Discussion in '6mm, 6.5mm, and .25 Cal (Not 6BR)' started by SWRS, Sep 11, 2019.
Looking for a solid big game load for my 25-243AI. Not much information out there....
What are you going to do with it ? Just long range/ heavy bullet's? Or hunting ? For hunting the 80ttsx is the ticket. 25-08 max loads should get you started. Or it should be just under 25-06 data. Ps. That is a good cartridge for sure. Twist ?
Neat cartridge idea. I wonder how it compares to 257 roberts for case capacity? Perhaps that could be of some help for starting loads?
If you can find any, I'd bet RL26 will be one of the top performing powders for you.
I'm guessing it would be real similar to a 25 WSSM.
As pointed out by Rdlningcltchdmpr, above, it's simply an Ackley Improved 25/308, or, in other words, very close to .257 Ack. Imp. capacity . . . it'll leave the ill conceived 25WSSM gasping for air! To get all the goodies out of it, the throat should to be long enough to keep [the base of] your bullet of choice in the case-neck, thus maximizing case - powder - capacity. Be safe begin with mild .257 Ack. Imp. charges, for your bullet weight, and work up. RG
My bad - don't know what I was thinking, but not good! I have edited my reply, removing the potentially dangerous reference to the incorrect cartridge. Thank you to those who pointed that out.
10 Twist, wanting a good hunting bullet. Today I shot 100 Nosler BT with 50.0g H4350 at 3515fps.
Thinking about the 110 Accubonds. I could get that 80gr TTSX screaming, but I need something for cow elk.
80ttsx is perfect for the job, you must remember that it enters at 80 and exits at 80 grains. No weight loss or lead fragments. They go through bones like nobodies business. Also more speed= deeper penetration. If you did a wet newspaper test you would see what i mean. Ps. I shoot a 257 weatherby / Krieger/ Tikka with 80ttsx @ 3950 fps - 400 yd point blank range. Farthest shot was 300 yds so far 8 point whitetail - complete passthrough. DRT. On two other occasions i had to shoot at deer moving fast and hit a branch once and a sapling once, and still killed em dead.
A 25-243AI has right around 57gr H20 case capacity where as a 25-06 has 67gr H20 case capacity, I'd think just about any load data published for a 25-06 would be a bad idea to use in a 25-243AI.
3515fps sounds extremely fast for this size case, that's up there around where a 257Wby mag shoots the 100's and the 257 Wby has substantially more case capacity.
B23 is exactly correct. There is no way a 308 based case has the capacity of a 30-06 based case. The end.
I shot a 257 wby for years and without looking I think 3600ish with a 100gr bullet was about topped out and that case capacity is stupid overbore.
I would take a WAG that you should be 47-48gr for a max load of h4350 and probably in the 3200fps max range. That is just a WAG and not reliable data.
Hodgens lists a 25-284 with a 100 gr bullet at 48gr max of h4350 and with a 26" barrel at 3126fps.
I don't think you will even approach this case capacity. That said it's hard to believe you dont have bolt lift and primer issues.
I like the idea of this cartridge.Been gathering components for another hunting XP-100,been thinking long and hard about the 25Creed,25x47,257 Bob sized cases,even thought about a 25 Dasher as the shorter cases do well in XPs too.I have lots of 6mm Rem brass and 243 brass which would reduce some of the fund expenditures and allow me to use what I already have.Been thinking the Roberts and it’s improved variants may be more than is really needed from an XP length barrel.Like the idea of a 25 caliber for hunting,plenty of good 257 hunting bullets out there and the 25s have a better expansion ratio than the 6s.Not wanting to shoot a 6.5 creed like everyone else either,sooooo.
Based on your info, .243 load data would be a safe place to start. At least in my opinion. I would rather be safe than sorry. It's easy to add more powder. I do it all the time! Lmao !
Thanks for the info, what a testament this cartridge is to the work of PO Ackley. Getting big magnum performance in an efficient improved case, in his book the .25's were some of his favorites that showed the most improvement, especially the .257 Roberts AI. This particular gun was built by @WSMNUT. We took the throat out a bit to allow for more case capacity. My top load (not my most accurate) was 50.0g H4350 behind a 100gr bullet at 3515fps in a 24in Proof barrel. We all know that the "reloading book" is a guide, not an end all of what cartridges are capable of given the right setup and components as a shooter takes their precautions and checks for excessive pressures. This load wasn't even marking the brass, and there was no expansion of case head or primer pocket.
I am still seeking someone with experience with this case and a good powder, I've heard a little feedback on RL25 being a go to powder?
No disrespect intended, but if you're truly getting 3500+ in a 25-243AI with a 100gr bullet from a 24in barrel, you are doing it with extreme pressure or your chronograph is lying to you.
There's no magic with any of this stuff, it takes more powder or pressure to increase velocity.
None taken, you don't have to believe it.
It was getting 3200 FPS with a 115
I used a throating reamer to extend the throat around .120 over what the reamer had to get the desired OAL.
THe OAL with a 115 was around 2.880
Extending the throat pushed the bullet away from the powder cavity allowing for more usuable powder space. It took more powder to increase the pressure.
The initial loads were flat at best because there wasn’t enough powder to build the necessary pressure. As powder increased the so did the speeds.
We were a little nervous at first as we were using powder charges well over the 257 AI.
No pressure signs with round edges on the primers.
We found pressure using H4350 but it was compressed before we even seen the first signs of ejector marks.
Lapua 243 Winchester brass was used in the initial tests.
swrs, if your chamber is not set up for CIP standards vs SAAMI standards, you will get premature "hard to extract" issues with the Lapua brass. If that is the case, then use Winchester brass.
SAAMI chamber will be .469-.470 in the web while a CIP chamber will be .4712-.4715. If you can find any new Lake City 308, neck down and Neck turn, it will be tougher than Lapua, till you go to the Lapua Palma brass(given that chamber dimensions will allow).
One of my former colleagues used nothing but RL-25 in his .243AI with the 87grn V-max. With his rifle, it seemed he ran out of powder capacity before velocity really came on board. He was ~100fps faster than my factory .243 using the same bullet & RL-19.
RL26 will probably give you a whole new gear when it comes to speed and will probably need a drop tube to get enough in there. Don't know on the accuracy front though.
I'd give IMR4350 a try too, perhaps start around 42gns and go up. I'd WAG a max around 46gns. It has given me the best accuracy in everything from a 22BR up through 30-06
When I had a .25-.308 (AKA .25 Souper) I used 85 Nosler BT's with H4350 for rodents and 100 grain Barnes 3X's with Re19 for deers. My loads were moderate but the 85's got about 3300 and the 100's just over 3000. The .25 Souper AI would probably use 2-3 grains more powder for possibly another 100 fps velocity or 2- 3% increase. That extra capacity should allow slower burning powders like Re23 and H4831. Bullet selection is sort of limited in .257 but there are some heavier 115-120 bullets available. I found the .257 100 gr. Barnes 3X a real good deer killer - a quartering hit on a big mule deer went thru 3 feet of deer at 351 yards. No bullet recovery on smaller deers. I would use .257 R loads for general guidance and start under maximum. I used Winchester .308 brass with turned necks.
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