.0gr Winchester Small Rifle Primer (WSR) 147gr Pulls
Unsuppressed: PMag-Closed Bolt
GI w/Magpul – Open Bolt
Stock GI- Closed Bolt
Suppressed: PMag-Closed Bolt
GI w/Magpul – Open Bolt
Stock GI- Closed Bolt

I changed this round by trying 2 different PMags. It held open while the other new PMag did not. I did not shoot suppressed on this round
19.2gr Winchester Small Rifle Primer (WSR) 147gr Pulls
Unsuppressed: PMag-Closed Bolt
GI w/Magpul – Open Bolt
Stock GI- Open Bolt

New Windowed PMag - (Shot twice and held open both times)
New black standard PMag - Closed Bolt

19.5gr Winchester Small Rifle Primer (WSR) 147gr Pulls
Unsuppressed: PMag-Closed Bolt
GI w/Magpul – Closed Bolt
Stock GI- Closed Bolt
Suppressed: PMag-Open Bolt
GI w/Magpul – Closed Bolt
Stock GI- Closed Bolt

20.0gr Winchester Small Rifle Primer (WSR) 147gr Pulls
Unsuppressed: PMag-Closed Bolt
GI w/Magpul – Closed Bolt
Stock GI- Closed Bolt
Suppressed: PMag-Closed Bolt
GI w/Magpul – Open Bolt
Stock GI- Closed Bolt


So I will be building up some more 19.2gr load along with some 19.1,19.3,19.4 From this I will try to dial in the most reliable load that will work with any mag I feed it. I really don't care much about the Stock GI but It would be nice to know they work. I really want to get the Pmags to work consistently as those are my main magazines.

I will also load up some once fired brass and try that along with some factory remington rounds

BTW: I saw no signs of overpressure in any of the rounds I shot.
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JohnInNH
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Re: A1680 Load Check

Post by JohnInNH »

Try making sure your bolt release is clean. Using a silencer can foul up the works n prevent the spring in the mag to lift the bolt release up far enough. Clean with a tooth brush n lube. Bolt hold open may be better.

After shooting lead bullets i was having this problem.. a quick cleaning n no more problems. Just something to keep in mind.
Long distance, the next best thing to being there!
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Tothemax!
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Re: A1680 Load Check

Post by Tothemax! »

JohnInNH wrote:Try making sure your bolt release is clean. Using a silencer can foul up the works n prevent the spring in the mag to lift the bolt release up far enough. Clean with a tooth brush n lube. Bolt hold open may be better.

After shooting lead bullets i was having this problem.. a quick cleaning n no more problems. Just something to keep in mind.
I will double check this but my gun is fairly clean.

I wonder what would happen if I threw in a heavy buffer spring? Slow that bolt down just a little more...
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