CM vs PRC

[can1010]

No problem on verification. Last night I loaded 5 each at the reduced charges of 57.2, 57.4, 57.6 gr of RL-26. This is under Berger 156 EOLs. After bad weather passes I'll be firing. Expecting 3025' -3100' at reduced charge that will be easier on brass & barrel. CBTO = 2.440, COAL = 3.13.
* The one I'm shooting is built on a Stiller XM action with 26" custom throated Bartlein barrel. * You cannot get this kind of efficiency with the long heavies out of a 6.5 PRC built on a short action. Even in Hornady commercial ammo a significant amount of bullet bearing surface is buried beneath case neck/shoulder junction.

keep us posted. when I had my PRC running once I started to get 3100 with the 153 Atip or 156 EOL no matter if I was using Retumbo or RL-26 I started to trash the brass and when I was at 3135 it was destroying brass only 3-5 reloads at most on Gunwerks brass.
I am running on a long action 28 inch barrel and didn't matter because accuracy was at much lower velocities
one of my biggest problems is people always posting unrealistic velocities with out qualifying how hard it is on brass and accuracy usually is no where near those velocities
I have had the opportunity to use a pressure trace on a few occasions and if people only knew how bad there pressure reading ability really is

 

[QuietTexan]

Cal Zant empirically showed that the better ballistics of the 6CM and 6.5CM is less significant than range and wind when it comes to outshooting the more mundane 308 Win (a derivative of my favorite 30-06). Sadly, he also showed my quest for single digit SD/ES bughole handloads is basically useless. Range and wind calls are THE most important part when it comes to making hits, buying a better club only goes so far. His analysis is based on improving your call from +/- 15 yards to +/- 3 yards... if you're in the +/- 50 yard camp on range calls, it's an even more outside benefit to working on range finding with whatever you have, rather than leaning on a crutch of a faster load to make up for a deficient skill. (I tell myself my 300 RUM is for power, and not because the MPBR of the 30-06 kind of sucks comparatively).

When it comes to speed, buy the chambering that hits the FPS you want/need. I don't see any practical value in hot-rodding. It's fine for it's own sake and I like pushing the envelope on speed sometimes too, but when it comes to a hunting round I'd rather buy something I can load in the 90% range and not have to push past 100% to get what I need. The 6.5PRC has more H20 capacity, it goes faster. If you need the speed over the CM, it's your ride.

How Much Does It Matter? Overall Summary

As long-range shooters, we tend to obsess over every little detail. After all, we’re trying to hit r...

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[CBH Australia]

Well, I solved the CM/PRC controversy by staying with my 260 and going to the 7:08 if I needed more. And as for putting more powder behind 6.5, try my 6.5 Gibbs. Just sayin...

How would a well built 7-08 compare with 6.5manbun if you had all being equal to run long projectiles etc?

My 7-08 is a factory Tikka CTR and I like it.
I saw a you tube clip comparing .308, 7-08 and the CM,

His bias was toward the 6.5 of course but the numbers he put up didn't show it was a real gain. He kept using terms like close and not far behind. I maintained the 7-08 seemed like a great round after his video. Ive always had a .308 on hand as well

 

[Sending156s]

keep us posted. when I had my PRC running once I started to get 3100 with the 153 Atip or 156 EOL no matter if I was using Retumbo or RL-26 I started to trash the brass and when I was at 3135 it was destroying brass only 3-5 reloads at most on Gunwerks brass.
I am running on a long action 28 inch barrel and didn't matter because accuracy was at much lower velocities
one of my biggest problems is people always posting unrealistic velocities with out qualifying how hard it is on brass and accuracy usually is no where near those velocities
I have had the opportunity to use a pressure trace on a few occasions and if people only knew how bad there pressure reading ability really is

Glad you are interested. Today has just been cloudy with just some drizzle. Wife is saying suppose to be bad weather tonight and staying wet until Wednesday when it turns beautiful. With a chance of rain I have been working on my shooting stations. I had a 25 yd pistol & a 100 yd rifle, but I've sold my horses and now have a 270 yd station 10 steps outside my reloading shop. About 75 yds farther I have a 300 yd station I'm setting up.

I'll include my reloading notes & data pages along with target & printout from the LabRadar. How did you cut the barrel throat to take advantage of the long action? What is a pressure trace you discussed? I was using 57.8 & 60.0 RL-26 to get the 3200+. Nothing bad happened, but I had a harder bolt lift & slight ejector marks on the brass. I'm using ADG & Nosler brass. I have had some Lapua brass on backorder since December, but still no word on it arriving. I cant see being so hard on my barrel & brass when I don't need to. I feel if I can back off the charge and still have over 3000 fps that is plenty good. Also, while working up to max I saw a couple of beautiful nodes where my SDs & ESs were low single digit. In addition to my barrel being custom throated for the 156 EOLs I received a seating stem from Forster hand polished to fit the 156 EOLs. That made seating my bullets a charm. I leave it set and don't use it for any other.

Have a good evening, Lynn

 

[can1010]

the pressure trace will register the barrel pressure. just like a labradar registers velocity. it really opened my eyes it made what you normally look for in pressure indicators don't always tell the whole story. I seen flat primers under 60000 psi and round primers just over 70000 psi, seen ejector marks all over the place depending on brass hardness and how you size your brass and quality of dies, I can honestly say things are not always what you think with pressures. measuring brass expansion is the best indicator but is also the hardest. bolt lift changes is a good indicator but quality actions will hide the truth.
I understand the weather issues. I have been working with the 6.8 western case and need to fireform some for the 30-6.8 western.
my second PRC barrel arrived today it has the wider chamber to help with the sizing issues and bolt click and we wont see good weather for a few days

 

[Kimber7man]

I don't know about a lesson as I'm really not that great of a shot, I'm a 3/4 moa Shooter at my best, knowing the wind is the hardest part of it

How about another Hoosier? I'll bring a Creedmoor and a 308...

 

[Kimber7man]

How would a well built 7-08 compare with 6.5manbun if you had all being equal to run long projectiles etc?

My 7-08 is a factory Tikka CTR and I like it.
I saw a you tube clip comparing .308, 7-08 and the CM,

His bias was toward the 6.5 of course but the numbers he put up didn't show it was a real gain. He kept using terms like close and not far behind. I maintained the 7-08 seemed like a great round after his video. Ive always had a .308 on hand as well

I think the 7mm08 with the 150 ABLR or the 162 ELD would give the Creedmoor a run for its money.

 

[ButterBean]

How about another Hoosier? I'll bring a Creedmoor and a 308...

Your welcome anytime Bud

 

[Subzero]

I'm not sure what the big deal is with the PRC. I don't think it has much of a practical purpose or advantage over the 6.5cm. If your hunting deer or pronghorn sized game, a 6.5 bullet is a great bullet diameter to do that with. I've used my 6.5cm for this purpose and it works great.

What I wouldn't do, is add 200fps to the same bullet and use it for elk. A couple hundred extra fps doesn't convert the same little bullet into an elk appropriate bullet.

I would recommend a 7SAUM over the 6.5PRC. The long 7mm bullets have a higher bc than the 6.5's, and would be more appropriate for elk.

 

[ButterBean]

I'm not sure what the big deal is with the PRC. I don't think it has much of a practical purpose or advantage over the 6.5cm. If your hunting deer or pronghorn sized game, a 6.5 bullet is a great bullet diameter to do that with. I've used my 6.5cm for this purpose and it works great.

What I wouldn't do, is add 200fps to the same bullet and use it for elk. A couple hundred extra fps doesn't convert the same little bullet into an elk appropriate bullet.

I would recommend a 7SAUM over the 6.5PRC. The long 7mm bullets have a higher bc than the 6.5's, and would be more appropriate for elk.

There's been plenty of Elk killed with a lot less

 

[Gibbshooter43]

I realize that we've strayed from the original question, but I'm wondering what the PRC does that can't be accomplished [for practical purposes] by the 260AI or the 6.5x284. For that matter, within the first 600 yards, the 260 will do most anything the CM will do, or am I completely off base here?

 

[Another Casual]

I realize that we've strayed from the original question, but I'm wondering what the PRC does that can't be accomplished [for practical purposes] by the 260AI or the 6.5x284. For that matter, within the first 600 yards, the 260 will do most anything the CM will do, or am I completely off base here?

What does anything do the 30-06 can't do? Lots of ways to get a 6.5 bullet to 2,800-3,100 fps. Long action, short action, mag bolt face, standard, wild cat, SAAMI. Variety is the spice of life.

Over the ones you mentioned, the PRC has more factory rifles chambered for it and a manufacturer that supports it. Us on the forum are in the minority, most people buy factory rifles and feed them a few boxes of factory ammo a year. Remington really dropped the ball on the 260 by not giving it more factory options when it launched, but Hornady has a rep for standing behind their products.

 

[ButterBean]

I realize that we've strayed from the original question, but I'm wondering what the PRC does that can't be accomplished [for practical purposes] by the 260AI or the 6.5x284. For that matter, within the first 600 yards, the 260 will do most anything the CM will do, or am I completely off base here?

Nothing that anything else won't do in the hands of a capable shooter who has put in the time and knows his weapon and his limitation's, as always is just boils down to personal preference

 

[762x51]

I realize that we've strayed from the original question, but I'm wondering what the PRC does that can't be accomplished [for practical purposes] by the 260AI or the 6.5x284. For that matter, within the first 600 yards, the 260 will do most anything the CM will do, or am I completely off base here?

there's just not enough marketing around the 260 in my opinion. my smith has been trying to get me to build a 260 for years to replace my .308 that he built me. but i had never heard about it until i first met him. my local cabelas carried one load of nosler 260 ammo and it was $40+ a box. meanwhile, there's 10 different boxes of 6.5 creed in all sorts of loads and bullet weights with hunting loads starting at $16 a box (pre-pandemic and demoturd takeover of our government).