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22GT load data
- Thread starter Krob95
- Start date
Looks like I may skip the 4350 and go to n550 for this next barrel. I pick it up on Saturday and will probably do a 27" finish length as well.
Any temperature sensitivity noticed with the N550 type powder you’re using?
Are you running suppressed by chance?
I noticed some temp sensitivity with N550. I just kept my ammo in a cooler so it did not bake in the sun. I have since gone to N555. Have to run a little bit more powder but no temp issues.
Took my match gun up to Jon Beanland of Beanland Custom Rifles to have my M24 contour Osprey Barrel Works barrel blank fitted. Jon does absolutely 1st class work and having used several ‘smiths over the years, I’m convinced there is no one that does better.
Anyway, Jon had good things to say about the Osprey barrel. Said it was super straight, so much so that there was no need to index the curve, because there just wasn’t any. Also said the groove depth was very uniform. He thought the barrel was a bit harder than most, judging by how many plunges he made with the reemer. He cut the chamber with an Alpha Munitions reemer, and the chamber was a thing of beauty. I had him finish the barrel at 20” for suppressor use.
Loaded a few round of ammo Friday night so I could shoot it yesterday. Used virgin Alpha brass, CCI 450s, H4350, and 88gr ELD-Ms. Loaded five rounds at 33.6gr to zero, and one round each of 34, 34.4, 34.8, 35.2, 35.6, and 36 to try and find max pressure. No case prep on the virgin brass, just deburring and chamfering. Used an RCBS Matchmaster 6mm GT seating die. Runout at the ogive went anywhere from .001” to .006”. I’m not satisfied with anything more than .002” runout, but with virgin brass, it’s not uncommon. I’m confident I’ll get much straighter ammo after I’ve fireformed the brass.
I’m using Magpul AICS patterned magazines and I ran five rounds through to check feeding. Feeding was flawless.
The thing that impressed me the most was how close the first round out of the barrel hit to the zero from the previous barrel (Bartlein 6.5 Creedmoor). Without even a boresight, the first round hit on the left edge of the bullseye, only 1/2 mil from the previous zero. I made an adjustment and shot the next four of the 33.6gr charge. They went into about .6” with 3 of the four being in the .2s. Made another adjustment and shot the last six in the pressure series. They are the ones on the left side of the bullseye. For six rounds with six different powder charges, from 34 to 36gr, I thought this wasn’t too bad. The high shot was the last one, 36gr. Based on how well 34 - 35.6gr grouped, I’m pretty sure I could pick from 34.8 to 35.2gr and run with it. Saw no excess pressure signs from any of the charges. Bolt lift was good, no ejector marks, and primers were nice and round.
Last night, I measured some of the fired brass. When checking runout at the neck, I struggled to see any needle movement on the fired brass, indicating a very concentric chamber. Using a headspace comparator, the brass grew less than .001” on firing. I was able to slide bullets into the necks of the fired brass with my fingers but there was some resistance, indicating it’s a fairly tight necked chamber. I ran a couple of the fired brass through the Matchmaster sizing die with a .249” bushing and bumped the shoulders about .0005”. Runout at the neck on the sized cases was well under .001”.
Finally, I loaded five more rounds from 36.4 to 38gr to continue finding my max charge. Once I determine that, I’ll continue load development in ernest, but I think it’s going to shoot…
What are you guys finding to be your max charge using Alpha brass, 88gr ELD-Ms, and H4350?
What is the max velocity I should expect from H4350 and 88gr ELD-Ms from a 20” barrel?
With a .169 freebore chamber, what is your base-to-ogive when kissing the lands with the 88gr ELD-M?
Thanks,
John
Anyway, Jon had good things to say about the Osprey barrel. Said it was super straight, so much so that there was no need to index the curve, because there just wasn’t any. Also said the groove depth was very uniform. He thought the barrel was a bit harder than most, judging by how many plunges he made with the reemer. He cut the chamber with an Alpha Munitions reemer, and the chamber was a thing of beauty. I had him finish the barrel at 20” for suppressor use.
Loaded a few round of ammo Friday night so I could shoot it yesterday. Used virgin Alpha brass, CCI 450s, H4350, and 88gr ELD-Ms. Loaded five rounds at 33.6gr to zero, and one round each of 34, 34.4, 34.8, 35.2, 35.6, and 36 to try and find max pressure. No case prep on the virgin brass, just deburring and chamfering. Used an RCBS Matchmaster 6mm GT seating die. Runout at the ogive went anywhere from .001” to .006”. I’m not satisfied with anything more than .002” runout, but with virgin brass, it’s not uncommon. I’m confident I’ll get much straighter ammo after I’ve fireformed the brass.
I’m using Magpul AICS patterned magazines and I ran five rounds through to check feeding. Feeding was flawless.
The thing that impressed me the most was how close the first round out of the barrel hit to the zero from the previous barrel (Bartlein 6.5 Creedmoor). Without even a boresight, the first round hit on the left edge of the bullseye, only 1/2 mil from the previous zero. I made an adjustment and shot the next four of the 33.6gr charge. They went into about .6” with 3 of the four being in the .2s. Made another adjustment and shot the last six in the pressure series. They are the ones on the left side of the bullseye. For six rounds with six different powder charges, from 34 to 36gr, I thought this wasn’t too bad. The high shot was the last one, 36gr. Based on how well 34 - 35.6gr grouped, I’m pretty sure I could pick from 34.8 to 35.2gr and run with it. Saw no excess pressure signs from any of the charges. Bolt lift was good, no ejector marks, and primers were nice and round.
Last night, I measured some of the fired brass. When checking runout at the neck, I struggled to see any needle movement on the fired brass, indicating a very concentric chamber. Using a headspace comparator, the brass grew less than .001” on firing. I was able to slide bullets into the necks of the fired brass with my fingers but there was some resistance, indicating it’s a fairly tight necked chamber. I ran a couple of the fired brass through the Matchmaster sizing die with a .249” bushing and bumped the shoulders about .0005”. Runout at the neck on the sized cases was well under .001”.
Finally, I loaded five more rounds from 36.4 to 38gr to continue finding my max charge. Once I determine that, I’ll continue load development in ernest, but I think it’s going to shoot…
What are you guys finding to be your max charge using Alpha brass, 88gr ELD-Ms, and H4350?
What is the max velocity I should expect from H4350 and 88gr ELD-Ms from a 20” barrel?
With a .169 freebore chamber, what is your base-to-ogive when kissing the lands with the 88gr ELD-M?
Thanks,
John
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34.8 - 35.2gr 4350 has been the sweet spot for me as well with 85.5gr LRHTs.
I can pretty much load the min-max in that range and have spreads no worse than 20fps. Haven’t felt the need to go higher than that as it’s already very close to speed limits from a 28” barrel.
I can pretty much load the min-max in that range and have spreads no worse than 20fps. Haven’t felt the need to go higher than that as it’s already very close to speed limits from a 28” barrel.
@Hondo64d I ran up to 37.4gr H4350 with 90 atips(same velocity as 88s w/ same charge) was running 3235 for two shots from a 26" M24 hawkhill 219 bore 7tw(similar config as your Osprey) the action is a bighorn so I did see minor ejector cut imprints on case head, I've found this common with several thousand rounds on the zermatt actions. No bolt lift observed. I'd think I could run warmer but don't see the point. I ended up running 35.8gr right at 3100fps.
So here's my question....
I have been looking at the hogdon data and they are saying that the 22GT with an 88gr ELDM has a max charge of 33.6gr @ 62K PSI.
Most people I know, including myself, are running upper 34's to 35 almost 36 grains.
If hogdon load data is getting almost 3000 FPS with 33.6gr of 4350 in a 24", could you assume they are using a .218" bore barrel? I'm at 3150 with 35.8gr of powder.
The reason I ask, is if they are saying 33.6gr is 62K PSI, 35.8gr has to be pushing the limits of where I would want to be pressure wise, theoretically anyway.
Last time I went shooting with virgin brass, I was getting heavy bolt lift and brass peeling from the ejector. Bad pressure... The stuff that had been shot before exhibited much less of this, but still did it intermittently. Terminus Zeus Action - Osprey barrel
I scoped the barrel when I got home and found a heavy build up of carbon in the first 8 or so inches of the barrel. (About 400 rounds on barrel) I guess my light cleaning after shooting wasn't doing enough. I cleaned it out good, but haven't shot it to see if it will solve my pressure issues.
Probably going to back my load down around 35gr to see if I can find something a little further away from pressure, just in case I have to shoot in the rain or start getting a hot barrel/hot ammo. In all reality, it doesn't make a huge difference in wind holds to drop some velocity, but every advantage does help.
I have been looking at the hogdon data and they are saying that the 22GT with an 88gr ELDM has a max charge of 33.6gr @ 62K PSI.
Most people I know, including myself, are running upper 34's to 35 almost 36 grains.
If hogdon load data is getting almost 3000 FPS with 33.6gr of 4350 in a 24", could you assume they are using a .218" bore barrel? I'm at 3150 with 35.8gr of powder.
The reason I ask, is if they are saying 33.6gr is 62K PSI, 35.8gr has to be pushing the limits of where I would want to be pressure wise, theoretically anyway.
Last time I went shooting with virgin brass, I was getting heavy bolt lift and brass peeling from the ejector. Bad pressure... The stuff that had been shot before exhibited much less of this, but still did it intermittently. Terminus Zeus Action - Osprey barrel
I scoped the barrel when I got home and found a heavy build up of carbon in the first 8 or so inches of the barrel. (About 400 rounds on barrel) I guess my light cleaning after shooting wasn't doing enough. I cleaned it out good, but haven't shot it to see if it will solve my pressure issues.
Probably going to back my load down around 35gr to see if I can find something a little further away from pressure, just in case I have to shoot in the rain or start getting a hot barrel/hot ammo. In all reality, it doesn't make a huge difference in wind holds to drop some velocity, but every advantage does help.
I would like to know what bore Hodson is using. I am loading 35.6 grains and the 88 grain Hornady bullets. No pressure signs in alpha brass h4350 powder .219 bore
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Man I'm running 3100fps with 90s and 35.8gr H4350. I went all the way up to 37.5gr before seeing any ejector marks on alpha brass. Im using a 219 bore hawkhill barrel. According to Hodgdon numbers, I'm bout to launch my bolt into my face.
This is really pissing me off. My load shows no pressure signs and legit shoots 1/8 moa and is right now the best shooting gun I have. However by Hodsons numbers sooner or later I will kill myself with this thing I guess. Does anyone have quick load data for these loads. I can't figure out how everyone is using 2 full grains more than Hodson with no pressure signs. I really would like to not change the load. I shot this load yesterday and was killing it at 1200 yards.
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Just shoot it. If you are not experiencing heavy bolt lift or other signs of pressure you are fine. Their data is very conservative, as is any published data.
Well by all accounts I should be dead and my AI would be circling the earth. Running 36.2gr h4350 in a .218 bore 6.5th barrel, but had a load for 3260fps at 37.something grains. If you’re not having pressure, send it.
Did some more load work up on my .22GT. Once I found max, I concentrated on higher charges hoping to find accuracy with 88gr ELD-Ms at 3000fps or more from my 20" Osprey barrel. Alas, it was not to be. This barrel decidedly did not like any charges of H4350 greater than 36gr, grouping a bit over 1" with for 10 shots. I remembered back to when I was finding max, that four consecutive charges from 34 to 35.6gr all went into the same ragged hole so decided to try 35gr. Bingo! 35gr grouped 10 shots into .443" center to center. You can see ”flyers” at 6 o’clock and 8 o’clock in the group. By the time I was six shots in, mirage off the suppressor was significant. Had it not been for that I think I could have done even better. Eight of the ten shots are probably in the high .2s. Didn't chrono it but based on come ups at 900, velocity is about 2900. I had hoped for more speed, but I don't think 100fps is going to make or break a shot. Overall, very pleased so far.
John
John
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What is the twist rate of your barrel? Have you tried other powders? How many rounds on it, did you see speed increase after the first 100 or so? I am running N555 and can easily get over 3200 at 36ish grains. My barrel is 26" but still, should only be 150ish fps difference.Did some more load work up on my .22GT. Once I found max, I concentrated on higher charges hoping to find accuracy with 88gr ELD-Ms at 3000fps or more from my 20” Osprey barrel. Alas, it was not to be. This barrel decidedly did not like any charges of H4350 greater than 36gr, grouping a bit over 1” with for 10 shots. I remembered back to when I was finding max, that four consecutive charges from 34 to 35.6gr all went into the same ragged hole so decided to try 35gr. Bingo! 35gr grouped 10 shots into .443” center to center. By the time I was six shots in, mirage off the suppressor was significant. Had it not been for that I think I could have done even better. Didn’t chrono it but based on come ups at 900, velocity is about 2900. I had hoped for more speed, but I don’t think 100fps is going to make or break a shot. Overall, very pleased so far.
John
20” 7 twist .219 bore. H4350 is all I’ve tried so far. I did work up to well over 37gr but was starting to see mild pressure signs, groups were garbage and I only achieved 3065fps, which from a 20” barrel, probably isn’t too bad. Going to try some 6.5 StaBall I guess.
John
N150 seems to work well with the 88's if you can find some to try. I am around 34 grains, about 3150 fps 24" barrel.
Just in case y’all haven’t heard yet, Forster is making .22GT dies. I picked up a full length sizer and Micrometer seater from Graf’s. Had to buy them separately, as they don’t offer that combo in a set.
John
John
Shot these five at 800 yards yesterday. 35gr H4350 behind 88gr ELD. As expected, barrel has sped up a bit. This load is doing 2930 from 20” barrel. Black dot is about softball size for reference.
Shot this sow with same load this evening at about 175 yards. Muddy spot is POI. No exit wound, but 88gr ELD did the trick. DRT. Sow is longer than the rifle and weighs every bit as much as I do.
John
I’ve seen where folks have had good results with R26, but has anyone tried H1000 in the .22GT yet?
Thanks,
John
Thanks,
John
Yes. The group sizes are comically small. I’m actually ditching my 85.5s because they’re shooting so well.
Think I ended up at 33.8gr 4350 around 15-20 thou. The little cluster in the bottom right quadrant of the target is a 10 round group… I picked out an existing hole in the paper and that was the result.
Ran them up to 3150 pretty easily. Settled around 3075. No jacket failures in a 6.5 twist.
Tried some StaBall 6.5 behind 80gr Amaxes in necked down Hornady 6GT brass yesterday. Weirdest thing I’ve ever seen. Apparently it does not pressure up fast enough for the brass to seal the chamber good. Powder was flowing between the brass and the chamber wall, enough that it left divots in the brass on both the body and the shoulder, and some even made it back to the bolt face. Thought maybe a hotter load would prevent this but not so. It did it even with loads that left an ejector mark on the case head, about 1gr over max. Anyone ever have this happen with StaBall 6.5?
John
John
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John, I had that happen with some low end loads of RL15.5. Carbon formed in the shoulder of the chamber I had to clean out. With loads closer to moderate pressure it went away. I know you asked about staball, but I haven’t had this happen in other cartridges with lower pressure loads. Interesting observation.
Huh. I ran from 35 to 39gr of h4831sc and never experienced any sort of issue with burn efficiency. And 35gr was very light. Granted I was running a 95gr smk. But still.
If you have Varget or something equivalent, I would try that with the 80gr amax's
If you have Varget or something equivalent, I would try that with the 80gr amax's
I will say my chamber develops gnarly carbon rings even with normal 4350 charges. Seems the neck length on the spec reamers is a little too long for the brass and is allowing building in the neck area. I and at least 3 other guys have had the same issue. Takes an overnight soak in C4 and an hour worth of scrubbing to get it clean.
30min to an hour of clr, a drill, universal hoppes cleaning rod, and nylon ar-15 chamber brush knocks that out quickly. My 6BR used to be like that too. 250rounds or so and it would get a nasty pressure spike from the carbon ring.
I've also used this on my previous 22GT barrel as well with no issues.
I've also used this on my previous 22GT barrel as well with no issues.
I have tried the StaBall with 88gr ELD-Ms and not noticed any blow by, and got some pretty good groups, but they were not repeatable and velocity ES pretty abysmal.
Have some loaded up to try in my 6.5CM, but if I don’t get good results there, I’m done with it.
John
Wondering if this is whats happening to me. I get get through about 40 rounds of a pretty mild charge of 4350 and all of the sudden i start getting hard bolt lifts and ejector marks. Had GAP chamber it and even sent it back to them for a second look. Still doing it but its on virgin brass so i was hoping it resolves after the initial firing. How many rounds before you start having issues?
FWIW I just ran 80 rounds fire forming virgin Alpha brass. Load was 37.5 of 6.5 Staball with 88's @ .023 off the lands 3050 (random pick). Cleaning after was a bit of a chore.
Aside from them all hang firing, the necks sealed well. No carbon on cases at all. Put 20 in .9 @ 100y. I think the old ass Wolf primers caused the hang fires. Previously with GM205's they all lit fine.
Aside from them all hang firing, the necks sealed well. No carbon on cases at all. Put 20 in .9 @ 100y. I think the old ass Wolf primers caused the hang fires. Previously with GM205's they all lit fine.
Experimenting with that now. Barrel has 1200+ rounds on it so that could be playing a factor, but it looks like it’s going to end up around 300 rounds for me. Definitely not 40 though, that seems extreme.
I will say mine was OK for like the first 600 rounds with no cleaning, and then I started getting crazy pressure spikes, missing targets high, and having hard chambering/bolt lift issues. Obviously it’s best not to let it get that bad.
For anyone that runs into similar problems though, I would start there. And when you think you’ve got it clean, scrub some more. A drill helps as Krob said.
Picked up my new GT barrel. Local store had some 8lb kegs of n555 so going to test that out. Going to break in the barrel with 88's and then run the 90's.
Not in this 219 bore, only 3110fps. 26" hawkhill hvy varm. Could be slow lot of 4350. Still on virgin brass too. Took 37.2 to get up to 3200+. My chamber is a bit off the norm, 257nk and 170 freebore. Most reamers are 255nk, but I didn't like that bullets would NOT go into a fired case unless I really forced them in. Loaded nk is around 2525-253, too tight.36gr of 4350 has to be pushing 3200
I use a PVA muzzle Jimmy and a bore scope they are both game changers for me keeping a barrel clean. I clean every 100 to 200 rounds. I soak my barrel over night with boretech c4. Then go to scrubbing with a nylon brush. Gets rid of any sign of a carbon ring.
