Has anyone tried RL26 in 257Wby?

[aardvaark]

Recently I bought a used 257Wby in a MarkV. Couldn’t justify spending $2 a piece for Hornady brass so I dug through my brass collection and came up with about 100 pieces of 7mm Rem Mag brass. Resized it thro the Wby full length die and fire formed it with 63gr of H4831 and Horn 117gr BTSP. Worked really well, the necks are between .050 - .080 short so it looks like I won’t have to trim them for a while. They ran around 3100fps and shot between 1.5 - 2”

Now for some accuracy. I happened upon a couple pounds of RL26 a few months back so I thot I’d try that. Cuz it’s supposed to be the bee’s knees for magnums. (See what I did there, bee’s knees in a ‘bee magnum?) Couldn’t find a recipe anywhere so I went to the burn rate chart and RL26 is right beside H1000. So I started at 71.6 which is .4 below the recommended min for H1000. And went up .2gr at a time one shot of each and chrony’d all of them. Didn’t get a reading on the first 2 cuz I didn’t have the chrony set up right. At 72.8 the bolt got stiff and the case head had some bruising on it so I knew it was maxed. And it was at 3649 FPS.

Compared that to the Hodgdon site that I got the H1000 recipe from and saw I’m over 300fps faster than the max H1000.

Should I be concerned about this huge FPS jump? I cannot find any pressure signs till I hit that 72.8 None at all. Measured the case head expansion ring and it was at par with the fire formed brass until it jumped .001 at the 72.8 as well as the other pressure signs. It doesn’t kick noticeably harder than my fireform rounds, hard to tell what it sounds like cuz of ear protection.

I’ll wait to see what the response is from you guys before I fire any more of that ammo. But I feel comfy with it in all respects except for the huge FPS jump.

[brewster29]

RL powders often don't show pressure signs in a linear fashion like many other powders. They will be happy until you are suddenly way over pressure. I found this QL data on line, not exactly what you have but similar enough to think you are running extreme pressures.

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[Dean2]

There is no polite way to say this; you are proving why so many people just should not reload. You are so far over pressure the only thing saving your azz is just how strong a MKV action is and the huge freebore on Weatherby chambers. DO NOT SHOOT any more of this ammo.

There are SO many things wrong with how you have proceeded here that I am not even going to try to get into giving you advice, you should shoot factory loads only.

[elkhunter11]

Originally Posted by Dean2

There is no polite way to say this; you are proving why so many people just should not reload. You are so far over pressure the only thing saving your azz is just how strong a MKV action is and the huge freebore on Weatherby chambers. DO NOT SHOOT any more of this ammo.

There are SO many things wrong with how you have proceeded here that I am not even going to try to get into giving you advice, you should shoot factory loads only.

A pretty good assessment.

[Salavee]

Originally Posted by aardvaark

Recently I bought a used 257Wby in a MarkV. Couldn’t justify spending $2 a piece for Hornady brass so I dug through my brass collection and came up with about 100 pieces of 7mm Rem Mag brass. Resized it thro the Wby full length die and fire formed it with 63gr of H4831 and Horn 117gr BTSP. Worked really well, the necks are between .050 - .080 short so it looks like I won’t have to trim them for a while. They ran around 3100fps and shot between 1.5 - 2”

Now for some accuracy. I happened upon a couple pounds of RL26 a few months back so I thot I’d try that. Cuz it’s supposed to be the bee’s knees for magnums. (See what I did there, bee’s knees in a ‘bee magnum?) Couldn’t find a recipe anywhere so I went to the burn rate chart and RL26 is right beside H1000. So I started at 71.6 which is .4 below the recommended min for H1000. And went up .2gr at a time one shot of each and chrony’d all of them. Didn’t get a reading on the first 2 cuz I didn’t have the chrony set up right. At 72.8 the bolt got stiff and the case head had some bruising on it so I knew it was maxed. And it was at 3649 FPS.

Compared that to the Hodgdon site that I got the H1000 recipe from and saw I’m over 300fps faster than the max H1000.

Should I be concerned about this huge FPS jump? I cannot find any pressure signs till I hit that 72.8 None at all. Measured the case head expansion ring and it was at par with the fire formed brass until it jumped .001 at the 72.8 as well as the other pressure signs. It doesn’t kick noticeably harder than my fireform rounds, hard to tell what it sounds like cuz of ear protection.

I’ll wait to see what the response is from you guys before I fire any more of that ammo. But I feel comfy with it in all respects except for the huge FPS jump.

According to Quickload your pressures are running just shy of 77,000 psi with
72.9 grs of RL26. The same charge wt of H1000 yields 66466 psi. for a MV of 3361 fps. Those are default values in QL, but will be pretty close. Your rifle will be different and/or your chrony may be off a bit .

[Salavee]

Originally Posted by Salavee

According to Quickload your pressures are running just shy of 77,000 psi with
72.9 grs of RL26. The same charge wt of H1000 yields 66466 psi. for a MV of 3361 fps. Those are default values in QL, but will be pretty close. Your rifle will be different and/or your chrony may be off a bit .

The above is with the proper brass.. not the brew you made up - I missed that when part when I first read your post. I'm with the other guys , Stupid strokes for stupid folks.

[jeprli]

Just because two powders are next to each other on burn rate chart does not mean equal charges are in order, nevermind starting at above max to begin with. 257bee is too fast even with slowest velocity powders, find a load that shoots and be done with it. No need to blow your face off in order to claim a few fps above reccomended.