25GT

[High Desert duck]

I have spent the past year shooting a 25 CM. The cartridge has been amazing. Recoil is slightly better than a 6.5, and with the 131 grain Ace cuts the wind and shoots like a laser. But, having said that as a gamer cartridge it left me short a couple of times on windy days. Shooting small targets inside of 400, seeing splash was difficult off of rickety barricades. So I started thinking about going to a low recoil round like a 6BR or maybe a dasher. Then I landed in the 6GT. I looked at the the data and decided I would team the 6GT case up with the blackjack 131 and get the best of both worlds.
Shot it for the first time at our club match and it was everything I had hoped for. Light recoil, bucked the wind, and easy load for. Final load was 2800fps. Made a 2nd round impact at 1200 yards in 12-15 mph x wind, and missed a prairie dog popper at 250 off a barricade, but saw the miss and was able to correct.
I have write-up on the development here 25GT
Drop table from the match yesterday.

 

[308Gunner]

That is pretty cool I guess it is the same as far as just changing the bushing. Obviously you have to run an expander but is that all

 

[jsel10]

I have had the idea in the back of my head for a 25 gt for a while now. Your findings are dangerous to my wallet.

 

[Dthomas3523]

Serious question:

Other than just doing it to do (which is is a perfectly fine reason), why go 25gt over any of the 6mm offerings?

Running from 2800-2950 with 105’s and 109’s, the wind drift is very similar to 131 going 2800. The allure of the 25cm is that you run the 131 at 3,000 or so.

Not crapping on your decision. Sincerely asking if you see a performance difference or just something interesting to shoot (again, perfectly fine reason).

 

[jsel10]

Bigger bullet running slower with almost identical dope to my dasher. Easier to spot trace and impacts on target. At least that was my thought process.

 

[High Desert duck]

That is pretty cool I guess it is the same as far as just changing the bushing. Obviously you have to run an expander but is that all

Correct just ran a mandrel to neck up and the run a larger bushing on fired brass. However I did end up having to machine the seating die and the shell holder for my Giraud trimmer to accommodate the larger neck and bullet.

 

[High Desert duck]

Serious question:

Other than just doing it to do (which is is a perfectly fine reason), why go 25gt over any of the 6mm offerings?

Running from 2800-2950 with 105’s and 109’s, the wind drift is very similar to 131 going 2800. The allure of the 25cm is that you run the 131 at 3,000 or so.

Not crapping on your decision. Sincerely asking if you see a performance difference or just something interesting to shoot (again, perfectly fine reason).

No worries its all good. I started thinking about it for recoil purposes. I liked the way my buddy’s 6BR ran on barricades and the GT had just come out. I thought if I could get that Ace up to 2800 FPS the recoil wouldn’t be much worse than his BR with 115s at 2800 and I would get much better wind drift performance than his DTAC. My second reason was barrel life. I figured if I necked up I might be able to get more life out of it than the 6GT. Time will tell on that one I guess. I’m going to check erosion at 500 rounds and see how that’s coming along.
So basically a ballistically better 6BR.
After running some numbers it turned out the 2800 mark actually matches the 6GT DTAC (for wind) pretty close and beats the Berger 105/and 108 ELD-M at 1000 and beyond for drift. (Using generic 6 data vs. actual 131 data .335 G7) I agree not a lot of benefit inside of 700. Shooting in the match this weekend it was definitely an asset in the wind as the only other round besides the 25GT to hit 1200 was a 6BR. As noted increased splash is definitely a perk at 1000 and beyond in damp dirt. I’d love to shoot it against a well developed 6GT to compare actual performance but haven’t had the chance yet. I’ve included a shooter drift comparison out to 1500 with a 270 wind at 10mph. The 6 info is generic. DA 7500. Don’t have any 109 data

 

[nrspence]

That’s a pretty cool idea, can’t argue with that data. I really like my 25 creedmoor.

 

[Geaux tigers]

I think it very interesting being case capacity to bore diameter is similar to the dasher if it can match the dasher for raw accuracy and gain 15” on a 10mph wind at grand it’ll be a winner.
Tom Jacob’s is doing similar things with the 6.5gt as it matches the 6bra.

 

[Raufoss]

As much as I love my 25 creed and the blackjack bullet , the 6BR family will always remain the standard and will still dominate the PRS circuit in the end.

I see the real benefit of my 131’s with my 25 Saum/PRC for longer range matches.

 

[Geaux tigers]

In all shooting sports no matter the discipline nothing remains the same. Everyone is looking for the next best thing and they will find it. Wasn’t that long a go 6.5 was king

 

[Raufoss]

In all shooting sports no matter the discipline nothing remains the same. Everyone is looking for the next best thing and they will find it. Wasn’t that long a go 6.5 was king

The 6.5’s remains the gold standard in a general multidisciplinary context.

The blackjackhas a sweet spot in my heart but sadly in the PRS gameI don’t think we’ll see anything change regarding 6’s because everything is only a question of recoil in that game.

 

[High Desert duck]

In terms of recoil we shot it directly against my buddy’s 18-19 pound 6BR (115 Dtac@ 2800) and with a can on my 20 pound 25 GT (131@2800) recoil was very similar. When I ran a brake in it they are very close in terms of recoil.

 

[High Desert duck]

I think it very interesting being case capacity to bore diameter is similar to the dasher if it can match the dasher for raw accuracy and gain 15” on a 10mph wind at grand it’ll be a winner.
Tom Jacob’s is doing similar things with the 6.5gt as it matches the 6bra.

The club match I shot it in we had a target at 1200. Made impacts with it in a12-15 mph 9 o’clock wind at 2.2 mils. (7500 foot DA) the extra weight was nice for seeing splash in the damp dirt as well.
I’d be interested in Tom’s results with his 6.5 GT.

 

[Geaux tigers]

I’d be interested in Tom’s results with his 6.5 GT.
[/QUOTE]
This is a quote from Tom on the 6.5gt


With a week and a half to get a new gun and a new cartidge tuned up for the 1000yd Nats, the 6.5 gt performed! 3rd place in light gun group agg. 4.5" over 3 targets , for the conditions I was pretty stoked. Fairly extreme mirage on day 1 and big winds on day 2, 1st in the agg was 3.6" and 2nd was 4.4". I couldn't find center of the target on day one at all. 12 th place in light gun overall due to poor score shooting.

A little info on the 6.5 gt, to my knowledge this is one of two of the first barrels ever chambered for it, all work was done by Alex Wheeler at wheeler accuracy , he had to use a 6.5x47 and my original 6gt reamer to pull it off, we ran out of time waiting on the reamer.
As of now I have one of Alpha Muntions new Legacy reamers in the shop ready to go, looking forward to using it.
The brass i used in this barrel was some of Alphas new pre production , "optimized case head technology " i hope i got that right, Andrew Rixon. This stuff is legit! I only had 50 pieces to start the project, turned the necks, expanded them and i went straight to 1000yds. I did some ladders at a grand to see what it liked, honestly I had a hard time wrapping my head around how forgiving it seemed to be, I saw it shoot good from 2800 to 2950fps, seeing pressure at 3000.
This testing was all done with h4895, and our 133gr and 139 gr bullets. I ended up settling on our 133gr at 2950, 36.7 gr of h4895, with a 205m primer.
Now that I have some time to actually test and not worry about running the match itself, im going to try some more tests, primers, bushings, and slow it down to 2840 ish as well.

These are the things that keep me motivated and this one has sparked my interest for sure!

I think this 6.5 has a bright future ahead

Thanks, Alex Wheeler, Andrew Rixson, Tom Danielson and Robert Danielson you guys are top notch!

 

[patscrazy]

Love seeing these new .25 cartridges getting developed and worked up. Still leaning towards one day replacing my 6.5 Creedmoor barrel with a 25 Creedmoor once it’s shot out. Same powders and same brass just necked down.

Those numbers he’s getting for his 6.5 GT are impressive, considering the smaller case capacity vs 6.5 creedmoor, but with same weigh bullets. I’m just a touch slower then that, 2867 avg with my 6.5 Creedmoor using 130 Berger hybrids with 44.5gr H4350. Then again I think my Bartein barrel or this particular lot of powder is on the slower side.

 

[High Desert duck]

Took the 25 GT out yesterday to stretch it out. Shot at 1500 and 1940. It was amazing at 1500 yards, missed with first round and then 6 in a row. Almost like cheating.
we then moved back to 1940 yards. Here it was kinda rough. Group opened up to 2+ mils. This range was about 100 yards past transonic. I ended up reco the jacket from that one. (It was in between the strap and the steel. I’m not sure but it didn’t look like it went through strait but hard to tell with the fire hose.
Watching the trace at 1500 (couldn’t see it at 1940) was hilarious. It would disappear out of the field of view and then drop back in just prior to impact.

muzzle velocity 2803 FPS
SD 8.2
ES 15
Station pressure 23.87
Temp 41
Winds 11-1 o’clock at 6-9 mph

1940 yards
1602 inch drop
23.4 mils
Time of flight 3.188
Impact velocity 1047
Energy 319 ft/lbs
Transonic between 1800-1850

1500 yards
761 inch drop
14.2 mils
Time of flight 2.318
Impact Velocity 1346
Energy 527 ft/lbs

 

[Geaux tigers]

I ended up settling on our 133gr at 2950, 36.7 gr of h4895, with a 205m primer.

Do you know the barrel length to get these speeds? Must be quite long, that small a case with those speeds.
[/QUOTE]
Not sure it’s a bench rest gun so at least 28” I’d say
Maybe contact him or Alex wheeler chambered it for him

 

[High Desert duck]

So I measured the throat erosion today. After 550 rounds throat erosion is .001 or .002.
I have been running the gun in a couple of local matches and running it hard in practice.
My buddy put a group down for me during a chrono session on my first batch of once fired brass. ES of 5 and SD of 2.2. Avg of 2798.

 

[beetroot]

Improved barrel life and easier to spot impacts sounds like a good trade off for a tiny bit more recoil.

Biggest issue here is that you are basically limited to a single projectile, which provided they stay available isn't really an issue.

How much slower is this shooting than your 25CM?

 

[beetroot]

Berger just released the 135 LRHT 257 pill yesterday, so there is another option. Bearing surface is slightly longer but g7 is about the same.

144gr 6.5mm Berger has a BC of .336
147gr ELD-M has an average BC of .334.

Maybe 2021 will be the rise of the 25cal, god forbid even the rise of the 27cal.

 

[High Desert duck]

Improved barrel life and easier to spot impacts sounds like a good trade off for a tiny bit more recoil.

Biggest issue here is that you are basically limited to a single projectile, which provided they stay available isn't really an issue.

How much slower is this shooting than your 25CM?

I’m hoping to get 3000+ match quality rounds out of it. Looks promising so far. As the other mentioned Berger just announced theirs, and I’ve heard rumors about maybe a Hornady. (125 A-tip would be awesome)

I’m was running my 25CM at the low node 2950. It also liked 3020 but the brass was trash after two firings.

 

[SweaterDood]

Correct just ran a mandrel to neck up and the run a larger bushing on fired brass. However I did end up having to machine the seating die and the shell holder for my Giraud trimmer to accommodate the larger neck and bullet.

I’m seriously looking into a 25 GT for myself. The 131 Ace is no joke, I currently shoot it from a custom chambered 257AI @ 3220-3250 FPS. Trace on that thing is like a ski boat, and it swings the steel out to about 1600yds.

After running the 6GT brass over the 25cal mandrel, what is your neck OD?


Thanks

 

[High Desert duck]

Sorry for the slow reply. Out of the house on business.
Neck diameter of .280. That is GAP (Hornady) brass prepped and unloaded. Loaded it’s .282.

I agree that 131 is awesome. Shot it out at 1940 yds and easy to see splash.

Edited for structure and additional info

 

[High Desert duck]

Did a ladder with Varget and Sierra 110 game changer (tipped game king) easy 3000 FPS. (Back up hunting round) also ran a ladder with N540 in case I run out of H4350. Made my 800 FPS 1.0 grain below max.

this is a case that has been through the gun 7 times. And max-pressured during my initial ladder. Never annealed.

edited for typo

 

[High Desert duck]

Sorry slow response

Made 2800 fps 1gr below pressure? Also the case, is thay Hornady or alpha?

sorry for the typo. Yes 2800 FPS 1 grain below max, with the 131. It is hornady (GAP) brass. The case has only been through a dry tumbler twice. I am running a batch of 20 to see how many firings to failure. They usually just get cleaned with steel wool.

 

[High Desert duck]

I also forgot to include the data on the Sierra bullets. The 110s made 3060 with no pressure signs using Varget. I ran a 5 shot group and without my called flyer put down slightly less than a .5 group (.7 with the flyer) and an avg of 2995 SD of 4.0 ES OF 10

 

[High Desert duck]

I have been asked about recoil on the 25 GT. This is a video off the barricade. The gun is 20.5 pounds.”, with a area 419 universal arca-lock rail. The brake is an Insite heathen (6.5mm). The bag is a heavy pint sized game changer. The first three shots are 100% free recoil. The 2nd three are loaded against the barricade. (200-300-400-400-300-200 yards course of fire)
Free recoil I could spot impacts at 300, loaded I could see splash at 200.
It is heavier recoil than 6BR but very manageable, much much better than the 25 CM.

25 GT a recoil Video.

 

[Hutch_WV]

So did this die as a cartridge or?….. I like the idea. With the availability of 6mm barrels(. I can’t get one ). Is this better. I like the ballistics but after reading, what am I getting over 6gt? Just asking for PRs distance.

 

[XLR308]

Allways loved my uncles 25-06 on hillcountry whitetail deer and wanted a 25 cal.
I just at the moment cant get past how accurate my 6.5x47 is and easy to tune with very little recoil with a sedate 2880fps with a 130 hybrid.
Its not a heavy rifle either by PRS standards would guess in the 12.5-13# range all in and have no issues with spotting splash although the 1/4 bore is interesting.

 

[XLR308]

One my shooting partners just switch from 6.5x47 to 6 dasher. His scores have improved as he can now see trace and splash much more consistently in positional settings where proper form isn't always obtainable. Shooting my 25creed w/ 131s @ 2940 vs my 6gt with 108s @ 2960 in exact weight setups, the gt is a lot more controlled recoil impulse. I think the 25gt is a good mix of the high BC, with low recoil. Although running ballistics of a 109 hyb @ 2950 vs 131s at 2800, they're equal in wind. If I was tooling up a 25cal for prs again, I'd probably build a 25x47 and run the low node with 131s @ 2800 or 2850. Problem is, 131s are unobtainable. I'm very low myself and we probably won't see any till late this year.

Im definately not trying to argure ballistics, i dont shoot PRS or comps i target shoot and hunt with my rifles.and tend to go with a larger diameter bullet.
The 6.5x47 is pretty much the smallest i have chosen other than a 1-8 twist 243win finished at 26" but prefer the smaller lapua.
If i did compete i think the .25 caliber or 6mm Dasher would be my favorite.

 

[Hutch_WV]

Have the 135 Berger LRHT hit stores yet?

 

[High Desert duck]

So did this die as a cartridge or?….. I like the idea. With the availability of 6mm barrels(. I can’t get one ). Is this better. I like the ballistics but after reading, what am I getting over 6gt? Just asking for PRs distance.

Cartridge is still doing well. I haven’t updated it much as there wasn’t a lot of traffic or new developments. My friend ended up building one as well. It has made a big difference in my local matches. I went from 3-4 place finishes to 1-2 place finishes. I did run it at a national match unfortunately I did not perform as well as the gun. The thing hurting it right now is projectile availability. I did not foresee the problems at Sierra for blackjack. Both my friend and I are completely out of bullets. We did just order 2000 of the new Bergers so hopefully I’ll be able to update the project when they arrive.
However,I pulled the barrel last week at 1300 rounds. I’ll try and get a erosion measurement when I get the barrel back.
it is as still shooting well but I only have one action so I ended up finding 1000 110 A-tips, 250 6cm brass, and a bartlien barrel. So I’ll be running a 6 creed for the summer.
The goal with this was to get a round that would match the BR recoil but have better wind drift. It has done that in spades. I can spot impacts/splash at 300-400 free recoil and 200 yards if I load the gun on a barricade. Wind drift is comparable to a 115 DTAC at 3150, and at my altitude it is supersonic past 1 mile. The surprise was how much of a difference the added energy made down range. I am seeing splash at 1200 when the 6BR dasher crowd is not. (Damp dirt/snow) also I was able to spin the spinners more easily with my poor timing than I would have with a 6. This is also the the first time I’ve been able to see trace through the scope. (Prone)
I like it and can’t wait to start shooting it again.

edited for crappy spelling

 

[High Desert duck]

One my shooting partners just switch from 6.5x47 to 6 dasher. His scores have improved as he can now see trace and splash much more consistently in positional settings where proper form isn't always obtainable. Shooting my 25creed w/ 131s @ 2940 vs my 6gt with 108s @ 2960 in exact weight setups, the gt is a lot more controlled recoil impulse. I think the 25gt is a good mix of the high BC, with low recoil. Although running ballistics of a 109 hyb @ 2950 vs 131s at 2800, they're equal in wind. If I was tooling up a 25cal for prs again, I'd probably build a 25x47 and run the low node with 131s @ 2800 or 2850. Problem is, 131s are unobtainable. I'm very low myself and we probably won't see any till late this year.

Yes the recoil has made a huge difference in my scores. The nice thing about the 25 is I don’t think I’m really pushing the limits to get 2800 FPS (28 inch barrel, slower powder). Another benefit I was thinking I’d get would be extended barrel life as it is running “under bored”. I like to 25x47 idea in a low node l, but, and This is just my opinion /experience, I like to run close to 100% case full as it seems to produce a better SD/ES. I’m running about 98% with this load. I agree about availability. See above.

 

[Lesco Brandon]

Serious question:

Other than just doing it to do (which is is a perfectly fine reason), why go 25gt over any of the 6mm offerings?

Running from 2800-2950 with 105’s and 109’s, the wind drift is very similar to 131 going 2800. The allure of the 25cm is that you run the 131 at 3,000 or so.

Not crapping on your decision. Sincerely asking if you see a performance difference or just something interesting to shoot (again, perfectly fine reason).

I shot my 25 CM at the nightforce ELR challenge in WY and it kept up with 300 Norma magnums.

 

[High Desert duck]

There was a couple of questions about inherent accuracy. The club just put in the shot marker system and we tried it out with the 2 25GT. This group is at 1000 yards and predicted average speed at 1000 was within 5fps (This is my friends group shot in pretty high mirage mid afternoon. if my maths are right that is a 0.86 MOA group). My group was 1.19 MOA and shot as fast as I could. Remember when looking at the velocity and SD/ES that is at 1000 yards.

 

[High Desert duck]

Did I understand correctly that your complaint was small targets inside 400?? And seeing splash??

Build it if you want but there is always a trade off.

Yes, the 25 creedmoor was great but I found I was struggling with small targets off barricades in gusty or variable winds. If I got the wind right on the first shot I’d shoot the stage well. If I didn’t, I’d have to guess on the wind call because I wasn’t able to see my miss. I guess I included the”small” because I wasn’t missing the large targets as the wind call wasn’t as critical.
The 25 GT has made a big difference there. My increase in scores has been primarily on those short to mid distance barricade/positional shots.
I wanted to go down in recoil, so 6 BR or 6GT would have been my choice, but wasn’t stoked about the wind drift on the 6BR. I was close to doing a 6GT, but it was kinda new and barrel life was looking like 2000 or so.(Seems to have turned out better than that generally) so the idea of getting a longer barrel life was also intriguing. When I started thinking about the project I was also on a tight budget (and I hate doing load work ups)
So I went with the GT case for lower recoil and the 25 Ace for better wind. The BR case wouldn’t have gotten me the velocity I needed or I might have gone that way. 25 BR.
I also did it because I’d never tried something like this, it’s been fun and a good learning experience.

 

[High Desert duck]

Well the 25GT is back in action. The 6CM barrel started giving up the ghost and I only had 100 6mm bullets left. so we spun the barrel back on, and I did a quick work up with the Berger 135 long range target hybrid. I measured the erosion and total throat erosion has been .007 after 1300 rounds. This matches what my friend is seeing, and he has not changed his load data in the 1500 plus rounds Rounds on his barrel. We are both working close to the lands. I believe he is jamming .010, I am jumping .020.

I did a quick work up, if your interested that’s in the reloading depot 25GT Load details. BC came in at .340 G7 @ 2780 FPS a little better than i saw from this barrel with the ACE (.335)

I ran it at a local club match this weekend, and it worked. Switchy light winds and it was still making consistent impacts that the light 6s were not. I missed some probably due to the 6 creedmoor eroding my windcalling ability, but the 25 was easy to see trace. The only problem I’m running into is the MDT mags. Might have to tweak them some more, they struggle with the first round with more than 9 in the mag but run fine after that. (These mags were like butter with the 6 creedmoor.)

this is how it is sitting now.
24 pounds empty
Impact action
28” bartlien 5r
vortex gen III 6-36
vortex Precision Machined Rings
foundation centurion
trigger tech diamond
hawkins M5 bottom metal
ACE muzzle brake

 

[nrspence]

Sounds great, may go that direction after my 6 bra barrel hits the grave.

 

[High Desert duck]

So bad news on the 25 GT front. Me and the cartridge are on the outs. Ever since I have switched to the Berger 135s I have been fighting pressure signs. Stiff bolt lift, ejector swipe, the works. I have downloaded it to 2750 fps, the bc has dropped to .320 G7. So the advantage of the slow high bc bullet over the 6mm’s is gone. There is a chance i have developed a carbon ring, and am planning on checking the throat soon. The barrrel is currently sitting at 2,073 rounds. Of which about are 800 have been working the bedgers.

my current load: 36.8 H4350, Berger 135, gap brass (5x fired annealed after 4), cci 450, .007 off the lands. impact Action, BartLein barrel.

My buddy is still having no problems with his load, i think he is 36.5 +/- IMR4451, Berger 135, cci 450, .010 jam, gap brass (3x fired annealed every load. Kelbly action bartlein barrel

I have another friend that built one. His was cut with a different reamer and smith, but the same specs from Manson. He is having problems with multiple loads and with his 200 shot round count can’t get Past 2730 without pressure signs, regardless of powder. Impact action bartlein barrel.

this weekend at the match my buddy with the Kelbly’s shot my rounds through his rifle for the whole match. His zero didn’t change and they were running at the same speed as his loads. (30 fps faster than mine: 2780). He had a little pressure but only at the end of the stage at 8+ rounds, a little stiff bolt lift. He did report that they felt a little spicier. (Perhaps that is just the different powder making a sharper pulse?)

So to make a long story endless, i need to concentrate on the rest of my season, and have decided to run a 6cm for the rest of the year. The death of the ACE bullet has lead to a pause of the cartridge. Perhaps this fall i will try some 133s and see if they help. But i am afraid the project may be shelved until the Ace comes back (not looking good) or someone else comes up with another heavy 25.

My write up on the transition to the 135s is here at the end of this thread in the reloading portion of the hide.

25GT revisited 11/2023

The 25 CM is awesome. The Blackjack 131 ACE is incredible. I have been shooting them over the past year and it has been a hammer. It only had one flaw that I could find. The recoil is on par with a 6.5 CM. Spotting shots off a barricade inside of 500 could be difficult. As I got to the end of...

www.snipershide.com

 

[SweaterDood]

Your findings confirm my suspected concerns with the 25GT. I really thought hard about going this route, but wanted to make Min PF for NRL Hunter, so I stepped up to the 25x47L for some extra insurance on speed. 2820fps minimum seemed just out of range of the 25GT with reasonable pressures.

For the 25x47L, H4350 is putting the 135s comfortably in the 2850fps range without any concerns whatsoever (27” bbl). Testing has been done at 90*F Temps, in 70+% Humidity. I also shot the same loads on a mid 80s rainy day without pressure.

 

[High Desert duck]

It ran great at 2820 with the 131s. It Had no problems at 2800-2850. But without that bullet it seems unable to get near 2800.

 

[SweaterDood]

It ran great at 2820 with the 131s. It Had no problems at 2800-2850. But without that bullet it seems unable to get near 2800.

For PF with the 25cal offerings. 131gr needs 2901fps, 135gr only needs 2815fps.

Have you looked into extending the throat on the GT chamber? I’m thinking ~ 0.160-170” FB. An AICS mag should accommodate this, no problem and the bullets will be very optimally seated.

 

[Hutch_WV]

I did a reamer through Manson. 175 FB. Still testing but should get speeds wanted with the 135.

 

[357Max]

Your findings confirm my suspected concerns with the 25GT. I really thought hard about going this route, but wanted to make Min PF for NRL Hunter, so I stepped up to the 25x47L for some extra insurance on speed. 2820fps minimum seemed just out of range of the 25GT with reasonable pressures.

For the 25x47L, H4350 is putting the 135s comfortably in the 2850fps range without any concerns whatsoever (27” bbl). Testing has been done at 90*F Temps, in 70+% Humidity. I also shot the same loads on a mid 80s rainy day without pressure.

Do you mind telling who did your chamber work?
I’m looking to get a large frame AR chambered for 25x47 & not to many smiths seam to have that reamer yet.

 

[beetroot]

What advantage does 25GT have over a 25CM if it's this difficult make NRL PF?

Is it just a case of the GT being somewhat 'better suited' to PRS and you are just trying to make it work for NRL?

Hot roding the GT to try achieve what would be a pedestrian load in a CM case seems unnecessary.
Other than burning a little less powder what advantage do you gain?
The ease of obtaining CM brass makes me think 25CM would be the better option.

 

[357Max]

What advantage does 25GT have over a 25CM if it's this difficult make NRL PF?

Is it just a case of the GT being somewhat 'better suited' to PRS and you are just trying to make it work for NRL?

Hot roding the GT to try achieve what would be a pedestrian load in a CM case seems unnecessary.
Other than burning a little less powder what advantage do you gain?
The ease of obtaining CM brass makes me think 25CM would be the better option.

I think the idea was recoil reduction + bad ass balistics of the 131 Black jacks. I get it, at the 2800 mark nothing but $$$ solids could deliver those kind of balistics at that recoil level. Sierra, however has royally fucked that up.

I cant tell the difference in recoil between 25c 135 vs 6.5c 130-140. I could download the 25C but that goes against my dna. Plus SD’s would likely go to hell with a low case fill.

I do think 25x47 is about perfect for a large frame AR limited by mag length. If the Blackjacks come back I will build one even if I have to buy a reamer.