.338-.378 Weatherby

Michael Lares

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Joined
Sep 22, 2017
Messages
14
Curious what people are running for fps. before they get into into barrel fouling, (copper etc.)?
Which bullet @ what speed etc.
I'd like to start off with factory 26" barrel. Then see where people are at with a 30" barrel.
 

Michael Lares

Member
Joined
Sep 22, 2017
Messages
14
So I'll add a few things.
Was at 3326 fps with factory barrel & Barnes 225 gr. TTSX. ( Reloader 25)
Shot very good. Some barrel fouling. ( Copper )
After wearing barrel out went to 30" Lilja.
3124 fps. with 300 gr. Nosler Accubond ( Hodgon 869 ) Didn't put over 20 rounds thru it with these, out of time.
Now working up some 325 RMB bullets with 869 again.
Hoping to slow things down a bit more plus better BC.
Hoping to hear some other people's experiences in this.
 

yobuck

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Aug 23, 2008
Messages
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Location
east central fl. /n.c. pa.
So I'll add a few things.
Was at 3326 fps with factory barrel & Barnes 225 gr. TTSX. ( Reloader 25)
Shot very good. Some barrel fouling. ( Copper )
After wearing barrel out went to 30" Lilja.
3124 fps. with 300 gr. Nosler Accubond ( Hodgon 869 ) Didn't put over 20 rounds thru it with these, out of time.
Now working up some 325 RMB bullets with 869 again.
Hoping to slow things down a bit more plus better BC.
Hoping to hear some other people's experiences in this.
Well for one thing, your velocity is considerably higher than any 338x378s ive seen, and ive seen more than one. But id rather be there and watch you shoot it at say 1500, than hear velocity claims.
 

Michael Lares

Member
Joined
Sep 22, 2017
Messages
14
Velocity #'s don't mean squat. It's only the shooting that matters in my book. I put the #'s I chronographed only as a point of reference. As I also said I'm just still working up loads etc. We'll see what it does when I'm done>
"velocity is considerably higher than any 338x378s I've seen".
Well, for starters I'm single shooting the gun because you couldn't even approach what
I'm doing and fit them in a magazine
I had to modify the magazine and do some machining even with the 225gr. Barnes, let alone the 300 or 325gr. 300gr. Nosler is 4" & 325gr. RMB is 4.130" COAL @ .050" off.
The barrel polishing is something an old gunsmith taught me long time ago to correct some barrel problems and I believe I over-did it with the factory barrel causing too much heat? That was a really fast shooting barrel for sure. Shot good groups.
Your thoughts?
 

Michael Lares

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Joined
Sep 22, 2017
Messages
14
I'm not sure what "over polish" means?

I think at 20 rounds it would be a little early to be thinking about abrasives.

Different bullets, and different barrels foul differently.
Not interested in putting bore polish in my new barrel. Just throwing it out there to gain some knowledge.
 

yobuck

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Aug 23, 2008
Messages
1,621
Location
east central fl. /n.c. pa.
Velocity #'s don't mean squat. It's only the shooting that matters in my book. I put the #'s I chronographed only as a point of reference. As I also said I'm just still working up loads etc. We'll see what it does when I'm done>
"velocity is considerably higher than any 338x378s I've seen".
Well, for starters I'm single shooting the gun because you couldn't even approach what
I'm doing and fit them in a magazine
I had to modify the magazine and do some machining even with the 225gr. Barnes, let alone the 300 or 325gr. 300gr. Nosler is 4" & 325gr. RMB is 4.130" COAL @ .050" off.
The barrel polishing is something an old gunsmith taught me long time ago to correct some barrel problems and I believe I over-did it with the factory barrel causing too much heat? That was a really fast shooting barrel for sure. Shot good groups.
Your thoughts?
I think it could even be higher than (anybodys seen).
Wait a minit, wait a minit, i do know one other guy, but nobody ever saw him shoot either. lol
 
Last edited:

sable tireur

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Oct 8, 2010
Messages
1,595
Anyone "over polish" a barrel? As in with JB bore polish?

This is one of those processes which needs to be handled very carefully. Having made cut rifled barrels before, one of the last things we did was to lap the barrels using a lead lap coated with extremely fine diamond paste. There is very little scientific method to this; cast the lap, coat it with paste and try to use a consistent motion and pressure. Never let the lap exit either end of the bore until finished. Clean thoroughly after every step and use a borescope to examine the progress. Knowledge and the experience to know what you're looking at and for is imperative.

Amateurs can use one of several bore pastes available on the commercial market in combination with a brush, patch and paste. Achieving the right finish comes with experience and practice. Going too far by attempting to achieve a mirror finish usually results in potential 'skidding' or slipping of the bullets on this finish. High polish finishes can also result in an increase of copper in the bore. Then there is the damage to the lands (rounded corners) and maybe even a change in the groove depth, allowing for plasma blow by which can damage the bullet and it's flight characteristics after this occurrence.

New barrels which have been lapped properly need very little attention except for judicious cleaning. New barrels which have not been lapped, can be lapped but go slowly and with great care. Consider your investment and let that be your guide. Otherwise, contact a professional and let them handle the problem.
 

Michael Lares

Member
Joined
Sep 22, 2017
Messages
14
This is one of those processes which needs to be handled very carefully. Having made cut rifled barrels before, one of the last things we did was to lap the barrels using a lead lap coated with extremely fine diamond paste. There is very little scientific method to this; cast the lap, coat it with paste and try to use a consistent motion and pressure. Never let the lap exit either end of the bore until finished. Clean thoroughly after every step and use a borescope to examine the progress. Knowledge and the experience to know what you're looking at and for is imperative.

Amateurs can use one of several bore pastes available on the commercial market in combination with a brush, patch and paste. Achieving the right finish comes with experience and practice. Going too far by attempting to achieve a mirror finish usually results in potential 'skidding' or slipping of the bullets on this finish. High polish finishes can also result in an increase of copper in the bore. Then there is the damage to the lands (rounded corners) and maybe even a change in the groove depth, allowing for plasma blow by which can damage the bullet and it's flight characteristics after this occurrence.

New barrels which have been lapped properly need very little attention except for judicious cleaning. New barrels which have not been lapped, can be lapped but go slowly and with great care. Consider your investment and let that be your guide. Otherwise, contact a professional and let them handle the problem.
Thanks for the info. I suspected I had went too far on that barrel and I paid for it. Was kind of addictive as it shot better and better and then>>>>
 

yobuck

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Aug 23, 2008
Messages
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Location
east central fl. /n.c. pa.
Well its a pretty popular cartridge in PA. Many guys are using 250s for the extra velocity, the 300s don't start to pay off till about 1500, which is further than most shooting is done at deer in PA anyway.
With 300s average seems to be right around 3000 fps with 30" barrels, with the 416 case the same.
My son uses 300s in his on the Wby case, and 106 gr Retumbo runs max about 2975 with a 30". 110 gr of the old h570 is about the same, but with slightly better accuracy. Those are the best in his gun.
My BIL has a 36" on a 416 case, and 3050 is what he gets for an accurate load using H50bmg.
Both guns built by Bruce Baer.

I don't think you would get the bolt open with that velocity, and for sure a new case would be trash if you did.
 

Michael Lares

Member
Joined
Sep 22, 2017
Messages
14
Well its a pretty popular cartridge in PA. Many guys are using 250s for the extra velocity, the 300s don't start to pay off till about 1500, which is further than most shooting is done at deer in PA anyway.
With 300s average seems to be right around 3000 fps with 30" barrels, with the 416 case the same.
My son uses 300s in his on the Wby case, and 106 gr Retumbo runs max about 2975 with a 30". 110 gr of the old h570 is about the same, but with slightly better accuracy. Those are the best in his gun.
My BIL has a 36" on a 416 case, and 3050 is what he gets for an accurate load using H50bmg.
Both guns built by Bruce Baer.

I don't think you would get the bolt open with that velocity, and for sure a new case would be trash if you did.
Well you might not with Retumbo or h570. Don't know about them so can't give an honest answer. I do know about 869 because that's what I've been shooting. What did you get shooting 869?
 

yobuck

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Aug 23, 2008
Messages
1,621
Location
east central fl. /n.c. pa.
Well to be perfectly honest we never tried that.
I don't know any others who have either as far as I know. As I recall the burn rate on that is pretty close to where old H570 would fit. Reloader 26 seems to work for some also. We tried RL 33 also but Retumbo works better for us. The old h870 and wc872 can be used also but cold weather can cause issues with those. Im sorta sorry we didn't use a 32"
on my sons gun.
 

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