I've been trying to get AR Comp to work in either 6ARC or 223/556 but it seems like it is way slow in both. I loaded 24.2 grains of comp in 223 with a Nosler 60 bt. If memory serves, QL had it expected to be in the 2900 range from my 16" AR. Actual is much lower at <2500 where 8208 runs 2700. My 8# jug of 8208 is well over 10 years old. The 1# bottle of Comp I just bought recently.
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Something seems off. For 24.0 gn of AR Comp, I get 2740fps with a 77 SMK or Nosler 77FMJ BT out of an 18in barrel.
Definitely seems off to me too. My 6 Arc is a 22" and seemed to fall in the 2400 range as well with 90 gr.
Not sure what it could be other than a bad lot? I got it from Powder Valley. They say they have not heard from anyone else with this concern. Very expensive fertilizer if that is what it becomes.
I set up a ladder with 8208 and LVR and want to run one for Comp but I don't want to waste any more resources with it.
Alliant 223 data as follows 25.6gr 55SBK 24" barrel 3350FPS That's pretty crunchy, but I loaded some
Back off 50fps per inch (8x50=400) for my 16" barrel to 2950 expected. My actual observed with this load is 2768 with mediocre sd of 28.3
In comparison 25.6gr of 8208xbr yields 2990 with sd of 3.9 and that is with a 5gr heavier bullet. Wish I had loaded some with 55SBK for direct comparison.
Not sure if anyone has ever drawn a direct comparison between comp and xbr but 230fps seems pretty significant and would be greater with same weight projectile . They aren't just too far apart in the burn rates. QL underestimates 8208 and overestimates my particular bottle of comp.
Back off 50fps per inch (8x50=400) for my 16" barrel to 2950 expected. My actual observed with this load is 2768 with mediocre sd of 28.3
In comparison 25.6gr of 8208xbr yields 2990 with sd of 3.9 and that is with a 5gr heavier bullet. Wish I had loaded some with 55SBK for direct comparison.
Not sure if anyone has ever drawn a direct comparison between comp and xbr but 230fps seems pretty significant and would be greater with same weight projectile . They aren't just too far apart in the burn rates. QL underestimates 8208 and overestimates my particular bottle of comp.
So jLorenzo gets similar velocity from 22.6gr and 75/77gr bullets that I get with 25.6gr and 55gr bullet. Both same barrels.
rmfield gets similar velocity from 22.3gr and 77gr bullets but 4" longer barrel
I think maybe I should send a sample to Alliant to test rather than having $60 worth of fertilizer.
rmfield gets similar velocity from 22.3gr and 77gr bullets but 4" longer barrel
I think maybe I should send a sample to Alliant to test rather than having $60 worth of fertilizer.
I think so also. There is a guy from Alliant on the accurateshooter forum. I can try and find him here in a little bit. I will send you his username if I can find it.
That might have actually been my 18" but one of the pics from that session says 16". I can't honestly remember, let me dig through my load dev targets and see what they say. It couldve been the 16 also. I am at 5000"+ altitude which gives a little boost in velocity also.
Yep those were the 18" white oak barrel. Not happy with the accuracy Ive got from this barrel. This was off a F clas 3 leg rest also.
I did shoot someof the 75s with 22.8 out of the 16" though. 2660.
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Testing from today below. I chose 4 powders that I have on hand that all fall in the same general burn rate with RL 15 being a few steps slower. All but the Comp is at least 10 years old by my estimation.
25.6gr comparison 3rds per load 55 SBK 2.250" COAL
XBR 3006 19.1sd QL estimates 2957
RE-15 2785 28.7sd QL estimates 2796
TAC 2947 3.1sd QL estimates 2709
Comp 2755 35.2sd QL estimates 3101
Same charge 60gr Nosler
8208 2957 sd 15.7 QL est 2932
Either QL has an issue estimating Comp or I have a bottle that is "off"
TAC is the big overachieving surprise here.
25.6gr comparison 3rds per load 55 SBK 2.250" COAL
XBR 3006 19.1sd QL estimates 2957
RE-15 2785 28.7sd QL estimates 2796
TAC 2947 3.1sd QL estimates 2709
Comp 2755 35.2sd QL estimates 3101
Same charge 60gr Nosler
8208 2957 sd 15.7 QL est 2932
Either QL has an issue estimating Comp or I have a bottle that is "off"
TAC is the big overachieving surprise here.
I had Gordons Reloading Tool be way off with AR Comp and only AR Comp. Every other powder was really close. It allows users to update the powder burn profiles some how but I don't know how to do that. Mine was faster than predicted though, by quite a bit.
OK so digging a bit further
My results with 55SBK and 25.6gr charge
Comp is negligibly slower with the same charge. Probably within the margin of error pretty much a draw. Close enough that I suspect I may have gotten a pound of RL 15 in a Comp bottle
RE-15 2785 28.7sd QL estimates 2796
Comp 2755 35.2sd QL estimates 3101
From Alliant I found comparative load data using a Sierra 69gr HPBT
Same speed with 2.3gr less charge for Comp
RE 15 2956 with a 25.5gr charge
Comp 2969 with a 23.2 gr charge
Load data: https://www.alliantpowder.com/reloaders/recipedetail.aspx?gtypeid=2&weight=69&shellid=46&bulletid=91
My results with 55SBK and 25.6gr charge
Comp is negligibly slower with the same charge. Probably within the margin of error pretty much a draw. Close enough that I suspect I may have gotten a pound of RL 15 in a Comp bottle
RE-15 2785 28.7sd QL estimates 2796
Comp 2755 35.2sd QL estimates 3101
From Alliant I found comparative load data using a Sierra 69gr HPBT
Same speed with 2.3gr less charge for Comp
RE 15 2956 with a 25.5gr charge
Comp 2969 with a 23.2 gr charge
Load data: https://www.alliantpowder.com/reloaders/recipedetail.aspx?gtypeid=2&weight=69&shellid=46&bulletid=91
23.5 grains in Lapua for 2925 fps w 75 ELD IS almost as good as 24.5gr RL15. Almost. But it’s less temp sensitive
This is loaded to 2.5” it is not an ar15 load
This is loaded to 2.5” it is not an ar15 load
