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Excessive pressure with Barne tripple shock
Ewelker
Member Posts: 46 ✭✭
I loaded up some rounds for my .264 mag. with 130 gr Barnes tripple shock. With H 4831 Sc Max is 63 gr min is 58 gr. I loaded 62 gr and the casings stuck after firing. I have dropped the load to 60 gr. but haven't shot any yet. Barnes data states that standard max can be exceeded because of less bullet surface area. Any sugestions? I hate having to guess.
Comments
how much neck tension?
Sounds like your rifle may not get to max charge,..which is not all that uncommon.
why chase the game when the bullet can get em from here?....
Got Balistics?
This is going to read like I'm a real bad guy but I'm only trying to help...
"Any sugestions? I hate having to guess."
But guess is what you did by just picking the 62 gr. load because of what you mis-interpreted in the Barnes statement.
Standard procedure for beginning any new loads for a cartridge and bullet combination is to start low and work your way up carefully and slowly, watching for signs of pressure. You ignored that and jumped right up to nearly the top end and surprise, the case stuck. Fortunately, it was only the stuck case and not a complete vaporization of the case which really could have ruined your day! Please re-read the Barnes Q&A either on their website or at least the ones that I copied below.
Do you know how long your chamber is so that you can start seating the TSX bullets 0.050" off of the lands? This is extremely important with most bullets but much more so with the Barnes bullets since they are monometallic in construction. If your bullets are seated right at or into the lands with an untested top end load, pressure can mount instantly and catastrophically.
Like I stated at the top, I'm only trying to help. Please start low and work up slow.
1. What load data do I use for the Triple Shock Bullet?
Answer. We recommend that you use the minimum X Bullet load data to start.
To compensate for the reduced pressures associated with the Triple Shock, you MAY have to work up 1 to 2 additional grains above listed loads to achieve equal pressures. Pressures can jump dramatically; therefore we recommend that you work up in 1/2 gr. increments until you are no more than 1 to 2 grains above the listed max load or until signs of excessive pressure are evident. Whichever comes first. You should watch for excessive case head expansion, sticky bolt lift, flattened primers or shiny spots on the base of the case. If you have case head expansion of more than .0005" with a once-fired case, this is a sure sign of excessive pressure. You will have to measure your case head with a Blade Micrometer just in front of the extractor groove, or you can use a regular micrometer and measure the belt on belted cases, before and after shooting. When any of these signs appear, back down one full grain and you will have a max load for your gun.
If you do not feel comfortable working up a load, or don't have the proper equipment, then we suggest following the recommended X-Bullet load data. For the 168gr .308 cal Triple Shock Bullet, use the 165gr X-Bullet data.
AND:
7. Where do I seat the Triple Shock Bullet?
Answer. As with the X and XLC Bullet, we recommend seating the Triple Shock .050" off the lands {rifling} of your rifle. This length can be determined by using a "Stoney Point Gauge" or other methods. You do not have to seat the bullet at or on one of the annular rings.
.
In a case where it is recommended the bullet is in contact with the lands, wouldn't it pose a problem in the case of a Weatherby rifle?
"at the lands" usually indicates that the ogive of the bullet just touches the lands in the throat of the barrel.
"into the lands" indicated that you have seated the bullet long, futher out of the case and it is being forced into lands further than just touching, by closing the bolt on the cartridge. Benchresters often claim that they "seated the 65 gr._______ bullet 0.040" (pick a number) into the lands."
"off of the lands" means that the ogive is 'x' number of thousandths away from the lands. In other words, short of the lands or not touching by some distance. Barnes Bullets recommends that we start testing reloads with their bullets seated at least 0.050" off of the lands.
In the case of a Weatherby rifle with a true Weatherby chamber, it is nearly impossible to reach the lands in the first place with 'normal' bullets. The Weatherby leade (freebore) is extremely long to allow for the higher pressures that the factory loads show and allows for blow-by of some of the plasma which reduces the operating pressure of the factory cartridges. I think that most other factory chambers include a substantial leade or freebore when they chamber for Weatherby cartridges. Non-factory chambers with shorter or no freebore are supposed to be marked that way on the barrel for safety reasons. If you can reach the lands in a factory rifle with reloads, you will have a pressure problem more than likely.
Hopefully that's clear.
Best.
idsman,..the lands are your rifling lands(forgive me for saying that as I am sure you know that already). If you are "in" the lands,..your bullet will be engraved by the rifling as it is chambered,..and if it is "off" the lands,..it is NOT in contact with the rifling. The theory is that when you get close to or into the lands,..the bullet has very little space to become off center before entering the rifling. That yields smaller groups (theoreticaly). When using VLD type pills, seating them into the lands by say .010" will help to square the whole cartridge in the chamber as the rifling will "center" the round in the chamber. That is a match rifle practice,..but can work wonders with a factory rifle as well. The long nose profile of the VLD pills many times necessitates the pill be jammed into the lands to get optimum accuracy, but every chamber and barrel is different. It matters less with very straight chambers in match barrels. But I would bet if you were to take exact measurements in a factory chamber versus it's orientation to the bore, you would fall in the floor. They can be VERY off center. Then have your smith take and run a runout guage on the outside dia of the tube as it spins in the lathe and you will freak out. Most factory tubes are very untrue. I was amazed when the smith showed me a factory barrel on the lathe with the guage,..it looked like the tachometer in a nascar engine just as it blows apart at 9000RPM's.
why chase the game when the bullet can get em from here?....
Got Balistics?
Ernie
Ernest,
This is going to read like I'm a real bad guy but I'm only trying to help...
"Any sugestions? I hate having to guess."
But guess is what you did by just picking the 62 gr. load because of what you mis-interpreted in the Barnes statement.
Standard procedure for beginning any new loads for a cartridge and bullet combination is to start low and work your way up carefully and slowly, watching for signs of pressure. You ignored that and jumped right up to nearly the top end and surprise, the case stuck. Fortunately, it was only the stuck case and not a complete vaporization of the case which really could have ruined your day! Please re-read the Barnes Q&A either on their website or at least the ones that I copied below.
Do you know how long your chamber is so that you can start seating the TSX bullets 0.050" off of the lands? This is extremely important with most bullets but much more so with the Barnes bullets since they are monometallic in construction. If your bullets are seated right at or into the lands with an untested top end load, pressure can mount instantly and catastrophically.
Like I stated at the top, I'm only trying to help. Please start low and work up slow.
1. What load data do I use for the Triple Shock Bullet?
Answer. We recommend that you use the minimum X Bullet load data to start.
To compensate for the reduced pressures associated with the Triple Shock, you MAY have to work up 1 to 2 additional grains above listed loads to achieve equal pressures. Pressures can jump dramatically; therefore we recommend that you work up in 1/2 gr. increments until you are no more than 1 to 2 grains above the listed max load or until signs of excessive pressure are evident. Whichever comes first. You should watch for excessive case head expansion, sticky bolt lift, flattened primers or shiny spots on the base of the case. If you have case head expansion of more than .0005" with a once-fired case, this is a sure sign of excessive pressure. You will have to measure your case head with a Blade Micrometer just in front of the extractor groove, or you can use a regular micrometer and measure the belt on belted cases, before and after shooting. When any of these signs appear, back down one full grain and you will have a max load for your gun.
If you do not feel comfortable working up a load, or don't have the proper equipment, then we suggest following the recommended X-Bullet load data. For the 168gr .308 cal Triple Shock Bullet, use the 165gr X-Bullet data.
AND:
7. Where do I seat the Triple Shock Bullet?
Answer. As with the X and XLC Bullet, we recommend seating the Triple Shock .050" off the lands {rifling} of your rifle. This length can be determined by using a "Stoney Point Gauge" or other methods. You do not have to seat the bullet at or on one of the annular rings.
You are probalby going to find that your rifle will shoot MUCH better seating the bullets a LOT closer to the lands...more like .005. Too much bullet jump adversely affects accuracy.
Eric
allamericanarmsco@frontiernet.net
All American Arms Company
www.galleryofguns.com
VIP Code: AAAC
Veteran Owned and Operated
It wasn't a theory in the first place because of all of the testing that Barnes did before releasing the bullets to the public. The advertising is written from the test results. But you should test them for yourself since that's what we all need to do when working up loads.
Eric,
"You are probalby going to find that your rifle will shoot MUCH better seating the bullets a LOT closer to the lands...more like .005. Too much bullet jump adversely affects accuracy."
Have you ever shot any of the Triple Shocks? The reason that I ask is because your statement sounds an awful lot like what the accuracy folks like to repeat and doesn't usually work for the Triple Shocks. Please note the 'usually' because certainly someone somewhere will take exception to this statement once again.
I used to believe that the concept of close to or into the lands was the only answer to accuracy until I had to shoot some Lost River bullets for a test. At $2.00/each, it was a fast lesson! I shot $40.00 worth with terrible accuracy before I checked on their recommendations for seating. They stated pretty much the same thing as Barnes does, work away from the lands to start. The accuracy wasn't stellar but it was certainly an improvement over the first attempts by a long shot.
I've been shooting the Triple Shocks in one caliber or another for the last 4 years and I have yet to find an accuracy node anywhere closer than 0.020" and I've shot with them into the lands, on the lands and find that off the lands gives the best results overall. Several calibers work best at 0.035" off the lands. So when Barnes suggests that we start at 0.050" off the lands, I go along with them.
Best.
Pinhead,
It wasn't a theory in the first place because of all of the testing that Barnes did before releasing the bullets to the public. The advertising is written from the test results. But you should test them for yourself since that's what we all need to do when working up loads.
Eric,
"You are probalby going to find that your rifle will shoot MUCH better seating the bullets a LOT closer to the lands...more like .005. Too much bullet jump adversely affects accuracy."
Have you ever shot any of the Triple Shocks? The reason that I ask is because your statement sounds an awful lot like what the accuracy folks like to repeat and doesn't usually work for the Triple Shocks. Please note the 'usually' because certainly someone somewhere will take exception to this statement once again.
I used to believe that the concept of close to or into the lands was the only answer to accuracy until I had to shoot some Lost River bullets for a test. At $2.00/each, it was a fast lesson! I shot $40.00 worth with terrible accuracy before I checked on their recommendations for seating. They stated pretty much the same thing as Barnes does, work away from the lands to start. The accuracy wasn't stellar but it was certainly an improvement over the first attempts by a long shot.
I've been shooting the Triple Shocks in one caliber or another for the last 4 years and I have yet to find an accuracy node anywhere closer than 0.020" and I've shot with them into the lands, on the lands and find that off the lands gives the best results overall. Several calibers work best at 0.035" off the lands. So when Barnes suggests that we start at 0.050" off the lands, I go along with them.
Best.
No I really don't have much experience with them...but I kind of figured their recommendations probably had more to do with safety than with accuracy (worried about excessive pressures if someone loaded them touching the lands). It's been my experience that just about everything I've tried seems to shoot the best under .01 from the lands...but then again every rifle is differnt...along with every bullet. So many combinations that there has to be variations[:)]
Eric
allamericanarmsco@frontiernet.net
All American Arms Company
www.galleryofguns.com
VIP Code: AAAC
Veteran Owned and Operated
Psalm 109:8