6.5 Hammer problem???

[HARPERC]

I had a 7 twist that would not stabilize the 137's at 6000 feet. Call and talk to Steve. He said they see that every so often for whatever reason.

Measure twist-even custom barrels come out of spec.

Regardless call Steve, and see about another bullet no point in ice skating uphill with this one.

 

[parshal]

Mine was measured at 7 twist.

 

[Petey308]

Are you crimping? How much jump to the lands do these loads have? How much bullet is in contact with the neck of your case? What's your brass prep method? What brass are you using?

Issues with stability aren't always due to twist rate, especially if it's an inconsistent/intermittent issue. If some rounds are experiencing excessive yaw in flight, that can result in bullets impacting at angles. If that's your issue, you have to start troubleshooting to find the actual cause.

Because you're not experiencing issues with other bullets, I tend not to think it's an issue with your crown or even twist rate. You need to start ruling out things though, one at a time, so verifying your twist rate is still something I'd recommend.

Sure, you can just stop using this bullet and try another, but ultimately that's not helping you figure out your actual problem so you can prevent it in the future. That's obviously up to you though.

 

[6.5shaggy]

Thanks guys for the input. I still haven't checked the twist but the way it shoots the 153 and 156 Bergers I am guessing it's a 8 or very close. I had multiple rifles to test today so the PRC stayed home. I had already tried faster powders (IMR and H 4831/4350) and got pressure at 3050-3200. I have RL 17, IMR 4064, and h414 left as for faster powders but I think 3300 with the 123 is pretty good by my research, any suggestions are appreciated. I am using a light crimp with a lee fc die. The Bergers have been very good for me for years. I have never used Hammers or monos in general but the customer wants me to develop a load so here we are.

 

[WYO300RUM]

I didn't have time to read thru all posts but those two powders are too slow for that bullet. I use RL23..Hard to find now but medium slow powders are better. Had same thing with 181 hammer in 300 RUM . H1000 better than Retumbo or N570 . Butterbean or GL Taylor can stear you in direction. He has spreadsheet on a lot of calibers with Hammers.

 

[Hard rock]

I didn't have time to read thru all posts but those two powders are too slow for that bullet. I use RL23..Hard to find now but medium slow powders are better. Had same thing with 181 hammer in 300 RUM . H1000 better than Retumbo or N570 . Butterbean or GL Taylor can stear you in direction. Bob has spreadsheet on a lot of calibers with Hammers.

N560 will be your powder , I'm getting 3722 fps with the 109 absolute . The123 is at 3450 with N165 I'm expecting 3500 plus with N560 so velocity is not a issue . You need too check twist even a quarter less twist could cause problems , also check bullet runout ,if it enters bore off center it can leave the bore off center causing the bullet too yaw . Keep us posted because this is out of the norm with hammer bullets .

 

[snox801]

IMr 4959 or re26.
26 looks best but with an absolute you may need more space in the case and imr give you the most room with very good speed. You will probably end up with a full case of it.

 

[WYO300RUM]

N560 will be your powder , I'm getting 3722 fps with the 109 absolute . The123 is at 3450 with N165 I'm expecting 3500 plus with N560 so velocity is not a issue . You need too check twist even a quarter less twist could cause problems , also check bullet runout ,if it enters bore off center it can leave the bore off center causing the bullet too yaw . Keep us posted because this is out of the norm with hammer bullets .

Was thinking of using N565 I have plenty of. Have only 1 pd. Of 560. Plenty 570 and 565. Couple 555. 124 hammer with RL23 shoots great.

 

[Hard rock]

Was thinking of using N565 I have plenty of. Have only 1 pd. Of 560. Plenty 570 and 565. Couple 555. 124 hammer with RL23 shoots great.

I can't remember who posted yesterday but the load was 124 gr hammers with 64 grs of N560 at 3472fps I think you will run out of powder space with N565 ,but it will work . If you look at the burn rate chart N 165 is real close too R23 and burns even cooler than H4350 .

 

[WYO300RUM]

I can't remember who posted yesterday but the load was 124 gr hammers with 64 grs of N560 at 3472fps I think you will run out of powder space with N565 ,but it will work . If you look at the burn rate chart N 165 is real close too R23 and burns even cooler than H4350 .

Thanks I will try 560.

 

[WildRose]

I'm doing load development on a 8 twist 6.5 PRC with 123 Absolute Hammers. Using H1000 or Retumbo around 3200 FPS or IMR 7828 at 3300 FPS I am getting tight 100 yard groups around .7 MOA, but the bullets aren't stable; about half the bullet holes are 1/4 oblong and occasionally one is almost sideways. Am I pushing too hard? I haven't checked twist but it's a Douglas XX I personally ordered and chambered. It shoots the 153 Bergers at 2900 FPS into tiny groups about .4moa. Any thoughts are appreciated, it's my first adventure with Hammers.

Shaggy something really sounds off here. Can you by chance post a picture of the target? At that velocity it should be very stable.

What is your H1000 load?

 

[Stonyman88]

I'm doing load development on a 8 twist 6.5 PRC with 123 Absolute Hammers. Using H1000 or Retumbo around 3200 FPS or IMR 7828 at 3300 FPS I am getting tight 100 yard groups around .7 MOA, but the bullets aren't stable; about half the bullet holes are 1/4 oblong and occasionally one is almost sideways. Am I pushing too hard? I haven't checked twist but it's a Douglas XX I personally ordered and chambered. It shoots the 153 Bergers at 2900 FPS into tiny groups about .4moa. Any thoughts are appreciated, it's my first adventure with Hammers.

What's your load in Gr.? my PRC shoots the Hornady factory 143Gr ELD-X sub mils, .18 - .20 groups at 100, now I have to find a load to work up for the Berger 140 Gr or the 130 Gr, as 143 ELD-X seeds are now where to be found.

 

[6.5shaggy]

Stony88,
I have not loaded 140s in a 6.5 PRC. My 153 load is 55.7 gr H1000 for 2889 fps avg, 30 es and shooting about .4 at 100 yds. That's the first load I tried after a quick ladder test. There is room for improvement I'm sure.

 

[6.5shaggy]

Wild rose,
I didn't take pics of the target, and it will be the weekend before I can get back to the range but I will try the 123s again and will take pics for everyone to see. When I did a preliminary ladder I didn't shoot for a group but I dug for bullets and I found a couple, both banana shaped with no expansion from the dry sand backstop. I thought it was odd but I was only aiming at a used target from a previous session. The second trip out with the next test ammo is when I found it was cutting oval holes. This is still in a barrel break in process so it could go away. I have been hobby gunsmithing for 18 years and reloading for almost 40. I'm not an expert by any stretch but have seen a thing or two. This is my maiden voyage with mono bullets other than a box of old Barnes X ten years back(very unhappy experience) so I knew you folks could probably help.