Early pressure signs with certain bullets.

[Rifleman513]

So I bought a new 257 wby back in January and have been working off and on to work up a load using 110 ABs. I bought one box of the cheaper 100gr loaded ammo to sight in and use the brass later and had no issues. I started with 7828 and started getting flattened primers and very faint ejector circles on loads that were only running 3150-3200 fps. I tried two other listed powders that I had on hand, multiple seating depths, and both Weatherby and Hornady brass. The only thing I didn't change were different primers.

So, this week I had enough and bought a box of 100gr Barnes TTSX and started fresh with some new brass. I got a great group with the max charge of 7828 at 3485 w/ a 24". Has anyone had trouble with excessive pressure with minimum or even below book charges and certain bullets. The accuracy was great but I never could get the pressure to come down enough with any decent speeds. I've never had any trouble like this with ABs and other guns I have loaded.

 

[Barrelnut]

I guessing it's the difference in bearing surface design of the two bullets. The 110 AB has a long bearing surface. The 100 TTSX has a smaller bearing surface area due to the pressure rings on the bullets bearing surface area. I have shot the 110 AB in my 25-06 and seem to remember it showing pressure quicker than 100 and 117 gr. Sierras.

Plus, Barnes bullets recommends seating their bullets far from the lands. This can decrease pressure also, if you had the ABs seated closer to the lands.

 

[Rifleman513]

I started with exact info from the Nosler site at 3.209 and the slowly started working out with same power charges. The velocities dropped off a bit but the pressure signs never disappeared. It seemed no matter what I did pressures and velocity were never going to match up. I was just curious if anyone had trouble with this. I assume that particular barrel and bullet just aren't going to work. It could be something with the bearing surface, jacket material, etc but so far I'm at a loss. At least the Barnes seem to be a good load so I will stick with them this year for pronghorn an mule deer. I just don't see any untested options that would be worth going back to try and make the accubonds work.

 

[cape cove]

Have you tried other loads in the cases you loaded with the 110 AB. Sometimes soft batches of brass can mislead you into thinking a load is hot when it is really OK.In my 257 WM i've used the 110 AB with a max load of 7828(71grs in mine) and gotten a vel of 3348 ft/sec from my 24" barrel. Seems to be inline with what others are getting.Also got good accuracy and vel with RL-22

 

[243winxb]

https://thefiringline.com/forums/showthread.php?p=4928827#post4928827

 

[JaoeyP]

So many variables go into the pressure formula, but yes, I have experienced different pressure signs with different bullets. I've been tinkering with a 243 HCR and was trying Sierra SMK's, Sierra TMK's, and Berger VLD's, all 95gr's. The SMK and TMK exibited similar velocities and pressure signs, but the VLD's could stand a bit more powder and velocity, all from the same batch of brass.

 

[Mikecr]

Forget a book, what is the seated relationship to your lands?