300 WSM reloading and chambering problems

[itchytriggerfinger]

Hello all,
I could use some input here. I recently bought a custom rifle built by a very well known and reputable gunsmith.
It is built on a Stiller Tac 30 action, Bartlein barrel chambered in 300 WSM. To date, I have only fired 30 rds thru it.
My problems started with some 1x and 2x fired brass I bought to start prepping brass for load development while I was waiting for the rifle. The 1x fired brass is Federal and the 2x is Norma. After running the cases thru a Redding FL size die in a RCBS RC press set to cam over, I found the cases were hard to chamber and harder to extract. This issue remains unresolved.
I was able to find 200 rds of Federal ammunition loaded with 180 gr soft points. On two different outings to the range, the first time I shot 10 rds, letting the barrel cool and then cleaning between shots. The gun shot nice and I noticed zero issues.
The second outing I fired 20 rounds letting it cool and cleaning every 2-3 shots. As I shot I noticed the bolt was getting hard to lift.
This progressively got harder to open the bolt and decided I had better quit. Looking at the cases, the first 10, only one I could see a faint mark from the ejector. The second round of 20, every case it is obvious, some bad enough I could feel the edge of the brass that had flowed into plunger hole.
I can't imagine what is causing this and what changed between outings. The condition was very close temperature and pressure wise, it was at two different ranges with the first one being 500' MSL elevation and the second 900' MSL.
It has been suggested that for reloading I should be using virgin brass, (which I would be if I could find it) or possibly re throating the chamber.
I'm not sure what my next move is, I'm considering pulling the Federal ammo apart and backing off the charge to see if this alleviates the sticky bolt.
Any input would be greatly appreciated...
Thanks,
Jim

 

[rsnell]

Where did you get your loading data and what is it? The load may be too hot for your rifle. This would not be an uncommon problem with a custom chamber.

 

[Rick Richard]

Hate to say it, but if in doubt send it back to the builder for their evaluation. You will be money ahead and fewer headaches.

 

[Another Casual]

With regards to the overpressure signs on your second outing, I'd make sure there's no oils or solvents in the chamber when you're cleaning every few rounds. As above, it is probably worth it to contact your smith and see what they recommend.

 

[itchytriggerfinger]

Rsnell : The Ammo was Federal power shock 180 gr soft pt. I have not shot reloads. I cannot chamber sized brass that has not been fired in this chamber. I did pull a bullet and weighed the powder charge at 69.0 grains but not have identified the powder.

Rick: spoke to the builder, he did not seemed concerned, he did indicate that it is a short throat and it was like a " race car". He did offer to rethroat it but said I would sacrifice accuracy. He basically said I should be working up a load starting with virgin brass. Which is exactly what I would do IF I COULD FIND ANY...lol
I thought the next best thing was to break it in using commercial Ammo and then reloading it.

Casual: I cleaned the chamber with alcohol after every cleaning so I am sure that residual solvent or oil is not an issue.

As far as seating depth, I am at least 35 thousand off the lands.

What really has me twisted is why, of the same lot of ammo and almost identical conditions were the first ten shots fine and the next 20 were not? What could have changed? I mean, I realize it is a very gradual process but as the round count increases, the throat erodes slightly and that should alleviate pressure somewhat. Which makes me think, it should have been the other way around, showing pressure signs with the first shots and lessening with the subsequent shots. Or am I missing something? Below are pics of the first ten cases fired.

 

[itchytriggerfinger]

There might be three cases there that I can faintly see the outline of the plunger.

 

[itchytriggerfinger]

Here are the following 20. It seems every case it is obvious that the plunger impression is blatant.

 

[th82457]

I would ask the gunsmith what weight/brand/style bullet he chambered this for ? Also what is twist rate ? Factory .300 WSM's are 1:10 twist (Sako/Tikka is 1:11) If it is a short throat with unusually fast twist, that could spike pressure on 180 grain factory loads. Just another idea - may not be the case. I would be looking for a definite answer/solution before sending any more rounds through the rifle.

 

[vancewalker007]

First off don't mix cases from different manufacturers when reloading. Brass varies in thickness and can cause crazy pressure changes. Reloading is fraught with enough issues without injecting them right off the bat. If those used cases were not from your rifle you may not be able to even resize them to fit anyway.

Your pressure issue could be some hot (for your rifle's chamber) factory loads. It happens, a lot lately seemingly.

Your cleaning might have left some fluid in the gun and that combined with marginally hot loads = heavy bolt etc.

Your chamber neck or head space might be a little tighter than SAAMI since its a custom. If you continue to have issues with other factory loads you have the chamber casted to check these dimensions.

When working up your hand loads start low and work up slowly like in 0.2gr increments watching for pressure issues. Try to use powders that are less temp sensitive since it looks like this rifle might have a lower pressure max to minimize issues in the future.

 

[cohunt]

You said it was new-- what barrel manufacture? Possibly copper build up if the barrel was a bit rough? Have you tried copper cleaner or a bore scope?

 

[itchytriggerfinger]

th: It is marked 1:10 twist. I verified it, it is very close, maybe a hair faster at 9 7/8".

vance: I want to be absolutey clear, I have not reloaded any Ammo yet, everything that has been fired has been factory. Also, I did buy two different brands of brass, Federal and Norma. If and when I do load these cases, I will work up a load for each case to find the preferred load for each.
I am also positive that fluid in the gun is a non issue. After cleaning, I run several dry patches, followed by mopping the chamber and cleaning with alcohol then let dry.
I am sure the combo of a tight chamber and short throat are causing the issue, I just didn't expect commercial ammo to run this hot.
I am considering pulling several of the Federals apart, backing of the charge by 1 1/2 to 2 grains and shooting them to see what difference it makes.
The only other option I guess would be to send it back to the builder and have it rethroated.

 

[itchytriggerfinger]

Cohunt: the barrel is Bartlein. 1/10 twist. I borescoped it after the last session and before I cleaned it and the bore looks fine. Very little copper shows up while scoping it. I mean, I really got to look to find one or two small streaks in the grooves. And that was before I cleaned it. I have not yet used any aggressive copper remover as I didn't see enough to be a problem.

 

[Vol1975]

2 things
did you chronographs your loads and check speed for any thing strange

second
all Barrels are different. Some can be tight.
cleaning between rounds can and will have an effect. If you leave any residue in barrel or chamber can increase pressure.
I have also found that at least in my guns that a new clean barrel will produce a slight increase in pressure.
one of my guns is just below it's pressure limit.
So when I clean my gun and it's sparkle clean I've seen pressure signs. Hince I shoot a couple reduced loads to foul the barrel. From that point I don't see any more problems.
im not saying this is your problem I'm saying I've see it with a gun I own.
that barrel may be close to pressure with those bullets. Personally I'd foul the barrel and check the speed.

last. Can you fit a bullet into the fired case. U should have a loose fit between a fired piece of brass and a bullet.
if not then u have a problem with neck clearance from the reamer The smith used.

 

[vancewalker007]

th: It is marked 1:10 twist. I verified it, it is very close, maybe a hair faster at 9 7/8".

vance: I want to be absolutey clear, I have not reloaded any Ammo yet, everything that has been fired has been factory. Also, I did buy two different brands of brass, Federal and Norma. If and when I do load these cases, I will work up a load for each case to find the preferred load for each.
I am also positive that fluid in the gun is a non issue. After cleaning, I run several dry patches, followed by mopping the chamber and cleaning with alcohol then let dry.
I am sure the combo of a tight chamber and short throat are causing the issue, I just didn't expect commercial ammo to run this hot.
I am considering pulling several of the Federals apart, backing of the charge by 1 1/2 to 2 grains and shooting them to see what difference it makes.
The only other option I guess would be to send it back to the builder and have it rethroated.

Just wanted to make sure you knew not to mix brass. Not everyone realizes the differences that exist in brass, but it sounds like you are on top of it. I threw the fluid issue out there as a long shot. I would bet its a slightly tight neck or short shoulder. Don't try any Hornady Factory stuff in it until you solve it as they have been putting out some really hot stuff lately.