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.
Super promising results! We really are in a time where there are a lot of really good barrel options without having to spend $1000 on a custom barrel. All the JP supermatch 5.56 and .223 chamber barrels I've had shoot really well and this seems like it's another one to add to the "easy button".
Random thoughts......first I'm often caught off guard how good groups for .223/.224 etc. measure when looking at them. I often shoot a group under 1 MOA and think it doesn't look very good just because of the "spread" that's allowed due to the small bullet until measured.
Second.....why are so many of these barrels 1:7? and not 1:8? I've heard in the past that the military does it to handle tracers, but from what I could find out tracers are usually 62-64 grain. I don't have as much experience as others but all of the 1:8 barrels I've had shot 69-77 grain rounds really well, but would still perform very well with 55-62 grain rounds (within the limits of the ammo of course). Meanwhile almost every 1:7 barrel I've had was basically worthless with 55-62gr rounds. You'd think the military would rather have a barrel that shot better with their standard issue ammo, and their specialty heavier ammo, rather than horrible with their standard issue ammo. Then again from what I've heard their 4 MOA standard leaves a lot of wiggle room.
The vast majority of gun owners are almost certainly buying 55-62gr ammo, not too many of us are spending $25-$30 a box on match .223/5.56 ammo or reloading for it. Though I suppose a case could be made that most guys shooting AR's at the range I see are running 0x red dots and happy if they put rounds on a 10" pie plate at 100 yards.
Random thoughts......first I'm often caught off guard how good groups for .223/.224 etc. measure when looking at them. I often shoot a group under 1 MOA and think it doesn't look very good just because of the "spread" that's allowed due to the small bullet until measured.
Second.....why are so many of these barrels 1:7? and not 1:8? I've heard in the past that the military does it to handle tracers, but from what I could find out tracers are usually 62-64 grain. I don't have as much experience as others but all of the 1:8 barrels I've had shot 69-77 grain rounds really well, but would still perform very well with 55-62 grain rounds (within the limits of the ammo of course). Meanwhile almost every 1:7 barrel I've had was basically worthless with 55-62gr rounds. You'd think the military would rather have a barrel that shot better with their standard issue ammo, and their specialty heavier ammo, rather than horrible with their standard issue ammo. Then again from what I've heard their 4 MOA standard leaves a lot of wiggle room.
The vast majority of gun owners are almost certainly buying 55-62gr ammo, not too many of us are spending $25-$30 a box on match .223/5.56 ammo or reloading for it. Though I suppose a case could be made that most guys shooting AR's at the range I see are running 0x red dots and happy if they put rounds on a 10" pie plate at 100 yards.
Same. I've shot a lot of groups where 3-4 of them look great and the 1-2 outliers make me think it's a trash group. Then I'm pleasantly surprised when it's still a .8" group.
I think 7 twist originally caught on because "mil-spec bro!" and then hung around because the general consensus is that faster twist is needed for heavier bullets and heavier bullets tend to be match bullets that are more accurate. So people took that to mean faster twist=better accuracy.
Obviously it's not quite that simple, but given how retarded most people on arfcom or reddit are it's no wonder that this stuff is so prevalent.
Not saying 7 twist is bad, but given the bullet weights you can fit in an AR mag in 223/5.56 I find 7 twist to have no advantages and potential for some disadvantages.
Just a little secret here, Craddock barrels may be labeled 1-7 but most of his barrels actually have a gain twist in them. My personal favorite is a 1-7.7 Twist with a wylde Chamber.
Just not sure what all of you have against the 7 twist. They have always worked fine for me. From 77 SMKs at 2700 to 69 TMKs at 3000 to 85.5 Bergers at 3400 a 22cal through a 7 twist has been a winner.
1:7 is great for heavies, as long as that's all you want to shoot out of them. However if you want better groupings with 55-62gr ammo that's more plentiful and cheaper there's a significant downside to them. There are exceptions of course, I've had a couple 1:7 JP 5.56 barrels that did pretty well with 62gr rounds, but overall most shoot them pretty poorly. Much worse than 1:8's do and 1:8's seem to still do very well with 69-77gr match ammo.
I suspect that we'd see a ton less posts about accuracy complaints with AR barrels if they were 1:8 instead of 1:7's for the general market. A lot of general buyers of AR's, outside the precision world, would probably rather have a barrel that shot better with the lighter ammo they are most often buying. Almost every forum for such platforms is filled with posts of people complaining about poor accuracy, only to later learn that they are forced into buying heavy match ammo to get accuracy because of the 1:7 barrels, and then their complaints change to that what they really want is a barrel that performs better with the lighter, cheaper more common 55-62gr ammo.
I totally see the use case and market for special use case precision orientated AR that are limited to only performing well with heavies but I'd still argue that for general use and the average consumer they'd be happier and better served with a barrel that shot 55-62gr ammo better, especially in lighter, non-precision setups. It just seems like the 1:7 barrels give up way more shooting lighter rounds than the 1:8's do shooting heavier rounds. Especially since at some point you run into mag length issues. I suppose that's really a consumer education issue, those looking for platforms that do well with lighter 55-62gr ammo should simply avoid options that are 1:7.
I suspect that we'd see a ton less posts about accuracy complaints with AR barrels if they were 1:8 instead of 1:7's for the general market. A lot of general buyers of AR's, outside the precision world, would probably rather have a barrel that shot better with the lighter ammo they are most often buying. Almost every forum for such platforms is filled with posts of people complaining about poor accuracy, only to later learn that they are forced into buying heavy match ammo to get accuracy because of the 1:7 barrels, and then their complaints change to that what they really want is a barrel that performs better with the lighter, cheaper more common 55-62gr ammo.
I totally see the use case and market for special use case precision orientated AR that are limited to only performing well with heavies but I'd still argue that for general use and the average consumer they'd be happier and better served with a barrel that shot 55-62gr ammo better, especially in lighter, non-precision setups. It just seems like the 1:7 barrels give up way more shooting lighter rounds than the 1:8's do shooting heavier rounds. Especially since at some point you run into mag length issues. I suppose that's really a consumer education issue, those looking for platforms that do well with lighter 55-62gr ammo should simply avoid options that are 1:7.
That's exactly what mine is, 1:7.7 gain twist 223 Wylde. I hope I never shoot this thing out, it is the most accurate AR barrel I've ever had, Bartlein barrel from Craddock
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I haven't seen much difference with cheap 55 - 62 grain ammo when shot with a 1:7 vs. 1:9 twist.
I've shot a lot of this ammo through many different AR barrels, I'm sure other people have as well, everyone's experience is different I'm sure. That said, I believe the rate of twist is the least impactful on dispersion when shooting bulk milspec 55-62 grain ammo. The bullets simply aren't designed for precision, with a large sample size, I'm always somewhere between 2-3 in at 100 yards. Occasionally, the groups are smaller, but just as often, they are larger
Molon did a good test years ago:
https://www.ar15.com/forums/ar-15/A..._9__Twist_and_1_7__Twist_Barrels_/118-687753/
That's certainly a huge factor, most 55-62gr ammo is not going to be near a quality level that is going to really get to tiny groups in any barrel. My sample sizes are not that large, and groups with 55-62gr ammo are never great, aside on a fluke, and I agree that even with a 1:8 barrel I'm unlikely to see many groups under 2" with it and most fall in that 2-3" range. However at least for the 1:7's I've shot that same ammo often spreads out another 1-2" while I see almost no obvious difference in how they shoot heavier match ammo. Perhaps that would be different if I was pushing rounds heavier than 77gr, or reloading etc.
Could always be worse, my MCX was 1:7 and it wouldn't shoot anything under 3-3.5" and that was with match 69-77gr ammo, it was lucky to keep rounds on an 8" paper plate at 100 yards. Not to mention that's with a barrel Sig charges $900 for
Could always be worse, my MCX was 1:7 and it wouldn't shoot anything under 3-3.5" and that was with match 69-77gr ammo, it was lucky to keep rounds on an 8" paper plate at 100 yards. Not to mention that's with a barrel Sig charges $900 for
Reality is that I do not expect a 55 gr to group like a 69-77gr. If I am shooting 55s it is in blaster mode and if I can hit a 3”-4” plate out to 100yrd then it is plenty accurate. It I want accuracy I shoot longer bullets. That us why I tend to use 7 twist although I do have two 8 twist barrels that do fine up to 77, but are very happy with 69TMKs.
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