300 WSM velocity

[BossGobbler]

I have a question for those with more knowledge and experience than I do. Some background is that I used to use only factory Fed 165 Trophy bonded tip or Vortx 165 gr Barnes because it shot 3/4 MOA using those and I didn't reload. Occassionally I would find that some rounds would stick the bolt using factory ammo and forcibly struggle removing the brass. All factory ammo that I chronographed was around 3100 FPS to 3150 FPS. I figure maybe the chamber is dirty as it was usually after shooting alot. Could have been a "faster" round with more pressure, I suppose. For years, I used this ammo in this gun. Well, along came COVID19 and my favorite factory ammo is scarce and now appears to be extinc so I started reloading ammo for my gun. For the past 2 yrs, I have been working loads for various rifles so maybe 2500 rounds for so according to the number of primer boxes I used up. In all that time, typically ,if I got to max load for a particular powder/bullet combo the velocity was not up to that shown for the charge in the manuals. Well, that changed with my current setup using 165 TSX and H4350 and 68.0 gr powder. I reloaded some 165 TSX for my Fierce 300 WSM CT Edge rifle bumping the shoulder back 0.002 and trim to 0.010 less than max. I had a MagnetoSpeed on my suppressed rifle shooting that load and shot one round (not a clean barrel as 20 rounds were already down the tube previously using RL 19) I was shocked at the readout of 3260 FPS. I had to struggle to open the bolt. I thought, that is not right. SO, I shot another 3238 FPS, same result with the bolt stuck. Max load according to Barnes is 69.4 @ 3126 FPS with 24 inch barrel. My Fierce has a 22 inch barrel plus 8 inch suppressor. I seated the bullet BTO 2.230 while jam measures 2.335 for this bullet in my chamber (with hornady gauge). I shot one more and didn't shoot any more of those and then shot some factory Fed Barnes 165 TSX and the bolt was tight and difficult after shooting those as well. So I cleaned the chamber with a bore mop and shot factory loads again and ran the bolt more smoothly. I am somewhat afraid to shoot the remaining loads as the velocity is higher than I have seen in any other manuals. I started at 68.0 gr so I am moving down a few grains but I welcome any thoughts on this and why the higher velocity when not at max charge. Seating depth is my thought but IDK........ I will attach the fired brass which shows the ejector marks and primer.

 

[sako2]

Manuals are only a reference. Hodgdon max is 65.5gn for a 165gn bullet. You should check the bullet and powder makers data. And why would you start 1gn under max? They list starting and max data for a reason. Your load is to HOT for your gun.

 

[SJB358]

I have a question for those with more knowledge and experience than I do. Some background is that I used to use only factory Fed 165 Trophy bonded tip or Vortx 165 gr Barnes because it shot 3/4 MOA using those and I didn't reload. Occassionally I would find that some rounds would stick the bolt using factory ammo and forcibly struggle removing the brass. All factory ammo that I chronographed was around 3100 FPS to 3150 FPS. I figure maybe the chamber is dirty as it was usually after shooting alot. Could have been a "faster" round with more pressure, I suppose. For years, I used this ammo in this gun. Well, along came COVID19 and my favorite factory ammo is scarce and now appears to be extinc so I started reloading ammo for my gun. For the past 2 yrs, I have been working loads for various rifles so maybe 2500 rounds for so according to the number of primer boxes I used up. In all that time, typically ,if I got to max load for a particular powder/bullet combo the velocity was not up to that shown for the charge in the manuals. Well, that changed with my current setup using 165 TSX and H4350 and 68.0 gr powder. I reloaded some 165 TSX for my Fierce 300 WSM CT Edge rifle bumping the shoulder back 0.002 and trim to 0.010 less than max. I had a MagnetoSpeed on my suppressed rifle shooting that load and shot one round (not a clean barrel as 20 rounds were already down the tube previously using RL 19) I was shocked at the readout of 3260 FPS. I had to struggle to open the bolt. I thought, that is not right. SO, I shot another 3238 FPS, same result with the bolt stuck. Max load according to Barnes is 69.4 @ 3126 FPS with 24 inch barrel. My Fierce has a 22 inch barrel plus 8 inch suppressor. I seated the bullet BTO 2.230 while jam measures 2.335 for this bullet in my chamber (with hornady gauge). I shot one more and didn't shoot any more of those and then shot some factory Fed Barnes 165 TSX and the bolt was tight and difficult after shooting those as well. So I cleaned the chamber with a bore mop and shot factory loads again and ran the bolt more smoothly. I am somewhat afraid to shoot the remaining loads as the velocity is higher than I have seen in any other manuals. I started at 68.0 gr so I am moving down a few grains but I welcome any thoughts on this and why the higher velocity when not at max charge. Seating depth is my thought but IDK........ I will attach the fired brass which shows the ejector marks and primer.

Seeing as you are getting some stiff bolt lift, even with factory ammo, I'd guess you have a very tight chamber or something along those lines. If it were me, I'd load some rounds as singles or maybe doubles (.5 grain at a rip) with charges starting at the min and work up to the 3100'ish range with your 165's. This will get you back into the safe range and also allow you to maximize your rifles potential. H4350 and a 165 should be an easy button, so since you have a Magnetospeed it shouldn't take you long to narrow down the safe charges.

 

[BossGobbler]

Manuals are only a reference. Hodgdon max is 65.5gn for a 165gn bullet. You should check the bullet and powder makers data. And why would you start 1gn under max? They list starting and max data for a reason. Your load is to HOT for your gun.

Thanks for the response. As noted, I did check the data on Barnes's website beforehand for this combo. As to why start where I did, I wanted the hardest hitting accurate load and I had been told by another that somewhere near max is usually the 'best' load. So, I don't want to waste time, money or limited, difficult to find resources on loads I don't want to use anyway. Did I start too high, obviously in this case. Does everyone start with the minimum load data?

 

[BossGobbler]

Seeing as you are getting some stiff bolt lift, even with factory ammo, I'd guess you have a very tight chamber or something along those lines. If it were me, I'd load some rounds as singles or maybe doubles (.5 grain at a rip) with charges starting at the min and work up to the 3100'ish range with your 165's. This will get you back into the safe range and also allow you to maximize your rifles potential. H4350 and a 165 should be an easy button, so since you have a Magnetospeed it shouldn't take you long to narrow down the safe charges.

I have a Redding dial comparator and fired cases from this gun will typically range from +0.0004 to +0.006 above Sammi reference case. I don't know if this is normal or small. I can say my wife's Browning 300 WSM is .002 shorter by comparison. Do you think the seating depth is causing the velocity to be so high? I have taken a reloading class and 0.020 was the suggested starting point and this is about 0.100 from the measured Jam. I have had many people tell that Barnes TSX like the 'jump". Appreciated your thoughts.

 

[TXbaldhunter]

I think you are a bit over pressure with your load.Those WSM's are loaded at high pressure 63k to around 65k,a bit higher than most cartridges.I've seen some factory stuff that left some extremely looking pressured headstamp and primers.I have a 300 WSM.They are built a little different in the throat.They really don't have hardly any freebore.They have a long tapered lead.If you look at the SAAMI Specs you will see what I mean.A couple of things that will also kick your pressures up is carbon and erosion.My barrel was probably out of spec from the start.With 165gr bullets,I could never get close to book max loads.I was getting max velocity a few grains under max load.I had to use 180gr data for 165gr.After I got hundreds of rounds down the tube,I saw my accuracy drop way off.I got a Teslong bore scope and was checking my rifles and I noticed the erosion and carbon was creeping up on the leads of my 300WSM.I shot 20 Tubb's Final Finish bullets in this rifle and gained .0100 freebore.That's a big amount,but like I stated before,the WSM's have a long tapered lead,so it doesn't take much to gain a lot.By the same token,it doesn't take much to change your pressures if your getting erosion or carbon build up.After shooting those Tubb's bullets,my load all dropped right around a 100fps.For the first time,I could you the data for the bullet weights I was loading for.Here are some before and after pictures of the rifle throat.
Before

After

New & Revised Cartridge & Chamber Drawings - SAAMI

Cartridge and Chamber Designs Standardized by SAAMI Note: Current Cartridge & Chamber Drawing documents are contained within the SAAMI Standards. They can be found HERE. Newly Accepted Cartridge and Chamber Designs Links to technical data and drawings for the newly SAAMI accepted Cartridge and...

saami.org

Some load data

 

[BossGobbler]

I think you are a bit over pressure with your load.Those WSM's are loaded at high pressure 63k to around 65k,a bit higher than most cartridges.I've seen some factory stuff that left some extremely looking pressured headstamp and primers.I have a 300 WSM.They are built a little different in the throat.They really don't have hardly any freebore.They have a long tapered lead.If you look at the SAAMI Specs you will see what I mean.A couple of things that will also kick your pressures up is carbon and erosion.My barrel was probably out of spec from the start.With 165gr bullets,I could never get close to book max loads.I was getting max velocity a few grains under max load.I had to use 180gr data for 165gr.After I got hundreds of rounds down the tube,I saw my accuracy drop way off.I got a Teslong bore scope and was checking my rifles and I noticed the erosion and carbon was creeping up on the leads of my 300WSM.I shot 20 Tubb's Final Finish bullets in this rifle and gained .0100 freebore.That's a big amount,but like I stated before,the WSM's have a long tapered lead,so it doesn't take much to gain a lot.By the same token,it doesn't take much to change your pressures if your getting erosion or carbon build up.After shooting those Tubb's bullets,my load all dropped right around a 100fps.For the first time,I could you the data for the bullet weights I was loading for.Here are some before and after pictures of the rifle throat.
Before

After

New & Revised Cartridge & Chamber Drawings - SAAMI

Cartridge and Chamber Designs Standardized by SAAMI Note: Current Cartridge & Chamber Drawing documents are contained within the SAAMI Standards. They can be found HERE. Newly Accepted Cartridge and Chamber Designs Links to technical data and drawings for the newly SAAMI accepted Cartridge and...

saami.org

Some load data
View attachment 21069View attachment 21070

Thanks for the detailed info. Would you tell me more about Tubbs bullets. I checked out the website seems interesting.

 

[BossGobbler]

Thanks for the detailed information. Never heard about Tubbs bullets. I checked out the website. I will purchase a set. Did you notice accuracy change with loads you had before using Tubbs or just velocity changes?

 

[TXbaldhunter]

Thanks for the detailed information. Never heard about Tubbs bullets. I checked out the website. I will purchase a set. Did you notice accuracy change with loads you had before using Tubbs or just velocity changes?

I've used both the Final Finish and The Throat Maintenance System(TMS) bullets.I did see improved accuracy in all riflesOne of them I shot all fifty Final Finish bullets,a couple I used 25 bullets.With the TMS bullets I've had great results after just five bullets.These are not as abrasive as some of the bullets in the Final Finish kit.These are designed to help polish the throat.I used these on a couple of Ruger1's and also a 300WSM.Just five bullets took these three rifle from shooting 1.5"-2" to around .75". As for velocity change,the 300WSM was the only one I noticed a velocity change.
I shot this three shot 200yd group after shooting all fifty Final Finish

This group was after 5 TMS bullets.Before this rifle wouldn't shoot better than 1.5"

 

[BossGobbler]

I've used both the Final Finish and The Throat Maintenance System(TMS) bullets.I did see improved accuracy in all riflesOne of them I shot all fifty Final Finish bullets,a couple I used 25 bullets.With the TMS bullets I've had great results after just five bullets.These are not as abrasive as some of the bullets in the Final Finish kit.These are designed to help polish the throat.I used these on a couple of Ruger1's and also a 300WSM.Just five bullets took these three rifle from shooting 1.5"-2" to around .75". As for velocity change,the 300WSM was the only one I noticed a velocity change.
I shot this three shot 200yd group after shooting all fifty Final Finish

This group was after 5 TMS bullets.Before this rifle wouldn't shoot better than 1.5"

That is an impressive 3 shot 200 yd grouping. Very nice!

 

[salmonchaser]

Couple of supporting comments.
Tubbs are good. I've had similar results to TX.b.h in my number ones
I have 2rifles that show pressure at max loadings with powders in the 4350 to Rl19 range. My 300 HH IS 1.5 under max.
Education, a good one, isn't free. You're going to need to send rounds down range in order to optimize your rifle. In your case you'll save money in the long run by burning slightly less powder. Ok that's a stretch. But you will learn a lot about your rifle.
Good luck, glad you were able to tickle the dragons tail early and not end up with something more than a sticky bolt.

 

[sako2]

Thanks for the response. As noted, I did check the data on Barnes's website beforehand for this combo. As to why start where I did, I wanted the hardest hitting accurate load and I had been told by another that somewhere near max is usually the 'best' load. So, I don't want to waste time, money or limited, difficult to find resources on loads I don't want to use anyway. Did I start too high, obviously in this case. Does everyone start with the minimum load data?

Not everyone starts at minimum but i bet 95% do. I like having all my fingers and seeing with both eyes. Most of my most accurate loads are around 1gn under max but i start low and work up to it. I never started load work up 1gn under max. As for seating the closer you get to jamming the bullet the pressure rises. It like pulling your car up to a curb and stopping then trying to go over the curb verses a running start.

 

[Blkram]

While I may not always start at 5% less then max loads as recommended, I do usually start approx 3 grains less than max and work up in 1/2 grain increments to see how they perform in my rifle.
When I first had my 300 WSM built, I did have sticky bolt lift with some factory loads and also thought that it might be a tight chamber, but they were also difficult to easily close the bolt on too. In the end I had a round discharge upon closing the bolt, without being close to the trigger. I took it back to the gunsmith and it was a headspace issue that had to be reset. No more issues closing or opening the bolt with factory or handloads.