Home Forums Reloading Big Game Rifles New barrel, need to start all over....

New Bartlein barrel, .300 wsm on a Winchester M70 action. Previously on the original factory barrel the rifle really 65/65.5 grains of H4350, no pressure signs anywhere that I was aware of,

Today, first shots through the brand new barrel were factory Nosler 180 grain accubonds, other than not even being on paper, no issues's, 6 shots total.

Went to handloads, brass fired 4 times in original factory barrel, I knew enough to start low and went 64 grains, same jug of H4350,

"sticky bolt lift" if that's we call it, no so much on the intial vertical lift of the bolt but more of just as you start to pull back horizontally to eject spent shell,

shot 3 more, all same issue.

I can chamber a full cartridge, and then eject the same unfired cartridge with no issue.

64 grains should be well with in book specs,

So lets start over, where?

Speer manual shows 61g to 65,

Hodgens shows 58 g to 62 for the GMX and 61 to 65.5 for the Nosler Partition.

So, looking at these numbers, I may have started a a little too high at 64g? I'm shooting 165 grain Sierra GameKings.

And, start with new brass in a new chamber?

and before anyone asks what speeds i was seeing, No chrono.

Also, any idea which bullet would give pressure more quickly, 165 grain SGK or a Barnes 165 TSX?

165 GK according to Sierra H4350 58.6 - 67. As usual start at the bottom and work up. Monos will usually hit pressure before cup and core. I can’t even begin to say why you had sticky extraction, but I do have 3 rifles that are tight, match chambered and all 3 had higher velocity per charge from the manuals, but then I never work up a load without a chrono. No Chrono means no facts which means just a guess.

Ditch the used brass, start with new because 9 times out of 10 the custom chamber is going to be tighter than factory. You said they chamber & extract fine before firing, but I still would use new brass with a new chamber.

Buy a chronograph, a prochrono digital is around $100. It'll tell you right off the bat if you're too heavy on the charge weight. I won't fire the first round through a new barrel without the chronograph out, it's a waste of components in my opinion.

I'll know if I'm heavy on the charge at what velocity?

My references list max V anywhere from 2976 fps to 3047....

shopping for chrono, next on the list, Like tonight.

shopping time, but what facts will the chrono tell me?

What will be my clues?

Better check your max cartridge length! You may be up against the lands. New barrel might be way shorter throat.

I was off the lands by .005

Pressure is directly related to velocity. If you chronograph your loads and you're seeing 3200 fps then it's likely pressure causing your hard extraction and you need to back off some. If you're seeing 2900 fps then you're not likely over pressure so it's something else causing it. 3047-2976 is only 71 fps, that's pretty much a rounding error or could be explained by one being a 24" barrel vs 26" on another. Reloading manuals are starting points but you need to let your rifle tell you what it likes. Manuals don't always agree with each other either, I've seen as much as 7 grs. difference listed for a max load between manuals, using a chronograph I found the max for my rifle was about halfway in between the two manuals.

Re-reading your post I saw you said factory loads ejected fine but handloads didn't. The first thing I'd do is chuck the brass from your old barrel and start with new brass, factory chambers are usually big and it's likely your old brass has expanded at the web where standard full length dies won't resize. Get the chronograph too, but start with some new brass instead of the stuff shot in another chamber.

Also .005" off the lands is fine if you've worked up to it but that close will give more pressure than something that's SAAMI length. Another reason to have the chronograph so you can see what changing your COAL does to your velocities.

thanks for the info,

For clarification, my hand-loads would load and eject just fine, if unfired,

Once fired, the hand-loads became difficult to extract.

Chrono on the way.

A slightly tighter neck and shoulder in the chambering will do what you are describing - I had that when I replaced my factory 260 barrel with a custom barrel, with slightly tighter spec’s than a standard reamer. I traded a bit of velocity for accuracy.

If you have old fired brass compare your fired neck sizes on the old and new barrels to see if there is any difference.

Bingo. Either start with new brass or try a SBD.

The web?

Near the case head.

http://blog.cheaperthandirt.com/wp-content/uploads/2016/03/The-Cartridge-Case-3.jpg

You may find the custom barrel to be a bit tighter than the factory barrel and you just might be getting a higher velocity than what you where getting from your old factory barrel.Since you didn't have issues with factory ammo,your load is probably too hot for your new barrel.Another thing I'd do is seat your bullet deeper..0005 off the lands is close enough to give you a pressure spike.That close probably isn't necessary with a good barrel.I usually start at .030 off and find that to be a very good starting place for most of my rifles.I've watched my velocities go way up as I've seated closer to the lands,especially if your At max load already.My 300WSM has no freebore to speak of.I usually cannot shoot max book loads.I'm getting good velocities with a bit less powder than what the book calls for.I can use max book loads for 180gr bullets and find it to be about the max load with 165gr bullets in my rifle.Shows you,every rifle is different and you should always work your way up to the max for your rifle.Getting the chronograph should help you a lot.At least you will know where your at with your loads.

'hunter, thanks for the reply,

what powder have you found to be top shelf for the .300wsm?

When you say you've found "good velocities",,,,,, what numbers are we talking here?

Now that I look at my Speer reloading manual, I see what you mean about using the 180 grain load has max for your 165.

Using that analogy, my 64 grains was a half grain over book. the 180 max is 63.5,

I’ve used the “pass thru” die from PVA on some 6 CM and BR brass and it’s legit. Josh makes bushings that’ll handle up to the non belted magnums... WSMs, SAUMs etc.

Worth a look.

Reloader-17 gave me the highest velocity with 165gr bullets @ 3228fps.That load was below book max.I didn't see any pressure signs,but my chronograph and my 4" group size told me it was time to quit.I shot 65.0grs of Reloader-17 before that and was getting 3150fps and 2" groups.Finally velocity that was getting into 300 Win Mag territory,but accuracy just wasn't there in my rifle.The powder I finally have settled on is Win 760.65.0grs gave me 3150fps with a 165gr bullet,but it was maxing out with this load,so I dropped downed to 64.5gr @ 3100fps and have used that load since.My rifle shoots it around 1/2".All these loads are below book max.Goes to show you how every rifle is different and why you also should start low and work your way up at least until your familiar with your rifle.

If I had to guess I would have to think the new barrel is shooting faster. This is the reason for a chrony. I would also try some new brass.

However .0050 off the lands is not the same as .00050.