Question for you guys running the 150gr NBT in your 7Mags. Are your getting anywhere near the Nosler manual listed top velocities?
Nosler shows 3248fps with 63gr IMR4350 out of a 24" tube. My Ruger likes 62gr but I'm only getting 2890. According to the manual, that's mediocre 280Rem speeds. I've had another member run my numbers through QL and it predicts that I can't get anywhere near 3200 at sane pressures.
I've got H and IMR4831 and RL22. Seems a lot of folks like these with the 150s, but some of the loads I'm seeing mentioned are above book max. Just wondering if anyone is getting accurate loads at anywhere near 3200 with these powders. If not, what speeds are you seeing with the 150s?
Just trying to decide whether to stick with the load I have or if there is actually enough extra velocity available out there to start looking for another load with a different powder.
I have no doubt that Nosler is getting exactly what it prints for velocities from the 7 Rem Mag. But they are getting those velocities from a Wiseman barrel(Wiseman for years made some very good pressure barrels for Nosler and others). These are likely made to very tight tolerances and will run pressures up with loads that will deliver lower velocities from other factory barrels.
The barrels of our factory rifles may have looser tolerances,different throat and leade configurations,made from different steels, different rifling, different lots of components,etc etc. This stuff can and does make a difference rifle to rifle and especially with a high velocity cartridge like the 7 Rem Mag. Other cartridges will easily show the same velocity differences and I have seen it with the 300 Win Mag.
as well,as just one example.Likely Nosler works loads in this very tight barrel just to be sure that we don't bump into pressure problems with our sloppier factory barrels but this causes us to see less velocity as well.
But the 7 RM is a very popular cartridge and has been chambered in many different rifles with different barrel characteristics.
I have a 24" Douglas barreled 7 Rem Mag that shows about 175 fps more velocity with a charge of H4831 and 160 gr bullet than a Krieger barreled rifle of the same length did. When manual data matches what I have gotten from my rifles it's more accident than anything else.
I know 4350 "works" in the 7 Rem Mag but it does not make my cut for powders in the 7 Rem Mag. I like powders a touch slower with that weight bullet...With the 150 gr bullet I have used H4831 and in my rifles have worked up to about 68 gr for about 3150 fps. This is a pretty "old" load and JOC used to use 69 of the WW II H4831 with 150 gr Partition for app. the same velocity.
When i see 3150 with a 150 gr bullet I stop,although a 26" barrel with more recent powders may do better.
I would reach for H4831 or 7828 with the 150. Recently I have been using 70 R25 and 150 BT for 3120 or so from a 24" barrel. Have not yet worked with the newer RL powders like 23 and 26. I'm still working on the last few pounds to R22 and 25.
