I tried some factory 77gr TMKs, it wasn't pretty close to 2 MOA IIRC
Geissele Cut Rifled SPR Build and Barrel Evaluation. (Part 4 (Load Development 28MAY25) Update!!!
- Thread starter Bigjake83
- Start date
I tried some factory 77gr TMKs, it wasn't pretty close to 2 MOA IIRC
It was the AAC 77gr TMKs, but I'll shoot if again just for you
I put the 1/2" red dots I shoot at 100rds on the boxes of ammo that don't work out, it also hated the 69gr AAC SMK's
When I take the 18" SPR out for load development I'll shoot every type of factory 5.56/.223 ammo I have on hand so y'all can see what she like and hates.
Keep in mind the AAC stuff isn't what I'd call consistent.
I just want to say... Thank you for all your time and effort, on all your posts.
All of us truly appreciate yours ( and many others ) lengthy, informative posts.
I look forward to this kind of "gunny" stuff every time I "login".
Lot to lot I have seen as much as a 100fps difference. Within lots seem to be fine though. Buy in bulk, zero for that lot, rezero for the next lot.It was the AAC 77gr TMKs, but I'll shoot if again just for you
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I put the 1/2" red dots I shoot at 100rds on the boxes of ammo that don't work out, it also hated the 69gr AAC SMK's
When I take the 18" SPR out for load development I'll shoot every type of factory 5.56/.223 ammo I have on hand so y'all can see what she like and hates.
Keep in mind the AAC stuff isn't what I'd call consistent.
@Bigjake83 how do you like the Xeno muzzle brake? I have one now that came with my Nomad, I made it direct thread, but thinking of moving it to my B&T to use on my semis for easier can swapping. See any downsides with the brake/can interface?
No Sir, no down side at all.
I started off with the Keymo Hub and Dead Air Muzzle break Set up and initially I really enjoyed it although it did add on a good amount of weight.
As time went on I started noticing that the CAN would come loose off of that last click creating just enough play to throw off the barrel harmonics and effect my accuracy.
I’ve swapped all my muzzle devices to Xeno now, the two Muzzle Devices that I run are extremely effective at what they do.
The Xeno utilizes left hand threads, I haven’t had one come loose yet on any of my Cans.
The Dead Air Muzzle Brake is a hybrid style muzzle brake that also does a great job at reducing Muzzle Flash, all of the Xeno muzzle devices are compact and lightweight.
I was initially a little skeptical because they all run a .30 caliber bore so I wasn't confident they would be effective at reducing felt recoil but they do a great job at it.
When you switch over from Keymo to Xeno you get to ditch that Ratchet Style Hub adapter that adds a significant amount of weight, the Hub Adapter for the Xeno is the same weight as a standard direct thread hub.
Dead Air Muzzle Brake: LEFT
LMT 4 Port Muzzle Brake: (NOT LEWIS & TOOL ) RIGHT
I use the Dead Air Xeno on all my SBR's in 5.56 and 6 ARC with 10.5" to 14.5" barrels.
The LMT 4 Port Muzzle Brake is extremely effective at reducing recoil, it lives on all my Large frame Rifles and a few Small Frames with 20" or longer barrels. You'll want the LMT 4 Port Muzzle Brake away from your ears
Hope this helps.
Jake.
Part 4: Load Development and Factory Ammo Testing
I've got my first round of Handloads to shoot today along with a good assortment of factory ammo.
HANDLOAD COMPONENTS:
77gr SMK
RAMSHOT TAC
STARLINE BRASS
CCI BR4 PRIMERS
Good Ejection pattern.
23.6gr TAC
24.2 TAC
Didn't realize I forgot to reset the chronograph until I was on shot #5
24.3 TAC
24.5gr TAC
Not sure who asked but here are two 20-round groups of Black Hills 5.56 77gr
I'll repeat the following loads for next Range Trip with 20rds of each.
I had a few flyers, shit happens. Should make @dms416 happy
knowing that I'm a mere mortal.
All groups were shot unsuppressed besides the last two 20rd Groups at the end.
23.6
24.2
24.3
24.5** 2753fps SD 9.2 / ES 21.8
And yes it still hates the AAC 77gr TMK's!
The 24.5gr of TAC really hit the sweet spot for Accuracy and Muzzle Velocity, matching the Black Hills 5.56 77gr.
I've got my first round of Handloads to shoot today along with a good assortment of factory ammo.
HANDLOAD COMPONENTS:
77gr SMK
RAMSHOT TAC
STARLINE BRASS
CCI BR4 PRIMERS
Good Ejection pattern.
23.6gr TAC
24.2 TAC
Didn't realize I forgot to reset the chronograph until I was on shot #5
24.3 TAC
24.5gr TAC
Not sure who asked but here are two 20-round groups of Black Hills 5.56 77gr
I'll repeat the following loads for next Range Trip with 20rds of each.
I had a few flyers, shit happens. Should make @dms416 happy
knowing that I'm a mere mortal.All groups were shot unsuppressed besides the last two 20rd Groups at the end.
23.6
24.2
24.3
24.5** 2753fps SD 9.2 / ES 21.8
And yes it still hates the AAC 77gr TMK's!
The 24.5gr of TAC really hit the sweet spot for Accuracy and Muzzle Velocity, matching the Black Hills 5.56 77gr.
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Load development results are up.
1st Handload Range Trip.
1st Handload Range Trip.
I might have one to sell , But have to buy my gas tube and AGB at cost tooInterested in doing some 77 TMK load development? I’ll send you a couple boxes if you sell me one of your 3 barrels at cost
Interested in doing some 77 TMK load development? I’ll send you a couple boxes if you sell me one of your 3 barrels at cost
Hard pass.
Well the SPR barrel is 18" so I'd say you could safely add 48fps, but keep in mind that you have a CLE Chamber. None of mine liked the Hot loads, my go to load for my CLE load is 77 SMK 23.5gr TAC, LC Brass and BR4 Primers.
I would start your load development at 23gr of TAC and work up 24gr it will be in that window, most Likely 23.5, 23.7 or 23.9
Here is the DOPE for my Pet Load out of the Geissele 18" SPR barrel.
The final Load is 24.3gr Tac / 77gr SMK / Starline Brass / BR4 Primers.
Good speed out of that load and single digit SD’s is just icing on the cake. Nice work
I’ve been waiting to see how those loads performed in hot weather, I was battling some serious Mirage so I'm going to load up another hundred of that 24.3 and go out early in the morning so my targets aren't dancing around in a mirage.
Yesterday was our first 90° day and my concern was that the TAC not being as temp stable would show pressure spikes at the 24.5gr mark and it did.
I'm still going to do some testing with XBR, with the 73's and 77's when I start load development for the Geissele Heavy Contour Chromed lined barrels.
Here is the data for the 24.5grs of TAC, just broke the 2900fps barrier but starting getting ejector swipes.
Those are definitely impressive numbers, if you look in the other thread I just Updated with a 22 ARC Build (The Green Goblin) the 20" 22 ARC barrel is pushing the 75gr ELD's around 2950fps.
The Geissele 18" SPR Cut Barrel is definitely among the fastest .224 Cal Barrels I own. Looking forward to the results of the 73gr Bergers and ELD's.
24.2-24.4 gr TAC pushing a 77 smk has been money in all my rifles. They all share 24.4, LC brass, cci #41 with 77 SMK’s and all shoot that load extremely well in 40-95* weather.
Those speeds though are crazy! My 20” barrels only run 2750
Those speeds though are crazy! My 20” barrels only run 2750
That Geissele 18" SPR barrel is definitely my fastest 5.56 barrel.
I'm not sure if you have any IMR 8208 on hand, but that powder with Berger 73's is the best shooting combo I've ever tried on both of my primary 5.56 AR's.
What are you running for that load? It's always printed well with 77 SMKs for me and been 50-75fps faster than Varget.
XBR is the best powder I have used for the 77gr SMK. 24gr is what I have used. Recently got some 73gr ELDM and the 24.5 load has been shooting well.
In the south I don’t see those temps enough to test it honestly. Sorry
That's warm! I usually start getting some light ejector marks around 23.8.
It's good it's been so available. They charge as if it's actually wrapped in gold haha.
Yes, it is on the warm side, especially if ambient temps get hot. I've used 8208 for quite a few years & have a good stock & I am 23.4-23.6 across numerous rifles.
24 gr is a bridge too far IMHO.
MM
Ive got a bunch, just haven't had a chance to conduct Load Development with the 73's
The powder charge I use varies based on the brass I use. Initially with Lake City brass, I was using 23.7 grains with the Berger 73's set at 2.252". I have since switched to Starline 5.56 brass which seems to have slightly less case capacity, so I have adjusted to 23.3 grains. I actually measure case capacity using water on one of those fancy fx120 scales, it has really helped take some mystery out of reloading for me. Basically, I am looking for somewhere between 2,650-2690 FPS, no matter what brass I use
I get an average of 2,680 FPS from a 16" barrel.
I use Gordon's reloading tool on my computer to help with load development, I believe pressure is right around 54k - 55,000 psi, which makes it a heavy 223 or light 5.56 load. Brass life has been outstanding, primer pockets remain good and tight after several reloadings, I haven't lost a single case yet, but I do anneal regularly.
This load absolutely hammers in both of my primary AR's, gives good velocity, good standard deviation, I really couldn't ask for anything more.
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I’ve had really good luck with XBR8208 and the 73gr Bergers. 23.2-23.4 has always been the sweet spot for a load that shoots good across all my 5.56/223wylde rifles using the 73 Berger, 77SMK, and 77TMK.
I must always get lots of powder that run hot because I’ve never been able to get above 23.8gr with XBR without swipes and flat primers. Seeing these 24-24.5 gr loads that aren’t blowing primers makes me scratch my head. I’m glad it’s working for people though.
I must always get lots of powder that run hot because I’ve never been able to get above 23.8gr with XBR without swipes and flat primers. Seeing these 24-24.5 gr loads that aren’t blowing primers makes me scratch my head. I’m glad it’s working for people though.
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