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SwissyJim
19 October 2016, 11:35
So, I finally got some free time to dial in my 5.56 SBR load. After picking up a number of the bonded 62gr soft points from RMR, I wanted to make a load that was efficient in my 10½" barrel. I did some reading on the intertubes about 'non-standard' powders. I wanted to find one that burned as complete as possible. Cross referencing what I read with Quickload, I narrowed it down to just a couple to try... IMR3031, IMR4198 and Alliant AR-Comp. All burned in the 95-99% range according to QL. Others I tried just for grins and giggles were Varget, CFE223, Benchrest, and H335 but they were no better than 88% complete burn.

I don't have a whizbang setup for testing, but using my Magnetospeed, a front benchrest only and a camera I was able to settle on the IMR4198 as my preferred load. I got the best FPS, and it was accurate, plus it seemed the least smokey with the can on, as told by my 'gas face'. The only issue was unsuppressed, I did not get BHO (it functioned in every other way tho). But, seeing as how my SBR has a dedicated can, and it ran flawless once I attached the can, I'm ok with that.

1861

Never mind the single holes, those were later and unrelated to the testing. The upper group was the 10 round test, while the group on the bullseye was 5 rounds suppressed, all at 50 yards. The chrono info:

Series 6 Shots: 10
Min 2315 Max 2404
Avg 2335 S-D 26.4
ES 89

Series Shot Speed
6 1 2328 ft/s
6 2 2331 ft/s
6 3 2320 ft/s
6 4 2316 ft/s
6 5 2315 ft/s
6 6 2326 ft/s
6 7 2333 ft/s
6 8 2354 ft/s
6 9 2329 ft/s
6 10 2404 ft/s

I had better ES and SD numbers when I measured by hand, but these were from my powder thrower as I wanted to see what 'real world' loading would produce.

My 2nd choice would be the Alliant AR-Comp, it was nearly as good but I rarely see it here whereas I see I4198 constantly. It ran about 100fps slower and the ES/SD numbers were greater, even with hand measured loads. Plus it seemed smokier with the suppressor on - I got more in my face (unscientificlly noted BTW) But a strong 2nd place. I all but eliminated the 3031 as I was getting beat up brass, even with loads that were not near the max... including ejector marks and a serious small dent on the neck/throat of the brass. Non of the others had these issues.

Now I get to start loading the 4k of the bullets I bought [BD]

tact
19 October 2016, 11:49
Interesting.. thanks for posting your work.

Uffdaphil
19 October 2016, 12:38
Looks like you have that dialed in nicely Jim. I never would have thought about most complete burn rate for suppressed. I need to train on exhaling while blasting my shorties with cans.

A couple semi-related Q's: Is burn % related to projectile weight? Would that CFE223 burn more completly in a 16-18" mid-gas barrel? I got a deal on that powder locally and have Nosler 77gr CCs and the aforementioned barrels for them. Thanks.

alamo5000
19 October 2016, 15:52
Looks like you have that dialed in nicely Jim. I never would have thought about most complete burn rate for suppressed. I need to train on exhaling while blasting my shorties with cans.

A couple semi-related Q's: Is burn % related to projectile weight? Would that CFE223 burn more completly in a 16-18" mid-gas barrel? I got a deal on that powder locally and have Nosler 77gr CCs and the aforementioned barrels for them. Thanks.

Heavier grain bullets have less powder to burn due to case capacity limitations.

It's complex but you have a smaller space with slightly less powder and doing a controlled burn in that space and a heavier grain bullet moving at a relatively slower rate. As far as I know a longer barrel like that will burn substantially more powder but it will depend on the burn rate of the powder. It's not an explosion. It's a controlled expansion. The kind of primer will matter too because some are able to ignite more powder and shoot the ignition through the flash hole with more force.

Anyhoo maybe Jerry will run the numbers for you on his software.

Uffdaphil
19 October 2016, 16:04
Thanks. I was just curious.

SwissyJim
19 October 2016, 16:09
Looks like you have that dialed in nicely Jim. I never would have thought about most complete burn rate for suppressed. I need to train on exhaling while blasting my shorties with cans.

A couple semi-related Q's: Is burn % related to projectile weight? Would that CFE223 burn more completly in a 16-18" mid-gas barrel? I got a deal on that powder locally and have Nosler 77gr CCs and the aforementioned barrels for them. Thanks.

From what I read, no - burn is not related to the weight of the bullet. It only ensures your load is as efficient as possible. Not a huge deal for most, but the way I see it is in a SBR it makes a difference. I was seeing some unburnt powder in the barrel with the slower burning stuff. With the faster ones (4198, AR-Comp, 3031) I found none. But in a longer barrel, it's all burned up... from Quickload, CFE223 with the 62gr bullets:

10.5" barrel, 27 grains (near max load) - 83% burned
16" barrel, same laod - 90% burned
18" barrel - 92% burned

Not sure how the difference between gas lengths would do, if anything. I use the CFE223 myself for the 55gr plinkers I run in my 6920.
Also, I should note I am not an expert, I don't play one on TV and I did not sleep at a Holiday Inn Express last night, so I may be talking out my ass...

Former11B
19 October 2016, 16:36
I had great results with IMR 4198 52-64gr bullets in my AR. I was trying less popular powders when things were scarce in 2012. It metered poorly from my Chargemaster, though.

Out of the powders you tried, IMR 4198 is by far the fastest, followed by 3031, Benchmark, 335, ARComp, Varget, and lastly CFE223

Edit:

Hodgdon lists a max for a 63gr bullet as 20.0gr (which is what I used on a 64gr SP, and 22.0gr w/ 52gr SMK). 27.0gr seems a tad....unsafe (unless you were talking about CFE223)

SwissyJim
19 October 2016, 17:02
I had great results with IMR 4198 52-64gr bullets in my AR. I was trying less popular powders when things were scarce in 2012. It metered poorly from my Chargemaster, though.

Out of the powders you tried, IMR 4198 is by far the fastest, followed by 3031, Benchmark, 335, ARComp, Varget, and lastly CFE223

Edit:

Hodgdon lists a max for a 63gr bullet as 20.0gr (which is what I used on a 64gr SP, and 22.0gr w/ 52gr SMK). 27.0gr seems a tad....unsafe (unless you were talking about CFE223)

I was talking CFE223 for the 27gr, but good catch that it was not clear... I edited my comment to reflect that.

In regards to the chargemaster, is it due to clumping at the end of the tube and too much falling in occasionally? I literally JUST got my chargemaster, but I also got this (http://www.ebay.com/itm/191978223894?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT) to go with it. I read about it on a couple of precision rifle sites and in trying it, I have yet to have a load go over, be it ball, stick or flake powder. Well worth the $18in my opinion. But, like I said, I just got the chargemaster for this last round of testing.

Sak007
19 October 2016, 18:13
I have 6k worth of 55gr projectiles & 16lbs of cfe223 that I need to find a nice load for my 10.5 barrel .
I know this isn't a good round for expansion/barricade/homedefense etc... but no way I'm getting 62gr or 75 or 77gr projectiles for anywhere near the price , and besides I would just go to my Ak or 300blk or 6.8spc if it was a huge deal .

Former11B
20 October 2016, 05:48
I was talking CFE223 for the 27gr, but good catch that it was not clear... I edited my comment to reflect that.

In regards to the chargemaster, is it due to clumping at the end of the tube and too much falling in occasionally? I literally JUST got my chargemaster, but I also got this (http://www.ebay.com/itm/191978223894?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT) to go with it. I read about it on a couple of precision rifle sites and in trying it, I have yet to have a load go over, be it ball, stick or flake powder. Well worth the $18in my opinion. But, like I said, I just got the chargemaster for this last round of testing.

I use RE15, RE10x, and AR Comp, all extruded stick powders, and don't have the dispensing issue I did with 4198, but the Alliant sticks are about a third of the size of 4198. When I get home tonight, I'll take a pinch of all four and show the difference.

That insert looks pretty cool, though. I'll bookmark it. Thanks

bandw1dth
20 October 2016, 15:08
So, I finally got some free time to dial in my 5.56 SBR load. After picking up a number of the bonded 62gr soft points from RMR, I wanted to make a load that was efficient in my 10½" barrel. I did some reading on the intertubes about 'non-standard' powders. I wanted to find one that burned as complete as possible. Cross referencing what I read with Quickload, I narrowed it down to just a couple to try... IMR3031, IMR4198 and Alliant AR-Comp. All burned in the 95-99% range according to QL. Others I tried just for grins and giggles were Varget, CFE223, Benchrest, and H335 but they were no better than 88% complete burn.

I don't have a whizbang setup for testing, but using my Magnetospeed, a front benchrest only and a camera I was able to settle on the IMR4198 as my preferred load. I got the best FPS, and it was accurate, plus it seemed the least smokey with the can on, as told by my 'gas face'. The only issue was unsuppressed, I did not get BHO (it functioned in every other way tho). But, seeing as how my SBR has a dedicated can, and it ran flawless once I attached the can, I'm ok with that.

1861

Never mind the single holes, those were later and unrelated to the testing. The upper group was the 10 round test, while the group on the bullseye was 5 rounds suppressed, all at 50 yards. The chrono info:

Series 6 Shots: 10
Min2315 Max2404
Avg2335S-D26.4
ES 89

SeriesShotSpeed
612328 ft/s
622331 ft/s
632320 ft/s
642316 ft/s
652315 ft/s
662326 ft/s
672333 ft/s
682354 ft/s
692329 ft/s
6102404 ft/s

I had better ES and SD numbers when I measured by hand, but these were from my powder thrower as I wanted to see what 'real world' loading would produce.

My 2nd choice would be the Alliant AR-Comp, it was nearly as good but I rarely see it here whereas I see I4198 constantly. It ran about 100fps slower and the ES/SD numbers were greater, even with hand measured loads. Plus it seemed smokier with the suppressor on - I got more in my face (unscientificlly noted BTW) But a strong 2nd place. I all but eliminated the 3031 as I was getting beat up brass, even with loads that were not near the max... including ejector marks and a serious small dent on the neck/throat of the brass. Non of the others had these issues.

Now I get to start loading the 4k of the bullets I bought [BD]

I'd be curious as to the accuracy of your load at 100yards. I've found that doing an OCW workup does wonders. I'll input all my data into QL just to make sure I won't blow myself up and then do an OCW workup to find the charge that's the most accurate. I've been able to shrink my groups from about 3moa - 4moa @ 100yards to half of that just doing the OCW. Now if you want to squeeze more you could sort by bullet weight, case volume and then mess with the OAL. Typically I will only do that for my 69gr and 77gr "match" loads.

If your not familiar with Optimal Charge Weight load development here's a great video to watch. Check the video description for Dan Newberrys paper on Optimal Charge Weight.

https://youtu.be/8hzcxytpKWU


Sent from my iPhone using Tapatalk

Former11B
20 October 2016, 18:42
1868


This is why 4198 meters poorly compared to the other three

Jim, you said you got more blowback from ARComp; what kind of charging handle are you using?

SwissyJim
21 October 2016, 22:25
Using an Armegeddon Tactical handle, which I have grown to love. Way better than the raptor with RTV treatment.

You should look into the adapter part I linked for your chargemaster... I did about 100 loads with it and 4198 and every one was spot on. I didn't have to dump, or trickle, a single one.

Former11B
24 October 2016, 05:09
I'll look into it for sure. I don't use much 4198 at all; for my small bore/light bullet charges, RE10x usually takes precedence over anything (52gr SMK + 22.5gr RE10x) but it can't hurt to make an improvement to the scale