6.5-7 PRC vs 6.5-300 PRC

[KH_Outdoors]

The new release of Lapua WSM brass has me wanting to make a bunch of 300 WSM parent case cartridges lol. But a 6.5-300 WSM sounds ideal.

I agree ...

 

[bultinkle]

That 6.5-300 sounds pretty hot. I sent jgs an email last night about a 6-7prc reamer

 

[Mike D Texas]

I think the 6.5 SAUM is the sweet spot in 6.5 bore diameter.

I am getting 3250fps with 130 grain terminal ascents in a 21" barrel with a 6.5 SAUM Improved and H1000 powder.

3125 with 144 LRHTs.

156s should be 3000'ish.

 

[liv4thehunt]

I have built 3 6.5-7wsm's, and one 6.5-300 wsm. All of the 6.5-7 wsm's peaked with 156's at 3300 on 26" barrels. The first one shot 142 ABLR's at 3400 sub 1/4 moa right before it burned out at 600 rounds. I just did the 6.5-300 wsm on a 22" Bartlein. It shoots 156's at 3100. The 6.5-7 PRC would be almost identical to the 6.5-7 wsm case. 3100-3150 should be very doable with a 22" barrel. I did the 6.5-300 for myself, hoping for 7-800 rounds of barrel life. Time will tell, but before I cut the barrel down it was only 50 fps slower than the 6.5-7 wsm with 5 grains less powder.

 

[Get_Saum]

Here's some food for thought. Load development with a long throated 264 Win Mag 26" Krieger. No necking down required

 

[Wallie]

I have some experience testing barrel lengths in a 7/300WSM. Started with a 26" barrel, RL23 and a 180vld at 1 grain under pressure signs load. Cut 1" off and measured velocity with the "standard" load all the way down to 18.
I found fairly linear loss per inch right down to 21", then it started dropping exponentially.
This one experiment has suggested to me that for any given combination of components there will be an obvious point of diminishing returns.
Also curious, if you take the time to measure your inputs carefully and tune your burn rate to match your recorded velocities, Quickload matched almost exactly the real world results I got with that experiment.

I think using Quickload is a wonderful idea in your case… model the various combinations you are considering. If your inputs are good you should get fairly close.

If it were me, I would go 300WSM case and never consider any PRC case.
This, and 25 cal, is what I built back in 2000/1 and was very successful, the PRC has no advantage over this case…none.

Cheers.

…other than you can actually, you know… find some to buy.

 

[Get_Saum]

 

[Huntnful]

I have built 3 6.5-7wsm's, and one 6.5-300 wsm. All of the 6.5-7 wsm's peaked with 156's at 3300 on 26" barrels. The first one shot 142 ABLR's at 3400 sub 1/4 moa right before it burned out at 600 rounds. I just did the 6.5-300 wsm on a 22" Bartlein. It shoots 156's at 3100. The 6.5-7 PRC would be almost identical to the 6.5-7 wsm case. 3100-3150 should be very doable with a 22" barrel. I did the 6.5-300 for myself, hoping for 7-800 rounds of barrel life. Time will tell, but before I cut the barrel down it was only 50 fps slower than the 6.5-7 wsm with 5 grains less powder.

Great info! Appreciate it!!

 

[Phil Rizzo]

I have built 3 6.5-7wsm's, and one 6.5-300 wsm. All of the 6.5-7 wsm's peaked with 156's at 3300 on 26" barrels. The first one shot 142 ABLR's at 3400 sub 1/4 moa right before it burned out at 600 rounds. I just did the 6.5-300 wsm on a 22" Bartlein. It shoots 156's at 3100. The 6.5-7 PRC would be almost identical to the 6.5-7 wsm case. 3100-3150 should be very doable with a 22" barrel. I did the 6.5-300 for myself, hoping for 7-800 rounds of barrel life. Time will tell, but before I cut the barrel down it was only 50 fps slower than the 6.5-7 wsm with 5 grains less powder.

did you use a fair bit of n570 in the one that lasted 600 rds?
R26? 565?

 

[floyd kittrell]

I have shortened the barrel on numerous rifles recently and have gained back most if not all of the velocity losses by switching those rifles to copper monos. Three things contribute:
1. Less engraving pressure makes more velocity.
2. Less weight needed in good quality monos that perform as designed.
3. Because there is less engraving pressure, you can typically use a faster burning powder without as steep of an initial pressure curve. Faster burning cuts down the flame-thrower and accelerates the bullet in a shorter tube.

Its worked for me in numerous cartridges

X's 2 , I have done and seen the same thing , some times run 100+ faster than book loads with no pressure but you have to work up slowly, some times the pressure come on very quickly depending on powder choice.

 

[Monterey21]

I think the 6.5 SAUM is the sweet spot in 6.5 bore diameter.

I am getting 3250fps with 130 grain terminal ascents in a 21" barrel with a 6.5 SAUM Improved and H1000 powder.

3125 with 144 LRHTs.

156s should be 3000'ish.

Where are you getting Terminal ascent bullets to reload.

 

[longtubeman]

The 264 Win Mag won't perform with even a 24" barrel, needs 26" plus imo. .284 barrels do a little better short but 30 cal and up does much better at 20-22"

I have no experience with PRC's but a lot with the 6.5x284. It has a 66-68gr water capacity so close to a 6.5PRC. 6.5X284 with a 20" or 22" barrel the fps is so close to a 260R or Creedmoor that that I wouldn't bother.

I have a 6.5x284 in 16.5" and it runs with a 6.5 creedmoor. 120gr at 3000 fps

 

[Rodbolt]

Impressive.

 

[Phil Rizzo]

i'd love to see some 6.5-7prc data if anybody has some, with the 153-156's.?