22GT load data
- Thread starter Krob95
- Start date
I built the 22GT in Gordon’s. Working out of town this week so can’t run your specific loads.
I have run close though in coarse testing just to get some speed baselines.
24” PVA 7T
Loads below are all under 100 rounds on barrel with virgin Alpha brass GM205 primers & loaded 2.522 OAL or .023 jump.
H4350 36.1 with 90smk = 3052 case fill 89.7
N555 36.5 90smk = 3012 Case fill 96.6
N555 37.7 90smk = 3097 case fill 99.7
Few more data points for powder comparison. Same as above except powder.
RL16 36.1 90smk = 3022 fill 98.7%
6.5 Staball 37.6 = 3026 fill 93.5%
6.5 Staball 38.0 = 3047 fill 94.5%
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I can say those speeds are slow. But my barrel is sped up. With 36.3rd 4350 I’m getting 3260 with 90 smks and 37gr n555 I’m getting 3150. That’s why I’m curious to see what kind of pressure I’m dealing with as n555 at 37gr is giving me a click on primary extraction and cratered primers but no hard bolt lift and 36.3gr of h4350 is giving me pretty gnarly cratered primers and no click and no hard bolt lift.
Ambient air temp was 48degrees. This is all out of a 218 bore 26” bartlein barrel.
To add, 88’s with 38gr of n555 on a brand new barrel was getting me 3150. They run the same speed as the 90’s for me.
Ambient air temp was 48degrees. This is all out of a 218 bore 26” bartlein barrel.
To add, 88’s with 38gr of n555 on a brand new barrel was getting me 3150. They run the same speed as the 90’s for me.
N555 37.4 with 88’s Gave me 3079 on this new 24”
None of those loads gave me any craters or pressure signs.
Any chance your getting some carbon build up in the throat?
I ran up to 37.9gr H4350 in initial testing with 90 atips, had about 150 Rds on the 26" hawkhill, origin action. I never found ejector slot marks or primer cratering till 3240, and found bolt lift at 3270. My barrel is a 219 bore 7tw, I think that keeps the psi down VS a 218 bore. My accuracy load is 36.4 H4350 with 90s running 3120-3130
Mine is on a Tika PVA nutted barrel. The Tika doesn’t hide pressure like my ARC actions. Not sure what the bore is on the PVA’s? Based on my previous PVA’s I’d expect it will speed up 50-100fps. I just ran another 100 through it fire forming with 88’s & Staball. Ready to do some load testing now that I have 200 rounds through it. Brass is prepped, but working out of town every week is slowing progress.
I know the new PVA Osprey 22 Cals are advertised 219 bore. However my Smith gauged the one I used for a 22cm, and 219 wouldn't go, but 218 was a bit sloppy, so they're likely somewhere in between, closer to 0.2187 or so.
How have carbon rings been with the 22GT? I’ve really had to stay on top of them with certain powders in my 6GT and 6 Creedmoors.
I clean with clr/iosso every 150 rounds or so, no carbon problems with that regemin.
Lets put it this way, they definitely form faster with 22GT for sure. One of the first things I noticed with 22GT and even 22BR. A borescope is a great tool to identify the carbon ring. You gotta keep an eye out for it and stay on top of it vs many other calibers thats for sure....
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I do have a bore scope and will keep up with it. Just trying to get a rough round count of when that might be? I know that it is powder dependent as well.
Could a guy take it to a two day match and not have issues? That’s possibly 230 or so shots with zero and long distance verification.
I'd honestly give it a clr treatment between day 1 and day 2. Clr has given me the best results fastest for breakdown of carbon. Run 3 - 4 wet patches with scrubbing motion. The use one wet patch pressed into the throat area to soak it for 30 mins, then hit with nylon brush, then 3-4 wet patches of your normal cleaning solution like eliminator, followed by dry patches and shoot. Should be good for a 2nd day. Carbon rings are a bitch.
I know my 6mm prs rifles shoot more consistently rounds 1-150 than they do 150-300 after a cleaning. Resetting to clean barrel between day 1 and 2, then shooting 10 fouling rounds morning of day 2 has been my process for the handful of 2 day matches I've shot. Single day match the barrel usually has 20 rounds on it from zero/dope check. This works for me, but cleaning every 3-400 works for others. I just know my velocity creeps up about 10-20fps from 0-150 rounds, and at 300 is up about 40 from fouling when I tested it with my 6gt/109/h4350 load last year that was at 2920, after 300 rounds I was up around 2960 and groups had opened up at distance from half to near 1 moa. The 22 would would only be worse. I'm building a 22br for a practice rig to run 88s and 90smk at 2950-3000fps from a 28" barrel. Hopefully I can find a powder that keeps fouling low. Varget/4166/N150/rl15.5 are what I will test.
Does anyone run IMR 4955 Enduron powder in their 22 GT? It’s a little slower burning than H4831.
I believe hodgdon recently discontinued the entire enduron line of powders, so unless you have a large stash of it you need to burn up that's kind of a dead end.
I have 9 pounds of it. Just wondering if anyone has used it for the heavies.
I heard an interview somewhere that the Enduron lines are discontinued for consumer sales. It should be back later if they get caught up with contracts. Sorta like how Lapua is only releasing certain brass calibers for the time being. Seems the whole world is gearing up for war.
Interesting, as a lot of the dealers are saying it's straight up discontinued and not on a temporary production pause like Lapua is doing right now. I also find it odd they would discontinue some of their newest tech powders, however the enduron line never seemed to gain much popularity in the US consumer reloading market.
I never got around to trying any of the enduron powders myself.
I'll try to remember to run some QL numbers tonight with 4955 and see what it shows; maybe it would be worth testing.
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I don’t remember where I heard that but I hope it’s true. If not when my stock pile of Enduron powders are gone there gone for good.
Not sure what bullet you're planning on running, but here's what QL is estimating for 4955 with a 90gr VLD loaded to 2.6" OAL.
For something lighter, here's data for a Hornady 80 ELD-M loaded to 2.500" OAL:
Note: I don't have my 22GT brass yet (it should be here tomorrow) so I'm using 44.90gr for case capacity which a few other people have measured.
QL's powder test table estimates that 4955 isn't the fastest powder for the 22GT, but it has a good case fill vs pressure relationship and the case won't be too empty if you load conservatively under max pressure nor excessively compressed if you load near max pressure. If you have 9# of 4955 left and aren't worried about chasing max velocity I'd load some up for testing.
Interesting. The three bullets I have on hand are 85.5 Bergers, 88 ELDMs and 90 SMKs. I would like to run in the 3050-3150 range to get the most KE on targets at distance.
Based on the QL numbers 3100-3150 is going to be pushing right at max or over max pressure with 4955 and 85-90gr bullets. It's possible, but environmental conditions and barrel cleanliness might push it above 65ksi max pressure.
IMO, a lot of people are loading way too hot nowadays especially when using brass like Lapua and Alpha that can take the high pressures and not exhibit obvious pressure signs like a sticky bolt open or flattened/smeared writing on the case head or ejector flow/swipes-- so they keep bumping charges up thinking the load is safe when it's likely already at or over SAAMI max pressure.
It's not just a 22GT thing, I've noticed the trend with many other calibers. I guess it depends on how much you want to push the envelope and how many firings you want out of your brass. If you have a spot where you can shoot the same place as you load and want to test brass longevity on a "hot" load, I like to load/fire/repeat a single case at that hot charge until the primer pocket gets loose and note now many firings it took.
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I’m with you on that. Dashers pushing 3000 FPS come to mind. My ARC actions have a flat face and mechanical ejector. Couple that with 450s, Lapua or Alpha OCD brass and you can be over 70,000 PSI without any signs of trouble.
I use a similar program, GRT, and try make sure I stay below pressures and run at a OBT node. Sadly the guy behind GRT died. It doesn’t have 4955 or the 22GT in the program. I am working on building the cartridge in there, but don’t know enough about it to “build” a powder.
Thank you for running the numbers in QL, I really appreciate it. I was curious about the 4955 since a lot of guys are using RL23 and RL26. Out of curiosity is 4955 too slow burning or too bulky for the fast speeds? Edit, I see from your files it’s too bulky.
Once I get my CDG action in I can start playing with GRT and the powders I have. I’ll have actual numbers for case volume and speeds from my barrel it should go fairly smoothly.
Thanks again.
I use a similar program, GRT, and try make sure I stay below pressures and run at a OBT node. Sadly the guy behind GRT died. It doesn’t have 4955 or the 22GT in the program. I am working on building the cartridge in there, but don’t know enough about it to “build” a powder.
Thank you for running the numbers in QL, I really appreciate it. I was curious about the 4955 since a lot of guys are using RL23 and RL26. Out of curiosity is 4955 too slow burning or too bulky for the fast speeds? Edit, I see from your files it’s too bulky.
Once I get my CDG action in I can start playing with GRT and the powders I have. I’ll have actual numbers for case volume and speeds from my barrel it should go fairly smoothly.
Thanks again.
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That is good data. Do you have a QL run for H4350, 88ELDMs and Alpha 22GT brass? I’m curious how the 35gr load looks.
The burn rate of 4955 looks too slow to achieve max velocity with the 85-90s, it hits max pressure at a slower velocity and isn't burning fully compared to more ideal powders like RL16 or RL26 which will produce higher velocities at the same pressure because the powder burn rate is different and better suited to the heavy for caliber bullets. It's just not a matter of case fill, 4955 will likely be at or above max pressure with a mildly compressed load (106% fill) but still be below your 3100-3150 target velocity.
I can run that today when I get home, but I'm not sure my version of QL has the 88ELD-M in the library so I might need some dimensions from you like bullet length, boat tail length, and base diameter, along with your desired loaded OAL. I know the latest updates for QL have the berger 85.5 and hornady 88 ELDM included but I haven't purchased this year's QL update yet as I'm waiting for them to add staball match and staball HD to the powder library. It's easy to add bullets on my own; powder data, not so much...
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It's a burn rate and pressure curve issue, not just fill. Fill is more of a guideline; you don't want to use a powder that leaves the case too empty as it might have inconsistent ignition, nor do you want a powder that's so compressed it results in inconsistent seating depths, and crunching the crap out of the powder with a heavily compressed load can break it down into smaller pieces which will alter the surface area of the kernels and can change the burn rate characteristics which can result in weird pressure spikes or increased SD/ES.
For instance, from the tables above 38.16gr of 4955 is 102% fill, yields 59.4ksi pressure and 3072 fps, and it isn't fully burned by the time the bullet leaves the barrel. Even if you altered the density of 4955 to make it more dense per grain (so you could physically pack more in the case) but maintained the same burn characteristics and overall energy content per grain of powder you still couldn't safely put more in the case to reach a higher velocity because it would be at max pressure; the burn characteristics of 4955 just aren't ideal for that case and bullet combo, it hits max pressure before achieving your targeted velocity.
On the other hand, if you use RL16 and adjust the charge to the same 59.4ksi target pressure it takes 35.76gr of RL16 which is 95.8% fill but QL comes back with 3158fps.
4955 is slower than RL16 based on Hodgdon's burn rate chart (RL16 is #129, while 4955 is #145.) Based on the QL data the 4955 burn characteristics aren't ideal for the 22GT even with 90s, so even with a near max pressure load of 4955 the estimated velocity is slower than the more ideal powders at the same or even lower pressures.
Oddly enough, at the same target pressure of 59.4ksi QL estimates the fastest powder for 90s in the 22GT would be RL26; using 41.6gr which is a 101% fill it's estimating 3250fps at the same 59.4ksi pressure as 4955 and RL16 above. What's kind of odd is RL26 is even slower on the burn rate chart than 4955 (RL26 is #157) but obviously the burn and pressure characteristics are different as the estimated velocity with RL26 is much higher. RL26 really seems to be the speed king in many loads that use heavy for caliber bullets, provided there's enough case capacity for it.
QL allows you to quickly "test" a bunch of powders in your case/bullet combo by specifying a target pressure and max fill percentage and it returns results sorted in order of velocity. I usually like to have it run that powder database test around 52.5ksi and 105% max fill. I haven't messed with Gordon's reloading tool but I'm guessing it would have a similar feature.
As mentioned earlier I don't have the dimensions for the 88 ELDM, but here's what QL shows for a 90 VLD @ 2.6" with H4350 in a 26" barrel which should be close...
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4451 is more in line for the creed, but 4955 is similar to H4831sc so that'd be a good choice for the 270 I'd think.
I have a good assortment to choose from. 4166, 4451, 4955, RL 15.5, 16, 23, 26, Varget, H4350, StaBall 6.5 and some others I'm surely forgetting. Yes, I have a problem. LOL
If anyone wants to build 22GT in GRT, this may help.
Start with 6GT in the cartridge builder & then modify with the dimensions shown here.
I used the GA precision reamer print with .169 free bore. Alpha brass. Seven twist, & .219 bore with 6 groove.
Check h2o of a once fired case, & adjust if it's a little off.
I tried to figure out how to export the file, but it must be a bug. If I save it & then try to open it gives an error???
This has been giving me pretty close estimates for the 5 powders I've tried.
Start with 6GT in the cartridge builder & then modify with the dimensions shown here.
I used the GA precision reamer print with .169 free bore. Alpha brass. Seven twist, & .219 bore with 6 groove.
Check h2o of a once fired case, & adjust if it's a little off.
I tried to figure out how to export the file, but it must be a bug. If I save it & then try to open it gives an error???
This has been giving me pretty close estimates for the 5 powders I've tried.
Rl23 works well in 22gt I'm told. I have all those powders as well, but started with H4350 and it shot lights out, never ventured away from it since I have near 50#. The gt cases just shoot! Love my 22 and 6.
I haven’t loaded anything for the 6GT in Alpha brass yet, still cycling through a few hundred Hornady cases. Been using 44.85 on those. To be honest though I can’t remember if I measured h2o on the Hornady GT brass. It was so easy to find loads for I’ve just rolled with it.
Measuring some 308 h2o today so I’ll throw 1 or 2 Hornady 6 GT in the mix.
I measured 44.6gr of water on fired alpha 6gt on my adi scale. Believe it was the first run of ocd. Before the OCD it held a bit more. I have 2 newer lots of OCD and the case weights are progressively a grain heavier from my original ocd lot, believe lot 1 was 141 avg, then newer 142, and newest from this last month is 143.
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Barrel life update:
Started shedding jackets with 1250 rounds on it 2 weeks ago. Confirmed with both 90SMK and Berger 85.5 LRHT. She gone.
Bore scope showed significant carbon retention around the shoulder/neck junction and into the leade.
Ran some Iosso patches through it and it unsurprisingly revealed some of the worst carnage I’ve ever seen. There were essentially no lands left in the throat, jagged edges where the lands remained in tact, and had significant fire cracking present 6-8” beyond the chamber. When I say it was torched it was TORCHED.
Interestingly enough, it shot well right up to that point. But once it started going, it fell off a cliff.
Notes of interest:
- Brux 28” - 1:6.5 twist - .218 bore diameter
- steady diet of 3120-3150fps over the life of the barrel
- adjusted the load after cleaning to see if slower speeds would keep the jackets together with no such luck
I would say a variety of factors contributed to this barrel being pretty short-lived. Between the speeds/firing intervals, twist rate, bore size, etc. I’m somewhat surprised it lasted as long as it did. That said, I have no idea how guys are getting 2k plus out of these things shooting anywhere near normal speeds. I just don’t see it.
Haven’t decided if I’m going to replace it and keep going or sell off the components and go a different direction. I would change a number of factors if I were to do it over again.
Started shedding jackets with 1250 rounds on it 2 weeks ago. Confirmed with both 90SMK and Berger 85.5 LRHT. She gone.
Bore scope showed significant carbon retention around the shoulder/neck junction and into the leade.
Ran some Iosso patches through it and it unsurprisingly revealed some of the worst carnage I’ve ever seen. There were essentially no lands left in the throat, jagged edges where the lands remained in tact, and had significant fire cracking present 6-8” beyond the chamber. When I say it was torched it was TORCHED.
Interestingly enough, it shot well right up to that point. But once it started going, it fell off a cliff.
Notes of interest:
- Brux 28” - 1:6.5 twist - .218 bore diameter
- steady diet of 3120-3150fps over the life of the barrel
- adjusted the load after cleaning to see if slower speeds would keep the jackets together with no such luck
I would say a variety of factors contributed to this barrel being pretty short-lived. Between the speeds/firing intervals, twist rate, bore size, etc. I’m somewhat surprised it lasted as long as it did. That said, I have no idea how guys are getting 2k plus out of these things shooting anywhere near normal speeds. I just don’t see it.
Haven’t decided if I’m going to replace it and keep going or sell off the components and go a different direction. I would change a number of factors if I were to do it over again.
In short:
- .219 bore diameter
- 1:7 twist at a minimum, preferably 7.5 or even 8
- use 4831 or something with a slower burn rate than 4350… temper velocity without sacrificing case fill
- don’t chase speed, stay in the 3k fps +/- range
- don’t expect great barrel life out of massively overbore cartridges
I've got 1100 on mine and it's definitely got some fire cracking and throat erosion. It's a 219 bore 7tw, haven't had any bullet failures yet. Still prints small groups. I had a 28" 22br barrel spun, will see how it compares velocity wise. I'm already seeing pretty good accuracy with break in loads just seating depth testing. When this 22gt is toast, likely only have 3 firings on the brass, likely will build a varmint rifle with maybe 120k freebore for 75-80gr bullets to use the brass up.
