How much more to safe pressure?

[TackDriver284]

I done load development on the 7mm Magnum with RL19 and 139 SST Interbonds and came across a nice group at 65.5 grains, with WMLR primer, at 3,090 fps. last week on a dry hot day. Nosler manual says 65.5 grains at 3,318 fps with a 140 grain bullet, of course different manuals may have different data, but this load is at 3,090 fps which is very slow. So I input all the data, including H20 case fill, in Quickload to see pressure and the max pressure is 61,000 psi and my 65.5 grain load pressure is 46,500 psi. It could be due to chamber size, slower burn rate on powder or maybe short bearing surface on the SST bullet. The 65.5 grain load shot nicely but I would like a little more speed. So I ran a ladder test this morning and it was very humid and wet:

66.0 - 3,062 fps
66.4 - 3,089 fps
66.8 - 3,116 fps
67.2 - 3,136 fps
67.6 - 3,176 fps
68.0 - 3,150 fps
68.4 - 3,184 fps
68.8 - 3,221 fps
69.2 - 3,239 fps

No pressure on brass. Book max is 65.5 grains and this ladder highest charge is 69.2 grains of RL-19 ( 3.7 grains over max ) and still have not achieved 3,300 fps yet. Is it possible to continue charges up to 70.2 grains which will be predicted at 56,000 psi (which is well under max pressure of 61,000 psi.) and right at the node of 1.1905 with a 26 inch barrel at a velocity of 3,300 fps.

What would you folks advise I do?

 

[RL338]

Hornady list 64.3gr of RL-19 as max @ 3100fps

 

[Tjay]

Alliant says .

Speer 140 gr SP Remington 3.28 24 CCI 250 Reloder 19 67 3,095 -

 

[TackDriver284]

Reloading manuals are just a guide and its tweaked lower than maximum because of liability reasons. I use the manuals to get a starting point to my load developments, but I see something is off here. You can increase charges if you understand how to read pressure to get to the maximum velocity. Not all cases have the same volume, some COALS are seated long which reduces pressure to make room to increase charges, bearing surface length, and bullet softness / hardness all affects velocity and pressure.

 

[Rocketvapor]

Sorry, that's from my Sierra book, not Speer,
says----64.6 for 3200 (rounded of course)
Nosler is the outlier in velocity.

 

[truck driver]

I have 4# of RL19 and no matter which cartridge I load it in the velocities are lower then published and lower then what was predicted by QL. You need some one to run you QL prediction tweaked to the velocities you are getting and then only use that lot of powder for that prediction and bullet weight only.

 

[TackDriver284]

I have 4# of RL19 and no matter which cartridge I load it in the velocities are lower then published and lower then what was predicted by QL. You need some one to run you QL prediction tweaked to the velocities you are getting and then only use that lot of powder for that prediction and bullet weight only.

TruckDriver, I agree, I already ran it after tweaking.

https://imgur.com/rUZ3uvR

https://imgur.com/aKBiT8N

https://imgur.com/i4PiPFl

 

[jimbires]

duplicate

 

[jimbires]

I would run up until I see pressure , or I get the velocity I'm looking for . I don't consider book max a definite top end charge stopping point . you have quickload adjusted to your specs , that's what I would work up towards . work up and watch for pressure . if you have short brass life back it off a little .

 

[69gto]

Book loads are kind of wimpy for 7mm Rem. you might do better with RL22.

 

[TackDriver284]

Book loads are kind of wimpy for 7mm Rem. you might do better with RL22.

True, RL-22 is my go to for the 7mm and 300 Mags. I just ran out of RL-22 and wanted to finish that last pound of RL-19 and get it cleared off my shelf before buying RL-22. I got so much un-used powder that I want to get rid of.

I haven't finished with this combo yet, highest velocity was 3,239 fps with 69.2 grains and I am sure it will push 3,300 fps once I get to 70.2 grains of Rl-19 to find my node of 1.190

 

[fightthenoise]

Everyone is really high on Reloader 26 as well for...well everything. 6.5 shooters love it, 30-06 shooters love it, magnum guys love it. I’m about to do some work up using 26 and a T3x Creedmoor and Model 70 .280 Rem so we’ll see if the hype is justified. If it pans out I will be loading some 162 ELD-X for my 7mm mag as well.


Sent from my iPhone using Tapatalk

 

[jimbires]

RL26 will give about 100 FPS over RL19 at the same case fill , and about 50 FPS over RL22 . I'm using RL22 in mine with a 160 AccuBond , but when it's gone I'll switch to RL26 . I have a load using RL26 for a 154 BTSP that shoots well . I used the 154 RL26 load in Kansas last year .

 

[69gto]

I am using RL26 in my 7mm WBY. getting 3250 fps with 150g BT, this is with a 24 inch barrel.

 

[TXbaldhunter]

I used to run IMR-4350 in my 7mag.It's an OK powder for the lighter weight bullets like 120-150gr bullets.I switched to Reloader-22 about ten years ago because it worked really well with everything all the way to 175gr.Recently I tested some Accurate 4350 and Reloader-26 with 150gr N.B.T.Both those powders worked real well,but I think Reloader-26 is the way to go in the 7mag with all bullet weights

 

[Dwh7271]

That’s a good shooting rifle.
Nicely done.

 

[DrMike]

Some fine riflery you're showing. Velocities?

 

[TXbaldhunter]

Some fine riflery you're showing. Velocities?

Each picture shows the velocity.The rifle is a Remington 700 Long Range Stainless Steel.All I did to it was work on the trigger and bed the recoil lug.

 

[DrMike]

Thank you. Aging eyes (and a fragile mind) overlooked the obvious. Those loads will work anywhere.

 

[desertcj]

Wow, that's a great shooting rifle with both A4350 AND RL26! I'm going to try H1000 with 140gr Etips mostly because I have a healthy supply.