Thought I'd throw this out there for feedback. Just got a new Kimber in 300WSM, and shot it for the first time today. I used the Federal Premium 180 Accubonds. Very accurate. Two 3 hot groups way under an inch at 100 yds. BUT; there were clear pressure signs. Bolt was sticky on opening (significantly so). There was some marking of the ejector slot on the case heads. Primers didn't look particularly flat however. Prior to first shot, I cleaned the barrel with a few patches of Hoppes and a brush. Ran a dry patch before shooting. Did so again after 4 shots (thinking of barrel break in). The above pressure signs were present on every round. Any ideas?

I'd suspect ammo rather than the rifle. I'd try a different make or lot # of ammo.

I certainly hope it is the ammo, and plan to call Federal about it. Definitely going to try another load.

Was your chamber totally dry. A little solvent in the chamber can cause pressure to go waaay up.

quote:

Originally posted by skunk:
Was your chamber totally dry. A little solvent in the chamber can cause pressure to go waaay up.

I can't be 100% sure. Thought it was (dry), but maybe I'm wrong. The next time I shoot it I'll take extra care with that. It has never been a problem with other rifles, but the WSM case is so fat, with such a sharp shoulder, maybe it takes a little more attention. Thanks for the tip.

WSM factory ammunition is famous for being loaded to the upper edge of pressure limits in an attempt to match the performance of larger cases.

Loading to abnormally high pressures is not unusual with newly-introduced cartridges, and the factories always scale back the pressure in a few years as they anticipate rifle caliber conversions will occur using actions of unknown strength.

Try another lot of ammunition to see if it behaves more properly in your rifle.

BTW, the presence of lubricant in the chamber has no effect on the pressure generated by the firing of the cartridge. Lubrication may have an effect on the dynamics of how the case stretches, which may result in the fired case head bearing more firmly against the bolt face, this causing sticky bolt lift.

The fact that your primers do not appear excessively flattened has more to do with your chamber's "headspace" (actually, the relationship of the cartridge's base-shoulder dimension to your chamber's corresponding dimension) being minimal than with the pressure generated by the firing of the cartridge.

I have never fired any factory fodder in my 300WSM, but the two rifles in this caliber that I have had hands on in this cartridge have had tight chambers. You may have to try a little lighter bullet as the heavier/longer slugs could be encroaching on the lands in the barrel which would increase pressure.

yay! my first post haha

I had high pressure signs in TWO guns, the same day, with Federal AccuBonds. One was my Browning 300wsm, the other was my brothers Howa in 300win. In both guns, the bolts got sticky. The Howa was VERY hard to open. This was a few years ago, right when the AB was first available. Didnt happen in my WSM with Winchester ammo. I think Federal loaded this particular bullet a bit hot. FWIW, accuracy was less then stellar in both. Acceptable to most, but for us, didnt cut it when (at the time available) Fail Safe's could print MOA or better in 180gr out of both guns

quote:

Originally posted by MileHighShooter:
yay! my first post haha

I had high pressure signs in TWO guns, the same day, with Federal AccuBonds. One was my Browning 300wsm, the other was my brothers Howa in 300win. In both guns, the bolts got sticky. The Howa was VERY hard to open. This was a few years ago, right when the AB was first available. Didnt happen in my WSM with Winchester ammo. I think Federal loaded this particular bullet a bit hot. FWIW, accuracy was less then stellar in both. Acceptable to most, but for us, didnt cut it when (at the time available) Fail Safe's could print MOA or better in 180gr out of both guns

Interesting! I talked to Kimber today, and of course they thought it was probably the ammo. They suggested trying different loads, which I certainly will do. They also thought the gun might be a little stiff as a result of being new. Given that the pressure is evidently quite high, I'm surprised it shot so well. The dealer may have had this ammo on the shelf for a year or two for all I know.

well all i can say is that after seeing the same pressure spike in 2 different guns, in 2 different calibers, outside of the fusion ammo...i'm sticking with Winchester for factory ammo when needed

I have a Kimber 8400 in 300WSM in which I have shot Federal factory ammo. I have shot 180 gr Accubonds and 180 gr TBBCs. Both loads are quite accurate with no pressure signs in my rifle.

sticky bolt and no flat primers? normally they flatten primers before you have to take your shoe off and hit the bolt to get it open.

I had a kimber 300WSM and it flattened primers with federal 180gr round noses. shot an inch for 5 shots so that was OK

I'm not sure about WSM ammo, but my dad and I encounter this fairly regularly with Weatherby factory ammo. They are noted as being loaded "hot" right off the shelf. So far, we haven't had any problems in either of our rifles firing this ammo. Unless you start seeing flattened primers or severe extractor marks, I'd let it go. Double check your rifle for all of the things mentioned above, and just keep it in the back of your head while shooting.

quote:

Originally posted by Clayman:
I'm not sure about WSM ammo, but my dad and I encounter this fairly regularly with Weatherby factory ammo. They are noted as being loaded "hot" right off the shelf. So far, we haven't had any problems in either of our rifles firing this ammo. Unless you start seeing flattened primers or severe extractor marks, I'd let it go. Double check your rifle for all of the things mentioned above, and just keep it in the back of your head while shooting.

I've heard that before about Weatherby ammo. The extractor marks were not severe. Perhaps some of the sticky bolt lift will go away as the gun shoots in, who knows. The idea of doing anything to the gun is not appealing since it shot so well.

Jeffrey, I've had four 300 WSM's including two Kimbers. Factory ammo has always given me high pressure signs... I tend to think the "problem" is two-fold.

WSM ammo is loaded to the gills.

WSM dimensions (ie, large surface area, minimal taper) lend themselves to "sticky" extraction at the highest pressures.

PS, where in the central coast are you located?

One of the guys I work with just got a new Savage in .270WSM. It BLEW primers twice in ten shots with its first box of factory loads. I talked him into starting reloading and pulled the rest.

quote:

Originally posted by Brad:
Jeffrey, I've had four 300 WSM's including two Kimbers. Factory ammo has always given me high pressure signs... I tend to think the "problem" is two-fold.

WSM ammo is loaded to the gills.

WSM dimensions (ie, large surface area, minimal taper) lend themselves to "sticky" extraction at the highest pressures.

PS, where in the central coast are you located?

Hi Brad,
Thanks for the comments. I do hope that some other factory load will not be loaded quite so high. I live near San Luis Opispo, on Morro Bay.

well it IS quite possible all WSM is loaded pretty stiff. really makes you wonder how much powder the factory sticks in there!! when you look at reloading mans for the wsm vs wm, the loads are usually very close in grains.

in my old rifle, i shot Fed Fusion 165, Winchester AB 180, Fed AB 180, Win FS 180, WIn FS 180, Win NBT 150 (neat to see what it does to an antelope!) Win FS 165, and Win PP 180.

out of all those, I only ever had pressure issues with the Fed AB 180's. The Win FS 165 is great ammo, my preffered factory round. Also bought 150 of them when they were going dirt cheap (should have bought more)

Jeffery

Strange thing is...

A buddy of mine had a Browning A Bolt and a Blaser R 93 in 300 WSM.

With Winchester ammo Both rifles had hard bolt manipulation.

With Federal both were fine.

quote:

Originally posted by JeffreyPhD:I live near San Luis Opispo, on Morro Bay.

Hah, was there last September... my best friend moved to your area from Montana... he lives just off Lake Lopez in AG.

Jeff,
I have a 270wsm, two 300 wsm, and a 325 wsm. All Model 70's. All have been tried on lots of factory ammo. Just had trouble with one of the 300 wsm's. It had scoring on the side of the casing after firing, and the bolt was very hard to raise. Just some slight extractor marks. These were the first two shots fired from this rifle. To say I was alarmed is an understatement. I took it to a nearby gunsmith who inspected the chamber to confirm his suspicions that the chamber was badly finished from the factory. He ran a ream through it and everything is fine now. It will shoot anything, and is a fine shooter.
Good Luck with yours.

Mike in Washington state.