25 Pronghorn Preliminary Range Report

[T_Widdy]

The 270 is .010 longer to the shoulder and .022 longer to the neck


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I believe Hornady is wrong, look at the actual Saami prints. I thought the same as you.

 

[cal30_sniper]

I’m interested in if you have any issues with the 270wsm brass? I thought win/baco made the 270 longer to the shoulder and neck junction than 300. Are you able to push them back with your die or was your chamber reamed off the longer 270 print?

270 WSM and 300 WSM (and 325 WSM) all use the same shoulder datum/headspace. Simple neck down. You may be thinking of 7mm WSM which has different dimensions than the others.

Neither cartridge is easier than the other the 6saum imp you literally neck down brass, load, shoot and reload. Same as your doing and would be doing with a 6WSM
The saum and saum imp are already diminished returns in 6mm the wsm case would be a waste.
The easy button 6mm is the PRC

I’ve done scads of improved cases for my 7x57AI. Fireforming improved cases is several steps more complicated (including consumption of extra components in the load shoot reload phase you describe above) compared to a straight neck size operation. These 25-300 cases come out of the sizing die as close to chamber spec as any other virgin brass in a SAAMI chamber.

My cases are holding 81grs of H2O after firing. 6 WSM would probably be 79-80grs with the smaller neck. Not sure what 6UM 40 deg holds, but it’s a big jump over 6-284 or 6PRC, so I’m guessing they’re close in capacity to the WSM case. Hence why I’m wondering why folks would go through fireforming to blow out the shoulder and form UM when the WSM is already there with a neck size.

 

[cal30_sniper]

I hope the OP doesn’t find my posts as an intrusion, did a ladder today with H1000, Fed 215 M, from 60-63.5 gr and 134s. Never hit pressure, started at 2960 with 60 gr and ended at 3115 from a 26 inch barrel. I have room to go but I’ll switch to N570 and let it rip.
More to come.

Keep it coming! I’m interested to see where you end up. 3200+ shouldn’t be out of the question with that long of a barrel.

 

[jjohnsonElknewbie]

First off, very cool that somebody is posting on here about this cartridge. I was torn between it and the 6.5 WSM, and ended up going with the 6.5. I'm using the 147 ELDM and chose N565 based on a scouring of the internet for load data. I've never used this powder before, and the rods meter excellent out of my Horndady auto dispenser. I plan to get out and shoot mine today for groups and will post later. Mine has factory Tikka 24", and I may try N570 if MV isn't where I want it. On the same note, in your 20" barrel, you may see a bump in MV with 565 or 560 if the 570 doesn't get it where you want. Anyways, good luck and keep us in the loop on your results.

Posted this in the reloading room thread, but as a FYI, got the following MV results today from Magneto.

6.5 WSM (6.5 Leopard)
147 ELDM
66 grains of N565
Hornaday brass and primer
24.3" Tikka OEM barrel

8 shot results:
3,094 Avg MV
3,121 Hi
3,070 Lo
22 SD
51 ES

A better chrono is on my Christmas List.

 

[hdc77]

Today I did a ladder with 134s and N570, 62.0 gr to 68.0 gr, 26 inch barrel, 1:7.5.
Started at 2990 and ended at 3263, mild ejector mark and flat primer, no bolt lift or anything else. I’m gonna probably stay at 66.5 gr at around 3150 not to trash the brass if the load shoots.

 

[cal30_sniper]

Today I did a ladder with 134s and N570, 62.0 gr to 68.0 gr, 26 inch barrel, 1:7.5.
Started at 2990 and ended at 3263, mild ejector mark and flat primer, no bolt lift or anything else. I’m gonna probably stay at 66.5 gr at around 3150 not to trash the brass if the load shoots.

What brass and COAL are you at again? Sounds really close to where I ended up.

 

[hdc77]

What brass and COAL are you at again? Sounds really close to where I ended up.

Im using ADG 270 WSM brass, COAL 3.035. I can probably push it harder but not sure I want to. Groups were better in the higher load charges which is not usual for me BTW.

 

[cal30_sniper]

Yeah man, we’re right in the same pocket then. My COAL is just a wee bit longer at 3.070, which probably explains the extra half grain of powder I’m using before seeing pressure signs.

 

[SloppyJ]

Cool stuff. My 25 western is extremely similar with N570, virgin brass, and those charge weights. Glad to see someone else with a hot rod 25.

 

[hdc77]

Any experience here with 138’Atips on deer?

 

[cal30_sniper]

Any experience here with 138’Atips on deer?

I’ve only picked up 134gr ELDMs and 133gr Bergers, but I’m interested to see if anyone else has messed with those yet.

I’ve also been wondering when Hornady is going to release the 128gr ELD-x in component form.

 

[T_Widdy]

I’ve also been wondering when Hornady is going to release the 128gr ELD-x in component form.

They are out, got some from midway a couple weeks ago

 

[cal30_sniper]

They are out, got some from midway a couple weeks ago

See, all I had to do was stop paying attention to it and then they could release them, haha.

 

[T_Widdy]

See, all I had to do was stop paying attention to it and then they could release them, haha.

Thanks! I just need to get some rifles put back together so I can try them!