6.5 prc with 153 Atip

[Z06pilot]

I am putting together a 6.5 prc with a proof carbon prefit (7.5 twist) on a lone peak action. I am trying to get reloading components while I wait. With limited availability I was considering153 atips with H1000. Is this bullet too long to work out of a short action with a saami spec chamber. What kind of accuracy are people seeing with this combo? I would like to get some yellow box bullets, but it seems unlikely. Otherwise i can find eldx/eldm and 135 atip.

 

[acourvil]

I shot the 153 ATips out of a 6.5 PRC SAAMI spec chamber with H1000 and was very happy with them until they started blowing up. My barrel was 7 twist, so 7.5 might be different. But on a hot day with maybe 1200 rounds through the barrel, I lost 5 out of 50 during a match. I used the 153.5 Bergers out of the same barrel and never had a problem. Both bullets are long and with a short action you will be putting the bullet pretty deep in the case.

 

[Z06pilot]

I shot the 153 ATips out of a 6.5 PRC SAAMI spec chamber with H1000 and was very happy with them until they started blowing up. My barrel was 7 twist, so 7.5 might be different. But on a hot day with maybe 1200 rounds through the barrel, I lost 5 out of 50 during a match. I used the 153.5 Bergers out of the same barrel and never had a problem. Both bullets are long and with a short action you will be putting the bullet pretty deep in the case.











I am sorry to hear that. Was that recently? I had read some reports on eldm and atip failures a couple years ago, but was unsure if they made any improvements to the bullet or manufacturing process. I would love to find some bergers. About the only berger around is the 156 eol in factory loaded ammo. I would consider buying them to get me started since they use lapua brass. But I would have a hard time spending $1000 on factory ammo without knowing how it shoots and if it is temp stable.

What kind of jump do you have for atips and 153 bergers at sa mag length?

 

[Frank Green]

I shot the 153 ATips out of a 6.5 PRC SAAMI spec chamber with H1000 and was very happy with them until they started blowing up. My barrel was 7 twist, so 7.5 might be different. But on a hot day with maybe 1200 rounds through the barrel, I lost 5 out of 50 during a match. I used the 153.5 Bergers out of the same barrel and never had a problem. Both bullets are long and with a short action you will be putting the bullet pretty deep in the case.

If I did the math right in my head….with a 7 twist barrel and lets say you where pushing them at 3000fps. That gives you a bullet rpm of 308,000rpm. You start even pushing 300k rpm and bullet failure is going to happen. It’s just a matter of time.

Now factor in barrel wear (throat starts getting rougher) fouling etc…that will just amplify your problem. Other factors will have a impact as well. Temps, conditions and even type of barrel/rifling etc….

Not hammering on ya…but just giving you food for thought.

Later, Frank
Bartlein Barrels

 

[straightshooter1]

I am putting together a 6.5 prc with a proof carbon prefit (7.5 twist) on a lone peak action. I am trying to get reloading components while I wait. With limited availability I was considering153 atips with H1000. Is this bullet too long to work out of a short action with a saami spec chamber. What kind of accuracy are people seeing with this combo? I would like to get some yellow box bullets, but it seems unlikely. Otherwise i can find eldx/eldm and 135 atip.

Do you intend to load them at mag length? If so, what length would that be?

I've done just a little testing before a bought a few hundred and they performed nicely out of my 26" 8:1 barrel, pushing them with 57.7 gr of Retumbo to just over 3000 fps (COAL=3.028). That was pushing the pressure very close to max. The accuracy I got with the small amount of testing was good, but I need to do more to confirm I can consistently get that kind of accuracy.

I do feel that a 7.5:1 is a bit fast for them, especially if you're going to try and push the velocity anywhere near 3000 fps. And that's probably not possible anyway if you're loading to mag length. At COAL of 2.995, you can probably be good at 56 grs of H1000 and get something like 2800 fps, which just might work out nicely with your Proof barrel. You won't know till you give it a try.

 

[acourvil]

Frank’s comments are absolutely true. But it’s also true that the Berger bullets did not have any problem In the same conditions.

 

[acourvil]

I am sorry to hear that. Was that recently? I had read some reports on eldm and atip failures a couple years ago, but was unsure if they made any improvements to the bullet or manufacturing process. I would love to find some bergers. About the only berger around is the 156 eol in factory loaded ammo. I would consider buying them to get me started since they use lapua brass. But I would have a hard time spending $1000 on factory ammo without knowing how it shoots and if it is temp stable.

What kind of jump do you have for atips and 153 bergers at sa mag length

IIRC, the jump at mag length was about .070 fo the ATips.. This was a couple years ago, but I don’t think that have changed anything with the ATips, not sure about the ELDs, but I haven’t heard nearly as many complaints about them recently.

I have a friend that thinks the Berger 156s shoot better than the 153.5s, but I think he is shooting them in a 6.5 Creedmoor, not a PRC.

 

[GCBigTex]

I am working up a load with A Tips and Retumbo for my 6.5 PRC/ Curtis Axiom/ 24" Proof CF 7.5" twist. This rifle was my introduction to the precision rifle world and I have about 600 rounds through it currently. I notice that after about every 50-75 rounds I start seeing pressure signs (flat primers, sticky bolt lift, ejector swipes) due to fouling and an angry carbon ring that builds in the throat. I shot my first PRS match with it this past weekend (80 round COF) and that is where I got my round count when I start seeing these issues. It was excellent at bucking the strong wind (20 sustained and gusts to 30) vs the 6mm calibers that most were shooting that day. I will give more feedback after I go shoot my ladder test that I already have loaded. It looks like the 153 ATips are going to have a bit of jump due to mag length constraints.
@Frank Green I received my Bartlein 6mm blank that is being spun into a 6 Creed for future matches and look forward to shooting it. This is my first Bartlein barrel...

 

[Frank Green]

Frank’s comments are absolutely true. But it’s also true that the Berger bullets did not have any problem In the same conditions.

Understood that he didn't have any Bergers fail.

That being said...I've had Bergers blow up on me but never had any Sierra's or Hornady's fail.

I've had both Hornady and Sierra send me ammo/bullets for us to test. It could be there customer had issues with accuracy or failures and asked us to run them as they couldn't duplicate what happen at they're place. Same thing...no accuracy issues or failure issues that we could see.

It might be jacket thickness, bore size, bore wear/round count, twist and velocity and when he got to that certain point the Hornady's just said...Eh...where done.

Just a combination of stuff that worked against that load etc...sometimes it's hard to put a finger on it.

Dave here in the shop in his 6.5PRC PRS gun....and I'm not naming the bullet maker (wasn't Hornady by the way)...all of a sudden at around 950ish rounds on the barrel and...boom a bullet failure. He brought the gun/barrel in and had me look at it. I said, no chunks out of the edges of the lands even though there is a lot of wear in there but the barrel is really heavily carbon fouled. That could be creating a tight spot in the throat area of the chamber. That tight spot could be just stressing the jacket enough to cause issues. So he cleaned it really good and the carbon was still heavy. So I told him to give the barrel a light finish lap. He got about 90% of the carbon out. I told him to go shoot it. Ever since then...no more bullet failures. Same lot of bullets/same bullet maker. His barrel is now to the point that it's still shooting good but it's on it's last legs and he's getting ready to pull it and put a new stick on the gun.

 

[Z06pilot]

Do you intend to load them at mag length? If so, what length would that be?

I've done just a little testing before a bought a few hundred and they performed nicely out of my 26" 8:1 barrel, pushing them with 57.7 gr of Retumbo to just over 3000 fps (COAL=3.028). That was pushing the pressure very close to max. The accuracy I got with the small amount of testing was good, but I need to do more to confirm I can consistently get that kind of accuracy.

I do feel that a 7.5:1 is a bit fast for them, especially if you're going to try and push the velocity anywhere near 3000 fps. And that's probably not possible anyway if you're loading to mag length. At COAL of 2.995, you can probably be good at 56 grs of H1000 and get something like 2800 fps, which just might work out nicely with your Proof barrel. You won't know till you give it a try.

Yes I intend to load to mag length. I believe in an accurate mag, that would be about 2.955. It would be a bit disappointing to get only 2800 fps since hodgon has a load for the creedmoor with the 153 at 2721 fps.

I see berger has factory ammo with the 156 eol and they claim 2960. I believe they load it with lapua brass, if it is accurate and temp stable, it might not be a bad route to go initially to get a couple hundred rounds of brass while I wait for more components to come back in stock. I can't seem to find any reviews on it though. I would also be curious about what powder they use.

 

[straightshooter1]

Yes I intend to load to mag length. I believe in an accurate mag, that would be about 2.955. It would be a bit disappointing to get only 2800 fps since hodgon has a load for the creedmoor with the 153 at 2721 fps.

I see berger has factory ammo with the 156 eol and they claim 2960. I believe they load it with lapua brass, if it is accurate and temp stable, it might not be a bad route to go initially to get a couple hundred rounds of brass while I wait for more components to come back in stock. I can't seem to find any reviews on it though. I would also be curious about what powder they use.

The problem with getting the velocity you want with H1000 is that there's just not enough space in the case for this powder. It's not that you can't get that velocity with the 153 A-tips, you just need the right powder. . . like you might want to take a close look at RL-26 or IMR 7828 SSC or MagPro.

Yes, those factory Berger's are loaded in Lapua brass. That idea is not a bad one and you'll wind up with some good brass to reload.

 

[acourvil]

In my original 26 inch barrel, I was shooting the ATips 2980fps with 57.8gn H1000 and ADG brass. That was not a max load, but iit was not far from a max load. And remember speed is affected significantly by barrel length with H1000 and heavy bullets.

 

[White Mamba]

Here's 4 at 300 yards with 147 eld.
Bartlien 26" , 1in 7 , H 1000 , 2960 fps.
I picked it up from Someone who was blowing up the atips. So far so good,ill see how she holds up

 

[Cascade Hemi]

If I did the math right in my head….with a 7 twist barrel and lets say you where pushing them at 3000fps. That gives you a bullet rpm of 308,000rpm. You start even pushing 300k rpm and bullet failure is going to happen. It’s just a matter of time.

Now factor in barrel wear (throat starts getting rougher) fouling etc…that will just amplify your problem. Other factors will have a impact as well. Temps, conditions and even type of barrel/rifling etc….

Not hammering on ya…but just giving you food for thought.

Later, Frank
Bartlein Barrels

I had the same problem with with 153 A-Tip and 7.5 twist going 3050fps out of a 30" barrel. The barrel had maybe 100 rounds through it and I was losing 1 in 10. I switched to 150SMK with the identical load data and the problem went away. I think that bullet needs a 1:8 twist max. If I had to do it over again I'd buy a 1:8.

 

[acourvil]

I had the same problem with with 153 A-Tip and 7.5 twist going 3050fps out of a 30" barrel. The barrel had maybe 100 rounds through it and I was losing 1 in 10. I switched to 150SMK with the identical load data and the problem went away. I think that bullet needs a 1:8 twist max. If I had to do it over again I'd buy a 1:8.

That's pretty close to what I experienced, i.e., a 10% loss, albeit I was shooting about 2980fps in 1:7 twist. At that time, Hornandy's box said 1:8 twist MINIMUM, and their reloading data showed loads to 3100fps. But if you used the Miller formula it showed the 153gn A-Tip as not better than marginally stable with an 1:8 twist even at the top end of the speeds that Hornady published. I also had a good load for the 147ELDs; I never noticed any of the 147s explode, but I never shot them in any matches.

 

[ATTkid]

I've been using RL-26 for both 140 A-Max and 153 A-Tips and had no bullet failures from a bone stock Christensen MPR, 1:8 twist, carbon wrapped 24" barrel. 55.7 grains for the 140s, 55.5 grains under the A-Tips. The 140s are at 3055 fps, the 153s at 2960 fps, LabRadar verified by physical connection to the scope, a 5HD 7-35X56, mil-2 reticle. I'm pretty OCD about brass prep, particularly the primer pockets and flash holes. The 140s group 1/4" @ 100 yds, the 153s < 1/2", same distance, both 5 shot groups. In my experience bullets blow up from extreme velocity coupled with over rotation (too fast a twist rate). I've seen newer production rifles at 1:7 and 1:7.5 but I don't know why the twist rates are so fast. Just my opinion, no gauntlets being cast on the ground! Good shooting Gentlemen.